HMS-23. HMS-15. HMS-16. HMS-19. HMS-17. H-208. Pedigree. C-214 x H-432. (H-432 x H-214) x ...... The weeds include Convolvulus arvensis,. Amaranthus ...
Proceedings of the
International Workshop on Chickpea Improvement
Hyderabad, India 2 8 Feb - 2 Mar 1 9 7 9
International Crops Research Institute for the Semi-Arid Tropics ICRISAT Patancheru P.O. Andhra Pradesh 502 3 2 4 , India
The correct citation for these Proceedings is ICRISAT (International Crops Research institute for the Semi-Arid Tropics). 1980. Proceedings of the international W o r k s h o p on Chickpea Improvement, 28 Feb-2 M a r 1979, Hyderabad, A.P., India. (Available f r o m ICRISAT Patancheru, A.P. 502 324, India.)
Workshop Coordinator J. M. Green Scientific Editors J. M. Green, Y. L Nene, J. B. Smithson Publication Editor Cynthia Garver
The international Crops Research Institute fo r the Semi-Arid Tropics (ICRISAT) is a n o n p r o f i t scientific educational institute receiving support f r o m a variety of donors. Responsibility f o r t h e information in this publication rests w i t h ICRISAT or t h e individual authors. Where trade names are used this does not constitute endorsement of or discrimination against any p r o d u c t by t h e institute.
CONTENTS Foreword
vii
Inaugural Session Objectives of the Workshop and of t h e ICRISAT/ICARDA Chickpea I m p r o v e m e n t Project
1 J. S. Kanwar
Session 1 — B r e e d i n g Strategies
3
9 D. E. B y t h , J. M. G r e e n , a n d G. C. H a w t i n
11
T h e Current Status of Chickpea G e r m p l a s m W o r k at ICRISAT
L. J. G. van der Maesen, R. P. S. P u n d i r , a n d P. R e m a n a n d a n
28
International Chickpea Trials and Nurseries
K. B. S i n g h , J. K u m a r , S. C. S e t h i , C. L. L. G o w d a , K. C. J a i n , a n d G. C. H a w t i n
33
Y. L N e n e , M. P. H a w a r e , and M. V. Reddy
43
ICRISAT/ICARDA Chickpea Breeding Strategies
International Disease Nurseries
Discussion
Session
45
2 — Y i e l d I m p r o v e m e n t t h r o u g h Kabuli-Desi I n t r o g r e s s i o n
49
G. C. H a w t i n a n d K. B. S i n g h
51
Studies on Desi a n d Kabuli Chickpea ( C i c e r arietinum L) Cultivars I. C h e m i c a l C o m p o s i t i o n
R. J a m b u n a t h a n and U. Singh
61
Disease Resistance in Kabuli-Desi Chickpea Introgression
M. P. H a w a r e , Jagdish Kumar, and M. V. Reddy
67
Kabuli-Desi Introgression: The Experience in Australia
E. J. K n i g h t s
70
Kabuli-Desi Introgression and Genesis of N e w Plant T y p e in Chickpea
P. N. B a h l
75
Kabuli-Desi Introgression: Problems and Prospects
81
Discussion
Session 3 — C h i c k p e a A g r o n o m y and Physiology
87
Recent Advances in Chickpea A g r o n o m y
M. C. Saxena
89
E f f e ct o f E d a p h i c F a c t o r s o n C h i c k p e a
S. Chandra
97
iii
Physiology Of G r o w t h , D e v e l o p m e n t and Yield of Chickpeas in India
N. P. Saxena a n d A. R. S h e l d r a k e
106
T h e Effects o f P h o t o p e r i o d a n d A i r Temperature on Growth and Yield of C h i c k p e a (Cicer arietinum L.)
R. J. S u m m e r f i e l d , F. R. M i n c h i n , E. H. Roberts, a n d P. Hadley
121 150
Discussion
S e s s i o n 4 — Chickpea M i c r o b i o l o g y Research on S y m b i o t i c Nitrogen Fixation by Chickpea at ICRISAT
Session
159 0. P. Rupela a n d P. J. Dart
5 — Plant P r o t e c t i o n
169
Diseases of Chickpea
Y. L N e n e
171
I n s e c t Pest M a n a g e m e n t o n C h i c k p e a
W. R e e d , S. S. Lateef, and S. S i t h a n a n t h a m
179 184
Discussion
S e s s i o n 6 — Chickpea B r e e d i n g at t h e N a t i o n a l Level
189
All India Coordinated Pulse Research P r o j e c t Chickpea I m p r o v e m e n t
Laxman Singh
Chickpea I m p r o v e m e n t at Pantnagar
B. P. P a n d y a a n d M. P. P a n d e y
197
S. Lal a n d Y. S. T o m e r
208
Chickpea B r e e d i n g P r o g r a m at Hissar
191
Discussion
221
Sessions 7 a n d 8 — C o u n t r y R e p o r t s
iv
161
225
Chickpea in Afghanistan
A. Q. S a m e t
227
G r o w t h of Chickpea in Chile
Jorge Aeschlimann A.
231
Chickpea Production in Ethiopia
Geletu Bejiga
236
D e v e l o p m e n t of Chickpea in Iraq
I s a m H. N a j j a r
243
Chickpea in M e x i c o
Enrique Andrade Arias
246
Chickpea Research and Production in Nepal
R. P. S a h
249
Chickpea Pathology in Pakistan
Inam Ullah Khan
257
Chickpea Report f r o m Pakistan
M. A. Khan
258
Chickpea Production in Peru
Cesar A p o l i t a n o S a n c h e z
264
Research on Chickpea in Spain
J o s e 1. C u b e r o
268
Chickpea in Sudan
Farouk A h m e d Salih
270
Chickpea I m p r o v e m e n t in Tunisia
M o h a m e d Bouslama
277
Discussion
Session
9 — M e e t i n g s of W o r k i n g G r o u p s
281 285
Recommendations of the Working Group on: Genetic Resources
287
Breeding
288
Plant Protection
289
Plant G r o w t h
291
A p p e n d i x — List of P a r t i c i p a n t s
293
V
Foreword I C R I S A T h o s t e d a g r a i n l e g u m e w o r k s h o p i n J a n u a r y 1975 , v e r y s o o n a f t e r t h e initiation of the Institute's chickpea breeding program. T h e object w as to bring together food l e g u me breeders of the w o r l d and to focus on the status of chickpea and p i g e o n p e a i m p r o v e m e n t . Several aspects of p r o d u c t i o n a g r o n o m y , ecological and physiological adaptation, and quality characteristics w e r e c o n s i d e r e d . ICRISAT scientists p r e s e n t e d a p r o p o s e d p r o g r a m f o r improving genetic potential for yield. I n 1979, a n i n t e r n a t i o n a l w o r k s h o p w i t h s i m i l a r o b j e c t i v e s w a s h e l d exclusively for chickpea. In the intervening 4 years m a n y contacts had been m a d e w i t h national programs, and multilocational testing of advanced genetic material w a s u n d e r w a y . A l s o d u r i n g t h o s e 4 y e a r s , t h e p r o g r a m s of ICRISAT and ICARDA, both of w h i c h have a m a n d a t e for chickpea i m p r o v e m e n t , w e r e integrated and plans were m a d e for eliminating unnecessary duplication of work. T h e a i m o f t h e 1979 w o r k s h o p p r o g r a m c o m m i t t e e w a s t o p r o v i d e a f o r u m f o r s u m m a r i z i n g d e v e l o p m e n t i n all a s p e c t s o f c h i c k p e a i m p r o v e m e n t r e search d u r i n g t h e previous 4 years a n d to g i v e special emphasis to b r e e d i n g , because n e w approaches to quantitative breeding for yield require an increased level of c o o p e r a t i o n b e t w e e n national breeding p r o g r a m s and t h e C e n t e r s . Basic d a t a t o b e o b t a i n e d a r e r e q u i r e d t o e v a l u a t e t h e p r o c e d u r e s , t o identify promising material, and to measure progress. The International W o r k s h o p on Chickpea I m p r o v e m e n t w a s held at H y d e r a b a d f r o m 2 8 F e b r u a r y t o 2 M a r c h 1979 t o d i s c u s s t h e s e a n d o t h e r p r o b l e m s related to increasing p r o d u c t i o n . T h e sessions w e r e attended by 82 scientists f r o m 14 countries. T h e c o n s e n s u s w a s that t h e ICRISAT/ICARDA proposal for quantitative breeding for yield was acceptable, and the participat i o n n e c e s s a r y f o r its i m p l e m e n t a t i o n w a s a s s u r e d . J o i n t p r o g r a m s f o r g e r m p l a s m collection and disease resistance ratings w e r e also endorsed by the participants. The proceedings of the W o r k s h o p are presented herewith. We believe t h e v o l u m e will be a valuable reference w o r k for chickpea research scientists. If cooperation proves effective, we should be in a position to hold another very profitable international w o r k s h o p approximately 4 years hence.
J o h n M. Green Workshop Coordinator
vii
Inaugural Session Chairman: J. M. Green
Objectives of t h e Workshop and of t h e I C R I S A T / I C A R D A Chickpea Improvement Project J. S. Kanwar*
In his overview, Dr. Swindale has outlined the objectives of ICRISAT and described s o m e h i g h lights of its five crop i m p r o v e m e n t programs. The Pulse Improvement Program includes research on chickpea and pigeonpea. The first international w o r k s h o p on pulses sponsored by ICRISAT was held in January 1975. This week's w o r k s h o p is the first international workshop devoted exclusively to chickpea improvement. The main objectives of the w o r k s h o p are to: 1. Assemble chickpea breeders of the w o r l d for critical assessment of the status of chickpea i m p r o v e m e n t ; 2. Discuss results and proposed f u t u r e strategies of the ICRISAT/ICARDA international p r o g r a m s ; 3. Encourage and p r o m o t e cooperation in chickpea improvement; 4. Assess needs for training, i m p r o v e d c o m m u n i c a t i o n , and technical assistance at the national level; 5. Provide breeders an opportunity to inspect and select germplasm and breeding material in ICRISAT fields. You are no doubt aware that ICRISAT has chickpea research programs at Hyderabad, in Hissar, and at Tel Hadia, Syria in cooperation w i t h the International Centre for Agricultural Research in Dry Areas (ICARDA). To achieve the objectives of this w o r k s h o p and to discuss rationally the strategies and programs of research in chickpea at ICRISAT, it is important to give y o u t h e background of the ICRISAT/ ICARDA joint project on chickpea improvement. Chickpea is an important pulse crop in the Indian subcontinent and in western Asia, but research on chickpea began only recently. The first international effort to i m p r o v e this crop was in 1962 w h e n t h e Regional Pulse Improve-
* Director of Research, ICRISAT.
ment Project (RPIP) began in India and Iran. The project was funded jointly by the United States Department of Agriculture (USDA) and United States Agency for International Development (USAID), in collaboration w i t h the Indian Pulse Research Program and the m a i n emphasis was on collection and distribution of germplasm and research in breeding, a g r o n o m y , and related fields. The chickpea improvement work at ICRISAT was initiated in 1973. The A r i d Lands Agricultural Development Program (ALAD) in t h e Middle East and North Africa started a regional program on f o o d legumes (broadbean, chickpea, and lentil) in 1972, and in 1977 this program was absorbed by ICARDA. Until last year, both ICRISAT and ICARDA had separate responsibilities for i m p r o v e m e n t of chickpea. In 1978 the boards of governors of the t w o institutes agreed to coordinate their efforts; ICRISAT has n o w appointed a chickpea breeder to w o r k at ICARDA. There are t w o m a i n types of chickpea — kabuli and desi. The former has smooth, generally large, light colored seeds w h i l e the seeds of the latter are yellow to black, generally smaller, and w i t h a rougher surface. The work at ICARDA is on kabuli-type chickpea since it is prevalent in t h e countries of that region w h i l e at ICRISAT the major emphasis is on desi types. The objectives of the chickpea i m p r o v e m e n t work at the t w o institutes are t o : 1. Strengthen national and regional programs; 2. Develop high-yielding disease and pestresistant breeding material w i t h g o o d grain quality; 3. Furnish parental lines, segregating populations, and advanced breeding material to local programs; 4. Arrange exchange of information and germplasm; 5. Train personnel.
3
To achieve the above-mentioned objectives, studies are under way at ICRISAT on breeding, pathology, e n t o m o l o g y , microbiology, physiology, quality and consumer acceptance and at ICARDA on breeding, pathology, agr o n o m y , physiology, microbiology, and entomology. There is a genetic resources unit at ICRISAT that maintains, evaluates, and makes available germplasm to interested scientists and organizations. There is close collaboration a m o n g t h e disciplines at each of the institutes, and there is frequent exchange of visits of scientists at the institutes.
Research Sites At ICRISAT, the work on chickpea was started at Hyderabad (17°N). However, since ICRISAT Center is outside the main chickpea belt in India, it was proposed to take up chickpea w o r k in northern India. After discussions w i t h the Indian Council of Agricultural Research (ICAR), Haryana Agricultural University in Hissar (29°N) agreed to provide land and facilities to ICRISAT fo r chickpea research. The soil type at Hyderabad is a black Vertisol w i t h g o o d waterretention capacity. The crop is s o w n after the cessation of m o n s o o n rains (total annual rainfall averages 760 m m ) and usually does not require any irrigation, in s o m e years, irrigation is required at s o w i n g if the rains are scanty or if they stop early. The soil type at Hissar is an Entisol; total annual rainfall averages about 450 mm and p r e s o w i n g irrigation is generally necessary. The w o r k on short-duration desis is conducted at ICRISAT Center and on m e d i u m and long-duration desis and on kabulis at Hissar. S o m e testing and multiplication is done at Gwalior (26°N) in central India. At ICARDA, the main p r o g r a m is based at Tel Hadia near A l e p p o (36°N) in northern Syria w h i c h is at a 350 m elevation w i t h relatively m i l d winters and l o w rainfall (350 m m ) . A second major site is planned at Tabriz (38°N), Iran, which represents the extreme high elevation of the Anatolian Plateau. In the m e a n t i m e , testing sites have been established at Tekmadash near Tabriz (1800 m elevation), w h i c h generally has frost and a snow cover f r o m October to A p r i l , and at Terbol (34°N), Lebanon, w h i c h receives 550 mm rainfall per year and being at 1000 m is
4
somewhat less cold.
Cultural Management of Research Areas Chickpea is generally g r o w n on conserved moisture during the dry season of the year. T h r o u g h o u t most of the Indian subcontinent and eastern Asia, desi types are g r o w n as an autumn-sown winter crop, w h i l e in western Asia the crop is mainly the spring-sown kabuli type. As a result of this reliance on conserved moisture, production is erratic. Low management inputs such as fertilization, pest c o n t r o l , and weed control, are the general rule. Consequently, most breeding efforts have been directed t o w a r d development of genetic material suited to l o w input management and rainfed conditions. At ICRISAT, irrigation is rarely applied to general breeding plots except to ensure establishment, and all evaluation is done under relatively low nutrient status. Insect and pest management is directed to avoid excessive plant d a m a g e rather than to provide total protection. Except for those used in special studies of disease resistance, most breeding plots are sited on land k n o w n to be relatively free of the major soilborne pathogens. The objective is to allow expression of genotypic differences for production characteristics in the absence of excessive bias due to environmental modification. The annual rainfall of approximately 350 mm at Tel Hadia is not considered adequate for a chickpea crop by farmers in the area; they consider 400 mm to be the m i n i m u m a m o u n t of rainfall required. Thus, it is necessary to irrigate early in the season (during the period of expectation of rain) to simulate the environment in which chickpea is normally g r o w n . The winterplanted crop receives no irrigation, but (with the exception of the disease nurseries) a fungicide is applied against blight. Because the site lies outside the normal chickpea area, the soils are deficient in natural Rhizobium, and it is necessary to inoculate to ensure adequate nodulation. As a precaution, until Rhizobium levels have been built up, a dressing of 30 kg N/ha is applied w i t h 50 kg P 2 O 5 /ha. Both the winter and spring-planted crops are currently protected f r o m pod borer and leaf miner.
Utilization of Germplasm The collection, evaluation, and maintenance of the w o r l d chickpea g e r m p l a s m , irrespective of type, are the responsibilities of ICRISAT, w h i c h has assembled over 11 000 accessions of desi and kabuli types. A collection of 3300 kabuli types has been established by ICARDA, and this will be integrated w i t h the ICRISAT collection. It is planned that eventually the entire collection will also be maintained at ICARDA as an insurance. A detailed report on germplasm is to be presented separately by Dr. van der Maesen and colleagues. The collection is being screened progressively for w i l t resistance, heat tolerance, and protein content at ICRISAT Center. In addition, it is being checked for Ascochyta blight resistance and winter hardiness at ICARDA, as well as for production characteristics and adaptation. To date, a number of lines w i t h superior yielding ability have been identified and distributed to national programs via the international and regional nurseries. Some of these lines have been f o u n d superior to the local check cultivar in those trials. These lines and others possessing particular characteristics, such as disease resistance, have been included in the crossing and general breeding programs of the centers. Further evaluation of the germplasm is planned in order to allow m a x i m u m exploitation of this resource. Collections of several w i l d species have been assembled and are being screened for various morphological and resistance characteristics. It is proposed to create a " g e n e park" to maintain these w i l d species in their " n a t u r a l " habitat at Tel Hadia, after the f a r m has been fenced to prevent grazing.
Off-season Nurseries The usefulness of an off-season nursery cannot be overemphasized in a breeding p r o g r a m . Since 1974, ICRISAT has g r o w n off-season crops in Lebanon and in the Lahaul and Kashmir valleys in India. The operational quarantine and other difficulties for the s u m m e r crop in Lebanon and unfavorable weather conditions in the Lahaul valley led us to abandon our efforts there. Of the five locations tried in Kashmir we have identified one site — Tapperwaripora
(1650 m) where a reasonably g o o d s u m m e r crop can be raised. The best s o w i n g t i m e appears to be the first week of June. There is little rainfall in June, and the crop is planted w i t h irrigation; it is ready by the end of September. We have n o w requested 2 ha of land at Tapperwaripora far m to advance F 1 s and raise important multiplications. At present we do not plan any hybridization work there. Some preliminary studies at ICRISAT Center indicate that a summer chickpea crop can be raised successfully if it is protected f r o m direct rain. Therefore, if the crop can be covered during June and July, it may be possible to g r o w a successful s u m m e r nursery here and advance some of our breeding materials and expedite breeding work. Several locations have been studied by ICARDA scientists for use as off-season sites. It appears that off-season advancement can be done at Terbol, Lebanon, for winter-planted materials at Tel Hadia, Syria. Spring-planted materials can be successfully advanced on a Government of Jordan experimental station at Shawbak; in fact, use has been made of this facility for the past 3 years.
Rapid Generation Turnover Presently, we are conducting an experiment to explore the possibility of g r o w i n g more than t w o generations of chickpea per year by modifying the environment in various ways, a system that has already been successful w i t h soybeans (Byth, personal communication). If it is successful in chickpea, we may be able to advance generations rapidly using the single-seed descent m e t h o d .
Regional Evaluation of Breeding Material Breeding material is made available to chickpea scientists, on request, in both desi and kabuli types in a range of stages; for example, as F 2 or F 3 unselected bulk populations; as early generation segregating lines; as advanced breeding lines; and as elite lines and cultivars. The distribution of international and regional nurseries and trials is discussed in m o r e detail in this workshop by Dr. K. B. Singh and colleagues.
5
The reason for f u r n i s h i n g near-homozygous advanced lines is to provide an opportunity for scientists to evaluate the material under local conditions fo r subsequent use directly in local experimentation, hybridization, release, and so on w i t h o u t t h e need for further reselection. As indicated above, multilocation testing over years is used by t h e centers to identify breeding material w i t h promise in a n u m b e r of environm e n t s ; that is, w i t h broad adaptation or w i t h specific adaptation to particular locations. W i t h respect to w i d e adaptation and phenotypic stability over environments, the testing programs of the Centers are being expanded by the addition of further test sites that differ in agroecological conditions. Most desi breeding material is n o w evaluated at ICRISAT Center and Hissar, and kabuli material at Tel Hadia and Terbol. Testing will be extended to Gwalior and Tabriz. S o m e material w i l l be evaluated over the years at ICRISAT Center, in Hissar and at Tel Hadia in an effort to identify differences in environmental adaptation.
Collaboration a m o n g Disciplines The basic rationale of plant i m p r o v e m e n t is the d e v e l o p m e n t of high-yielding cultivars w i t h stable performance across environments and acceptable quality characteristics. This is a multidisciplinary activity w i t h the plant breeder as a m e m b e r of a broad-based team of scientists in pathology, entomology, physiology, microbiology, and biochemistry. At ICRISAT we have a t e am of scientists w o r k i n g together to achieve the aforementioned objectives. Likewise, the Indian p r o g r a m has a g o o d team of scientists w o r k i n g together at different centers. We collaborate w i t h the Indian p r o g r a m and w i t h national p r o g r a m s in other countries. ICRISAT pathologists are interacting w i t h breeders in India in t h e identification and dev e l o p m e n t of lines resistant to Fusarium w i l t disease and at ICARDA for Ascochyta blight resistance. There is close collaboration w i t h physiologists and a g r o n o m i s t s for identificat i o n of factors l i m i t i ng g r o w t h and d e v e l o p ment, and of genotypes that can tolerate stress conditions such as c o l d , heat, d r o u g h t , and salinity. We hope, this w i l l lead to definition of
6
specific breeding objectives and d e v e l o p m e n t of appropriate breeding and selection strategies. Similarly, the development of optimal agronomic systems for new cultivars and for n e w plant habits is a critical part of any continuing breeding p r o g r a m . Crop adaptation studies are necessary to introduce chickpea into new areas or different cropping systems, such as winter planting in the M i d d le East, late planting under irrigation in northern India, and early planting under southern Indian conditions.
International Activities Both ICRISAT and ICARDA have active p r o g rams of international cooperation in a number of different areas, the main objectives being to coordinate chickpea research and to facilitate development and interchange of superior genetic materials and improved technologies. Some of the m o r e important activities are discussed briefly here.
I n t e r n a t i o n a l Trials and Nurseries A number of international trials and nurseries are distributed annually for specific purposes. Until 1978, ICRISAT distributed both desi and kabuli trials. In future, ICARDA will coordinate all kabuli trials internationally and ICRISAT will handle the desi materials.
Training Training of personnel in research m e t h o d o l o g y at various levels is an important activity, and courses of study are offered in five main categories: (1) group residential courses, (2) short-term training, (3) individual training, (4) graduate training in collaboration w i t h a university, and (5) national level training. ICRISAT primarily participates but not exclusively in this activity w i t h countries interested in desi t y p e s ; similarly, ICARDA participates w i t h countries interested in kabuli types. A 6-month group-training course on f o o d legumes research, attended by 18 participants, was conducted by ICARDA in 1978 and w i l l be repeated in 1979. Three African research w o r k ers w e r e trained at ICRISAT during the 1976-77 crop year and one postgraduate student is
presently conducting research in this area. These research training p r o g r a m s will be strengthened and expanded to meet the requirements of specific countries. A training p r o g r a m in chickpea pathology was organized in January 1979 at ICRISAT; it had nine particip a t e s , including three f r o m Mexico, the Sudan, and Iraq.
Workshops and Conferences Periodic workshops and conferences are organized for exchange of ideas and experiences and to develop close contacts w i t h the national programs and between ICRISAT and ICARDA. A 4-day w o r k s h o p was conducted by ICRISAT in 1975 to identify the m o r e important problems in chickpea production in the w o r l d , and the proceedings were published. The c o m m o n p r o b l e m s of f o o d legume production and i m p r o v e m e n t w i t h i n t h e west Asian and Mediterranean regions were examined at a 6-day w o r k s h o p organized by ICARDA in 1978, and the proceedings will be published soon by the International Development Research Centre (IDRC). An annual breeders' meet has been regularly organized by ICRISAT, largely to p r o m o t e per-
sonal contacts and exchange of ideas a m o n g breeders and to provide t h e m w i t h an opportunity to select material f r o m the ICRISAT breeding plots. In addition to the Indian chickpea breeders, a number of breeders f r o m other chickpea producing countries also participate.
Visits t o N a t i o n a l Programs Frequent visits are made by ICRISAT and ICARDA scientists to the national programs, and limited funds are available to support visits by scientists of national programs to the ICRISAT and ICARDA centers.
Publications Research developments are reported t h r o u g h annual technical reports, technical manuals, project reports, workshop proceedings, and other publications. Recently, a bulletin, Diagnosis of some Wilt-like Disorders of Chickpea, has been published. Training manuals have also been prepared by ICARDA. A bibliography on chickpea research has been published by ICRISAT scientists.
7
Session 1 Breeding Strategies Chairman : E. A b e r g C o - C h a i r m a n : J. I. C u b e r o
R a p p o r t e u r : D. S h a r m a
ICRISAT/ICARDA Chickpea Breeding Strategies D. E. Byth, J. M. Green, and G. C. Hawtin*
Appropriate breeding procedures f o r an international breeding p r o g r a m will vary w i t h the crop, philosophy of the p r o g r a m , and stage of development of national p r o g r a m s , but in any case these procedures will be based on the same genetic principles as any national or local p r o g r a m . W i t h 5 years' experience behind us, we have made an analysis of the efficacy of the work d o n e and developed a proposal for the future p r o g r a m . We expect the collective j u d g ment of the w o r k s h o p to be b r o u g h t to bear on the proposed p r o g r a m ; we recognize that experience w i l l also dictate modifications of the best t h o u g h t - o u t plans, but we s u b m i t the f o l l o w i n g as a w o r k i n g basis f o r the chickpea breeding p r o g r a m s of ICRISAT and ICARDA and suggest that there are features of the p r o g r a m w o r t h y of serious consideration by coordinated national and regional programs. Singh and Auckland (1975) reviewed the status of chickpea production and i m p r o v e m e n t internationally and Hawtin (1975) described the status of chickpea research in the M i d d l e East. These aspects and papers w i l l not be discussed in detail here. However, Singh and Auckland (1975) concluded that initial breeding emphasis should be on yield and consumer acceptance, w i t h stability of y i e l d , resistance to pests and diseases, and seed protein quantity and quality at a lower level of priority. They advocated the use of a bulk pedigree m e t h o d involving select i o n a m o n g F 2 derived families, w i t h individual plant selection w i t h i n the best families, and the bulk m e t h o d for less p r o m i s i n g crosses. The use of off-season nurseries f o r generation turnover and selection w a s envisaged, and recurrent selection f o l l o w i n g Jensen's (1970) diallel selective mating scheme was suggested. * Consultant to t h e Chickpea Breeding Program, ICRISAT, a n d Reader, University of Queensland, Australia; Program Leaders at ICRISAT and ICARDA, respectively.
Singh and Auckland recognized that ICRISAT Center near Hyderabad is geographically outside the main area of chickpea culture in India and internationally, and they recommended acquisition of a selection and testing site in northern India. Subsequently, close collaboration in chickpea improvement developed w i t h ICARDA, and the t w o programs were integrated in 1978. This statement of breeding strategies applies to the improvement program of both institutes.
Experience to Date in Chickpea Improvement Breeding Objectives The overall objectives of the programs are as follows: 1. To develop high-yielding disease and pest-resistant cultivars w i t h g o o d grain quality; 2. To furnish advanced breeding lines and segregating populations to national and local breeding programs; 3. To support regional and national programs through exchange of information, g e r m p l a s m , and training of personnel. Specific aims exist w i t h i n these general objectives and are already the basis of particular projects. S o m e of these will be discussed in this paper. ICARDA has been concerned primarily w i t h kabuli chickpea, w h i l e ICRISAT has developed programs on both desi and kabuli types.
Testing end Selection Strstegies Despite the projected use of bulk pedigree and bulk-breeding methods at ICRISAT (Singh and Auckland 1975), almost all breeding material to date has been handled using the classical
11
pedigree m e t h o d . At ICARDA, m o s t of the breeding has involved advancing bulks to the F 2 generation and using conventional pedigree breeding thereafter. In both cases, elite material is made available to international cooperators as early-generation or selected, advancedgeneration bulk lines t h r o u g h screening nurseries or yield trials.
Selection Procedures Hybridization and Choice of Parents A large n u m b e r of crosses involving many parents have been made and evaluated w i t h i n the ICRISAT/ICARDA programs (Table 1). In the absence of adequate information on their breeding value and regional performance, parents have been chosen on the basis of ecogeographical diversity or complementary characteristics or of specific characteristics, such as disease resistance, high yield, seed characters, double-pod development, maturity class and so on. Single and multiple crosses are made largely w i t h i n the desi or kabuli types; however, considerable hybridization of the t w o types has also occurred.
Table
1.
Selection a m o n g Crosses In v i e w of the large number of crosses and diverse parentage used, there is considerable interest in discarding crosses in order to allow concentration on those crosses most likely to be productive. Selection has been practiced a m o n g crosses on F 1 performance based on a visual estimation of merit, both agronomically and in terms of disease resistance. A f o r m a l study of a restricted set of crosses that w e r e relatively high, m e d i u m , and l o w yielding in the F 1 generation has indicated that rejection of crosses on the basis of l o w F 1 yield w o u l d eliminate f e w crosses w i t h relatively high mean performance in later generations (Table 2). However, the correlations of rank mean performance of the crosses over generations w e r e not particularly high, and this may reflect cross x environment interaction. S o m e crosses w i t h l o w mean performance and/or w i t h restricted variation for yield in t h e F 3 generation were retained. This suggests that w h i l e grossly inferior crosses may be discarded on F 1 performance w i t h m i n i m a l risk, all crosses retained should be subjected to bulk F2 or F3 tests or evaluated using random F2 or F3 derived lines in order to determine their real potential in breeding.
C h i c k p e a crosses c o m p l e t e d a t I C R I S A T a n d I C A R D A , 1 9 7 3 - 7 8 . Off season
M a i n season
No. of parents
ICRISAT Center
Hissar
Lahaul
Lebanon
Total
ICRISAT 1973-74 1974-75 1975-76 1976-77 1977-78 Total
424 1337 1586 1232 884 5463
0 0 693 597 298 1588
247 598 148 0 0 993
86 23 0 0 0 109
757 1958 2427 1829 1182 8153
ICARDA
Lebanon
Egypt
Syria
Total
No. of parents
1 9 7 4 - 75 1976-77 1977-78 Total
224 0 31 255
0 202 0 202
0 0 48 48
224 202 79 505
85 69 0
Year
D = Desi, K = Kabuli
12
130 248 337 150 D ; 16K 89 D ; 49 K
Table 2.
M e a n y i e l d s and r a n k s o f c r o s s e s p l a c e d i n h i g h , m e d i u m , a n d l o w g r o u p s a n d F 1 y i e l d I n F 1 , F2 a n d Fa g e n e r a t i o n s , 1 9 7 6 — 7 8 . F2
F1
Cross
Yield (g/plant)
Rank
Yield (kg/ha)
F 3 p r o g e n y mean
F 3 bulk Rank
Yield (kg/ha)
Rank
Yield (kg/ha)
Rank
High JG-39 x P-436 P-502 x BG-1 T-3 x L-532 T-3 x P-4375 T-3 x NEC-721 Mean
50.0 44.5 43.9 43.3 42.7 44.9
1 2 3 4 5 3.0
2367 1981 1647 1853 1960 1963
3 5 10 8 6 6.4
1034 902 435 631 625 726
1 3 13 11 12 8.0
1100 970 473 1003 510 811
2 5 15 3 13 7.6
Medium P-861 x T-103 P-502 x P-514 P-861 x Pant-104 T-3 x T-103 P-648 x P-1243 Mean
34.7 34.7 34.7 34.5 34.5 34.6
6 7 8 9 10 8.0
2400 2427 1927 2260 1093 2141
2 1 7 4 9 4.6
938 805 878 895 649 833
2 6 5 4 10 5.4
477 1217 873 567 977 823
14 1 7 11 4 7.4
Low Ceylon-2 x P-662 P-648 x G-543 JG-39 x Pant-102 Ceylon-2 x NEC-835 JG-39 x P-3172 Mean
21.3 20.7 20.3 19.5 19.0 20.2
11 12 13 14 15 13.0
1567 1620 1527 1320 1613 1529
13 11 14 15 12 13.0
411 702 753 325 681 574
14 8 7 15 9 10.6
733 700 903 510 837 737
9 10 6 12 8 9.0
Selection w i t h i n Crosses As indicated above, most of the breeding programs at both institutions have involved conventional pedigree methodology. At ICRISAT, a general strategy has been adopted that involves g r o w i n g F 2 populations at both Hissar and ICRISAT Center w i t h visual selection of desirable phenotypes, followed by evaluation of all plant progenies at both sites in the F3. In subsequent generations, visual ranking of plant rows and selection of plants w i t h i n the best progenies is f o l l o w e d by testing at both of these sites. The selection intensity has been high (Table 3); thus, the breeding strategy has been based heavily on visual phenotypic ranking of plants and progenies for selection and on testing at t w o main locations — one in southern India and the other in northern India. M o r e recently facilities for yield testing of progenies have been developed. At ICARDA, the breeding strategy in the past has been based mainly on advancing crosses as
bulks to the F 3 generation and using a conventional pedigree selection system thereafter. In F 2 bulk populations f o l l o w i n g kabuli x desi crosses, mass selection of kabuli and near kabuli types is practiced. In the F 3 generation, selection of individual plants is based on a visual phenotypic rating for w h i c h plant g r o w t h characters, seed characters, maturity, and pods per plant are all considered. In winter-planted chickpea, special emphasis is placed on selection for cold tolerance and Ascochyta blight resistance. Because of the shifting program base in the past ( 1 9 7 3 - 7 5 in Lebanon, 1975-77 in Egypt, and 1 9 7 7 - 7 9 in Syria) it has not been possible to develop a definite strategy on multilocation testing and selection. Now, however, w i t h t h e p r o g r a m f i r m l y established in A l e p p o and w i t h a substation located at Terbol in Lebanon, it is intended that populations and selections be evaluated in both environments. When a high elevation site is developed, it will also be in-
13
Table
3.
P o p u l a t i o n s a n d Unas g r o w n a n d s e l e c t i o n s e v a l u a t e d a t I C R I S A T , 1 9 7 7 - 7 8 . No. of lines bulked
No. of plants selected
No. of lines and Populations g r o w n
ICRISAT Center
ICRISAT Center
Hissar
ICRISAT Center
Hissar
Desi t y p e F2 p o p u l a t i o n s F 3 progenies F 4 progenies Fs progenies F 6 progenies F 7 progenies
154 4649 2074 794 1008 315
234 4733 2204 859 1190 315
1118 1337 662 635 102 0
1338 1374 551 267 462 0
0 0 0 33 36 18
0 0 0 30 48 18
Kabuli t y p e F2 p o p u l a t i o n s F 3 progenies F 4 progenies F 5 progenies F 6 progenies F 7 progenies
0 862 468 43 150 45
0 862 489 45 148 45
746 952 238 15 109 0
709 119 200 7 62 0
0 0 0 0 12 6
0 0 0 0 4 0
N e w plant t y p e F 2 populations F 3 progenies F 4 progenies
58 517 312
33 517 312
376 233 199
203 251 95
0 0 0
0 0 0
Generation
cluded in t h e testing/selection scheme. Depending on t h e availability of seed, progenies are being evaluated in winter and spring plantings at Tel Hadia.
Methods of Evaluation As indicated previously, visual appraisal of plant and line performance and multilocation testing have been adopted at ICRISAT w i t h i n a pedigree system framework. The effectiveness of these methods requires evaluation. EFFECTIVENESS OF V I S U A L
APPRAISAL.
In
an
effort to determine t h e effectiveness of visual appraisal of phenotypic merit in a range of genetic backgrounds and habits, 150 F 4 lines w e r e sampled at r a n d o m f r o m a large n u m b e r of crosses involving three c o m m o n parents of differing crop duration (H-208, 850-3/27, and JG-62). Phenotypic rank score ( 1 - 5 , with 1 most favorable and check cultivars usually scoring 3) and seed yield of each line w e r e c o m p a r e d for both ICRISAT Center and Hissar (Table 4). For each of these populations in each location,
14
Hissar
there was a close association of rank score and mean yield of lines w i t h i n a rank, indicating that, on the average, visual ranking distinguished differences in seed yield. The correlation between rank score and seed yield over all lines was l o w to moderate (r = - 0 . 3 8 to - 0 . 6 4 ) , and the distribution of seed yields of t h e rank groups overlapped substantially (Table 4). Apart f r o m the highest ranked g r o u p in each case, most classes included virtually t h e entire range of yield distribution. A similar situation existed w h e r e the three populations of lines w e r e pooled and separated into early, m e d i u m , and late m a t u r i n g groups of lines (Table 5). Furthermore, w i t h i n those F 8 lines yielding at least 50% m o r e than the moving average of the best check cultivar at ICRISAT Center or Hissar in 1 9 7 7 - 7 8 , there was a w i d e range of rank score and l o w association of seed yield as a percentage of the nearest check r o w and visual ranking (Table 6). These data indicate that w h i l e visual scoring of phenotypic merit does reflect average differences in seed y i e l d , t h e ranking has only limited
Table 4.
M e a n a n d r a n g e o f s e e d y i e l d ( k g / h a ) w i t h i n f i v e v i s u a l r a n k scores f o r 1 5 0 r a n d o m F 4 lines f r o m each of three c o m m o n parents (H-208, 8 5 0 - 3 / 2 7 , JG-62) evaluated at ICRISAT C a n t o r a n d Hissar, 1 9 7 5 - 7 6 ICRISAT Center
Rank H-208 parentage 1 2 3 4 5 Mean r 850-3/27 parentage 1 2 3 4 5 Mean r JG-62 parentage 1 2 3 4 5 Mean r
N u m b e r of lines
1 5 16 44 94
Hissar
Mean
Range
N u m b e r of lines
3122 2600 2199 2123 1655 2340
3122 2250-3028 1242-2488 747-2977 670-2827
0 9 35 45 61
Mean
Range
NA 3173 2525 2390 1690 2445
NA 2292-4167 1292-3417 646-3917 250-3389
-0.38
2 6 48 57 37
3021 2466 2123 1922 1794 2265
2917-3125 2110-2847 805-2958 708-2932 887-2377
-0.61 0 3 22 58 67
NA 3333 2606 2453 1745 2543
-0.48
-0.43
1 5 35 66 43
2383 2122 2054 1862 1509 1986
2383 1795-2533 1283-2643 975-3333 753-2180 -0.39
NA 2833-3833 1208-3694 722-4104 271-3354
1 5 32 39 73
4083 3042 2422 1935 1367 2870
4083 2354-3917 979-3944 354-2875 146-3854 -0.64
r = C o r r e l a t i o n coefficient b e t w e e n rank scores a n d seed yields. NA = Not applicable
association w i t h seed yield for individual lines. Thus, truncation of rank may be expected to result in only limited selection differential for seed yield. This may be d u e to the fact that a number of traits were considered in allocating rank; for example, w h i l e p o d n u m b e r was the primary consideration, lower rankings were given because of unsuitable maturity, possession of undesirable seed characteristics (color, size), and other reasons. Further, the correlations between rank score and actual yield were substantially greater than those between rank score and yield as a percentage of the nearest check cultivar plot (Table 6). This indicates that little consideration was given to the check plots of the augmented designs in allocating rank score, and this is disturbing.
The heritability of rank score is of concern. To examine this question, large populations of F 3 lines derived f r o m F 2 plants selected visually at ICRISAT Center and Hissar, and evaluated in those locations in 1976-77 and 1 9 7 7 - 7 8 , w e r e ranked visually (Table 7). These locations provide distinctly contrasting environments for chickpea, and any effective selection for performance at either site should have been reflected in an expression of differential adaptation between the sites in the F 3 generation. Despite the large populations and extremely high selection pressures used in the F2, there was never greater than 2% of t h e F 3 progenies in ranks 1 and 2, and there was no apparent influence of location of F 2 selection on F 3 line performance. Similarly, populations of F 4 lines
15
Table
5.
M e a n a n d range of seed yield ( k g / h a ) w i t h i n five visual rank scores f o r early, m e d i u m , and late maturing F4 lines, ICRISAT Center, 1 9 7 5 - 7 6 .
Rank Early lines 1 2 3 4 5 Mean r M e d i u m lines 1 2 3 4 5 Mean r Late lines 1 2 3 4 5 Mean r
No. of lines
Mean
Range
1 3 10 15 8
3122 2471 2056 2222 1637 2302
2250-2597 805-2675 1395-3267 1108-2100 -0.44
1 11 59 118 83
1795-3028 1283-2958 708-3333 753-2827 -0.32
2 2 28 33 76
derived as single plant progenies f r o m F 3 lines selected on visual rank at ICRISAT Center and Hissar, and evaluated at these sites in 1 9 7 6 - 7 7 and 1 9 7 7 - 7 8 , revealed a very l o w frequency of lines w i t h high rank (Table 8). There was a trend for the selected g r o u p to have a greater frequency of lines w i t h higher rank in the environment of selection of t h e F 3 than in the alternate test environment, but t h e effect was small. The conclusion is unavoidable that visual rank score has little relationship w i t h seed yield, and that visual discrimination a m o n g F 2 or F 3 rows w as relatively ineffective in influencing rank score in t h e subsequent generation. Since there is no evidence of differential adaptation of t h e selections f r o m contrasting sites in t h e F2, and only very l i m i t e d evidence of it in t h e F 3 - F 4 , the limitation in visual ranking appears to be in the reproducibility of the scoring, rather than in genotype x e n v i r o n m e n t interaction. Clearly, effective use of visual discrimination in select i o n of chickpea requires the development of a
16
2917 2367 2139 1974 1808 2241
2754 2478 2103 1768 1673 2155
2383-3125 2377-2578 1115-2615 747-2775 670-2595 -0.42
scoring system that is m o r e reproducible and m o r e closely related to seed yield. U S A G E OF M U L T I P L E L O C A T I O N S . Both ICARDA
and ICRISAT have investigated the use of particular locations as off-season nurseries to attain rapid turnover of generations of breeding populations. At ICARDA, it may be possible to advance winter-planted material f r o m Tel Hadia during t h e off-season at Terbol and a Government of J o r d a n experiment station at Shawbak has been used successfully for s u m m e r advancement of spring-planted material. Offseason advancement has been attempted by ICRISAT at several sites in northern India and can be accomplished reliably w i t h spring planting at Tapperwaripora, Kashmir. The major breeding activities of ICRISAT are conducted at t w o sites in India: ICRISAT Center near Hyderabad and Haryana Agricultural University, Hissar. These locations represent contrasting e n v i r o n m e n t s for chickpea, the f o r m e r
Table
6.
D i s t r i b u t i o n o f r a n k scores f o r F 6 lines y i e l d i n g a t l e a s t 5 0 % m o r e t h a n t h e m o v i n g a v e r a g e o f t h e b e s t c h e c k c u l t l v a r a t I C R I S A T C e n t e r a n d Hissar, 1 9 7 7 - 7 8 . Correlation of rank score with Rank score No. of lines
Seed yield as percentage of check yield
Actual seed yield
31 0 1 30 4 6 2
97 18 17 62 20 24 16
0.33 0.03 0.09 0.59 0.01 0.28 0.28
0.71 0.79 0.43 0.59 0.62 0.66 0.60
0 0 0 0
24 6 9 9
0.05 0.05 0.07 0.09
0.14 0.53 0.37 0.04
Site and population
1
2
3
4
5
ICRISAT Center All lines Early crosses M e d i u m late crosses Late crosses JG-62 parentage H-208 parentage 850-3/27 parentage
0 0 0 0 0 0 0
5 3 2 0 2 2 1
16 5 8 3 5 4 5
45 10 6 29 9 12 8
Hissar All lines Early crosses M e d i u m - l a t e crosses Late crosses
2 0 0 2
5 2 2 1
12 3 4 5
5 1 3 1
Table
7.
F r e q u e n c i e s o f F 2 l i n e s i n p a r t i c u l a r v i s u a l r a n k classes f o r p o p u l a t i o n s s e l e c t e d o n r a n k a t I C R I S A T C e n t e r o r Hissar I n t h e F 2 a n d e v a l u a t e d a t b o t h sites I n t h e Fa, 1 9 7 6 - 7 7 a n d 1977-78. RANK SCORES
Selection location
2
3
4
5
Total
8 0.29 9 0.25
228 8.34 194 6.13
1162 42.52 1222 38.60
1328 48.59 1735 54.80
2733
F 3 progenies g r o w n at Hissar, 1 9 7 6 - 7 7 1 ICRISAT Center No. 0.03 % 4 No. Hissar 0.13 %
28 1.02 46 1.45
631 23.09 919 29.61
1712 62.64 1877 50.19
361 13.21 305 9.62
F 3 progenies g r o w n at ICRISAT Center 1977-78 1 ICRISAT Center No. 0.05 % 3 No. Hissar 0.11 %
13 0.68 19 0.70
380 20.03 185 14.11
942 49.66 1098 40.25
561 29.57 1223 44.83
F3 progenies g r o w n at Hissar, 1977-78 5 ICRISAT Center No. 0.26 % 7 Hissar No. 0.25 %
31 1.64 47 1.65
315 16.68 803 28.23
616 32.61 1350 47.47
922 48.81 637 22.40
1
F 3 progenies g r o w n at ICRISAT Center, 1 9 7 6 - 7 7 7 No. ICRISAT Center 0.26 % 7 Missar No. 0.22 %
3166
2733 3171
1897 2728
1889 2844
17
Table
8.
F r e q u e n c i e s o f F 4 l i n e s i n p a r t i c u l a r v i s u a l r a n k classes f o r p o p u l a t i o n s s e l e c t e d o n r a n k a t I C R I S A T C e n t e r o r Hissar i n t h e F 3 a n d e v a l u a t e d a t b o t h s i t e s i n t h e F 4 , 1 9 7 6 - 7 7 a n d 1977-78. RANK SCORES
Selection location
2
3
4
5
Total
0 0 3 0.34
72 8.51 51 5.86
563 66.55 421 48.34
211 24.94 393 45.12
846
10 1.19 16 1.83
132 15.73 158 18.12
551 65.67 652 74.77
146 17.40 45 5.16
F 4 progenies g r o w n at ICRISAT Center, 1977-78 15 ICRISAT Center No. 1 1.64 % 0.11 Hissar 5 No. 0 0.43 % 0
239 26.15 252 21.61
479 52.40 580 49.74
180 19.70 329 28.22
F 4 progenies g r o w n at Hissar, 1 9 7 7 - 7 8 ICRISAT Center No. 1 % 0.12 Hissar No. 3 % 0.22
135 16.26 282 20.52
372 44.82 572 41.63
310 37.35 485 15.30
1
F 4 progenies g r o w n at ICRISAT Center, 1 9 7 6 - 7 7 ICRISAT Center No. 0 % 0 Hissar No. 3 % 0.34 F 4 progenies g r o w n at Hissar, 1 9 7 6 - 7 7 ICRISAT Center No. 0 % 0 Hissar No. 1 % 0.11
12 1.45 32 2.33
being considered suitable for short duration desi types and the latter for m i d and long duration desi and kabuli types. To date, all segregating material has been tested initially at both sites, and selection is practiced for adaptation to each environment. Marked differences exist in the relative performance of lines and populations between these sites. F 4 lines of 85 crosses w e r e evaluated at both sites in 1 9 7 5 76, each cross being represented by at least 5 lines and s o m e up to 57 lines. The relative cross mean performance varied substantially between sites. Of the t o p 21 crosses at each site, only one (7399, 850-3/27 x JG-221) w a s c o m m o n to both sites; it was ranked 7th at Hissar and 21st at ICRISAT Center. W i t h i n t h e t o p 33 crosses at each site, only seven crosses w e r e c o m m o n , and those ranked high at one site w e r e inevitably ranked l o w at the second site (Table 9). The top ten crosses at each site are listed in Table 10. Despite the lack of correspondence of crosses w i t h i n t h e superior g r o u p at each of the t w o sites, s o m e parents occurred
18
871
839 872
914 1166
830 1374
m o r e c o m m o n l y than others in the best crosses; e.g., H-208 occurred five and four times, 850-3/27 occurred twice and five times, and Annigeri occurred t w i c e and zero times at ICRISAT Center and Hissar, respectively. Similarly, all crosses c o m m o n to the top 33 crosses at these sites included H-208 or 850-3/27 parentage (Table 9). In the absence of m o r e specific information on the breeding value of particular parents at these locations, these results provide s o m e guidelines as to the potential value of parents. The most c o m m o n parents involved in the crosses evaluated in 1 9 7 5 - 7 6 w e r e H-208, 850-3/27, JG-62, and G-130, and a crude estimate of their breeding value may be obtained as the mean of all crosses involving each of these parents at ICRISAT Center and Hissar (Table 11). These data suggest that H-208 and 850-3/27 were, on t h e average, superior in hybrid c o m b i nation and that JG-62 and G-130 w e r e relatively inferior as parents at Hissar and ICRISAT Center, respectively.
Table
9.
Crosses c o m m o n t o t h e s u p e r i o r 3 3 crosses f o r m e a n y i e l d ( k g / h a ) o v e r F 4 l i n e s a t I C R I S A T C e n t e r a n d a t Hissar, 1 9 7 5 - 7 6 . ICRISAT Center
Hissar
Cross
Parentage
Rank
Mean yield
Rank
Mean yield
739 7310 7341 7388 7398 7399 73114
H-208 x Pant-110 H-208 x T-3 H-208 x N o . 59 850-3/27 x F-61 850-3/27 x Pant-110 850-3/27 x JG-221 850-3/27 x GW-5/7
19 3 23 29 31 21 22
2082 2506 2052 1990 1985 2074 2063
23 25 29 4 17 7 32
2409 2396 2315 2945 2502 2870 2270
Table
10.
T e n crosses w i t h t h e g r e a t e s t m e a n y i e l d s o v e r F 4 lines a t I C R I S A T C e n t e r a n d a t Hissar, 1975-76. ICRISAT Center
Rank
Cross
1 2 3 4 5 6 7 8 9 10
73129 738 7310 7314 73217 73143 7394 7330 7389 7315
Table
11.
Hissar Parentage
JG-62 x H-208 x H-208 x H-208 x F-404 x JG-62 x 850-3/27 H-208 x 850-3/27 H-208 x
Rank
Cross
1 2 3 4 5 6 7 8 9 10
73119 7392 73111 7388 7333 73167 7399 73185 7332 7328
Radhey BEG-482 T-3 Annigeri Ceylon-2 Annigeri x N-59 EC-12409 x F-378 B-108
Parentage 850-3/27 850-3/27 850-3/27 850-3/27 H-208 x JG-62 x 850-3/27 G-130 x H-208 x H-208 x
x H-223 x C-235 x H-208 x F-61 F-496 F-496 x JG-221 Chafa F-370 CP-66
M e a n y i e l d o v e r F 4 lines w i t h i n all crosses i n v o l v i n g f o u r d i f f e r e n t c o m m o n p a r e n t s , I C R I S A T C e n t e r a n d Hissar, 1 9 7 5 - 7 6 . Location mean yield (kg/ha)
Common parent H-208 850-3/27 JG-62 G-130 Mean
No. of crosses
No. of lines
29 27 35 10
478 302 524 114
Hissar 2329 2260 1836 2148 2143
(1) 8 (2) (4) (3)
ICRISAT Center
Average
1906 1984 1809 1520 1805
2118 2122 1823 1834 1974
(2) (1) (3) (4)
(2) (1) (4) (3)
a. N u m b e r s in parentheses indicate rankings in t h e trial.
19
Adaptation of Chickpea Genotypes As indicated in the paper by Singh et al. (this workshop) on the international trials and nurseries, substantial entry x location interaction has existed in each of the international trials g r o w n to date. This has been so for most plant characters examined, as well as for seed yield. For y i e l d , relatively f e w entries occurred c o m m o n l y in the superior g r o u p at many of the test locations. The importance of such interactions has i m plications on the strategy of research into chickpea i m p r o v e m e n t , and three main aspects will be considered here. First, since f e w lines have s h o w n w i d e adaptation over locations, there is a clear need to select for local adaptation as well as for broad adaptation, using multilocation evaluation across regions. This has been discussed in other sections of this paper. Second, it is necessary to understand the similarities and differences a m o n g the cultural environments internationally in order to identify the major factors that differentially influence or limit plant development of the test lines. This has basic importance in defining new methods and objectives in selection and clearly requires detailed consideration of plant characters in addition to seed yield and close collaboration w i t h physiologists. The importance of obtaining data on the characteristics of the test environments is emphasized. T h i r d , subdivision of the cultural environments internationally into groups that elicit generally similar responses f r o m chickpea genotypes w o u l d allow rationalization of testing, rapid adoption of superior genetic material, and m o r e objective definition of relevant breeding objectives. As discussed in the c o m p a n i o n paper on the international trials and nurseries (Singh et al. this workshop), there is a disturbing lack of evidence of reproducibility of line performance t h r o u g h o u t the non-Indian international test environments examined. While this implies the need to select simultaneously for local and broad adaptation, it is i m p o r t a n t also to consider the relevance of selection at particular locations w i t h i n t h e main ICRISAT/ICARDA breeding programs. The correlations of line performance at the main ICRISAT testing sites at Hissar and Hyderabad in 1975-1978 w i t h that at the various non-Indian international test loca-
20
tions in the International Chickpea Cooperative Trial, Desi-Late (ICCT-DL) trial are presented in Table 12. Twelve entries w e r e c o m m o n to these trials. W i t h f e w exceptions, line performance at Hissar and ICRISAT Center was poorly associated w i t h that at all other locations considered here. Many negative coefficients existed, some being reasonably strong (ICRISAT Center 1 9 7 5 - 7 6 w i t h Faisalabad), suggesting that selection at a central site prior to distribution of lines for local evaluation could actually be counterproductive. However, the magnitude and direction of the coefficients w e r e relatively consistent across years of test at the central sites, and some evidence of specific association of performance existed, e.g., for Hissar and Faisalabad. Furthermore, as discussed in the c o m p a n i o n paper on international trials and nurseries (Singh et al. this workshop), reasonable degrees of association of line performance have occurred in s o m e cases between ICRISAT Center and certain southern Indian locations, and between Hissar and certain northern Indian locations. These results are limited in scope, and further investigation of the implications of selection at particular sites on adaptation elsewhere is required as a matter of priority. However, three aspects appear reasonably clear. First, ICRISAT and ICARDA need to examine the use of additional central testing sites to strengthen their m a i n breeding programs and the international implications of their use in selection. Second, the importance of dissemination of relatively unselected but reasonably h o m o z y g o u s breeding lines for regional and local evaluation and selection is self-evident. T h i r d , national and local programs should exploit to the fullest the facilities available t h r o u g h ICRISAT and ICARDA for requesting hybridization and advancement of specified crosses for selection by the local cooperator. Each of these aspects is being developed w i t h i n the institutes and has been discussed in other sections of this paper.
Progress M a d e t o D a t e While the assessment of the effectiveness of selection in the program to date is not encouraging, nonetheless advanced lines have been developed that have given high yields in the Indian coordinated trials. Of five lines sub-
Table
12.
C o r r e l a t i o n s o f l i n e p e r f o r m a n c e s f o r s e e d y i e l d a t I C R I S A T ' s Hissar a n d H y d e r a b a d t e s t i n g sites I n 1 9 7 5 - 1 9 7 8 w i t h t h a t a t v a r i o u s I n t e r n a t i o n a l t e s t sites f o r 1 2 c o m m o n entries. ICRISAT-Hyderabad
ICRISAT-Hissar Entry
1975-76
1976-77
1975-76 Colchagua, Chile La Platna, Chile Ibb, Y.A.R. Debre-Zeit, Ethiopia Ed-Damer, Sudan D.I. Khan, Pakistan Faisalabad, Pakistan
0.16 0.44 0.01 0.18 -0.20 0.37 0.79
1976-77 Parwanipur, Nepal 1977-78 Feni, Bangladesh Yezin, Burma Dokri, Pakistan Faisalabad, Pakistan Tarnab, Pakistan
1977-78
1975-76
1976-77
0.14 -0.28 -0.03 0.18 -0.13 0.11 0.20
0.29 0.24 0.08 0.06 0.08 0.43 0.48
-0.25 -0.36 -0.44 -0.15 0.49 0.05 -0.59
-0.29 -0.15 -0.11 -0.05 0.38 -0.17 -0.48
-0.21
0.21
-0.19
0.18
-0.12
-0.12 0.09 -0.23 -0.15 -0.03
0.00 -0.19 0.12 -0.26 0.21
0.04 -0.20 -0.21 0.23 0.11
0.08 -0.12 -0.19 0.02 -0.24
0.00 0.00 0.07 -0.03 -0.31
mitted for testing in 1977, t w o were advanced f r o m the initial evaluation trial to the Gram Coordinated Varietal Trial (GCVT) in 1978. Eight new lines were included in the initial evaluation trial in 1978 on the basis of their performance in observation nurseries at 13 locations. Additional evidence of yield gains was seen (Table 6); 97 F 6 lines at ICRISAT Center and 24 at Hissar yielded at least 50% more than the m o v i n g average of the check. It is fair to conclude that high yielding material has been d e v e l o p e d ; nonetheless we will address the question of increasing the effectiveness of breeding for yield in a later section.
Future Breeding S t r a t e g i e s Organization of Programs W i t h the integration of the chickpea programs of t w o Centers, there is an opportunity to optimize utilization of resources for m a x i m u m efficiency. W i t h the availability of skilled workers in India, we intend to make most of the crosses at ICRISAT Center. Limitations of this approach will exist in adaptive requirements of
some parents and the nonavailability of most of the kabuli germplasm lines at ICARDA. However, we will expedite the transfer of germplasm between Centers, w i t h the objective of ultimately maintaining complete collections at both. Crosses will necessarily continue at all sites in order to utilize newly identified parent material and to meet other needs of the program at each site.
Breeding for High Yield We consider the i m p r o v e m e n t of genetic yield potential to be our primary objective. Yield, however, is the least heritable of the traits u nder selection, and ample evidence exists not only for specificity of adaptation to location, but to years within a location. We consider the pedigree method utilizing visual selection to be well adapted for highly heritable characters, such as disease resistance and specific plant characters, but poorly adapted for yield. Selection of individual plants in Fa for yield in chickpea has not been effective for us. Similar results have been reported w i t h other crops; in wheat by Knott (1972), McGinnis and Shebeski (1968), DePauw and Shebeski (1973); in barley
21
by Fiuzat and Atkins (1953); and in oats by Frey (1962). Additional disadvantages of th e pedigree m e t h o d are: (1) selection w i t h i n a single environment for local adaptation, w h e n our m a n date is to p r o v i d e superior material for many locations, (2) the uniqueness of each year's climate, w h i c h results in changing selection pressure each year, and (3) the limitation on the a m o u n t of material and particularly genetic diversity that can be advanced. We propose to be continually m o r e selective in choice of parents f o r the yield p r o g r a m and to restrict the n u m b e r of crosses. Bulk F 2 testing is proposed at a n u m b e r of sites to identify not only crosses w i t h high yield over locations but also those w i t h specific adaptation. Yield testing of F2 (or F3) bulks has been suggested for dry beans by H a m b l i n g and Evans (1976), and for wheat by Knott and Kumar (1975), Cregan and Busch (1977), and Bhullar et al. (1977). In 1978, ICRISAT planted tests of 172 F2 bulks at three locations, and of 46 of those bulks at an additional four locations in cooperation w i t h the All India Coordinated Program. Cooperators can choose the best crosses for use in their programs. ICARDA is testing F3 bulks at ten locations. Single seed descent (Goulden 1939; Brim 1966) is a logical means of advancing populations w i t h o u t selection w h i l e preserving genetic variance for later selection. However, single pods will be harvested instead of single seeds to permit overseeding and t h i n n i n g as a means of maintaining population size. The objections to use of bulk advance on the basis of its being slower than pedigree breeding have been answered recently by Jensen (1978). However, if t h e contention of Harrington (1937) that homozygosity is reached more rapidly in pedigreed lines than in the bulk populations should be true, we w o u l d consider this an additional advantage in avoiding rapid fixation of genotypes. We do agree w i t h Jensen's arguments, however, and expect to f i n d practical homozygosity in the progeny of many F 5 plants. Our choice of single p o d descent over bulk hybrid advance is based on the avoidance of the effects of selection, competition a m o n g seed sizes, and other factors as discussed by Hamblin (1977). Crosses not tested as F2 or F3 bulks will be evaluated on the basis of performance of F3 or
22
F 4 derived lines in perhaps five environments internationally. The best crosses w i l l be reg r o w n subsequently in larger populations of F 3 or F 4 derived lines for rigorous selection. We plan to restrict our selection for yield to progeny tests of derived lines. Those crosses tested in early generation bulks will ordinarily be advanced to F 4 or F5, w h e n plants will be taken for g r o w i n g lines for evaluation in the next generation. It will be desirable to do only m i l d selection in the first year at a given locat i o n , to a l l o w for maintenance of selections that w o u l d be extremely well adapted to the next year's climatic conditions, or at other locations. All breeding material will be tested and advanced as far as possible under reasonably favorable, but not idealized, agronomic management; that is, w i t h plantings made on a full profile of moisture, g o o d stands ensured, irrigat i o n applied to avoid unnecessary stress, and avoidance of excessive insect or disease pressure. The objective is to encourage expression of genetic differences for production characters in order to facilitate truncation in selection, and to avoid excessive bias in selection due to entry x year interaction by using a m o r e reproducible selection environment. Advanced lines will be evaluated in insecticide-free conditions and in disease nurseries prior to distribution in cooperative trials. Breeding material will continue to be supplied to cooperators internationally as elite lines t h r o u g h the International Chickpea Cooperative Trials, as advanced lines t h r o u g h the International Chickpea Screening Nurseries, and as bulk F 2 and F 3 populations of specific crosses on request. Further, cooperators will be encouraged to select amon g th e random F 3 or F 4 derived lines of most crosses, w h i c h w i l l be g r o w n annually at four or five sites internationally.
Rapid Generation Turnover The yield-breeding program visualized can be effectively speeded up by rapid generation turnover. Conceptually, it should be possible to attain turnover of three generations annually, at least in winter-grown chickpea, using an autumn crop planted in August or September, a spring crop planted in late December, and a summer crop planted in May or June. Research is under
w a y to determine the environmental modifications necessary to attain this objective and the availability of suitable locations. It is emphasized that the objective is generation advancement only, and that selection w o u l d normally be practiced only in the normal cropping season. A s s u m i n g that three generations could be g r o w n per year, this system w o u l d allow field testing of F 3 derived lines in the F 5 generation only 2 years after making the initial cross. We hope modifications of photoperiod and temperature will permit even mor e rapid advance of s o m e material.
Breeding for Resistance to Diseases and Insects Pedigree selection is expected to be the most effective method for developing resistance to diseases and pests, and this m e t h o d is currently being used in the development of lines in disease-sick plots and laboratory screening. Bulk advance of resistant plants in early generations will be used in some crosses to increase the amount of material handled, and single pod descent will be used to maintain variation in advanced populations. The race situation is not clear as yet for most chickpea diseases, and if their existence is proved, other methods will be employed. In the case of multiple races, it may be possible to identify or develop sources resistant to all races, perhaps t h r o u g h gene pyramiding. However, if the race situation is complex, horizontal resistance may be sought through the development of composite crosses, as proposed by van der Plank (1968). This involves biparental intercrossing of lines w i t h moderate levels of resistance and wide adaptation, and bulking the F2S equally to f o r m a composite population. This w o u l d be g r o w n in multilocation tests annually, w i t h bulk harvest followed by m i x i n g seed f r o m all locations in equal proportions to reconstitute the population. If this method is effective, such a population could be distributed to national programs for release, reselection, or breeding purposes. The status of research on disease and insects will be reported in other w o r k s h o p papers. Considering the distribution of disease problems, it is not realisticfor an international center to undertake to c o m b i n e local adaptation for
yield and disease resistance for all locations. For this reason, we are advocating the quantitative approach for breeding for yield as a separate objective, and we r e c o m m e n d resistancebreeding procedures appropriate for the specific disease situation. All advanced lines developed in t h e y i e l d p r o g r a m will bescreened to classify them for disease reaction. Local breeding programs w i t h a severe disease problem will find it necessary to use disease resistance as a first culling objective, but they will then be able to profitably use quantitative methods to select for yield w i t h i n the resistant population. The ineffectiveness of single-plant selection for yield is as real in local programs as in regional, national, or international programs. Preliminary evidence exists regarding differences a m o n g chickpea lines for resistance t o , and tolerance of, Heliothis armigera. Exploratory studies of inheritance will be initiated shortly in this area. In the general breeding p r o g r a m , resistant or tolerant lines will be used as parents and all advanced breeding lines will be evaluated under insecticide-free conditions to determine their reaction.
Breeding for Quality and Consumer Acceptability Chickpea is recognized as one of the most digestible of the pulses. Considering the relative importance of increasing yield and incrementally improving a highly acceptable f o o d product, we have put little effort on quality to date. The need for m o n i t o r i n g cooking t i m e and chemical composition of advanced lines has been emphasized (Hawtin et al. 1976). Currently, routine screening for protein content is done on material f r o m both the desi and kabuli programs, and a special project of breeding for a higher level of protein in desi has been initiated. If and w h e n protein percentage is increased substantially, the quality of protein in the high lines will be compared with that of normal cultivars so we can determine if higher protein percentage per se is a w o r t h w h i l e objective. Visible characters influencing consumer acceptability are m o r e complex in desi than in kabuli cultivars; we hope information brought to this conference will help to catalog local preferences for seed size and color.
23
Breading for Modified Plant Habit In general, chickpea is characterized by a semiprostrate bushy plant habit and by singleflowers per peduncle and l o w numbers ( 1 - 2 ) of seed per p o d . Genotypes producing t w o flowers per peduncle exist and have been studied genetically and used in breeding at ICRISAT. Lines w i t h up to five ovules per p o d have been identified elsewhere. Tall, erect kabuli types have been obtained f r o m the USSR. These characters open exciting prospects in chickpea breeding since they offer an opportunity to redesign the canopy structure and to develop prolificacy of reproductive sinks per plant and per node. Considerable research is planned in both desi and kabuli types using these traits. The use of tall erect types w o u l d facilitate harvesting, both by hand and by mechanical methods. In one trial at Tel Hadia, a tall t y p e (NEC-138) produced 60% m o r e yield at 500 000 plants/ha than at 167 000 plants/ha, w h i l e a local bushy cultivar showed little response. The possibility exists that redesigning the canopy t y p e and the agronomic system may result in substantial yield increases. Currently there are 22 tall g e r m p l a s m accessions available. ICARDA scientists are investigating populations of tall x bushy kabuli types, and ICRISAT is w o r k i n g mainly w i t h crosses between tall kabuli and bushy desi parents. Segregating material involving these parents will be selected using the pedigree system and/or bulk populations w i t h mass selection for plant habit. Studies are being made of the inheritance of plant habit and of the interrelationships of plant habit w i t h other plant characters at different densities.
Breeding for New Applications of Chickpea Increasing emphasis w i l l be put on t h e dev e l o p m e n t of chickpea breeding material adapted to n e w or relatively unexploited cultural regimes. The objective is to p r o v i d e f u r t h e r options for chickpea cultivation in new or existing areas of culture of the crop. The potential benefits to be realized t h r o u g h advances in new applications can hardly be overemphasized.
24
Winter Cropping of Kabuli Chickpea in Western Asia In the Mediterranean region, chickpea is g r o w n almost exclusively as a spring crop. A l t h o u g h farmers have argued that this is related to inability of t h e c r o p t o withstand severe winters, winter plantings at Kfardan, Lebanon, in 1 9 7 4 - 7 5 resulted in survival of all lines and in higher yields than for the spring crop. Subsequently, other studies have suggested that the m a i n danger involved w i t h a u t u m n plantings is t h e higher risk of occurrence of Ascochyta blight. Significant yield increases have been obtained f r o m winter cropping as c o m pared w i t h spring cropping, where this disease did not occur or w h e r e it was controlled by use of fungicides (Table 13). There is a strong possibility of introducing chickpea as a winter crop in the region. Costbenefit ratio studies on fungicidal use are planned for 1 9 7 8 - 7 9 in large scale trials, and new cultural practices are being developed and s o m e p r o m i s i n g cultivars are being multiplied . In s o m e years, early c o m m e n c e m e n t of the rains may prevent planting before spring so that cultivars w h i c h perfor m well over a w i d e range of planting dates w o u l d be desirable. This appears to be a feasible objective; e.g., ILC-263, w h i c h ranked sixth in the winter planted yield trial, ranked third in the same trial planted in spring. The entire kabuli g e r m p l a s m has been sown at Tel Hadia and Tekmadash to screen for winter hardiness, and it is envisaged that Ascochyta blight resistance will be incorporated into high yielding cultivars adapted to winter planting. Depending on the results of the 1 9 7 8 - 7 9 studies, an international nursery may be distributed to national programs interested in developing winter planting.
Late Sowing in Northern India For various reasons (largely involving rotation w i t h rainy-season crops), considerable interest exists in adaptation of chickpea to late winter (November) sowings in northern Indian conditions. C o m m o n l y , lines exhibit substantial flower drop, p o d curling, and restricted p o d set under these conditions, but differences in adaptation have been identified. The cause of these s y m p t o m s is not k n o w n but probably involves differential sensitivity and reaction to l o w
Table
13.
Yield
I n c r e a s e off w i n t e r o v e r s p r i n g p l a n t i n g I n t h e a d v a n c e d t r i a l , 1 9 7 7 - 7 8 , A l e p p o . Yield (kg/ha) Winter
Spring
Increase over spring (%)
Highest y i e l d i n g ILC-262 ILC-51 ILC-237 ILC-23 ILC-493 Syrian local
1852 ( 1 ) 1807 ( 2) 1737 ( 4) 1725 ( 6) 1719 ( 8 ) 1677(11)
1073 (23) 1098 (22) 1005 (30) 988 (35) 1146(13) 1027 (27)
73 64 73 75 50 63
Lowest y i e l d i n g ILC-52 ILC-205 ILC-673 ILC-812 ILC-1028
1532 (24) 1086 (36) 1457 (32) 1548(22) 1473 (31)
1201 ( 5) 860 (47) 1108(20) 1163(10) 1142(16)
28 26 31 33 29
Entry
a. N u m b e r s in parentheses indicate t h e rankings in t h e t r i a l .
m i n i m u m temperature. Breeding studies have been initiated at Hissar to i m p r o v e adaptation to late sowings, including mass selection for pod and seed production under these conditions and screening of g e r m p l a s m . E a r ly S o w i n g i n S o u t h e r n I n d i a Crop g r o w t h in southern Indian environments c o m m o n l y is terminated by a c o m b i n a t i on of high temperature and l o w available soil water. Early s o w i n g in these environments may extend the duration of the crop and possibly result in i m p r o v e d utilization of available moisture. This may incur problems associated with seedling response and root and other diseases. particularly w h e r e late rains are received. Screening of germplasm and of populations of breeding lines has been initiated to determine the genetic variability available for ability to tolerate and respond to early (September) sowing. Apart f r o m its potential f o r dry seed product i o n , this system may also offer potential for early production of green pods for vegetable use.
Development of Chickpeas for High-Input Culture As indicated previously, chickpea is generally
g r o w n as a rainfed crop on conserved moisture w i t h low inputs, and most breeding effort is directed to i m p r o v e production under these regimes. However, the development of irrigation has resulted in a challenge by cereals for acreage in traditional chickpea areas. This has had an unfavorable influence on the availability and price of chickpea and can only be met by the development of chickpea cultivars m o r e responsive to high-input culture. ICRISAT and ICARDA have conducted only limited investigations in this area to date, but screening of germplasm and breeding populations for response to high-input culture has been initiated.
Study of Environmental Interactions Very little detailed study of the response of chickpea cultivars and lines to different product i o n environments has been made. The evidence available suggests that substantial line x environment interaction exists and that there is considerable specificity of adaptation of lines for particular locations. It is apparent that the attainment of broad adaptation to a range of production environments presents a significant breeding challenge in chickpea. Three main lines of attack on this p r o b l e m w i l l be involved.
25
Analysis of Multilocation International Trials The international trials and nurseries are the major points of contact between t h e centers and chickpea workers and production environments internationally. Detailed analysis of the results of such trials w i l l provide hard evidence on differences in adaptation of lines, and this information can be used to guide the selection of parents a n d t h e definition of specific directions of selection for adaptation. The importance of collecting all possible plant and environmental data f r o m each site is e m phasized so that an adequate data base can be provided for interpretation of differences a m o n g lines in response.
Use of Multilocations w i t h i n the Breeding Program The use of m u l t i p l e environments for testing w i t h i n t h e breeding p r o g r a m s of t h e centers will allow o p p o r t u n i t y to identify and select material w i t h specific f o r m s of response to environment, including w i d e adaptability. This occurs in all segregating generations, ranging f r o m the multilocation bulk F 2 or F 3 tests to final selection a m o n g elite advanced generation lines. It is emphasized that because of the apparent m a g nitude of genotype x e n v i r o n m e n t interaction in this crop, rigorous selection of early generation material should be avoided, particularly on a single plant basis. Local cooperators can contribute substantially to t h e developmen t of w i d e adaptation by instituting m u l t i - e n v i r o n m e n t trials over years w i t h i n their areas as part of their testing p r o g r a m .
Response to Selection for Photoperiod- and Thermo-insensitivity Special exploratory studies are possible. For example, it appears that photoperiod and temperature have i m p o r t a n t influences on chickpea adaptation, so that genotypes w i t h lower p h o t o - and thermo-sensitivity may be m o r e w i d e l y adapted. At ICARDA, crosses w i l l be m a d e between parents of different origin and between relatively widely adapted parents, and a composite population w i l l be f o r m e d by m i x i n g equal proportions of F 2 seed of each cross. Selection w i l l be practiced in alternate generations for earliness under very short day
26
conditions in Egypt or Sudan for m a x i m u m seed p r o d u c t i o n and under l o n g day conditions in Syria, Lebanon, and Iran, and a new c o m posite will be f o r m e d for further cycles of selection. The impact of such selection on environmental response will be determined subsequently. This is a f o r m of phenotypic recurrent selection, w i t h selection practiced in t a n d e m for different f o r m s of adaptation. We are considering methods of incorporating regular cycles of recombination into this breeding scheme.
Summary and Conclusions We have reviewed t h e first 5 years of the chickpea breeding p r o g r a m at ICRISAT. Evidence on the relative ineffectiveness of visual scoring and the lack of availability of the ratings suggests that m o r e efficient breeding m e t h o d s might be e m p l o y e d ; however, progress was m a d e in yield potential, as evidenced by the performance of advanced lines. We are suggesting modifications that we n o w think w o u l d be appropriate f o r a breeding program at an international center. We will rely largely on quantitative evaluation in selection for yield and will devote a substantial portion of our resources to that part of the p r o g r a m w i t h high y i e l d as a sole objective. Conventional pedigree selection w i l l be the m a i n m e t h o d of breeding for highly heritable characters; pest and disease resistance will be the primary objective of other phases of the breeding p r o g r a m . All new lines will be tested for disease and pest reaction, and the incorporation of disease resistance into high yielding cultivars w i l l be part of the p r o g r a m at each of the Centers' breeding locations. Emphasis on breeding fo r new applications of chickpea — including winter s o w i n g in western Asia, late planting in northern India, and early planting in southern India — w i l l increase. Attention to high input production will begin. Breeding fo r m o d i f i e d plant types and plant characters is an open ended p r o g r a m in w h i c h various plant types and combinations of plant characters will be developed. Present emphasis is on tall, erect plant types fo r high population and f o r mechanical harvest. Implicit in our suggested p r o g r a m for quantitative breeding for yield — including m u l t i -
location testing at early as well as advanced stages of breeding — is a high level of cooperat i o n a m o n g chickpea breeders. Problems of disease and pest resistance or tolerance also
G O U L D E N , C. H. 1939. Problems in plant selection. Pages 132-33 in R. C. Burnett (ed.), Proceedings of the 7th International Genetics Congress. C a m b r i d g e University Press, England.
require c o o p e r a t i o n at several locations. Cooperation of national programs and individuals to date is greatly appreciated; we have made a g o o d beginning. Closer cooperation, more effective
communication
(including
better
f o l l o w - t h r o u g h ) , and m o r e j o i n t p l a n n i n g w i l l help us a c c o m p l i s h w h a t m u s t be our overriding objective: to get to t h e f a r m e r s ' fields, in t h e shortest possible t i m e , w i t h chickpea cul-
H A M B L I N , J. 1977. Plant breeding interpretations of the effects of bulk breeding on f o u r populations of beans (Phaseolus vulgaris L.) Euphytica 26: 1 5 7 168. H A M B L I N , J . and E V A N S , A. M. 1976. T h e e s t i m a t i o n of
cross yield using early generations and parental yields in d r y beans (Phaseolus vulgaris L ) . Euphytica 25: 515-520.
tivars that w i l l p r o d u c e m o r e calories and p r o H A R R I N G T O N , J.B. 1937. The mass-pedigree m e t h o d in the hybridization i m p r o v e m e n t of cereals. Journal of the American A g r o n o m y Society 29: 3 7 9 - 3 8 4 .
tein in a f o r m desired by t h e consumer.
Acknowledgments
H A W T I N , G. C. 1975. The status of chickpea research in the M i d d l e East. Pages 109-116 in Proceedings of the International Workshop on Grain Legumes, ICRISAT, Hyderabad, India.
T h e substantial c o n t r i b u t i o n s by K. B. S i n g h ,
H A W T I N , G. C., RACHIE, K. 0 . , and G R E E N , J. M.
C. L. L. G o w d a , S. C. S e t h i , O n k a r S i n g h , K. C. J a i n , and J. Kumar, chickpea breeders of lCRISAT, are acknowledged.
1976.
Breeding strategy for the nutritional i m p r o v e m e n t of plants. International Development Research Center, TS 7e: 4 3 - 5 1 . J E N S E N , N. F. 1970. A diallel selective mating system f o r cereal breeding. Crop Science 10: 6 2 9 - 6 3 5 . J E N S E N , N. F. 1978. Composite breeding m e t h o d s and the DSM system in cereals. Crop Science 18: 6 2 2 626.
References BHULLAR, G.
S., G I L L ,
K.
S.,
and
KHERA, A.
S.
1977.
Performance of bulk p o p u l a t i o n s and effectiveness of early generation testing in wheat. Indian J o u r n a l of Agricultural Science 47: 3 0 0 - 3 3 2 .
K NOTT, D. R. 1972. Effects of selection for F 2 plant yield on subsequent generations in wheat. Canadian Journal of Plant Science 52: 721-726.
B R I M , C. A. 1966. A m o d i f i e d pedigree m e t h o d of selection in soybeans. Crop Science 6: 220.
K N O T T , D. R., and K U M A R , J. 1975. Comparison of early generation yield testing and a single seed descent procedure in wheat breeding. Crop Science 15: 295-299.
C R E G A N , P. B., and B U S C H , R. H. 1977. Early generation bulk h y b r i d yield testing of adapted hard red spring wheat crosses. Cro Science 17: 8 8 7 - 8 9 1 . D E P A U W , R. M . , and SHEBESKI, L H. 1973. A n e v a l u a t i o n
of an early generation yield testing procedure in Triticum aestivum. Canadian Journal of Plant Science 53: 4 6 5 - 4 7 0 .
M C G I N N I S , R. C., and SHEBESKI, L. H. 1968. The reliabili-
ty of single plant selection f o r yield in F2. Pages 109-114 in Proceedings of t h e T h i r d International Wheat Genetics S y m p o s i u m , Canberra, Australia.
S I N G H , K. B., and A U C K L A N D , A. K. 1975. Chickpea
e n v i r o n m e n t a l variability in segregating barley populations. A g r o n o m y J o u r n a l 45: 4 1 4 - 4 2 0 .
breeding at ICRISAT. Pages 1 3 - 1 7 in Proceedings of the International W o r k s h o p on Grain Legumes, ICRISAT, Hyderabad, India.
FREY, K. J. 1962. Effectiveness of visual selection u p o n yield in oat crosses. Crop Science 2: 102-105.
VANDER PLANK, J. E. 1968. Disease resistance in plants. Academic Press, N e w York. 206 pp.
FIUZAT,
Y.,
and
ATKINS,
R.
E.
1953.
Genetic and
27
The Current Status of Chickpea Germplasm Work at ICRISAT L. J. G. van der Maesen, R. P. S. Pundir, and P. Remanandan*
ICRISAT's Genetic Resources U n i t is serving as a w o r l d center fo r t h e assembly, evaluation, preservation, and supply of g e r m p l a s m of five crops, o n e of w h i c h is chickpea (Cicer arietinum L ) and its w i l d relatives. An introduction to t h e w o r k w a s prepared earlier (van der Maesen 1976).
t e r m storage r o o m s at 4°C and 3 0 % RH; longt e r m storage (IBPGR 1976) is in the planning stage. A naphthalene ball per bottle keeps out insects. At 4°C this precaution w i l l no longer be necessary; however, a pot test revealed no harmful effects of naphthalene on g e r m i n a t i o n and g r o w t h w h e n seeds w e r e stored for 3 years w i t h a naphthalene ball (see Seed Viability, this paper).
Collection At present the collection contains 11 225 accessions of chickpea. Of w i l d Cicer spp, we have 33 accessions of 8 annuals and 14 accessions of 6 perennials (see Introgression, this paper). The largest n u m b e r s of chickpea accessions are f r o m India (4863) and Iran (3868). From 33 other countries, we have 2207 accessions (287 unknown). The major part of t h e collection has been received f r o m various agricultural universities and research institutes in India and abroad. Our o w n collection expeditions to various states in India, Turkey, Pakistan, and Afghanistan have so far yielded 787 entries. In 1978 we collected 13 samples in Pakistan, of w h i c h 8 were cleared for postentry quarantine isolation. Mimeographed travel reports are available. For future explorations, our o w n analyses and priorities declared by t h e International Board for Plant Genetic Resources will be f o l l o w e d . A p a r t f r o m Ethiopia, w h e r e only limited roadside collection is done, the existing geographical coverage is very reasonable.
Seed Storage Seeds are stored in plastic bottles arranged on m e t a l t r a y s in h u m i d i t y - c o n t r o l l e d , airconditioned r o o m s ( 6 0 - 6 5 % relative h u m i d i t y [RH], 14-18°C). Soon we will shift to m e d i u m * Germplasm ICRISAT.
28
Botanists, Genetic Resources U n i t ,
Evaluation and Rejuvenation Routine Evaluation and Rejuvenation Evaluation and seed multiplication are carried out at ICRISAT Center and Hissar to obtain data on the performance of cultivars under peninsular and north Indian conditions. Each entry is s o w n in t w o rows, 4 m long. Ridge-to-ridge spacing is 75 c m ; each ridge accommodates t w o rows, and plant-to-plant spacing in t h e r o w is 10 c m . At Hissar, however, single rows of 6 m and a r o w spacing of 60 cm are used. One of three standard check cultivars — JG-62, G-130, and L-550 — is s o w n every 21st row, the checks being repeated in sequence. This year we planted 2691 accessions at ICRISAT Center on 1 7 a n d 18 October f o r evaluation and rejuvenation. The material includes 2137 exotic lines and 554 lines f r o m different parts of India. At Hissar, 2263 accessions w e r e sown on 21 and 22 October. For chickpea, data on 22 morphological and agronomic traits are recorded. We have 40 descriptors, including t h e passport data, f l o w e r ing data, flower and seed colors, maturity, yield, seed w e i g h t , resistance to pests and diseases, and protein content. Rejuvenation of chickpea is no p r o b l e m as the crop is self-pollinated. Rejuvenation is carried out simultaneously w i t h evaluation. However, we have s o m e problems in keeping pace w i t h t h e ever-increasing d e m a n d for seeds of w i l d
Cicer. Perennial species do not flower under n a t u r a l c o n d i t i o n s at ICRISAT Center. Temperature-, humidity-, and light-controlled rooms are required for maintenance and seed production of the perennials. A m o n g the annuals, C. yamashitae and C. echinospermum are difficult to maintain. Their emergence is poor and seed set is not satisfactory. A pedicel mutant was detected in cv L-550 (Pundir and van der Maesen 1977). In addition to the standard evaluation the f o l l o w i n g special tests were conducted:
Yield Test and Harvest Indices Replicated trials w e r e conducted for 84 early and 100 late cultivars during the 1 9 7 6 - 7 7 and 1977-78 postrainy seasons; results of the ten best cultivars are presented in Table 1. The yield test, repeated in 1977-78 for the 100 late cultivars, did not yield data because of poor emergence and bad field conditions. Harvest index w a s m e a s u r e d on 100 c u l t i v a r s (germplasm selections) during 1977-78, and the results of the best 12 w i t h high harvest index at late-maturity stage are listed in Table 2. This year we are repeating these tests. For yield testing, 100 early cultivars and 100 late cultivars w e r e s o wn w i t h three replications on 17 October 1978. To measure harvest index, 100 germplasm selections were also sown on 17 October 1978, w i t h t w o replications. There was an initial incidence of root rot by Sclerotium and a heavy attack by Heliothis during the m i d d l e of November; however, the crop g r o w t h has improved after spraying w i t h insecticide (Endosulfan).
Seed Viability Seed viability tests are carried out four times a year to m o n i t o r germination percentage under normal r o o m and cool-room conditions w i t h various seed containers. Every 3 months the germination is tested f o l l o w i n g the first test after 6 m o n t h s ' storage. Germination tests (nonreplicated) on seeds of five cultivars stored for 18 m o n t h s after harvest revealed t h e f o l l o w i n g : At cool temperatures, the cultivars BEG-482, P-3090, and Hima did not reveal any difference in g e r m i n a t i o n percentage w h e n seeds w e r e stored in fairly airtight plastic bottles or paper packets. However, fo r
29
Table
2.
H a r v e s t I n d e x (%) a n d s e e d y i e l d ( k g / h a ) f o r t h e 1 2 c u l t i v a r s w i t h t h e h i g h e s t h a r v e s t i n d e x at maturity, 1 9 7 7 - 7 8 .
ICC No. 1341 5594 5794 5823 920 5810
Pedigree P-1209 W F W G x 810140-15T G r a m pink Ujjain K-4-2 P-732-1 Harigantas
Yield
P-690 JG-62
58.75 58.63
2455 2178
1859
P-1499
58.54
2337
3505 7708 5434
P-4206 147-3 Ponaflar-2
57.64 57.63 57.58
1907 2263 1633
Yield
ICC No.
63.08 61.94
2159 2100
867 4951
61.83
2300
60.71 60.22 59.08
2363 2466 1474
L-550 (kabuli) and kaka (black-seeded desi) g e r m i n a t i o n dropped considerably in paper packets (50% and 2 0 % , respectively). No appreciable difference in g e r m i n a t i o n was noted between the t w o temperatures w h e n seeds w e r e stored in plastic bottles. On the other h a n d , w h e n stored in paper packets at r o o m temperature, seeds of all five cultivars lost most of their viability. Seed coat structure appears to be an important factor in controlling m o i s t u r e uptake, w h i c h in turn affects viability. For example, L-550 (kabuli) seeds increased f r o m 7 to 12% m o i s t u r e after one rainy season storage in cloth bags, whereas desi cultivars BEG-482, P-3090, and Hima hardly took u p any moisture ( 1 % increase).
Collaborative W o r k w i t h i n ICRISAT Pathology A total of 6913 samples w e r e sent to the Pulse Pathology section between J u n e 1977 and November 1978 for various secreenings and collaborative works. This total includes a number of w i l d species and introgression materials. From about 2000 g e r m p l a s m accessions screened against w i l t , 30 w e r e f o u n d w i t h o u t infection. Of the nine w i l d annual species screened, only Cicer judaicum was f o u n d to be resistant to w i l t Of 1334 entries screened against stunt, 67 w e r e f o u n d disease free and
30
Harvest index
Harvest index
Pedigree
are under further testing. Against Ascochyta blight, 2159 entries w e r e screened and a few lines w e r e f o u n d tolerant. Within the 12 w i l d species screened against this disease, s o m e entries of C. bijugum and C. judaicum s h o w e d tolerance. C. reticulatum s h o w e d resistance, but not in all entries. The resistance in s o m e accessions of C. reticulatum has been successfully transferred to some of the popular cultivars by our o w n introgression efforts (see Introgression, this paper). Further attempts to cross C. bijugum w i t h chickpea are being made, w i t h the same objective.
Entomology A total of 2270 entries w e r e supplied to the Entomology section in 1977-78. Of 1596 n e w accessions screened in nonreplicated plots, 67 had no borer damage. From 8629 accessions screened previously, 955 lines were selected and w e r e again tested this year. Several lines w i t h markedly less pod d a m a g e were selected for further testing. Microbiology We sent 561 entries to the M i c r o b i o l o g y section and the data on the nodulation of 500 lines are under analysis. Lines w e r e compared w i t h cultivar 850-3/27. Biochemistry For protein estimation, we sent 2034 samples including ten wi Id materials to the Biochemistry
section. During 1970, 3440 cultivars w e r e analyzed, and the data are available. Protein percentage varied f r o m 17.3 (cv ICC-10962) to 27.7 (cv ICC-9913).
Table
3.
Breeding and Physiology We supplied 294 samples to the Pulse Breeding section and 28 to the Physiology section for
Chickpea g e r m p l a s m lines supplied to research agencies in India and other nations during 1977-78.
Institution
Location
Entries
India Regional Station, Indian A g r i c u l t u r a l Research Institute
Kanpur, Uttar Pradesh
109
Agricultural Experimental Institute
V a y a l o g u m , T a m i l Nadu
100
Department of Plant Breeding, Punjab Agricultural University
Ludhiana, Punjab
71
Department of Plant Breeding, Banaras H i n d u University
Varanasi, Uttar Pradesh
64
Department of Genetics and Plant Breeding, Haryana A g r i c u l t u r a l University
Hissar, Haryana 50
D e p a r t m e n t of Genetics & Botany, Osmania University
Hyderabad, A n d h r a Pradesh
Department of Plant Breeding, G. B. Pant University of A g r i c u l t u r e and T e c h n o l o g y
Pantnagar, Uttar Pradesh
Department of Plant Breeding, A n d h r a Pradesh A g r i c u l t u r a l University
Rajendranagar, A n d h r a Pradesh
40
23 23
Indian A g r i c u l t u r a l Research Institute
N e w Delhi
Department of Genetics, Chandrasekhar Azad University of Agriculture & Technology
Kanpur, Uttar Pradesh
Pulse I m p r o v e m e n t Project
Bhubaneswar, Orissa
6
Department of Botany, Punjabrao Krishi Vidyapeeth
Akola, Maharashtra
5
Department of A g r i c u l t u r e & Plant Breeding, Jawaharlal Nehru Krishi V i s h wa Vidyalaya
Jabalpur, Madhya Pradesh
20 9
5
Other Nations 1514
ICARDA
A l e p p o , Syria
Division of Genetics, National Institute of A g r i c u l t u r a l Sciences
Hiratsuka, Kanagawa-254, Japan
Crop D e v e l o p m e n t Centre, University of Saskatchewan
Saskatchewan, Canada
300
Estacion Experimental Sociedad Nacional de Agricultura
Fundo la Vega, Hueiguen, Paina, Chile
100
Department of A g r o n o m y , University of Florida
Florida, U.S.A.
33
Kenya Agricultural & Forestry Organization
N a i r o b i , Kenya
20
Rangpur Dinajpur Rehabilitation Service
Lalmanirhat, Rangpur, Bangladesh
11
M/s M a c o n d r a y & Co., Inc.
M a n i l a , Philippines
10
500
Project Tapis Vert
Niamey, Niger
3
A g r i c u l t u r e Research Institute, W a g g a W a g g a
W a g g a W a g g a , Australia
2
31
various tests, e.g., development of droughtscreening methods.
foliage, light-green foliage, fasciated s t e m , and w h i t e and black seed coat colors, the F 2 and BC 1 populations are n o w being studied.
Introgression Documentation W i l d Cicer spp at ICRISAT are as f o l l o w s : Perennials
Annuals C. C. C. C. C. C. C. C.
bijugum* chorassanicum* cuneatum* echinospermum judaicum* pinnatifidum* reticulatum* yamashitae
C. C. C. C. C. C. C. C.
anatolicum floribundum graecum isauricum microphyllum montbretii pungens rechingeri
(* Seeds available for supply) Only C. reticulatum hybridizes readily w i t h cultivated species. To transfer Ascochyta blight resistance, C. reticulatum was crossed w i t h cultivars G-130, JG-62, and P-5462; F 2 and BC 1 w e r e produced. The seeds w e r e harvested f r o m individual plants and handed over to the Pathology and Breeding sections for screening against Ascochyta blight. Pulse Pathology has raised the Fa and BC 1 F 2 generations, and f r o m their screening several tolerant lines ( 3 - 5 on a scale of 1-9) w e r e selected. These will be tested further, and the m o r e tolerant lines will be used in breeding programs. A t t e m p t s to cross chickpea w i t h C. bijugum will be intensified to transfer resistance against blight. Other crosses are being attempted. Cicer judaicum was f o u n d to be w i l t resistant and only moderately susceptible to blight. Cicer pinnatifidum and C. bijugum w e r e crossed w i t h C judaicum w i t h limited success; the F 1 s produced a f e w seeds. W i t h C. judaicum x C. bijugum, only one F 2 seed developed into a plant.
Full m o r p h o l o g i c al and agronomic data w e r e obtained fo r 3085 accessions (excluding checks), and prepared for computerization. For 10 842 entries evaluated o n e to three times during previous years, the computer storage and retrieval system was further developed. The catalog will not be published as such. Instead, specialized catalogs matching the requirement of the user will be supplied on request. A publication to this effect is under preparation.
Seed Supply outside ICRISAT In t o t a l , 525 samples of cultivated and w i l d Cicer were supplied to 13 institutions in India and 2493 samples to 10 institutions abroad (Table 3).
References IBPGR. 1976. Report of IBPGR (International Board for Plant Genetic Resources) w o r k i n g g r o u p of eng i n e e r i n g , design and cost aspects of l o n g - t e r m seed storage facilities. Rome, 19 pp. VAN DER M A E S E N , L. J. G. 1975. Cicer g e r m p l a s m collection trip to Trukey J u n e - J u l y 1975. ICRISAT M i m e o g r a p h , 15 pp. VAN DER M A E S E N , L. J. G. 1976. Germplasm collection and evaluation in Cicer and Cajanus. Pages 2 2 9 - 2 3 7 in W o r k s h o p on Grain Legumes, 1975. ICRISAT, Hyderabad, India. VAN DER M A E S E N , L J. G. 1977. Food legume collection trips in A f g h a n i s t a n. ICRISAT M i m e o g r a p h , 21 pp.
Inheritance Studies Inheritance of three morphological charact e r s — prostrate g r o w t h habit, d o u b l e p o d ded peduncle, and green seed-coat color — were studied in the F 2 and BC 1 . These characters w e r e f o u n d to be recessive and monogenically inherited. To d e t e r m i n e t h e genetic behavior of bipinnate leaf, simple leaf, n a r r o w leaf, purple
32
VAN DER M A E S E N , L J. G. 1978. Genetic Resources at ICRISAT. Position paper, IBPGR/Government of India W o r k s h o p on the Genetic Resources of S o u t h Asia, N e w Delhi, 9 - 1 2 M a y 1978. ICRISAT M i m e o g r a p h , 16 pp. P U N D I R , R. P. S., and VAN DER M A E S E N , L. J. G. 1977. A
pedicel m u t a n t in chickpea (Cicer arietinum L ) . Tropical Grain L e g u m e s Bulletin IITA, Ibadan, (in press).
International Chickpea Trials and Nurseries K. B. Singh, J. Kumar, S. C. Sethi, C. L. L. Gowda, K. C. Jain, and G. C. Hawtin*
Chickpea is g r o w n in m a n y countries of the w o r l d . The major producing areas for the desi type are in and around the Indian subcontinent and for the kabuli type, in western Asia and North Africa. There are strong local preferences for the different types, and different production systems are used for desi and kabuli types, w h i c h are g r o w n mainly as winter and spring crops, respectively. Furthermore, chickpea exhibits substantial specificity of adaptation. Because of these factors, evaluation and breeding work must be carried on in the different regions of culture. Until 1977-78, ICRISAT and ICARDA had separate, but largely complementary, responsibilities for chickpea improvement. The programs w e r e integrated in 1978 so that in the future, ICRISAT w i l l organize and coordinate th e international testing trials and nurseries of the desi type and ICARDA will do the same for the kabuli type. In 1977-78, ICRISAT dispatched international trials and nurseries (desi and kabuli) to 63 locations in 28 countries and ICARDA (kabuli only) to 23 locations in 14 countries. Desi trials w e r e sent to Afghanistan, Australia, Bangladesh, Burma, Ethiopia, India, Iran, Iraq, Mexico, Nepal, Pakistan, Philippines, Tanzania, Thailand, Venezuela, and Yeman Arab Republic. The kabuli trials w e r e distributed to Afghanistan, Algeria, Argentina, Australia, Bangladesh, Burma, Chile, Cyprus, Egypt, Ethiopia, India, Iran, Iraq, J o r d a n , Lebanon, Libya, Mexico, Morocco, Nepal, Pakistan, Peru, Spain, Sudan, Syria, Tanzania, Tunisia, Turkey, and Yemen Arab Republic. Table 1 lists thetrials and nurseries at ICARDA * Chickpea Breeder, ICARDA, A l e p p o , Syria; Chickpea Breeders, ICRISAT, Patancheru, A n d h r a Pradesh, India; and Program Leader, Food Legumes I m p r o v e m e n t P r o g r a m , ICARDA, respectively.
and ICRISAT; these acronyms are used in Tables 2 to 4 and throughout the text.
T h e Trials and Their Objectives The international chickpea trials and nurseries were established in 1975 w i t h the f o l l o w i n g objectives: 1. To strengthen national and regional programs; 2. To supply cultivars, segregating populations, and advanced breeding lines having specific characteristics (disease resistance, high yield, high protein, etc.) to cooperators for evaluation, use in breeding, and (if promising) finishing for release; 3. To identify among line differences in adapt a t i o n regionally and internationally through multilocation testing, and to characterize environments in w h i c h chickpea is g r o w n ; 4. To p r o m o t e international cooperation t h r o u g h personal visits and information exchange. To achieve the above mentioned objectives, a wide range of types of breeding material is offered to any individual or organization engaged in chickpea improvement work. Types of chickpea materials distributed are described below; particular trials distributed through 1978 are listed in Table 2.
Parent Lines These are genetic stocks and advanced breeding lines w i t h specific traits w h i c h include high yield, high pod number, tall plant habit, large seed size, double pods, disease and insect resistance, and high protein content. This material is distributed on request (mainly to stations where hybridization work is undertaken) for
33
Table
1.
Chickpea trials and nurseries, ICRISAT and I C A R D A .
Abbreviation ICARDA CRN CISN
1974
Chickpea Regional Nursery Chickpea International Screening Nursery (kabuli) Chickpea Regional Preliminary Yield Trial Chickpea International Yield Trial (kabuli) Chickpea A d a p t a t i o n Trial (kabuli)
CRPYT CIYT CAT ICRISAT ICSN-A -B -C ICRISAT ICCT-D -DE -DL -K ICMT ECGN ICON
Table 2.
Year b e g u n Superseded by
Title
CISN
1978 1975
CIYT
1978 1978
International Chickpea Screening Nursery (short d u r a t i o n desi) (long d u r a t i o n desi) (kabuli)
1976 1976 1976
International Chickpea Cooperat i v e Trial (desi) (desi early, short duration) (desi late, long duration) (kabuli) International Chickpea M i c r o p l o t Test Elite Chickpea G e r m p l a s m Nursery International Chickpea Observational Nursery
1975 1977 1977 1975 1977 1975 1976
ICON
Total number of I C R I S A T / I C A R D A chickpea trials and nurseries distributed, 1 9 7 5 - 7 8 . N a m e of trial or nursery a
1975-76 (Winter) 1976 (Summer) No. of countries 1976-77 (winter) 1977 (summer) No. of countries 1977-78 (winter) 1978 (summer) No. of countries
ICCT-D
ICCT-K/ CRPYT
ICSN-A, B
ICSN-C/ CRN
ICMT
F2/F3 Bulks
ECGN/ ICON
31
29 (13)
0
13 (13)
0
18 ( 0)
28
17
13
0
0
12
20
34
49 (13)
25 (20)
0
43 (11)
35
16
28
17
0
20
20
35
42 ( 9)
41 (23)
5
47 (13)
0
12
26
20
4
19
0
35 7 40 8
8
a. Figures in parentheses are n u m b e r s of trials sent f r o m ICARDA. See Table 1 f o r a b b r e v i a t i o n s : CRPYT, CRN, a n d F 3 f r o m ICARDA, rest f r o m ICRISAT.
local evaluation and use in b r e e d i n g . This nursery w a s originally d i s t r i b u t e d
as t h e
Early Generation Segregating Bulks
Elite
Chickpea G e r m p l a s m Nursery (ECGN) b u t w a s
Breeders can request a n d o b t a i n F 2 and F 3
r e n a m e d as t h e International Chickpea Obser-
g e n e r a t i o n unselected bulks of crosses w h i c h
vational Nursery (ICON) in 1976. Cooperators
have s h o w n p r o m i s e at ICRISAT sites. These
w e r e requested t o f o r w a r d i n f o r m a t i o n o n the
p o p u l a t i o n s are intended particularly f o r those
usefulness of t h e lines in their area.
breeders w i t h only l i m i t e d resources f o r sys-
34
tematic hybridization. It is anticipated that cooperators will evaluate these bulk populations for local adaptation and select w i t h i n the superior populations. Three types of early generation bulks (desi x desi, desi x kabuli, and k a b u l i x kabuli crosses) have been supplied, according to the requirement of particular regions. Cooperators are requested to f o r w a r d information on the usefulness of specific bulks in their area.
Advanced Breeding Lines A number of u n i f o r m superior lines are bulked individually in advanced generations every year at our research centers and are distributed on request, for local evaluation. These populations of lines are particularly useful to breeders w h o s e facilities for sustained reselection are limited. Cooperators test and characterize the performance of these breeding lines, and can evaluate promising material in larger scale multi-environment trials in subsequent years. The I n t e r n a t i o n a l Chickpea S c r e e n i n g Nursery-A (ICSN-A), w h i c h includes shortduration desi lines; the International Chickpea Screening Nursery-B (ICSN-B), comprising long-duration desi lines; and the International Chickpea Screening Nursery-C (ICSN-C), w h i c h includes kabuli lines, have been offered since 1976-77 by ICRISAT. Beginning in 1974, ICARDA distributed the Chickpea Regional Nursery (CRN) substituting it in 1978 w i t h the Chickpea International Screening Nursery (CISN), w h i c h includes only kabuli lines. In each case, cooperators are requested to record and f o r w a r d specific information on plant performance as well as information on the test env i r o n m e n t s used.
Elite Lines and Cultivars These trials are intended to make available to cooperators those lines and cultivars that
Table 3.
have shown greatest p r o m i s e regionally or internationally. This material is particularly relevant to those cooperators w i t h very limited facilities for breeding, but w h o wish to evaluate in their area improved genetic material, w i t h a view to its subsequent release. Beginning in 1975-76, ICRISAT distributed the International Chickpea Cooperative Trial (ICCT), which included desi and kabuli lines w i t h varying maturity periods. In 1976-77, the trial was split as ICCT-D for desi and ICCT-K for kabuli types. In 1977-78, ICCT-D was further subdivided into the ICCT-DE (desi early) and ICCT-DL (desi late) in order to service the specific demands in areas w i t h short and long g r o w i n g seasons. Beginning in 1975-76, ICARDA distributed the Chickpea Regional Preliminary Yield Trial (CRPYT) and in 1978-79 renamed it the Chickpea International Yield Trial (CIYT) w h i c h includes only kabuli types. The trials distributed in 1978-79 are listed in Table 3.
Allocation of Trials Care is used in allocating the trials to national programs. Some important considerations are: (1) requestsfor material by national cooperators; (2) flexibility of consumer demand — desi or kabuli, or both; (3) crop duration of the trial; (4) facilities and expertise available; (5) specific problems of the area; and (6) season of g r o w t h . We n o w follow the All India Coordinated Pulse Improvement Project (AICPIP) in allocating long-duration desi-type trials to northern India and short-duration desi chickpea to southern India. We are using the results of trials to characterize the environments of other countries and regions regarding the relevance of long and short-duration desi chickpea. ICARDA has initiated a chickpea adaptation trial c o m prising material f r o m the national programs of the region. This trial is being conducted at 25
N u m b e r of International chickpea trials distributed by I C R I S A T / I C A R D A , 1 9 7 8 - 7 9 .
ICCT-DE
ICCT-DL
CIYT
ICSN-A
ICSN-B
CISN
CAT
F2/F3 bulks
11
14
23
13
18
22
26
26
35
locations in 18 countries and w i l l continue fo r 3 years. Thereafter efforts w i l l be m a d e to characterize the w h o l e region. Seed color of the desi type (yellow, b r o w n , black, green) and seed size in kabuli types are other important criteria in f u r n i s h i n g material.
Conduct of t h e Trials Guidelines for Experimentation ICRISAT and ICARDA prepare and distribute broad guidelines to cooperators for the conduct of nurseries and trials. These include general information on the material, design of the experiment, guidelines for character observation, and field books for recording data. The cooperator is invited to make any alterations in cultural m a n a g e m e n t necessary to suit local conditions and to add either a local check cultivar or substitute it for a nominated entry. They are requested to f o r w a r d data for subsequent analysis and publication, using a d u p l i cate field book supplied. Data are requested on several specific plant characters, such as days to first f l o w e r i n g , plant stand, plant height, days to maturity, 100 seed w e i g h t , plot y i e l d , and insect and disease damage, as well as inform a t i o n on the location, cultural management, and environmental conditions of the test site. Cooperators are encouraged to provide their o w n assessment of t h e material and to n o m i nate lines f o u n d useful in that area.
Entry Recommendations by Cooperators A n y individual or organization may n o m i n a t e specific entries fo r inclusion in t h e international trials and nurseries, and all entries proposed to date have been included. If excessive n u m b e r s of entries are nominate d in the f u t u r e , it w i l l become necessary to establish criteria for choosing a m o n g t h e nominate d lines. A n y person n o m i n a t i n g a particular entry is informed that any other breeder or region m a y adopt that entry as a cultivar for local use, after duly acknowledging its source of origin. The entries nominated — including germplasm lines, nominations f r o m cooperators, and ICRISAT/ ICARDA breeding lines — are allocated to the
36
various international trials according to t h e criteria described earlier. In v i e w of the importance of the source of seed used and the need to correctly classify the material into varioustrials , all lines proposed f o r entry will be g r o w n at the ICRISAT or ICARDA c e n t e r f o r s e e d increase and w i l l be included in the trials in the f o l l o w i n g year. It is hoped that this w i l l ensure u n i f o r m and high seed quality for all trials.
Visits by ICRISAT/ICARDA Staff to Trial Sites ICRISAT/ICARDA scientists visit as m a n y trial sites as possible in order to develop a better understanding of local and regional p r o b l e m s and to interact w i t h local cooperators. Obviously it is not possible to visit all test locations each year. In 1977-78, we visited 21 of the 63 locations to w h i c h ICRISAT trials w e r e sent. During the same period 6 of 23 locations w e r e visited w h e r e ICARDA nurseries w e r e sent.
Data Collection, Analysis, and Publication Cooperators are requested to f o r w a r d the data books to ICRISAT or ICARDA fo r all trials received, including those not planted or w h i c h w e r e partial or complete failures. U n f o r t u nately, data have not been received f r o m all locations in the past (Table 4). The importance of reporting data, even if the results are i n c o m plete, cannot be overemphasized. The value of the trials to all cooperators will be increased greatly if all results are available for analysis. The results received f r o m all locations are c o m b i n e d for analysis to determine differences in adaptation of the entries over the test environments. Various analyses are conducted. The primary objective is to identify any entries w i t h superior performance over all environments or in particular regions and locations. However, we also investigate t h e interrelationships a m o n g plant characters w i t h i n each location, t h e phenotypic stability of entries over locations, and the degree of similarity of relative performance of the entries in the different locations. The last aspect is i m p o r t a n t in characterizing differences and similarities of locations for chickpea production, and this has impor-
Table 4.
N u m b e r s a n d p e r c e n t a g e s (in p a r e n t h e s e s ) o f t r i a l s f o r w h i c h c o o p e r a t o r s s u p p l i e d d a t a , 1975-78.
Year
ICCT-D
ICCT-K
13 3 11 1 24 0
0 4 9 5 13 3
ICSN-A, B
ICSN-C
ICMT
0 0 26 (58) 0 29 (73) 0
0 0 4 (40) 0 6 (60) 2 (25)
0 0 0 0 2 (40) 0
ICRISAT 1975-76 1976 1976-77 1977 1977-78 1978
(winter) (summer) (winter) (summer) (winter) (summer)
1975 1976 1977 1978
(50) (19) (39) (20) (77)
CRPYT 2 (67) 3 (38) 6 (67) 6 (50)
(80) (38) (42) (62) (25) ICARDA CRN 4 (40) 6 (40) 8 (40) 12 (85)
F3
5 (50) 7 (70)
See Table 1 for a b b r e v i a t i o n s .
tance in breeding and recommendation of cultivars. In this context, the full reporting of background information on the environmental and cultural conditions of each trial can assist greatly in establishing t h e causes of differences in line performance between locations. A detailed report on the results of each international trial and nursery is compiled and published annually. These reports are distributed to all scientists interested in chickpea improvement. Results of the first and second ICRISAT international trials and nurseries have been published, and the t h i r d report is now available. Similarly, ICARDA is publishing reports of its international trials.
Results of t h e Trials No attempt will be made here to summarize results of the international trials and nurseries, since these have been presented and discussed in detail in the various published reports. Rather, we w i l l consider only the f o l l o w i n g t w o important aspects w h i c h arise f r o m the results of these trials.
Identification of Superior Lines Entries w i t h superior performance at individual locations or over locations are identified and comparison is m a d e over years for those entries
c o m m o n to more than one year of testing. Local and c o m m o n check cultivars are used for c o m parison. At most locations, substantial differences amon g the entries for seed yield have been identified, and this indicates that considerable opportunity exists for selection for local adaptation in most cases. However, entry x location interaction has been of major importance in trials g r o w n to date, and relatively f e w entries have s h o w n w i d e adaptation; that is, f e w have occurred c o m m o n l y in the superior g r o u p of entries at several test locations. This infers that selection for high yield and broad adaptation will be difficult in chickpea. In 1977-78, A n n i g e r i , 73129-16-2-B-BP, 7384-18-5-B-BP, and P-127 in ICCT-DE; 73327-2-B-BH, BG-203, B-108, Pant G-113, and P-324 in ICCT-DL; and L-550, 7385-17-2-B-BH, 73476-4-B-BH, and 7358-8-2-B-BH in ICCT-K w e r e the highest yielding lines w h e n averaged over all locations. Of the lines c o m m o n to 3 years of testing, P-436 and JG-62 in ICCT-DE and P-324, K-468, C-214, B-108, and P-436 in ICCT-DL had the greatest seed yields. P-436 has s h o w n superior performance over years, both in ICCT-DE and ICCT-DL, indicating that it has some breadth of adaptation for both short- and long-duration environments. Based on t h e 2-year average for ICCT-K, L-550, GL-629, K-4, and P-2221 were the highest yielding entries. In general, the ranking of entries c o m m o n to 2
37
years of testing in ICSN-A, B, and C was similar, although specific exceptions existed. This suggests that 1 year of multilocation testing in t h e ICSNs should be sufficient for rejection of those lines w i t h poor performance. A n u m b e r of lines exceeded the best check in each of the ICSN nurseries. The best checks w e r e ranked 7th (JG-62 in ICSN-A), 18th (G-130 in ICSN-B), and 2nd (L-550 in ICSN-C) for mean seed yield over all test locations. The ranges of n u m b e r of lines exceeding the best check by m o r e than one or t w o standard deviations at the individual locations are listed in Table 5. Clearly, lines p e r f o r m i n g substantially better than the best check cultivar existed at each location. Entries 7310-26-2-B-BP, 7343-14-3-B-BP, and 7394-14-2-B-BP in ICSN-A; and 73111-7-2-B-BH, 7380-1-1-B-BH, 73126-6-2-B-BH, 737-18-B-BH, 7310-26-2-B-BH, and 7343-14-3-B-BH in ICSN-B had the greatest average yields across locations of all lines c o m m o n to the 1976-77 and 1977-78 trials. In ICSN-C, although one line in 1976-77 and t w o in 1977-78 w e r e marginally superior to L-550, n o n e of these yielded higher than it in each of the years or on the 2-year average.
Table 5.
For the 1977-78 season, the CRPYT comprising 36 entries including checks was furnished to 12 locations representing six countries, five of w h i c h supplied complete data. W h i l e a detailed report w i l l be prepared separately, a brief m e n t i o n is m a d e here. The yields of the best cultivars, the yields of the check, the n u m b e r of cultivars exceeding the check, and the percentage of increase of the best cultivars over the check for each location are given in Table 6. The best yielding cultivars exceeded the local checks by a margin of 21 to 215%. The n u m b e r of cultivars outyielding the local checks varied f r o m 2 in Jordan to 33 in Algeria. The results indicate the usefulness of the nursery in different countries of the region. In a f e w of the countries, the t o p yielding cultivars have been included in multilocation trials in national programs. For example, Syria has included a few entries in a Chickpea Regional Trial being conducted at five locations in the country. We have had a large number of requests (over 40) during 1978-79 for this nursery. Unfortunately, we could not meet all the demand, and some of our cooperators were disappointed.
R a n g e s o f n u m b e r o f lines e x c e e d i n g t h e b e s t c h e c k c u l t i v a r b y o n e o r t w o s t a n d a r d deviations (SD) at Individual locations, I C S N trials 1 9 7 7 - 7 8 . Ranges of n u m b e r of lines for the test locations
M a r g i n of superiority 1 SD 2 SD
Table 6.
ICSN-A
ICSN-B
ICSN-C
2-10 0- 5
1-13 0- 5
2-11 0- 7
Performance of cultivars in CRPYT at different locations during 1 9 7 7 - 7 8 . Yield (kg/ha)
Country Algeria Jordan Cyprus Tunisia Syria ICARDA (winter planting) ICARDA (spring planting)
38
Best cultivar
Check
Cultivars exceeding check
1524 1302 1795 1786 481 1607 1837
484 1073 867 1272 364 1235 932
33 2 18 12 13 15 29
Increase of best cultivar over check % 215 21 107 40 32 30 97
Differences among Locations in Line Response As indicated above, substantial entry x location interaction has existed in each of the international trials to date. This complicates discrimination a m o n g entries, because c o m parisons of performance become confounded w i t h the e n v i r o n m e n t of testing. The interactions are complex and cannot be interpreted simply. One approach to interpretation is to search for similarities of relative performance of the entries in the different locations; that is, to characterize the environments of the locations in terms of the degree of similarity of the responses they elicited f r o m the entries. In this way, it may be possible to identify groups of locations that are generally similar in their characteristics as far as chickpea performance is concerned. This could lead to rationalization of testing sites, since relative line performance could be extrapolated across those locations w i t h some confidence, and this w o u l d allow more efficient experimentation
Table 7.
Correlation coefficients b e t w e e n locations of seed yields of 12 entries at five major Indian locations, I C C T . 1 9 7 5 - 7 8 . ICRISAT Center
ICRISAT Center Jabalpur
N e w Delhi
Pantnagar
Hissar
and rapid capitalization on superior genetic material. Equally, the characterization of locations into subsets that elicit different responses of the entries must lead to definition of specific breeding objectives for particular target environments. We have used the correlation coefficients of line performance for seed yield in the different locations to quantify the relative similarity of the locations in the ICCT-DE, ICCT-DL, and ICCT-K for 3 years. The results fo r the different trials were generally similar, and we will only consider the ICCT-DL results here. For this case, 13 test locations outside India and 5 within India w e r e used over the 3 years, and 12 entries w e r e c o m m o n to all trials. Correlation coefficients of line performance a m o n g the Indian locations are presented in Table 7. In most cases, there was little similarity of relative line performance for different years at the same location, and in s o m e cases there were negative coefficients. There was no correlation of line performance between locations in the same year exceeding 0.70, and there was
0.70 ND ND -0.13 to 0.25 -0.08 to -0.43 0.25 to 0.37 -0.40 to 0.27
Jabalpur 0.36 0.30 ND -0.40 -0.12 0.29 -0.45 to 0.82 -0.24 to 0.27 -0.37 to 0.38
N e w Delhi -0.54 -0.32 ND 0.21 0.22 -0.05 0.33 0.05 0.02 -0.27 to 0.16 0.05 to 0.42
Pantnagar -0.06 0.18 ND 0.21 0.10 ND 0.21 -0.18 ND -0.21 ND ND -0.14 to 0.20
Hissar -0.37 0.14 ND 0.02 -0.24 0.29 0.64 -0.02 -0.12 0.16 0.49 ND 0.42 0.05 0.37
a. ICCT ( 1 9 7 5 - 7 6 ) , ICCT-D ( 1 9 7 6 - 7 7 ) , a n d ICCT-DL (1977-78). ND = No data. Note: The t h r e e sections of t h e table are as f o l l o w s : t o p , 1 9 7 5 - 7 6 v s 1 9 7 6 - 7 7 ; m i d d l e , 1976-77 v s 1 9 7 7 - 7 8 ; b o t t o m , 1 9 7 5 - 7 6 v s 1977-78. Diagonal: t o p , 1 9 7 5 - 7 6 ; m i d d l e , 1 9 7 6 - 7 7 ; b o t t o m , 1977-78. Upper t r i a n g l e : r a n g e over different c o m b i n a t i o n s of years 1 9 7 5 - 7 6 , 1 9 7 6 - 7 7 , a n d 1977-78. Lower t r i a n g l e :
39
marked inconsistency of association w i t h i n different years. This was also t r u e of line performance at different locations in different years For t h e non-Indian locations, correlations of line performance in the different sites were generally very low, c o m m o n l y negative, and the closest positive association (0.52) occurred between Colchagua, Chile and Tarnab, Pakistan Table 8. The consistently l o w m a g n i t u d e of association emphasizes the importance of entry x location interaction in these trials. The generality of this result for t h e three ICCT trials suggests that chickpeas exhibit marked and highly specific adaptation responses to environments. As indicated above, s o m e lines have revealed s o m e breadth of adaptation, but these clearly are exceptions. For s o m e data sets, closer degrees of association of line performance at different locations have been identified w i t h i n regions of India. W i t h i n the south Indian area, generally similar relative performance of entries over locations w i t h i n years has occurred in the ICCT-D 1 9 7 6 77 and ICCT-DE 1977-78, particularly for ICRISAT Center, Gulbarga, Rahuri, and Junagadh (Table 9). Similarly, for northern Indian conditions, line performance at Hissar, New Delhi, and Ludhiana has been closely associated in some years. These similarities w i t h i n regions need to be c o n f i r m e d , but in general they support the decision by India to separate the advanced All India Gram (chickpea) Coordinated Varietal Trial into subzones for testing purposes. These results indicate that, w i t h the possible exception of India, we are presently unable to characterize g r o u p s of locations w i t h respect to adaptation of chickpea. This is disturbing and requires further study. It implies that selection for local adaptation should be emphasized w i t h i n t h e national programs in the short t e r m , and that breeding activities by ICRISAT/ICARDA should emphasize i m p r o v e m e n t in local adaptation as well as multilocation testing and select i o n for broad adaptation. Aspects of this are discussed in the c o m p a n i o n paper on breeding strategies (Byth et al., this workshop).
Adoption of Lines by Cooperators Cooperators are encouraged to utilize superior test entries in local breeding w o r k and to con-
40
Table 9.
Rahuri 1976-77 1977-78 Gulbarga 1976-77 1977-78 Hyderabad 1976-77 1977-78 Junagadh 1976-77 1977-78
Correlation coefficients b e t w e e n locations of seed yields of c o m m o n entriesa at f o u r south Indian locations, I C C T b , 1 9 7 6 - 7 8 . Gulbarga
Hyderabad
Junagadh
0.40 0.66
0.64 0.66
ND 0.65
0.44 0.70
ND 0.49 ND 0.59
a. 49 a n d 16 entries c o m m o n to 1 9 7 6 - 7 7 a n d 1977-78, respectively. b. ICCT-D (1976-77) and ICCT-DE (1977-78). ND = No data.
duct m o r e extensive evaluation of selected individual lines locally. ICRISAT and ICARDA do not release cultivars in any country; however, any cultivar or line f r o m these trials can be released by the national or regional p r o g r a m , the only stipulation being that the origin of the line should be acknowledged. Most cooperators have reported the outstanding entries in the various international trials and nurseries. For example in 1977-78, the cooperator f r o m Berhampore (West Bengal, India) reported that a desi line P-326(ICCT-DL) was well adapted for his area. The breeder f r o m Ankara (Turkey) has included a kabuli line f r o m ICSN-C, 7358-8-2-B-BH (L-550 x K-4), in advanced trials. Similarly, the cooperator at Akola (Maharashtra, India) has selected entries 73241-3-1-1P-LB-BP (Chafa x JG-61) and 73111-8-2-B-BP(850-3/27 x H-208) f r o m ICSN-A for multiplication and inclusion in his advanced trials. Particular F 3 bulks have been f o u n d to be useful by cooperators in Syria, Pakistan, India, Burma, and Nepal. Trial results f r o m locations in India are summarized separately, and those breeding lines w h i c h perform best in the ICCTs and ICSNs are offered to the AICPIP for multilocation testing. In 1977-78, we proposed five entries ICCC-1 to ICCC-5, f o r the Gram Initial Evaluation Trial (GIET). T w o of these, ICCC-4 and ICCC-2, have n o w been p r o m o t e d to the GCVT. Eight
new entries, ICCC-6 to ICCC-13, were offered for testing in GIET in 1978-79. A l t h o u g h several lines furnished by ICARDA t h r o u g h regional nurseries have performed exceedingly well in a number of countries, adoption of those lines has generally been disappointing. The main reason for this is the lack of manpower and support for research on f o o d legumes. Therefore, one of the major efforts has been to build up technical competence in the region through training programs. In several countries research on f o o d legumes has been strengthened by ALAD/ICARDA trainees. ICARDA has been assisting countries in obtaining support f r o m donors. IDRC is no w supporting projects on f o o d legumes in Turkey, Algeria, Egypt, and the Sudan.
Exchange of Visits Cooperators are invited to annual meetings and occasional workshops that are held at each institute. This allows exchange of material, information, and ideas among cooperators and ICRISAT/ICARDA staff. Cooperators are encouraged to visit ICRISAT/ICARDA Centers to exchange ideas and to select material for evaluation and use in their specific environments. The selected material is sent to the cooperators soon after harvest. To date, we have held four
41
Breeders' Meets at ICRISAT, and similar meetings of f o o d legumes breeders are planned at ICARDA. An international chickpea workshop was organized by ICRISAT in 1975 to identify priorities in chickpea research, t h e proceedings of w h i c h w e r e published and distributed to chickpea workers internationally. A 6-day workshop to discuss c o m m o n problems of f o o d legume production was organized by ICARDA in May 1978. Proceedings of this will be published soon.
Future D e v e l o p m e n t of Trials Since an important purpose of distribution of the international trials and nurseries is to meet the needs of local programs, the types of trials m a d e available m u s t be adjusted to fit changing needs. In this context, one significant change has occurred in the past year. A decision was jointly taken by ICRISAT and the AICPIP to t e r m i n a t e t h e conduct of the ICCT trials in India and instead to channel elite lines t h r o u g h th e All India Coordinated Trials. Recent experimentation in t h e Mediterranean region has s h o w n that considerable potential exists for winter planted chickpea, provided Ascochyta blight can be controlled or avoided. Further research is in progress, and if the current indications are c o n f i r m e d , it is proposed to initiate a winter planted trial next season. Multilocation replicated F 2 or F 3 bulk trials have been initiated for both desi and kabuli chickpea, the main objective being to determine the potential value of particular crosses and parents locally and regionally. As indicated previously, any person or national p r o g r a m may nominate lines for entry into the various international trials and nurseries. This offers the opportunity for international multilocation evaluation and for w i d e dissemination of superior genetic material. To
42
date, relatively f e w chickpea breeders have submitted lines for entry, and this is regrettable. We urge the fullest possible exploitation of the facilities n o w available for international evaluation. An International Grain Legume W o r k s h o p held at ICARDA in 1978 identified a lack of information on appropriate agronomic practices as one of the major constraints in increasing the productivity of f o o d legumes including chickpeas, in several parts of the ICARDA region. It was recommended that national programs in the region be encouraged and supported in generating the needed information. Therefore, ICARDA initiated in 1978-79 an international fertility plant population trial on kabuli type chickpea in the region w i t h the aim of quantifying responses to application of starter nitrogen dressing, phosphate fertilization, and inoculation, and to determine o p t i m u m levels of plant population for different fertility levels. The cooperators have been provided w i t h complete details of treatments and layout and the necessary supply of Rhizobia inoculant for the purpose. It is envisaged that studies of other agronomic aspects w o u l d be initiated in future.
Acknowledgments We very much appreciate and acknowledge the contribution of chickpea breeders internationally for conducting these trials and nurseries over the years and sending the results for analysis and compilation. The substantial contribution of J. M. Green, Program Leader, Pulse Improvement, ICRISAT, and D. Byth, Consultant, University of Queensland, Australia in the preparation of this paper is acknowledged.
International Disease Nurseries Y. L. None, M. P. Haware, and M. V. Reddy*
One of the major objectives of ICRISAT's Chickpea I m p r o v e m e n t Program is to breed for disease resistance. It is important, therefore, to identify stable sources of resistance to serious diseases, and to do so, testing of promising material in widely different agroclimatic regions is essential. The first International Chickpea Cooperative Disease Nursery, 1976-77 was operated mainly to get feedback on the types of diseases prevailing in various chickpea g r o w i n g countries. The nursery consisted of 31 entries that had been claimed resistant or tolerant to one or m o r e diseases in some part or other of the w o r l d . Also included were s o m e entries claimed to be superior, presumably because of tolerance to various stresses, including diseases. This multilocation testing was considered a logical step to initiate the cooperative effort so that all cooperators and ICRISAT pathologists could have an opportunity to critically look at some of the lines and cultivars that had been considered resistant or tolerant. The nursery was sent to 16 locations in 6 countries, and data w e r e received f r o m 12 locations in 4 countries. The report is available separately. Of the 31 entries, three that merit special consideration are listed in Table 1. After operating the ' ' t r i a l " nursery, we realized that Ascochyta blight is the major disease and that root rots and w i l t are m i n o r in some countries. The reverse is true in others. In a f e w countries, all three diseases are serious. Therefore, f r o m 1977-78 we initiated t w o disease nurseries, i.e., the International Chickpea Root Rots/Wilt Nursery (ICRRWN) and t h e International Chickpea Ascochyta Blight Nursery (ICABN). These nurseries w e r e initiated w i t h three clear objectives: 1. To identify stable genetic sources w i t h tolerance or resistance to various root rots, wilt, and Ascochyta blight; * Principal Pulse Pathologist, and Pulse Pathologists, ICRISAT.
2. To develop improved varieties that incorporate disease resistance; 3. To provide a convenient m e d i u m for the exchange of genetic material and information among cooperators.
International Chickpea Root Rots and Wilt Nursery For 1977-78, the ICRRWN w h i c h contained 60 entries originating in 6 countries and f r o m ICRISAT was sent to 27 locations in 12 countries. A l t h o u g h data books w e r e received f r o m 16 locations in 6 countries, results of only 10 locations in 4 countries could be considered. A report on this nursery is available separately (ICRISAT Pulse Pathology Progress Report 4). Entries that merit consideration are listed in Table 2. Nine entries were found promising at 5 locations and 16 entries at 4 locations. For 1978-79, the ICRRWN w i t h 63 entries has been sent to 37 locations in 19 countries. The first results are expected in March 1979.
International Chickpea Ascochyta Blight Nursery For 1977-78, the ICABN consisting of 24 entries originating in four countries and f r o m ICRISAT was sent to ten locations in eight countries. Data books were received f r o m six locations in four countries. At one location, disease did not develop and hence results f r o m five locations were analyzed. A report on this nursery is also available separately (ICRISAT Pulse Pathology Progress Report 4). Entries that merit consideration are listed in Table 3. In the ICABN for 1 9 7 8 - 7 9 , 46 entries have been sent to 13 locations in 9 countries. N o w that an ICRISAT sponsored chickpea breeder has been positioned at ICARDA, we propose to operate ICABN t h r o u g h ICARDA f r o m 1979-80.
43
Table1.
Pedigree
ICC No.
Tolerant to Ascochyta blight (AB) at Ankara (Turkey) and to root-knot nematodes at Ludhiana (India). 12-071-10050 Tolerant to AB at Ankara and Eskisehir (Turkey). WR-315 Resistant to w i l t at Kanpur, Jabalpur, and ICRISAT (India). Susceptible to other soil pathogens at most locations. Susceptible to p o w d e r y m i l d e w at Karaj (Iran), to rust at Debre-Zeit (Ethiopia), and to stunt at Hissar (India). Susceptible to AB at all locations.
7519 8933
Table2.
Promising entries i n ICRRWN, 1 9 7 7 - 7 8 . Pedigree
ICC No. 788
Locations w h e r e f o u n d p r o m i s i n g against root rots and w i l t
P-623
B e r h a m p o r e , Hissar, Ludhiana, Gurdaspur, and Varanasi (India); Ethiopia; U.S.A. (7 locations out of 10) B e r h a m p o r e , Hissar, ICRISAT, Ludhiana, Gurdaspur, and Varanasi (India); Ethiopia; P-678 U.S.A. (8 locations o u t of 10) Hissar, Hyderabad, Ludhiana, and Varanasi (India); Ethiopia; U.S.A. (6 locations out of P-1265 10) P-1270 B e r h a m p o r e , Hissar, Ludhiana, Gurdaspur, and Varanasi (India); Ethiopia (6 locations ou t of 10) P-1590 B e r h a m p o r e , Hissar, Ludhiana, and Gurdaspur (India); Ethiopia; U.S.A. (6 locations out of 10) NEC-790 Hissar, Ludhiana, Gurdaspur, and Varanasi (India); Ethiopia; U.S.A.; Y e m e n A r a b Republic (7 locations out of 10) Hissar, Ludhiana, Varanasi, and Kanpur (India); Ethiopia; U.S.A. (6 locations out of 10) NEC-920 NEC-1639 Hissar, ICRISAT, Ludhiana, and Varanasi (India); Ethiopia; U.S.A. (6 locations out of 10) NEC-2413 Hissar, Ludhiana, Varanasi, and Kanpur (India); Ethiopia; U.S.A. (6 locations out of 10)
858 1443 1450 1967 6671 6761 7777 8250
Table3.
1903 4935 5127 7520 4939 7513 7514
Remarks
C-235
4935
ICC No.
Promising entries In the first International Chickpea Cooperative Disease Nursery, 1976-77.
E n t r i e s r e s i s t a n t t o Ascochyta b l i g h t i n t h r e e o r m o r e l o c a t i o n s i n 1 9 7 7 — 7 8 . Pedigree
Locations w h e r e f o u n d p r o m i s i n g against Ascochyta blight
P-1528-1-1-1 C-235 F-8 12-071-10054 F-61 12-071-05132 12-071-05093
Ethiopia; Latakia a n d Tel Hadia (Syria); Tunisia; Eskisehir (Turkey) (all 5 locations) As above Ethiopia; Latakia a n d Tel Hadia (Syria); Eskisehir (Turkey) (4 locations out of 5) As above Ethiopia; Latakia (Syria); Tunisia (3 locations out of 5) Ethiopia; Latakia and Tel Hadia (Syria) (3 locations out of 5) Latakia and Tel Hadia (Syria); Eskisehir (Turkey) (3 locations out of 5)
Problems Encountered
cooperators are unable to f o l l o w the design s u g g e s t e d ; s o m e t i m e s seed does not reach the destination or arrives very late; and reports are
For ICRRWN, u n i f o r m "sick p l o t s ' ' are not avail-
received late and t h i s results in the o m i s s i o n of
able.
s o m e p r o m i s i n g entries in the next season's
Enough facilities to p r o d u c e Ascochyta
blight artificially, if necessary, are not available
nursery. Reports f r o m s o m e locations are not
at all locations because of local difficulties;
received.
44
Session 1 - Breeding Strategies Discussion Byth et al. Paper R. M. Shah What is m o r e rewarding — a t t e m p t i n g a greater number of crosses and rejecting on the basis of F 1 performance, or making fewer crosses and carrying all of them in F 2 and then making selections? Give reasons to support your opinion. J. M. Green Where resources are limited, I prefer carrying all crosses m a d e to F 2 and then selecting a m o n g crosses, preferably on the basis of replicated F 2 tests, for crosses to advance. Where resources permit a large number of crosses to be made, very poor F 1 s can be discarded on a visual basis and F 2 populations can be compared for mean yield. Probability of successful selection for yield will be increased if (1) critical c o m parison of a large number of crosses is made in early generations and (2) the number of crosses advanced is reduced so the number of derived lines per cross can be increased. M. C. Kharkwal This is w i t h reference to future breeding strategies. I w o u l d like to c o m m e n t that in pulse crops in general, and chickpeas in particular, mutation breeding offers a large scope for i m p r o v e m e n t of various characteristics, such as yield, plant type, a n d disease resistance. I w o n d e r if ICRISAT/ ICARDA can afford to ignore this potential tool altogether in their future strategies of chickpea breeding. J. M. Green We recognize the potential value of m u tation breeding but think that our priorities should be on utilizing existing variability, w h i c h is considerable. We are f o l l o w i n g w i t h interest a study of mutation breeding currently in progress at Haryana Agricultural University, and will continue to con-
sider mutation breeding as an option as our program progresses. T. S. Sandhu The lines in F 4 or F 5 giving yields 150% of the m o v i n g average of the check generally come d o w n to about 15% higher yield or even less in regular large scale yield trials. Probably wider spacing used as a matter of necessity during the selection process may be the underlying factor. What can we do in this respect? J. M. Green Certainly we have observed more realistic differences w h e n lines are evaluated in replicated tests. We consider the large yield advantages observed in single unreplicated plots compared w i t h a nearby check result f r o m random effects. In the ICRISAT p r o g r a m , F 2 and F 3 generations were space planted, while F 4 and more advanced generations were g r o w n at crop density. R. B. Singh 1. In your Table 9 and other tables, the female parents are usually H-208 or 850-3/27. If so, it w o u l d be better to make use of these elite parents randomly as male or female parents (considering no maternal effect) to avoid the problem of narrow cytoplasmic base. 2. Keeping in view l o w heritability of yield and high instability, the bulk method or the single-seed descent (provided adequate F 2 plants are sampled) method coupled w i t h multilocation testing should be preferred over routine pedigree method. J. M. Green 1. Your point is well taken. However, H-208, for example is listed first only because it was the c o m m o n parent. Crosses are made reciprocally, and reciprocals are often bulked in F2. 2. Thank y o u for your support.
45
S. Chandra In keeping w i t h the ICRISAT policy of not releasing a named line and in consonance w i t h its ability to provide genetic materials to breeders for local selection, w o u l d it not be w o r t h w h i l e to pile up genetic diversity in different types of crosses and pass on early generation materials to respective breeders? This m i g h t avoid problems w i t h supply of h o m o g e n e o u s lines that have failed to p e r f o r m well at such stations.
1975 w i t h a v i e w to handle long-duration material, and the pedigree m e t h o d w a s to be used for short-duration material. After the site at Hissar was available, the entire material was handled by the pedigree m e t h o d . We believe the pedigree m e t h o d is m o r e effective and can produce results m o r e quickly than the bulk m e t h o d .
J. M. Green Our proposed p r o g r a m is intended to provide a broad spectrum of genetic diversity to local programs. However, we will necessarily be providing F 6 generation by the t i m e we have an adequate increase of seed for distribution. These lines will be bulks of F 4 derived lines, w h i c h w i l l permit profitable reselction w i t h i n and among lines. Since this material will have been s u b j e c t t o m i l d selection at one location, we will not expect a high percentage of superior lines at any given location. The real advantage to the local p r o g r a m is in having near homozygous material in w h i c h to select. We do, however, fill requests for material in any generation desired.
R. C. Misra Temperature and moisture are important w i t h regard to earliness and lateness.
M. C. Kharkwal Isn't mutation ICRISAT?
breeding
overlooked
at
J. M. Green No blight resistance was f o u n d after considerable m u t a t i on breeding efforts by Dr. A b d u l l a h Khan, Lyallpur. S. Chandra Is it s o m e sort of coincidence that "despite the projected use of bulk pedigree and bulk m e t h o d at ICRISAT, almost all breeding w a s handled using the pedigree m e t h o d " or w e r e there s o m e reasons that necessitated this change? J. M. Green This question should be referred to K. B. S i n g h , w h o w a s i n the p r o g r a m atthat t i m e . K. B. Singh The bulk pedigree m e t h o d was proposed in
46
van der Maesen et al. Paper
L. J. G. van der Maesen These are mentioned in the d o c u m e n t that introduces evaluation of chickpea g e r m p l a s m at ICRISAT. The d o c u m e n t is issued as a prepublication.
Singh et al. Paper D. C. Erwin I w o n d e r if the lack of correlation between performance of varieties at different locations could be d u e to the variation in ino c u l u m levels of different pathogens? If so, root pathogens could be limiting factors that confound yield results. J. Kumar We do get data on plant stand and disease ratings f r o m various locations. In earlier years, not many locations reported damage by root diseases. A l t h o u g h m i n o r variation in plant stand of chickpeas may not make much difference, we agree that this cannot be ignored as a factor in line performance. P. N. Bahl In order to quantify the relative similarity of the location, we may choose those culti vars s h o w i n g m a x i m u m entry x location interaction and then run rank correlations (based on relative yield ranking of cultivars at different locations). J. Kumar The 12 entries that were c o m m o n to 3 years of testing showed considerable entry x lo-
cation interactions. We ran rank correlations in addition to those on actual yield. There w a s general similarity of values.
races very definitely exists. As we go along, I am sure we will gain m o r e knowledge on this aspect.
L. Singh Lack of correlation for performance, between and w i t h i n locations, is caused by t w o factors c o m p o u n d e d together: 1. M a n a g e m e n t of conduct of trials under rainfed conditions. 2. Location effect. There is need for a standardization of test practices under rainfed conditions. J . Kumar The Indian locations for w h i c h correlations w e r e reported have fairly well managed trials, and in northern India pre-sowing irrigation is generally given to ensure g o o d stands. If we standardize cultural practices for these trials, I w o n d e r h o w will the results of these be relevant to particular areas.
J. S. Kan war (to all breeders) Do breeders agree on F 3 testing? L. Singh Breeders w o u l d like to get an indication of superior crosses as early as possible. Since multilocation testing in F 1 is not feasible, and even in several cases in F2, perhaps F 3 multilocation testing is the best bet. J. Kumar We have a trial of 50 F2 bulks g r o w n at seven locations, and I have visited four. There are considerable differences a m o n g entries at t w o of the four sites. As an international institute, we wish to test a number of such bulks at many different sites and supply the best ones to local breeders on the basis of multilocation performance.
Nene et a/. Paper J. S. Grewal ICC 5127 was infected by Ascochyta rabiei in India as early as the 1950s, but it has been f o u n d to be free f r o m blight at Eskisehir in Turkey in 1977-78. Blight-resistant ICC1903, however, has shown disease reaction 2 or 3 in Turkey. Should I presume that physiologic races of A rabiei in Turkey are different f r o m those in India. Or are there any other reasons? Y. L. Nene We know nothing about the existence of physiologic races of Ascochyta rabiei in Turkey. The possibility of the existence of
J. S. Sindhu Chickpea line 850-3/27 evolved at Kanpur has been released and named as K-850. It is a happy note that this line is being used quite extensively as a parent in most of the hybridization programs at ICRISAT, and for convenience only, henceforth this line may be referred to as K-850. M. V. Reddy Differential reaction of the parents involved in the progenies to diseases tested at Hyderabad and Hissar appears to be the major factor for lack of correlation. Parents w i t h good levels of resistance have given progenies w i t h stable yields.
47
Session 2 Y i e l d I m p r o v e m e n t through Kabuli-Desi Introgression Chairman : Laxman Singh C o - C h a i r m a n : I. H. Najjar
Rapporteur: S. C. Gupta
Kabuli-Desi Introgression: Problems and Prospects G. C. Hawtin and K. B. Singh*
The value of crossing between divergent subgroups w i t h i n a species has been recognized by plant breeders for some time. Much of the success of the Corn Belt dent maizes, which were so w i d e l y g r o w n before the introduction of hybrid varieties, has been attributed to the natural introgression of genes f r o m the w h i t e southern dents, t h o u g h t to have originated in Mexico, and the American Indian northern flints. The heterosis that frequently results f r o m crossing between inbred lines f r o m different geographic origins has been made use of repeatedly by breeders in the production of hybrid and synthetic varieties. In Kenya, for example, a significant breakthrough in yield was achieved in the mid 1960s f o l l o w i n g the development of hybrid varieties based on crosses between local synthetic varieties and lines introduced f r o m Ecuador in Latin America (Harrison 1970). A similar story has been reported in the case of s o r g h u m (Doggett 1970). The cultivar Martin, the most widely g r o w n grain s o r g h u m in the United States up to the release of hybrids in 1956, was selected f r o m the variety Wheatland, which in t u r n originated for a Kafir x M i l o cross made in 1919. Studies on hybrid vigor in sorg h u m have indicated that, in general, heterosis for yield is greatest f o l l o w i n g crosses between different types, e.g., Milo's w i t h grain s o r g h u m s such as Kafirs f r o m southern Africa, Feteritas f r o m East and West Africa and Sudan, and Kaoliangs f r o m China, and w i t h b r o o m corn. Most m o d e r n grain s o r g h u m hybrids in the United States are based on Kafir x M i l o crosses. In addition to crossing between genetically divergent groups for increased heterosis, w h i c h in turn may or may not become fixed through selection, it has frequently been the case that * Leader and Plant Breeder (Chickpea), respectively, Food L e g u m e P r o g r a m , ICARDA.
one group may contain genes for particular characters that might usefully be transferred to another group within the same species. It is this possibility, rather than increased vigor alone, that has stimulated much of the recent interest in hybridization between t w o - r o w and six-row barleys. Attempts are being made by breeders to transfer the tillering capacity of t w o - r o w barleys into the six-row type and to transfer earliness in the opposite direction. In crosses between winter and spring wheats, considerable success has been achieved in transferring the drought resistance of the winter into the spring types. T w o features of drought resistance in the winter wheats that are not present in the spring wheats are a deepset crown (leading to stronger secondary root development), and the ability to withstand atmospheric drought without reaching the wilting point. In the reverse direction, spring wheats may act as a source of genes for disease resistance that is lacking in the winter wheats. In both the ICARDA (previously ALAD) and ICRISAT breeding programs, the first w i d e crosses within chickpea were made both to transfer specific characters between groups and in the hope that the introgression of " y i e l d " genes f r o m substantially different genetic backgrounds might produce transgressive segregants for high yield. While the usefulness of the scheme for yield improvement per se in chickpea is still open to question, there is no doubt that the subgroups w i t h i n Cicer arietinum have many characters that can usefully be transferred to each other.
Intraspecific Classification in Chickpea Many attempts have been made to describe subgroups w i t h i n the species Cicer arietinum. A historical review of these systematics has
51
been given by van der Maesen (1972) starting w i t h t h e classifications of Jaubert and Spach w h o recognized three varieties: vulgare, rytidospermum, and macrocarpum. He, van der Maesen, based his o w n classification on the work of Popova w h o recognized f o u r subspecies (orientate, asiaticum, mediterraneum, and eurasiaticum), w h i c h w e r e further subdivided into 13 proles (subraces) and 64 varieties. Systems of intraspecific classification based on geographic systems are complicated by ancient and recent exchanges of materials and hybridization. Recognizing this p r o b l e m , van der Maesen proposed a system for general use based entirely on seed characters. In this classification he recognized ten types. Recently, intraspecific classification has been the subject of attention by M o r e n o and Cubero (1978) w h o presented data taken on a collection of 150 lines f r o m major chickpea g r o w i n g regions throughout the w o r l d . They undertook a series of analyses, on 23 characters, and reported the existence of t w o complexes w i t h i n t h e cultivated chickpea, w h i c h they designated macrosperma and microsperma. Of the metrical characters studied, pod length, p o d w i d t h , and seed size all showed a clear b i m o d a l dist r i b u t i o n , w h i l e other characters (e.g., leaflets per leaf, leaflet size, and n u m b e r of primary branches) showed a tendency t o w a r d b i m o d a l ity or a clear u n i m o d a l distribution (e.g., rachis length, p o d s and seeds per plant, and seeds per pod). They described the t w o groups as f o l l o w s : Microsperma groups, populations, and cultivars w i t h small pods (less than 23 mm long), small seeds (weight less than 0.35 g), small leaves (rachis length less than 4 cm), and small leaflets (length less than 12 m m ) . The seeds s h o w a great diversity of colors, f o r m s , and reliefs w i t h 1-3 seeds per pod. A high frequency of colored flowers and vegetative organs characterizes this race. Macrosperma groups, populations, and cultivars w i t h big pods, seeds, leaves and leaflets. Seeds are mainly w h i t e , pinkish, reddish or black, but other colors exist at l o w frequencies. Seeds are strongly sheepheaded, in most of the cases w i t h a rough coat and l o w in number of seeds per p o d . High frequency of w h i t e flowers and colorless vegetative organs occur.
52
They indicated that the microsperma g r o u p can be f o u n d t h r o u g h o u t the range of geographic distribution of the species but is very scarce in western Mediterranean countries where macrosperma types predominate. The system proposed by M o r e n o and Cubero (1978) has a certain taxonomic merit and goes s o m e w a y t o w a r d putting the intraspecific classification of chickpea on a sound scientific basis. Certain problems still exist, however, especially in relation to the types c o m m o n t h r o u g h o u t much of North Africa, Egypt, Sudan, western Asia, and Afghanistan and to the types c o m m o n l y referred to as kabuli in India. These types w e r e poorly represented in the 150 entries of M o r e n o and Cubero (only 17 originated in eastern Mediterranean countries), and their relative absence may have biased the results. Table 1 shows mean seed sizes for certain entries in the ICARDA g e r m p l a s m collection, originating in this region. A l m o s t all the entries are light beige in color, s o m e w i t h a pinkish or slightly darker tinge, a characteristic "sheeph e a d " or " b r a i n " shape, w h i t e flowers, and no anthocyanin pigmentation in the vegetative parts. In many respects, therefore, these types have m u c h in c o m m o n w i t h the macrosperma group. As can be seen f r o m Table 1, however, samples f r o m many countries have a mean seed w e i g h t of less than 35 grams per 100 seeds, w i t h individual samples being less than 10 grams per 100 seeds. Clearly, many of these types are intermediate between macrosperma and microsperma, as defined by M o r e n o and Cubero. Until these types have been examined further in genetic and biosystematic studies, the syst e m c o m m o n l y used by many breeders of dividing chickpea into kabuli and desi types is probably still the most useful. There is a fairly clear distinction between the t w o types, w h i c h is generally agreed upon by breeders but is difficult to define systematically. This distinction is based almost entirely on seed shape and color but also takes account of geographical origin and uses. A third g r o u p having round pea-like seeds w i t h the characteristic Cicer beak, is also to be found in world collections. These are comparatively rare in local markets, but are frequent in breeding programs following kabuli x desi crosses. Such round-seeded types (which may be any color f r o m light beige to black, including green) are generally desig-
Table 1.
S e e d size o f e n t r i e s , s e l e c t e d a t r a n d o m f r o m t h e I C A R D A k a b u l i c o l l e c t i o n a n d originating f r o m various countries of West and Central Asia and N o r t h Africa. No. of samples
M e a n 100-seed weight (g)
Range in 100-seed w e i g h t (g)
Afghanistan Algeria Egypt Iran Iraq Jordan
6 10 10 10 10 10
19.9 36.1 13.7 23.1 32.6 29.1
14.5-28.3 23.2-43.9 9.7-27.7 14.2-34.8 25.3-37.3 16.0-35.0
Lebanon Morocco Sudan Syria Tunisia Turkey
10 8 3 10 10 10
29.9 33.6 10.4 37.6 37.2 32.3
18.6-41.6 28.0-39.9 9.6-11.0 27.1-41.2 27.2-42.3 23.7-40.3
Country
nated " i n t e r m e d i a t e " or " p e a " types by breeders. Since it is not proposed to discuss intraspecific classification in detail in this paper, but rather to consider the breeding implications of crossing between divergent subgroups, the terms kabuli, desi, and intermediate w i l l generally be used.
Kabuli and Desi Gene Pools Within C. arietinum, it is generally considered that the kabuli g r o u p originated by selection f r o m the m o r e primitive desi. The divergence probably occurred in comparatively recent times and almost certainly in the Near East or Mediterranean region. M o r e n o and Cubero (1978) hypothesized that the basis of the selection was w h i t e f l o w e r e d plants (and its correlated colorless seed), w h i c h appeared as a mutant in t h e local microsperma populations. In v i e w of this, they suggested that the macrosperma group has very f e w starting points, w h i c h may account for its relatively narrow gene pool compared to t h e microsperma group. The study of M o r e n o and Cubero certainly indicated that genetic variation w i t h i n macrosperm a was less than in microsperma in the samples analyzed. In v i e w of the arguments outlined in the section on classification, however, it is highly questionable whether this id also necessarily true if one considers the full
range of kabuli versus desi types. This commonly held view may reflect to a large extent the greater amount of work that has been done on collecting and describing the variation in desis, especially in the Indian subcontinent. Now, w i t h greater emphasis being put on the genetic improvement of kabulis in the Mediterranean region and elsewhere, it is probable that this view will change. As an example of this, the ICABN nursery of ICRISAT contains only desi types, reflecting the preponderance of desis in the collection. When 1200 kabuli accessions were screened in the field at Aleppo in 1978, 40 kabuli entries f r o m diverse geographical origins were identified as having Ascochyta blight resistance, of which 37 were reconfirmed as resistant this year. Whatever the extent of the respective gene pools, it is certainly true that each group has certain characteristics that might usefully be transferred to the other. The kabuli group, for example, in addition to having a greater range in seed size, tends to have m o r e primary branches, greater cold tolerance, a m o r e upright and in some cases taller g r o w t h habit, and greater resistance to chlorosis caused by a shortage of available iron in the soil. Desis, on the other hand, tend to have a bushier g r o w t h habit, m o r e seeds per p o d , m o r e pods per plant, and greater tolerance to drought and heat. A number of specific characters have also been identified in the desi background, such as double-podding and resistance to wilt and salini-
53
ty. However, the presence of the latter characters in t h e desi background, m a y again merely reflect t h e greater research i n p u t on this g r o u p .
specific genotypes involved and was not related to either the botanical g r o u p or geographic origin of the parents. Experience at ICRISAT, at both Hissar and Hyderabad, has led to the s o m e w h a t different conclusion that, at least in those environments, crossing is m o r e successful w h e n the desi parent is used as the female. Kabuli x kabuli and kabuli x desi crosses are generally less successful. Clearly, further studies are required on this. Little w o r k has been d o n e on the genetics of kabuli vs desi chickpeas. Martinez et al. (1979) reported the results of three sets of diallel crosses (one w i t h i n macrosperma, one w i t h i n microsperma, and one i n v o l v i n g lines f r o m both groups) and concluded that, in general, characters that can be considered p r i m i t i v e , such as small leaflets, leaves, pods, grains and high seeds per p o d , tended to be dominant. Table 2 summarizes s o m e data on the segregation into kabuli vs desi and intermediate types in F 2 populations f o l l o w i n g crosses between kabuli and desi parents. The F 2 plants w e r e classified into the t w o types based on the visual appearance of the F 2 -F 3 seed. As can be seen in t h e table, the average of recovery of true kabuli seeded types in the F 2 was 16%. Considerable variation between different populations was recorded, however, ranging f r o m less than 6% to over 2 2 % . In order to study t h e recovery of kabuli types in the F 3 generation, F 2 and F 3 bulked seed f r o m seven of t h e populations was divided into kabuli, intermediate, and desi types and was planted out. Table 3 s h o w s t h e recovery of
Genetics of Kabuli and Desi Types Several attempts have been m a d e to look for cytogenetic differences between kabuli and desi types. Ladizinski and Adler (1976) reported that w h e n red f l o w e r e d cultivars of C. arietinum w e r e crossed w i t h C. reticulatum, meiosis was n o r m a l and the hybrids fertile. However, in a cross between a w h i t e flowered cultivar and C. reticulatum, a quadrivalent, anaphase I bridge and f r a g m e n t w e r e f o u n d at meiosis, resulting in l o w pollen fertility and no seed set in the F 1 . This has been taken to indicate c h r o m o s o m e r e p a t t e m i n g w i t h i n C. arietinum; however, Ladizinski and Adler did not indicate whether or not the w h i t e f l o w e r e d cultivar was a true kabuli. In a study of crossability between groups, Martinez et al. concluded that cytogenetic differences are of little importance in preventing crossing. They reported average success rates of 14.9, 15.8, and 13.6% f o r macrosperma x macrosperma, microsperma x microsperma, and macrosperma x microsperma crosses, respectively. They concluded that t h e variances were large enough to cover the differences between these figures. Large differences in success were reported, however, between individual crosses, but this depended on the
Table 2.
N u m b e r s and percentage of plants classified as kabuli and I n t e r m e d i a t e / d e s i types In F2 populations of kabuli x desi origin. Intermediate and desi
Kabuli Cross
No. of F2 plants tested
No.
%
No.
%
X74IC X74IC X74IC X74IC
1 5 10 21
112 112 86 86
14 25 16 15
12.5 22.3 18.6 17.4
98 87 70 71
87.5 77.6 81.4 82.6
X74IC X74IC X74IC X74IC
22 32 33 43
52 69 74 33
3 13 7 7
5.8 18.8 9.5 21.2
49 56 67 26
94.2 81.2 90.5 78.8
624
100
16.0
524
84.0
Total
54
very small. It can thus be concluded that in a p r o g r a m a i m e d at the i m p r o v e m e n t of kabulis, there is little point in retaining intermediate and desi types b e y o n d F2, w i t h the possible except i o n of those intermediate types having characteristics very close to tru e kabulis. The recovery of t r u e desi types in segregating populations is also comparatively low, the major portion of the segregates falling into the intermediate category. Data are not available on this at present, b u t it is expected that a picture similar to that w h i c h has been f o u n d in t h e kabulis w o u l d emerge. Unfortunately, data are also not yet available on the effects of backcrossing or three-way crossing on seed characters. It is to be expected, however, that backcrossing or three-way crossing to kabulis w o u l d greatly enhance t h e recovery of kabuli types, and vice versa f o r the desis. Backcrossing also has other i m p o r t a n t implications in relation to kabuli x desi introgression, and these are discussed in t h e next section. In the absence of a backcross or three-way cross, F 2 populations should be sufficiently large to allow adequate gene recombination f o r
kabuli types f r o m each of t h e t h r e e groups. Over 8 0 % of t h e types classified as kabuli in F 2 gave rise to kabuli progenies in the next generation. Neither of the types classified as intermediate or desi in F2, however, produced many kabuli segregates in the F 3 and t e n d e d , as t h e kabulis, to breed true. W h i l e the figures in Tables 2 and 3 may be biased d u e to the s o m e w h a t arbitrary nature of t h e classification m e t h o d , the trend is very clear and indicates both the l o w recovery of kabuli types in the segregating generation f o l l o w i n g a kabuli x desi cross and the speed at w h i c h the seed characters are to a large extent " f i x e d . " The study was taken a stage further in three populations in w h i c h F 2 and F 3 seeds classified as intermediate w e r e further subdivided into those closest to the kabuli end of the spectrum (near-kabuli) and the r e m a i n i n g intermediate types. The recovery of kabuli types in the F 3 f o l l o w i n g this separation is s h o w n in T a b l e 4 . As can be seen, 41.9% of the g r o u p classified as near-kabuli in F 2 w e r e classified as kabuli in the F3. A l t h o u g h this figure m a y be inflated due to classification problems, recovery of kabuli types in the other t w o F 2 classes was clearly
Table 3.
N u m b e r s and percentages of plants classified as kabuli and i n t e r m e d i a t e / d e s i types In F3 b u l k s o f k a b u l l , I n t e r m e d i a t e , a n d desi t y p e s I n Fa. ( M e a n s o f 7 c r o s s e s ) . F 3 plants intermediate/desi
Kabuli F2 class Kabuli Intermediate Desi
Table 4.
Total no. tested
No.
%
No.
%
281 344 370
228 44 33
81.7 12.8 8.9
51 300 337
18.3 87.2 91.1
N u m b e r s a n d p e r c e n t a g e s o f p l a n t s classified a s k a b u l i a n d i n t e r m e d i a t e / d e s i t y p e s i n F 3 b u l k s o f k a b u l i . I n t e r m e d i a t e , a n d desi t y p e s i n F 2 . ( M e a n s o f 3 p o p u l a t i o n s ) . F 3 plants Kabuli
F 2 class Near-kabuli Intermediate
Total no. tested 43 165
Intermediate/desi
No.
%
No.
%
18 14
41.9 8.5
25 151
58.1 91.5
55
characters other than seed quality to occur w i t h i n t h e small p r o p o r t i o n of the total p o p u lation having the desired quality. Kabuli and near-kabuli types, or desi and near-desi types, can be mass selected in the F 2 for subsequent evaluation and selection in the F 3 and later generations.
Kabuli x Desi Introgression for increased Yield A l t h o u g h cultivars c o m m o n l y g r o w n t h r o u g h out the Mediterranean and West Asia region are kabuli, several desi types (originating mainly in Iran) have been f o u n d to p e r f o r m very well in the region, especially under spring planting conditions. Table 5 shows the yield and other attributes of the t o p entries in advanced yield trials g r o w n at A l e p p o in t h e 1977-78 season. In t h e w i n t e r planted trial the top t w o entries w e r e kabuli, whereas in the spring (the n o r m a l planting t i m e in the region), the t o p t w o w e r e desi. This may be attributed, at least in part, to a greater heat tolerance in the desis, although a desi entry was also ranked t h i r d in t h e winter trial. In the Chickpea Regional Preliminary Yield Trial (CRPYT) conducted in t h e 1977-78 season, 8 out of the 35 entries supplied w e r e desi; the rest w e r e all kabuli. Data received f r o m eight locations in six countries s h o w e d that f o u r of t h e top five entries w i t h the highest mean yield over all locations w e r e desi types. The transfer of kabuli seed characteristics into the genetic background of these desis, or conversely, the introgression of " y i e l d " genes into
Table
5.
Origin, yield, a n d seed t y p e of t h e t h r e e highest yielding entries in t h e advanced yield trials planted in winter and spring, Aleppo, 1 9 7 8 .
Pedigree W i n t e r planted 74TA 528 74TA 60 75TA 16947 Spring p l a n t e d 74TA 1619 74TA 1629 NEC 293
56
the kabuli b a c k g r o u n d , m i g h t reasonably be expected to result in the d e v e l o p m e n t of superior kabuli cultivars for West Asia. Apart f r o m the hope of raising kabuli yields t h r o u g h hybridization w i t h already superior yielding desis, t h e original intergroup crosses w e r e m a d e in the hope of obtaining transgressive segregates, based on the theory that such segregants are most likely w h e n crossing between diverse gene pools. Auckland and Singh (1977) reported that transgressive segregation w i t h respect to g r o w t h habit, seed size, pod number, and yield was greater in populations involving both kabuli and desi parentage than in populations involving only desis. Apart f r o m this report, however, there is little evidence for widespread transgressive segregation f o l l o w i n g kabuli x desi crossing. Studies conducted by ICRISAT at both Hyderabad and Hissar in the 1975-76 and 1976-77 crop seasons have indicated, in general, that F 2 populations i n v o l v i n g 100% desi in their parentage w e r e evaluated as promisin g more frequently and discarded less frequently than populations containing a portion of kabuli genes. This is s h o w n in Table 6 (adapted f r o m 1976-77 ICRISAT Chickpea Breeding Annual Report) w h i c h summarizes the data for threew a y crosses having 100%, 7 5 % , 50%, and 25% of desi genes in their parentage. Progenies of single plants selected in the p r o m i s i n g F 2 populations w e r e rated in the F3, and in general, little overall difference was f o u n d w i t h respect to the percentages rated p r o m i s i n g or discarded between those w i t h and w i t h o u t kabuli genes in their background (Table
100-seed w e i g h t
Country of o r i g i n
Yield kg/ha
Rank
Seed t y p e
(g)
Turkey Iraq Iran
1852 1806 1769
1 2 3
Kabuli Kabuli Desi
33 28 27
Iran Iran Turkey
1442 1252 1233
1 2 3
Desi Desi Kabuli
21 24 33
7). The general conclusion to this study was that there w a s little to be gained f r o m the introgression of kabuli genes into the desi background for t h e i m p r o v e m e n t of desis in the Indian subcontinent. Both in India and West Asia, however, the current indications are that kabuli x desi introgression m i g h t prove of great value in the improvement of kabuli types rather than desis. At ICRISAT in 1976-77, F 4 progenies were evaluated for yield at both Hissar and Hyderabad, and the best 29 kabuli entries w e r e entered in the international testing p r o g r a m for the 1977-78 season. Of these t o p 29 progenies, 20 originated f r o m kabuli x desi crosses. The Indian cultivar L-550 was originally released in Punjab in 1973 and subsequently released by the All India Variety Release Committee in 1975. This cultivar, renowned for its
Table 6.
w i d e adaptation, originated f r o m a desi x kabuli cross made at Ludhiana. In 1977 in Aleppo, 190 F 2 populations were rated on a 1-5 scale for overall growth and yield characteristics, where 1 indicated the most promising and populations rated 5 were discarded. The results are shown in Table 8. Based on the information in this table, it w o u l d appear at first glance that kabuli x desi crosses were considered less promising than kabuli x kabuli crosses. When the figures were considered on the basis of the origin of the parents, however, a somewhat different picture emerged, as shown in Table 9. When both parents originated in West Asia, the F 2 populations were very promising; in fact, it appeared that overall, the origin of the desi parent had a greater influence on the performance of the F 2 than did the origin of the kabuli. While this last point certainly requires
N u m b e r o f F 2 p o p u l a t i o n s i n v o l v i n g v a r i o u s p r o p o r t i o n s o f d e s i (D) a n d k a b u l i (K) g a n a s e v a l u a t e d a s p r o m i s i n g (PR) a n d t h o s e d i s c a r d e d ( D I S ) . T h e d a t a a r e t o t a l s f o r t h e 1 9 7 5 - 7 6 and 1 9 7 6 - 7 7 seasons. No. of F 2 populations
Percentage of genes D 100 75 50 25
Hyderabad
Hissar
Total
K
PR
DIS
PR
DIS
0 25 50 75
33 13 13 4
89 44 42 33
64 15 26 9
58 26 42 14
PR
DIS
97 (40)a 28 (29) 39 (32) 13 (22)
147 70 84 47
(60) (71) (68) (78)
a. Figures in parentheses are percentages. A d a p t e d f r o m ICRISAT Chickpea Breeding A n n u a l Report, 1 9 7 6 - 7 7 .
Table 7.
N u m b e r o f F 3 p r o g e n i e s I n v o l v i n g v a r i o u s p r o p o r t i o n s o f dasl (D) a n d k a b u l i (K) g a n a s e v a l u a t e d a s p r o m i s i n g (PR) a n d t h o s e d i s c a r d e d ( D I S ) . T h e d a t a a r e t o t a l s f o r t h e 1 9 7 6 - 7 6 a n d 1 9 7 6 - 7 7 seasons. No. of F 3 progenies
Percentage of genes D 100 75 50 25
Total
Hissar
Hyderabad K
PR
DIS
PR
DIS
0 25 50 75
78 15 5 22
946 129 28 282
67 11 6 23
259 54 27 151
PR 145 (11)a 26 (12) 11 (17) 45 (10)
DIS 1205 183 55 441
(89) (88) (83) (90)
a. Figures in parentheses are percentages. A d a p t e d f r o m ICRISAT Chickpea Breeding A n n u a l Report, 1 9 7 6 - 7 7 .
57
phenotypic variability and the plants w e r e all of short stature and gave l o w yields. It was not possible to select individual plants f r o m these populations. W i t h i n F2 populations of kabuli x desi crosses, however, and to a lesser extent w i t h i n Indian desi x Iranian desi crosses, they reported that large phenotypic differences w e r e observed and " s i n g l e plant selection could be carried out w i t h i m p u n i t y . " They hypothesized that if adaptability is i m p o r t a n t in chickpea, a superior cultivar f o r East Asia w o u l d be p r o d u c e d by a (kabuli x desi) x desi backcross and for West Asia by a (kabuli x desi) x kabuli backcross. S o m e evidence for this was provided by t w o reciprocal backcrosses involving the cultivars F-378 (an Indian desi) and Rabat (a Moroccan kabuli). The t w o populations were g r o w n contiguously. All the plants w i t h i n these t w o backcrosses w e r e harvested, and individual plant seed yield was recorded. The results are given in Table 11 and show clearly the advantage of the backcross to the kabuli in the West Asian environment. From each F 2 backcross population, the 15 highest yielding, 15 lowest yielding, and 15 random plants were selected. The results of this are given in Table 12. As expected, the backcross to the desi
further study, the question of adaptation of the parents seems to be of far greater significance in the cross performance than merely w h e t h e r they w e r e of kabuli or desi origin. A similar picture emerges if we look at t h e o r i g i n of the kabuli parents in kabuli x kabuli crosses, as s h o w n in Table 10. The question of adaptation in chickpea and its implications in chickpea breeding was discussed briefly by Auckland and Singh (1977). They reported that, w h e n F 2 populations of crosses involving Indian desi x Indian desi parentage w e r e g r o w n in Lebanon in 1975, there was little
Table 8.
Performanc e of F2 crosses, g r o w n in Aleppo, 1977.
T y p e of cross Kabuli x Kabuli Kabuli x Desi Desi x Desi
No. of crosses
Mean rating a
M e a n no. of plants selected
23 146 21
2.2 3.2 3.4
5.6 2.5 0.5
a. 1 = M o s t p r o m i s i n g , 5 = Least p r o m i s i n g .
Table 9.
Rating of Fa populations of kabuli grown in Aleppo, 1977.
Origin of kabuli parent West Asia West Asia Nort h and N o r t h East Africa N o r t h and N o r t h East Africa
x d e s i crosses f r o m W a s t A s i a n a n d a x o t l c p a r e n t s ,
O r i g i n of desi parent
No. of crosses
Mean rating a
M e a n no. of plants selected
Iran India Iran India
6 61 5 61
1.7 3.2 1.6 3.4
5.7 2.3 6.0 2.0
a. 1 = M o s t p r o m i s i n g , 5 = Least p r o m i s i n g .
Table
10.
Rating of F2 populations of kabuli grown in Aleppo, 1977.
O r i g i n of parents West Asia West Asia Exotic
x West Asia x Exoticb x Exotic b
x kabuli crosses f r o m parents of d i f f e r e n t origins,
N o . of crosses
Mean ratinga
M e a n no. of plants selected
4 11 8
1.5 2.0 2.9
6.25 6.6 3.9
a. 1 = M o s t p r o m i s i n g , 5 = Least p r o m i s i n g . b. Exotic i n c l u d e s India, S u d a n , Egypt, Ethiopia, a n d A f g h a n i s t a n .
58
Table
11.
Production of divergent segregants by backcrosses of F-378 and Rabat strains of chickpea (F2 generation, Lebanon, 1 9 7 5 ) . % frequency: seed w e i g h t (g) classes
Cross/parent (F378 x Rabat) x Rabat (F378 x Rabat) x F378 F378 Lebanese local a
0-40
40-80
80-120
120-140
43.4 79.7 90.0 85.0
46.6 19.7 10.0 15.0
9.7 0.6
0.3
M e a n seed w e i g h t (g/plant) 46.3 32.8 22.4 25.5
a. Rabat w a s not g r o w n . Lebanese l o c a l , a large-seeded k a b u l i , has similar characteristics. F r o m A u c k l a n d a n d S i n g h (1977).
Table
12.
M e a n s e e d w e i g h t s ( g / p l a n t ) o f s e l e c t e d s e g r e g a n t s f r o m b a c k c r o s s e s o f F-378 a n d Rabat strains of chickpea ( m e a n of 5 plant samples for each progeny r o w ) . M e a n seed w e i g h t (g/plant) Lebanon (F2), 1975
India (F 3 ), 1975-76
Correlation of F2/F3
(F378 x Rabat) x Rabat High-yielding segregants Random segregants Low-yielding segregants Cross m e a n
90.7 46.4 10.4 49.8
21.7 22.2 23.4 22.4
0.25 0.18 - 0.47* -0.10
(F378 x Rabat) x F378 High-yielding segregants Random segregants Low-yielding segregants Cross mean
73.3 33.0 3.4 36.5
30.6 32.9 31.6 31.7
0.37 0.00 - 0.52* - 0.31
Cross
* Denotes significance at P < 0 . 0 5 . F r o m A u c k l a n d a n d S i n g h (1977).
parent, F-378, performed comparatively better in India. It is interesting that there was little difference in mean F 3 performance between the progenies of the three classes of F 2 segregants w i t h i n each cross; however, on average, the F3S of the backcross to F-378 were nearly 50% higher yielding than the backcross to t h e kabuli p a r e n t A l t h o u g h the evidence is meager, and further studies are certainly needed, all the data point in the same direction indicating the importance of backcrossing to the adapted parent. Some further studies on this have been initiated at ICARDA, including a look at the value of a second backcross to t h e adapted (kabuli) parent in crosses w i t h both adapted and highly u n adapted desi parents.
Conclusion The importance of crossing between the t w o major subgroups of chickpea has been clearly established. Each type can benefit f r o m the transfer of certain specific genes f r o m the other. The kabulis for example, might be i m p r o v e d by the transfer of greater secondary branching or heat tolerance f r o m the desis, which in t u r n , might benefit f r o m the addition of genes for a taller, m o r e erect g r o w t h habit or cold tolerance f r o m the kabulis. Since it is probable that the respective gene pools have been separated for many years, it is likely that genes for certain characters, e.g., disease resistance, might differ between the
59
t w o groups. It is thus possible that crossing, say Ascochyta blight resistant kabulis w i t h resistant desis, m a y result in an increased chance of raising overall resistance levels or i m p r o v i n g resistance to a greater n u m b e r of strains of t h e pathogen. This aspect of kabuli x desi introgression is currently receiving attention at ICARDA. The introgression of a f e w specific genes f r o m one group into the other can best be achieved by a conventional backcrossing p r o g r a m , and it m a y be desirable to make several backcrosses to the recurrent parent in the process. The transfer is likely to be simplest w h e n the d o n o r parent is well adapted to the local environment. The original hopes of making significant yield advances f o l l o w i n g crossing between high yielding West Asian kabulis with high yielding (in India) Indian desis have not so far been achieved. The implications are that adaptation is very important in chickpea and that yield genes cannot be considered independently of this. Part of the problem can be o v e r c o m e by backcrossing to the adapted parent, t h o u g h in the first instance a greater emphasis should be placed on kabuli x desi crossing w h e n both parents are well adapted. In either case, the backcross will significantly increase the percentage of recovery of the desi red seed type. Following the backcross, the F 1 plants can be selected on t h e basis of seed characters. In v i e w of the close association between kabuli seed characters and w h i t e flowers, pink-flowered plants can be removed f r o m the F 2 bulks w h e n breeding for improved kabulis. This, in t u r n , will help to increase the proportion of F2/F3 kabuli seed. From the F 3 generations the populations can be handled exactly as in any other conventional breeding system.
60
If we are going to achieve significant y i e l d advances in chickpea, a bold approach must be taken t o w a r d the breeding of the crop. W i t h m o r e t i m e and study, kabuli x desi introgression in t h e future m i g h t provide an important contribution t o w a r d achieving such advances.
References A U C K L A N D , A. K., and S I N G H , K. B. 1977. T h e e x p l o i t a -
t i o n of natural genetic variability f o r t h e chickpea (Cicer arietinum). Pages 8 3 - 9 5 in Genetic Diversity in Plants. Eds. A. M u h a m m e d , R. Aksel, and R. C. v o n Borstel. Plenum Publishing Corporation. D O G G E T T , H. 1970. S o r g h u m i m p r o v e m e n t in East Africa. Crop i m p r o v e m e n t in East Africa, ed. C. L. A. Leakie. C o m m o n w e a l t h A g r i c u l t u r a l Bureaux, London. H A R R I S O N , M. N. 1970. Maize i m p r o v e m e n t in East Africa. Crop i m p r o v e m e n t in East Africa, ed. C. L. A. Leakie. C o m m o n w e a l t h Agricultural Bureaux, London. LADIZINSKI, G., and A D L E R , A.
1976. T h e o r i g i n of
chickpea Cicer arietinum L. Euphytica 25 : MARTINEZ,
A,
COIDURAS,
A.,
MORENO,
211-217. M.
T.,
and
CUBERO, J. I. 1979. Quantitative inheritance and barriers to crossability in Cicer arietinum L. Theoretical and A p p l i e d Genetics 54. (in press). M O R E N O , M . T , and CUBERO, J . I. 1978. V a r i a t i o n in
Cicer arietinum L. Euphytica 27 :
465-485.
VAN DER MAESEN, L. J. G. 1972. Cicer L A m o n o g r a p h of t h e genus w i t h special reference to the chickpea (Cicer arietinum L.), its ecology, and cultivation. V e e n m a n and Z o n e n , W a g e n i n g e n , T h e Netherlands. 342 pp.
Studies on Desi and Kabuli Chickpea (Cicer arietinum L.) Cultivars I. Chemical Composition R. Jambunathan and U. Singh*
A l t h o u g h t h e existence of desi and kabuli chickpea cultivars has been k n o w n for a long time, little information on chemical composition of the t w o types is available. Therefore, it is desirable to obtain more information on the chemical composition of desi- and kabuli-type cultivars so that the relative importance of various constituents may be identified. Such information m i g h t be useful in a selection p r o g r a m involving desi x kabuli crosses. Preliminary analysis carried out in our laboratory on five desi- and five kabuli-type chickpea samples revealed striking differences in fat and fiber contents of these t w o types (ICRISAT 1977). We are reporting herein the chemical c o m p o s i t i o n of a rather limited number of cultivars of desi and kabuli types g r o w n in t w o locations.
Materials and Methods Seeds of eight desi and seven kabuli cultivars g r o w n at ICRISAT Center (17°N) and at Hissar (29°N) during the rabi (postrainy) season of 1977-78 were obtained by pooling seeds f r o m single plots and w e r e received f r o m our chickpea breeding section. Whole-seed samples for analysis were g r o u n d dry. Dhal (decorticated split seeds) samples w e r e prepared by soaking w h o l e seeds in an excess of distilled water and storing t h e m at 5°C overnight. After decanting the excess water, seed coats w e r e removed by forceps and samples w e r e air dried. Air-dried samples of w h o l e seed, dhal, and seed coat were ground in a Udy cyclone mill to pass t h r o u g h a 6 0 - m e s h sieve, and the g r o u n d materials were stored in a l u m i n i u m containers w i t h tight-fitting caps. * Principal Biochemist and Biochemist, respectively, ICRISAT.
Portions of the material were oven dried to determine moisture content, and appropriate corrections were made to express results on a moisture-free basis. Crude protein was estimated by multiplying the nitrogen content, determined by the standard micro-Kjeldahl procedure, by a factor of 6.25; fat, ash, and crude fiber were estimated f o l l o w i n g the standard AOAC procedures (Association of Analytical Chemists 1975). Soluble sugars were extracted f r o m the defatted materials w i t h hot ethanol (80%) and were estimated by the phenol-sulphuric acid method (Dubois et al. 1956). Starch was determined using the enzyme glucoamylase (Sigma Chemical Co., USA); the procedure (Thivend et al. 1972) was slightly modified as follows. The sample (75 mg) was placed in a conical flask, and a few drops of ethanol and 10 ml of distilled water were added. After heating the suspension on a water bath for 10 minutes, the suspension was autoclaved at 19 lb pressure (125°C) for 90 minutes. The suspension was cooled; 1 ml of acetate buffer (2 M, pH 4.8) was added, followed by 25 mg glucoamylase enzyme (3460 units/g); and the final v o l u m e was made up to 25 m l . Then the flask was incubated in a water bath at 55°C w i t h continuous mild shaking for 2 hours. The glucose thus liberated was estimated as described by Dubois et al. (1956). Starch content was calculated by multiplying the glucose content by a factor of 0.9.
Results and Discussion Mean values of all constituents are presented in Table 1. To make the data availableto interested scientists, results of proximate analysis of samples of each of the eight desi and seven kabuli cultivars that were g r o w n at ICRISAT Center and Hissar are presented in Tables 2-5.
61
Table
1.
Mean
v a l u e s off c o n s t i t u e n t s o f d e s i a n d k a b u l i c h i c k p e a c u l t l v a r s , 1 9 7 7 - 7 8 . W h o l e seed
Protein (%) Kabuli Desi Starch (%) Kabuli Desi Sugars (%) Kabuli Desi Fiber (%) Kabuli Desi Fat (%) Kabuli Desi A s h (%) Kabuli Desi 100-seed w e i g h t (g) Kabuli Desi Seed coat (%) Kabuli Desi Seed coat N (%) Kabuli Desi
Dhal
ICRISAT Center
Hissar
ICRISAT Center
Hissar
22.4 22.0
24.0 22.4
24.0 25.9
25.0 26.8
49.2 45.6
48.6 43.7
56.0 56.3
55.6 54.4
6.1 5.3
6.1 5.4
5.2 4.6
5.4 5.2
2.7 8.4
3.2 9.2
1.0 1.1
1.2 1.1
5.4 4.6
4.7 4.1
6.0 5.8
5.3 4.8
3.1 3.4
3.2 3.3
3.1 2.7
3.1 2.9
23.4 18.1
22.7 17.6
ND ND
ND ND
6.4 16.2
7.1 16.0
ND ND
ND ND
ND ND
ND ND
0.86 0.46
0.95 0.59
N D = N o data.
Protein Content The mean protein content of whole-seed samples of desi and kabuli cultivars f r o m both locations did not differ m u c h , w h i l e dhal samples of desi cultivars had a slightly higher protein content than did the kabuli dhal samples. Mean protein values of desi dhal samples w e r e about 4.2 units higher in comparison to whole-seed mean protein values, w h i l e the mean protein difference between kabuli w h o l e seed and dhal samples w a s less than 2 units (Table 1).
Starch Content and Soluble Sugars Usually, starch values of grain samples are
62
reported by subtracting all values, except that of starch, f r o m a total of 100 and then assuming that the difference in values represents the total starch content in the sample. Earlier workers have used either the difference m e t h o d to calculate the starch content (Verma et al. 1964; Meiners et al. 1976) or have determined the starch content alone w i t h o u t analyzing for other constituents (Srinivasa 1976). To our knowledge, this is the first t i m e that the starch values have been chemically determined in addition to other constituents on desi and kabuli chickpea samples g r o w n in t w o locations. W h e n t h e mean starch values of samples f r o m the same location w e r e compared, the desi whole-seed sample values w e r e 4 to 5 percentage units lower tha n t h e kabuli w h o l e seed samples, w h i l e no such difference seemed
Table 2.
Cultivar (desi) USA-613 850-3/27 Pant G-114 CPS-1 T-3 Annigeri BG-203 P-5462 Mean
a. b. c. d.
P r o x i m a t e a n a l y s i s o f c h i c k p e a (desi) w h o l e - s e e d s a m p l e s g r o w n I n t w o l o c a t i o n s a , 1977-78. Protein c Starch Sugars Fiber Location6 HY Hl HY HI HY HI HY HI HY HI HY HI HY HI HY HI HY HI
(%)d
(%)
(%)d
Fat (%)d
Ash
(%)d
(%)
100-seed Seed coat Total weight (g) (%)
24.0 22.8 20.4 22.8 23.1 24.0 25.9 23.8 23.3 21.5 17.7 22.1 20.6 21.9 20.7 20.2 22.0 22.4
44.6 43.1 49.3 44.9 41.0 42.0 43.7 40.8 46.8 46.2 50.8 44.0 42.6 44.4 45.9 44.4 45.6 43.7
5.3 5.2 5.4 5.6 4.9 5.3 5.3 5.4 5.5 5.5 5.8 5.5 5.3 5.1 4.8 5.2 5.3 5.4
7.9 9.6 4.9 7.1 10.7 9.6 8.8 9.7 7.4 8.2 8.0 9.6 10.2 8.9 9.3 10.8 8.4 9.2
4.0 3.9 5.0 4.4 3.8 3.1 4.7 5.0 5.1 4.6 5.8 4.4 3.9 3.6 4.3 3.8 4.6 4.1
3.6 3.3 3.7 3.7 3.8 4.2 2.9 2.9 3.3 3.1 3.3 3.0 3.7 2.9 2.9 3.2 3.4 3.3
89.4 87.9 88.7 88.5 87.3 88.2 91.3 87.6 91.4 89.1 91.4 88.6 86.3 86.8 87.9 87.6 89.2 88.0
16.8 16.9 25.3 28.4 14.1 11.5 18.5 17.2 21.7 20.6 19.4 18.5 10.6 12.6 18.7 15.2 18.1 17.6
15.6 17.6 13.7 12.8 17.9 17.3 15.4 16.9 13.1 13.9 16.3 16.2 19.4 16.8 17.9 16.7 16.2 16.0
Seed coat N(%)d 0.44 0.55 0.50 0.58 0.43 0.51 0.43 0.64 0.48 0.64 0.52 0.78 0.48 0.45 0.46 0.59 0.46 0.59
M o i s t u r e - f r e e basis. HY = ICRISAT Center, H y d e r a b a d ; HI = Hissar. N x 6.25. A v e r a g e of t w o d e t e r m i n a t i o n s .
Table 3.
Cultivar (kabuli) K-4 C-104 Rabat L-550 GL-629 Giza No. 501 Mean
P r o x i m a t e analysis o f c h i c k p e a ( k a b u l l ) w h o l e - s e e d s a m p l e s g r o w n I n t w o locations a , 1977-78.
Location b HY HI HY HI HY HI HY HI HY HI HY HI HY HI HY HI
Protein c Starch Sugars Fiber (%) d (%) (%)d (%)d 20.7 22.9 21.5 24.8 21.6 24.0 22.1 21.7 24.1 23.8 24.3 25.6 22.8 25.0 22.4 24.0
50.8 48.7 48.6 47.3 49.4 49.9 49.8 51.1 48.8 49.2 47.6 45.7 49.6 48.2 49.2 48.6
6.3 5.9 6.2 5.8 6.3 6.1 6.4 6.2 5.9 6.1 5.9 6.4 5.8 6.0 6.1 6.1
3.5 3.8 2.3 2.6 2.5 2.8 2.4 2.9 2.3 2.9 3.8 4.7 2.2 2.7 2.7 3.2
Fat (%)d
Ash (%)
100-seed Total w e i g h t (g)
4.5 4.1 6.4 5.3 5.6 4.5 4.6 4.8 5.8 4.8 5.2 4.3 5.4 4.8 5.4 4.7
2.7 3.1 2.8 2.9 2.5 3.2 4.3 3.1 3.1 3.1 3.1 3.6 3.3 3.5 3.1 3.2
88.5 88.5 87.8 88.7 87.9 90.5 89.6 89.8 90.0 89.9 89.9 90.3 89.1 90.2 89.0 89.7
21.7 20.0 24.5 25.8 27.8 23.4 19.0 22.3 20.7 20.1 16.2 15.8 33.6 31.7 23.4 22.7
(%)
Seed coat N(%) d
6.7 8.3 6.2 6.0 5.9 6.7 7.1 5.7 5.8 6.1 7.8 8.2 5.2 8.8 6.4 7.1
0.80 1.04 0.89 0.52 0.86 1.26 1.05 0.98 0.89 1.01 0.70 0.82 0.85 0.99 0.86 0.95
Seed coat
a. M o i s t u r e - f r e e basis. b. HY = ICRISAT Center, H y d e r a b a d ; HI = Hissar. c. N x 6.25. d. A v e r a g e of t w o d e t e r m i n a t i o n s .
63
Table 4. Cultivar (desi) USA-613 850-3/27 Pant G-114 CPS-1 T-3 Annigeri BG-203 P-5462 Mean
a. b. c. d.
P r o x i m a t e a n a l y s i s o f c h i c k p e a (desi) d h a i s a m p l e s g r o w n i n t w o l o c a t i o n s , a 1 9 7 7 - 7 8 . Protein c
Starch
Sugars
Fiber
Fat
Ash
Location b
(%) d
(%)
(%)
(%)
(%)
(%)
Total
HY HI HY HI HY HI HY HI HY HI HY HI HY HI HY HI HY HI
28.3 27.7 24.0 28.0 29.6 30.5 27.4 26.9 25.3 23.8 20.6 24.7 25.2 27.1 26.8 25.3 25.9 26.8
54.9 54.6 56.3 52.7 56.0 51.1 55.8 54.6 55.9 55.1 58.1 54.9 55.7 56.2 57.8 56.2 56.3 54.4
4.8 5.0 4.4 5.6 4.3 5.4 4.3 4.7 4.6 5.0 5.4 6.0 4.9 4.9 4.1 5.3 4.6 5.2
1.0 1.2 1.2 1.1 1.1 1.1 1.0 1.1 1.1 1.2 1.1 1.3 1.0 1.1 0.9 0.7 1.1 1.1
5.0 4.2 6.1 4.8 5.3 3.5 6.7 5.5 5.8 6.2 7.5 5.4 4.8 4.5 5.5 4.3 5.8 4.8
2.7 2.5 2.9 2.9 2.6 3.1 2.1 2.8 2.6 2.8 2.5 2.8 3.3 3.3 3.0 3.1 2.7 2.9
96.7 95.2 94.9 95.1 98.9 94.7 97.3 95.6 95.3 94.1 95.2 95.1 94.9 97.1 98.1 94.9 96.4 95.2
M o i s t u r e - f r e e basis. HY = ICRISAT Center, H y d e r a b a d ; HI = Hissar. N x 6.25. Average of t w o determinations.
Table 6. Cultivar (kabuli) K-4 C-104 Rabat L-550 GL-629 Giza No. 501 Mean
P r o x i m a t e analysis of chickpea (kabuli) dhai samples g r o w n in t w o locations,a 1 9 7 7 — 7 8 . Protein c
Starch
Sugars
Fiber
Location b
(%) d
(%)
(%)
(%)
HY Hl HY Hi HY Hi HY Hl HY HI HY HI HY HI HY HI
23.1 24.4 24.4 27.8 22.3 24.7 22.6 22.1 25.1 23.8 26.7 26.6 24.5 26.7 24.0 25.0
56.8 55.7 55.2 55.7 57.4 56.0 58.1 57.0 55.2 54.1 54.3 53.5 54.9 57.5 56.0 55.6
5.3 5.4 5.5 5.0 5.3 5.6 5.2 6.0 4.8 5.5 4.8 5.5 5.2 5.0 5.2 5.4
1.0 1.2 1.1 1.2 1.0 1.2 1.1 1.2 1.0 1.2 1.0 1.2 1.0 1.1 1.0 1.2
a. M o i s t u r e - f r e e basis. b. HY = ICRISAT Center, H y d e r a b a d ; HI = Hlssar. c. N x 6.25. d. A v e r a g e of t w o d e t e r m i n a t i o n s .
64
Fat
5.8 5.2 6.8 5.8 5.8 4.9 4.8 5.8 6.2 5.8 6.1 4.6 6.1 5.4 6.0 5.3
Ash (%)
Total
2.7 2.8 3.2 2.9 3.2 3.4 3.3 3.2 3.7 3.1 2.7 3.1 3.0 3.0 3.1 3.1
94.7 94.7 96.2 98.4 95.0 95.8 95.1 95.3 96.0 93.5 95.6 94.5 94.7 98.7 95.3 95.8
to exist between mean starch values of the desi and kabuli dhal samples (Table 1). Pure starch was used as a check in the starch-estimation m e t h o d . Recovery studies were carried out by adding starch to the cultivar 859-3/27 and a mean recovery value of 99.2% was obtained. Mean soluble sugar values were slightly higher in the whole-seed kabuli types w h e n compared w i t h desi types f r o m either location (Table 1).
Fat, Fiber, and Ash Contents Although we observed marked differences in the fat content of desi and kabuli cultivars earlier (ICRISAT 1977), in the present study there was an overlap in the fat contents of these different types (Tables 2 - 5 ) . A clear distinction between desi and kabuli types was observed in fiber contents of w h o l e seeds (Table 1). The mean value of fiber content of whole-seed samples of desi f r o m both locations was 8.8% (range 4.9-10.8%) w h i l e that of kabuli was 3.0% (range 2.2-4.7%). Mean values of ash content of kabuli w h o l e seed and dhal did not differ in desi types; ash content was slightly lower in dhal samples.
Seed Weight and Seed Coat Content The 100-seed w e i g h t of desi whole-seed samples f r o m both locations varied f r o m 10.6 to 28.4 g (mean 17.9 g), while for kabuli it varied f r o m 15.8 to 33.6 g (mean 23.1 g). A l t h o u g h kabuli chickpea cultivars are often described as generally having larger seeds than desi cultivars, there was considerable overlap in the cultivars studied (Tables 2, 3). A striking difference between the desi and kabuli cultivars was the percentage of seed coat. Desi types ranged f r o m 12.8 to 19.4 w i t h a mean of 1 6 . 1 % , w h i l e kabuli types ranged f r o m 5.2 to 8.8% w i t h a mean of 6.8% seed coat. A l t h o u g h the 100-seed weights of s o m e of the desi and kabuli cultivars were similar, the seed coat percentage of these cultivars s h o w remarkable differences (Tables 2, 3). For example, the 100-seed weights of cv Giza from the t w o locations were 16.2 and 15.8 g and
their seed coat percentages 7.8 and 8.2, respectively. W h e n these values were compared w i t h the desi chickpea cv USA-613, it was observed that although the 100-seed weights f r o m both locations were 16.8 and 16.9 g, the seed coat percentages were 15.6 and 17.6%, respectively — a l m o s t twice the amount present in kabuli cultivars of similar weight. Thus, the quantitative difference in seed coat appeared to be consistent and real. The nitrogen content of seed coat of kabuli cultivars ranged f r o m 0.70 to 1.26% (mean of 0.90%); that of desi cultivars ranged f r o m 0.43 to 0.78% (mean of 0.53%).
T o t a l of all t h e C o n s t i t u e n t s In desi whole-seed samples, the range of the total constituents varied f r o m 86.3 to 91.4, with a mean of 88.6%. For kabuli whole-seed samples, the range was f r o m 87.8 to 90.5, and the mean was 89.4%. Total constituents when added up in the case of desi dhal samples varied f r o m 94.1 to 98.9, with a mean of 95.8% and for kabuli samples, the range was f r o m 93.5 to 98.7, w i t h a mean of 95.5%. We believe that one reason for the lower recovery of whole-seed samples might be due to the dilution effect of seed coat in the estimation of starch and other constituents. Another reason could be the method employed for the estimation of crude fiber. Acid detergent fiber and neutral detergent fiber methods w o u l d give us a better idea of the amount of hemicellulose, cellulose, and lignin content of chickpea, and perhaps could provide an explanation for the lower recovery reported in this paper. Starch values of desi and kabuli dhal samples did not show any appreciable difference, while the starch content of desi and kabuli whole-seed samples exhibited greater differences (Table 1). Differences in other constituents tend to disappear as well in dhal samples of desi and kabuli types. This is another indication of possible seed-coat influence in the chemical estimation of constituents. Preliminary analysis carried out on t w o samples revealed that the seed coat of desi and kabuli contained 11 and 15% of carbohydrate material, respectively, as determined by the glucoamylase method. Further work is in progress.
65
Influence of Seed Coat on Dhal Recovery It is estimated that only about 1 0 - 1 5 % of the total w o r l d production is of the kabuli types. Most of the desi chickpea is processed into dhal for h u m a n c o n s u m p t i o n . Therefore, our f i n d ings are relevant because seed coats are lost d u r i n g processing and a higher percentage of seed-coat reduces the yield of dhal. This can be o v e r c o m e by breeding for desi-type varieties that have higher seed weight or lower seed coat percentage, as we observed a negative and significant correlation between seed w e i g h t and seed coat percentage. Not only does this strategy increase the effective yield of d h a l , but also it increases the fat and starch contents, w h i c h provide the bulk of the energy in the diet. The objective of this study was to f i n d out th e chemical c o m p o s i t i o n of desi and kabuli cultivars. A l t h o u g h samples w e r e obtained f r o m t w o locations, the experiment was not designed to p r o v i d e i n f o r m a t i o n on genotype and environment interaction. Samples are fro m single plots at the t w o locations, so statistical analysis for relative effects of genotypes and environment is not possible. A s i m p l e w a y to evaluate these effects is to use the data presented in Table 1. Differences between locations can be obtained by subtracting the results obtained f r o m each location s h o w n in t h e c o l u m n s , w h i l e t h e differences between kabuli and desi types can be obtained by subtracting the values across the table. In w h o l e seed, genetic differences appeared to be m o r e i m p o r t a n t than e n v i r o n m e n t a l effects for starch, sugars, fiber, 100-seed weight, seed coat percentage, and seed coat nitrogen contents. In d h a l , genetic differences w i t h the possible exception of protein w e r e not important.
Conclusion
cultivars. It w o u l d be desirable to m o n i t o r the seed-coat content of desi types and breed f o r varieties having lower seed-coat percentage.
Acknowledgments We thank Miss. R. Seetha and Mr. A. Laxma Reddy for technical assistance and Dr. Jagdish Kumar for the supply of chickpea samples. We are grateful to Dr. J o h n M. Green and G. D. Bengtson for c o m m e n t s on earlier drafts.
References AOAC (Association of Analytical Chemists). 1975. Official m e t h o d s of Analysis (12th ed). The Associat i o n , W a s h i n g t o n , D.C. D U B O I S , M., G I L E S . , K. A., H A M I L T O N , J. K., R EBERS, P. A,
and S M I T H , F. 1956. Colorimetric m e t h o d for determ i n a t i o n of sugars a n d related substances. A n a l y t i cal Chemistry 28: 350. ICRISAT (International Crops Research Institute for the Semi-Arid Tropics). 1977. Page 111 in ICRISAT A n n u a l Report, 1 9 7 6 - 7 7 , H y d e r a b a d , India. M E I N E R S , C. R., DERISE, N. L., L A U , H. C., and M U R P H Y ,
E. W. 1976. Proximate c o m p o s i t i o n a n d y i e l d of r a w and cooked m a t u r e d r y legumes. J o u r n a l o f A g r i c u l tural and Food Chemistry 24: 1122. S R I N I V A S A R A O , P. 1976. Nature of carbohydrates in pulses. J o u r n a l of A g r i c u l t u r a l a n d Food Chemistry 24: 958. THIVEND,
VERMA,
Of the constituents analyzed, percentage of seed-coat and fiber can be considered as the only t w o constituents that coul d be used to distinguish t h e d e s i and kabuli types of chickpea
66
P.,
CHRISTIANE,
M.,
and
GUILOD,
A.
1972.
D e t e r m i n a t i o n of starch w i t h g l u c o a m y l a s e . Page 105 in R. L. W h i s t l e r and J. N. BeMiller (Eds.), M e t h o d s in Carbohydrate Chemistry, V o l . VI. A c a d e m i c Press, N.Y. S.
C.,
LAL,
B.
M.,
and
V E D PRAKASH.
1964.
Changes in the chemical c o m p o s i t i o n of t h e seed parts d u r i n g ripening of Bengal g r a m (Cicer arietinum L.) seed. J o u r n a l of t h e Science of Food and A g r i c u l t u r e 15: 25.
Disease Resistance in Kabuli-Desi Chickpea Introgression M. P. Haware, Jagdish Kumar, and M. V. Reddy*
Experience in transferring disease resistance f r o m desi to kabuli chickpeas and vice versa has been very limited to date. A n o t h e r paper (Nene) in this w o r k s h o p covers the general situation on chickpea diseases, so in discussing our w o r k on resistance to w i l t (Fusarium oxysporum f sp ciceri) and other diseases, we will give particular reference to kabuli-desi introgression. The major problems in chickpea are w i l t (F. oxysporum f sp ciceri), dry root rot (Rhizoctonia bataticola), stunt (virus), Ascochyta blight, and root/collar rots. W h i l e w i l t and root rots are reported f r o m most chickpea-growing c o u n tries, Ascochyta blight is mostly confined to areas w i t h l o w temperatures and high h u m i d i t y d u r i n g the g r o w i n g season. In Ethiopia, w h e r e chickpea is s o w n in July and August, it is caught by Ascochyta blight. Desi and kabuli types alike are attacked. Sept e m b e r sowings escape the blight. The situation is different for wilt and root rots, w h i c h may take their toll t h r o u g h o u t the season. In India, blight is only occasionally a p r o b l e m ; w i l t is m o s t serious and appears in most areas t h r o u g h o u t the g r o w i n g season. We are screening for disease resistance in the desi and kabuli types of chickpea. Most of the kabuli chickpeas are highly susceptible to major chickpea diseases. Most of our resistant sources are desi types.
Wilt Sources of Resistance So far, m o r e than 6000 g e r m p l a s m accessions have been screened in the wilt-sick plot at ICRISAT Center and 118 appear to be p r o m i s i n g for w i l t resistance. Many of these lines have * Pulse Pathologists and Chickpea Breeder, respectively, ICRISAT.
been included in t h e second International Chickpea Root Rots/Wilt Nursery.
Breeding Material Screened The wilt-sick plot first became available in the 1977 planting season, and we planted F 2 to F 4 breeding material, w h i c h involved one or m o r e wilt-resistant parents and all F 5 to F 7 generation progenies (Table 1). JG-62, the susceptible check, was planted on every third ridge and showed almost c o m p l e t e and u n i f o r m mortality because of wilt. Inoculum obviously was pres e n t t h r o u g h o u t t h e plot. Initial stand w a s t a k e n , and wilted plant counts were taken at 20-day intervals. Desi and kabuli selections are listed in Table 1; recovery of kabuli segregants was very low.
Evidence on Inheritance of Wilt Resistance Not m u c h w o r k has been done on the inheritance of Fusarium w i l t resistance in chickpea. We could f i n d only four reports, all of w h i c h indicate simple inheritance for resistance to this disease. Ayyar and Iyer (1936) reported one gene pair w i t h incomplete dominance responsible for resistance. Lopez (1974) presented data to s h o w that resistance was governed by one or t w o pairs of genes and susceptibility was dominant. Pathak et al. (1975) and Tiwari et al. (1978) showed that resistance was governed by one single recessive gene. These studies w e r e d o n e under field conditions. We also have similar results f r o m the wilt-sick plot in several single crosses, and results for those involving desi x kabuli parents are listed in Table 2. Since these studies w e r e conducted in t h e f i e l d , w h e r e other pathogens cause mortality, the results are to be considered w i t h caution. In wilt-sick pots we g r e w F 1 s and parents of
67
crosses of h i g h l y susceptible cv JG-62 w i t h putative resistant lines. The F 1 s and JG-62 died w i t h i n 21 days after s o w i n g . The resistant parents CPS-1 and WR-315 w e r e free f r o m disease. In wilt-sick pots we g r e w F 3 progeny of resistant segregants (selected in the wilt-sick plot) f r o m a f e w crosses. All progenies of kabuli types and s o m e f r o m t h e desi types w i l t e d completely. The r e m a i n i n g desi t y p e progenies showed segregation. Even if we consider those that w i l t e d completely as escapes in the wiltsick plot, segregation for w i l t in the progency of resistant F 2 plants cannot be explained on the basis of a single recessive gene for resistance. One p r o b l e m in such studies is that plants f r o m a resistant parent can also get w i l t e d as was s h o w n in flax wilt ( K o m m e d a h l et al. 1970), and d r a w i n g conclusions becomes difficult. The reasons for such w i l t i n g are not apparent. We are presently g r o w i n g parents, F 1 s, F2s, and F 3 single-plant progenies of a f e w crosses to study the inheritance in detail.
Stunt Screening f o r stunt resistance is d o n e at Hissar under natural conditions. To date, no resistant kabuli has been f o u n d . A n u m b e r of p r o m i s i n g lines have been identified a m o n g desis. Since t h e resistance of ICC-3735 is almost c o n f i r m e d , it w i l l be included in desi-kabuli introgression for stunt resistance.
Table
1.
Ascochyta
Blight
Sources of Resistance M o r e t h a n 3500 g e r m p l a s m accessions have been screened in isolation plant propagators at ICRISAT. The disease reaction was rated 1-9, with 9 most susceptible. Only 18 lines rated as l o w as 3. S o m e of these are included in the International Chickpea Ascochyta Blight Nursery. Five desi types included in ICABN, i.e., ICC-4935 (C-235), -5127 (F-8), -7513 (12-071-05132), -7514 (12-071-05093), and -7520 (12-071-10054) w e r e
Table 2.
Percentage of plants wilted in desi x k a b u l i F2 p o p u l a t i o n s involving one resistant parent, ICRISAT Center, 1977. Total plants Plants w i l t e d (no.) (%)
Pedigree P-36 x x x x x x x x
Lebanese local NEC-141 Ofra NEC-139 NEC-108 L-534 Giza P-9623
WR-315
x GL-651 x Bet Degan-302
470 473 466 462 472 421 469 491
70 72 72 70 76 78 82 85
441 489
83 77
F 2 -F 7 b r e a d i n g m a t e r i a l g r o w n a n d t e n t a t i v e l y s e l e c t e d i n t h e w i l t - s i c k p l o t , I C R I S A T Center, 1977. N o . of plants selected
Generation
Total
F2 p o p u l a t i o n s S i n g l e Cross M u l t i p l e Cross F 3 progenies F 4 progenies F 5 progenies a F 6 progenies F 7 progenies
62 47 371 417 750 1173 280
Desi
x Kabuli
11 23 190 209 148 221 40
Desi
Kabuli
2694
83
317 548 687 620
30 50 26 59 5
a. in F 5 , F 6 , a n d F 7 g e n e r a t i o n s , t h r e e , n i n e , a n d o n e p r o g e n i e s , respectively, w e r e f r o m kabuli x k a b u l i - t y p e crosses.
68
f o u n d resistant to blight, b o t h at Tel Hadia and Latakia, (K. B. S i n g h , ICARDA, personal c o m m u n i c a t i o n ) . We h a v e three F 1 crosses a n d t e n
inheritance of Ascochyta b l i g h t resistance in chickpea (Cicer arietinurn L.). Ankara Univ. A g r i c u l t u r a l Faculty, Turkey 620: 40 pp.
F2 p o p u l a t i o n s i n v o l v i n g these and kabuli parents available, and t h e y w i l l be screened f o r blight
Ascochyta
resistance
at
ICARDA
next
year.
HAFIZ,
A,
and
ASHRAF,
M.
1953.
Studies
on
inheritance of resistance to Mycosphaerella cochyta) b l i g h t in g r a m . P h y t o p a t h o l o g y 4 3 : 581.
the
(As580-
K O M M E D A H L , T., C H R I S T E N S E N , J. J . , and FREDERIKSEN,
Inheritance of Resistance Three studies (Hafiz and Ashraf 1953; Vir et al. 1975; Eser 1976) on t h e inheritance of Ascochyta
R. S. 1970. A half century of research in M i n n e s o t a on flax w i l t caused by Fusarium oxysporum. Tech. Bull. 273. A g r i . Expt. Sta., U n i v . M i n n e s o t a , 36 p p .
blight resistance all report t h a t o n e d o m i n a n t gene was
responsible f o r
resistance
in
the
materials s t u d i e d . W e are c u r r e n t l y a t t e m p t i n g crosses
betweenAscochyta
blight-resistant and
susceptible parents of b o t h desi and types.
These studies w i l l
kabuli
be undertaken
at
ICARDA.
References A Y Y A R , V. R., and IYER, R. B. 1936. A preliminary note on t h e m o d e of inheritance of reaction to w i l t in Cicer arietinum. Proceedings of Indian A c a d e m y of Sciences 3: 4 3 8 - 4 4 3 .
LOPEZ GARCIA, H. 1974. Inheritance of the character resistance to w i l t (Fusarium sp) in chickpea (Cicer arietinurn) under field c o n d i t i o n s (in Spanish). A g ricultura Tecnica M e x . 3: 2 8 6 - 2 8 9 . PATHAK,
M.
M.,
SINGH,
K.
P.,
and
LAL,
S.
B.
1975.
Inheritance of resistance to w i l t (Fusarium oxysporum f ciceri) in g r a m . Indian J o u r n a l of Farm Science 3 : 1 0 - 1 1 . TIWARI,
A.
S.,
PANDEY,
R.
L.,
MISHRA,
P.
K.,
and
K O T A S T H A N E , S. R. 1978. Studies on w i l t inheritance in g r a m (Cicer arietinurn L ) . Paper in All India Rabi Pulse W o r k s h o p , 3 - 6 Oct 1978, B h u b a n e s h w a r , India. V I R , S., G R E W A L , J. S., and G U P T A , V. P. 1975. Inheri-
ESER, D. 1976. Heritability of s o m e i m p o r t a n t plant characters, their relationship w i t h plant y i e l d a n d
tance of resistance to Ascochyta blight in chickpea. Euphytica 24: 2 0 9 - 2 1 1 .
69
Kabuli-Desi Introgression: The Experience in Australia E. J. Knights*
Production of w i n t e r crops in Australia occurs m o s t l y in t h e t e m p e r a t e zones between latitudes 27° and 37°S. In this region, w h e r e climate varies f r o m t r u e Mediterranean t o h u m i d m e s o t h e r m a l w i t h m o r e or less evenly distributed rainfall, wheat and other w i n t e r cereals have traditionally been t h e mainstays of agriculture. However, t h e t e m p o r a r y i m p o s i t i o n of w h e a t p r o d u c t i o n controls in 1969 has led to a gradual diversification in c r o p p i n g enterprises. Grain legumes a r e o n e group of crops gaining acceptance as a useful part of farm rotations. In these rotations a l e g u m i n o u s pasture ley of 3 - 5 years is f o l l o w e d by an exploitative phase of cereal c r o p p i n g . The length of the croppin g phase is partly d e t e r m i n e d by the rate of deplet i o n of soil nitrogen. Recently, alkaloid-free varieties of narrow-leafed lupins (Lupinus angustifolius) have been used to extend this phase. Lupins are well adapted to the higher rainfall parts of the Australian wheatbelt. However, no grain l e g u m e is currently available for t h e drier areas w h e r e severe m o i s t u r e and t e m p e r a t u r e stress normally occurs for at least part of the reproductive phase. It was recognized that chickpea w a s theoretically suited to this env i r o n m e n t , and work on the d e v e l o p m e n t of the crop c o m m e n c e d in 1972. The f u t u r e availability of adapted chickpea varieties w i l l offer farmers in t h e drier wheatbelt areas a source of nitrogen for subsequent cereal crops. The grain could be used on the f a r m as a feed reserve in t i m e s of drought. Alternatively, it could be sold as a cash crop for use in stockfeed f o r m u l a t i o n s , either locally or on export markets.
Chickpea Breeding in Australia A l t h o u g h m a n y centers t h r o u g h o u t Australia are currently undertaking research into chickpea (Corbin 1975), the only breeding p r o g r a m is being conducted by the N e w South Wales Department of A g r i c u l t u re at Wagga Wagga. Initially, t h e pedigree m e t h o d of breeding was used, and this p r o g r a m has n o w been advanced to the F 3 stage. Recently, s o m e emphasis has shifted to the use of a m o d i f i e d f o r m of singleseed descent w i t h field evaluation of r a n d o m h o m o z y g o u s lines. The aims of the breeding p r o g r a m are t w o f o l d . Highest priority is given to the dev e l o p m e n t of small-seeded, high-yielding " s t o c k f e e d " varieties tall enough to p e r m i t mechanical harvesting. The preferred seed type is kabuli. Culinary types are presently i m p o r t e d into Australia to service a small but increasing market. The second objective of the Wagga program is to breed high-yielding, lodging-resistant culinary varieties. In this case, the seed t y p e must be kabuli.
Seed Type Classification From observation of g e r m p l a s m collections and segregation studies, three general seed types are proposed — pea, desi, and kabuli.
Description and Characteristics Pea
* Research A g r o n o m i s t , A g r i c u l t u r a l Research Instit u t e , W a g g a W a g g a , N e w S o u t h W a l e s , Australia.
70
This t y p e is nearly spherical except for the characteristic chickpea beak. A very loose
adherence of t h e seed coat to cotyledons predisposes it to severe seed damage. Presumably this t y p e has consistently been rejected d u r i n g domestication and i m p r o v e m e n t .
Desi A wrinkled surface and irregular shape differentiate this type. The seed coat is thick w i t h a generally tight adherence to the cotyledons.
harvest is generally slight. The reduced seed coat c o m p o n e n t is reflected by a considerably lower fiber content than that of desi seeds. A compensatory increase in the level of carbohydrate and possibly protein is expected. Seed weights and percentage seed coat, fiber (acid determined) and crude protein values for desi and kabuli types are presented in Tables 1 and 2.
Desi x Kabuli Crosses Kabuli This is a more rounded type than desi, w i t h a less w r i n k l e d surface. In m a n y ways it appears to be intermediate between t h e pea and desi types. The seed coat is very t h i n , yet it adheres well to the cotyledons, and seed d a m a g e d u r i n g
Table
1.
The breeding p r o g r a m at W a g g a has m a d e use of single, three-way, and d o u b l e crosses, both w i t h i n and between desi and kabuli groups. Mean success rates for the three cross t y p e s — desi x desi, desi x kabuli (and reciprocal), and kabuli x k a b u l i — a r e presented in Table 3.
Seed w e i g h t s and percentages of seed coat and fiber of desi and kabuli cultivars at Wagga Wagga, 1977.
Line/Variety
Seed t y p e
(g)
Seed Coat (%)
Fiber (%)
CPI 56296-b K1184 C235 NP53
Kabuli Kabuli Desi Desi
14.1 20.2 10.4 11.6
7.4 5.8 19.7 19.9
5.6 5.3 17.4 17.4
100-seed w e i g h t
Table 2.
Crude protein percentages (%N
x 6 . 2 5 ) o f desi a n d k a b u l i c u l t i v a r s . Location and year
Seed t y p e
Condobolin (1974)
Condobolin (1976)
Temora (1976)
Wagga (1976)
25.87 26.40
20.81 21.60
24.45 25.08
21.83 22.53
Desi Kabuli
Table 3.
Cross-success rates. % Success rate ( w i t h o u t ) e m a s c u l a t i o n
Cross t y p e
1977
1978
Desi x desi Desi x kabuli (and reciprocal) Kabuli x kabuli
48.1 34.2 23.1
82.0 75.0 insufficient crosses f o r reliable f i g u r e .
71
It can be seen f r o m the data that no apparent barriers to hybridization existed between the desi and kabuli genotypes u s e d ; however, in order to maximize the recovery to F 1 seeds f r o m desi x kabuli crosses, desi types should be used as t h e f e m a l e parent.
Inheritance of Seed Type The d o m i n a n c e relationships are: pea d o m i n ant to both desi and kabuli; and desi d o m i n a n t to kabuli. The F 2 segregations f r o m desi x kabuli crosses generally produce up to five classes—pea, desi, kabuli, and the t w o intermediate f o r m s , pea-desi and pea-kabuli. Frequencies of these classes are variable and dependent on the parental lines used. In the F 2 generation, recovery of desi types has ranged f r o m 2.3 to 53.3% and that of kabuli types f r o m 0 to 9.8%. W i t h continued inbreeding, there is further segregation of desi and kabuli f r o m pea and intermediate types. Conversely, a lower frequency of desi and kabuli lines revert to pea or intermediate types. Generally, there is a net increase of desi and kabuli segregants w i t h i n b r e e d i n g , w i t h desi being n u m e r i c a l l y superior. The small n u m b e r of segregation classes suggests that seed t y p e is under the control of only a f e w major genes; however, the variable frequencies of segregation classes, together w i t h the instability of desi and kabuli types in early generations, indicate epistasis.
Table 4.
Breeding Strategies Stockfeed Varieties The aim of incorporating a kabuli-type seed into " s t o c k f e e d " chickpea varieties has already been stated. Kabuli seeds have a fiber content of approximately 5 - 6 % c o m p a r e d t o 1 7 - 1 8 % for desi seeds. For monogastric animals at least, a higher energy value of kabuli seeds is implied. This, together w i t h the possibility of a small increase in protein content, is the reason for inclusion of kabuli types in selected progeny. Nearly all kabuli lines have w h i t e seeds. These lines are generally susceptible to preemergence d a m p i n g off, and surviving plants are not as v i g o r o u s as those of colored desi lines. A relationship between seed color and establishment has been recorded in Phaseolus vulgaris (Deakin 1974; Ma and Bliss 1978),P. lunatus (Kannenberg and Allard 1964), and Pisum sativum (Muehlbauer and Kraft 1978). A similar relationship in chickpea is evident f r o m Table 4. It is interesting to note that CPI 56296-b, a kabuli line w i t h light b r o w n seed, had an establishment s i m i l a r t o t h a t of the colored desi lines. W h i l e seed color (or the chemical factors responsible for or linked to it) is clearly related to establishment, sufficient data are not available to associate reduced establishment w i t h kabuli seed type. Accordingly, s o m e kabuli lines have been used in single, three-way, and d o u b l e crosses
Establishment and seed color in chickpea. Plant establishment (%)a
Line/variety
Seed t y p e
Seed color
Without seed dressing
With seed dressing
Difference
CPI 56329 K 1190 CPI 56296-b CPI 71173 NP 53 CPI 56564 CPI 56315
Kabuli Kabuli Kabuli Desi Desi Desi Desi
White White Light b r o w n Brown Brown Dark b r o w n Black
54.0 47.3 85.7 89.7 87.7 82.3 88.0
77.0 88.0 91.6 91.3 89.0 94.0 87.7
23.0 40.7 5.9 1.6 1.3 11.7 -0.3
a. Send d r e s s i n g = 1:1 t h i r a m / c a p t a n 0.6% w / w .
72
w i t h tall desi lines. The aim has been to c o m b i n e in the one variety acceptable yield, protein, height, and earliness w i t h a colored kabuli seed. Of 139 F 2 plants selected f r o m such crosses, only 12 (8.6%) w e r e f o u n d to have kabuli seed t y p e at maturity. The remainder w e r e c o m posed of desi (32.4%) and pea or intermediate types (59.0%). W h e n a single seed f r o m each of the 12 kabuli plants was selfed, only 8 retained the kabuli f o r m . Clearly, m u c h selection pressure can be wasted t h r o u g h the inability to determine F 2 and F 3 seed type until plant maturity. This p r o b l e m can be partly o v e r c o m e by increasing the p r o p o r t i o n of kabuli and/or desi segregates. Three ways are suggested: 1. Particular combinations of parent lines can be chosen that segregate a high proport i o n of kabuli and/or desi types. This inf o r m a t i o n can be obtained either t h r o u g h single-seed descent w i t h rapid generation turnover or by recording class frequencies d u r i n g the course of breeding. 2. The type of cross used will largely determ i n e the frequency of types segretated. For example, a high proportion of kabuli types can be recovered by making the three-way cross (desi x kabuli-1) x kabuli-2 and selecting only those hybrids having kabuli seed. One cross of this type made at Wagga yielded 77.0% kabuli plants in the first segregating generation. This m e t h o d w o u l d be useful w h e r e only a small n u m b e r of characters need to be introgressed f r o m the desi line. 3. Uncertainty of seed genotype may be avoided by permitting segregating generations to self until near homozygosity — say F5. At W a g g a , under controlled glasshouse conditions, one generation can be obtained every 110 days, w i t h only 19 m o n t h s being required f r o m the s o w i n g of parent material to the harvesting of F 5 plants. The derived F 6 lines, w h i c h are effectively h o m o z y g o u s , can then be s o w n in the field in single r o w s for preliminary yield evaluation. A m o d i f i e d f o r m of single-seed descent, w h e r e m i l d selection can be practiced, is n o w being used at Wagga. In the glasshouse at a spacing of 50 plants per m 2 , it is possible to discard plants on the basis of height, earliness, seed size, and pod set. The advantages of this
m e t h o d are a progressive reduction in the w o r k l o a d and considerable saving in t i m e . The major disadvantage is t h e likely loss of superior segregates t h r o u g h r a n d o m selection of single seeds.
Culinary Varieties Over a long period of t i m e , intense selection fo r large-seededness has probably been at the expense of yield. An objective of the Wagga p r o g r a m is to i m p r o v e the yield of presently available culinary varieties t h r o u g h the introgression of desi g e r m p l a s m . Culinary chickpea production in Australia w i l l most likely be confined to irrigation districts. The greater vegetative p r o d u c t i o n under irrigation w i l l make the incorporation of lodging resistance essential. This resistance is available in the subrace bohemicum (van der Maesen 1972); m a n y representatives of w h i c h have thick, strong stems and an erect g r o w t h habit. One line in particular, K-368, has s h o w n excellent lodging resistance but has t h e disadvantages of pea-type seed and very late m a turity. It has been crossed w i t h th e high-yielding early maturity variety JG-62 to derive a tall, lodging-resistant line w i t h m e d i u m maturity and desi seed (WWC1). This has subsequently been crossed w i t h culinary lines in t h e f o l l o w i n g ways, namely, (WWC1 x culinary-1) x culinary-2; and (WWC1 x desi) x culinary-1. The first cross, as previously discussed, can provide a high frequency of kabuli segregates, but it has the disadvantage of introgressing only 25% of desi genes. The second cross introgresses 50% of desi genes, but it has the disadvantage of reducing the proportion of segregates having kabuli and/or acceptably large seed.
References C O R B I N , E.J. 1975. Present status of chickpea research in Australia. Pages 8 7 - 9 4 in Proceedings, International W o r k s h o p on Grain Legumes, ICRISAT, 13 Mar 1975, Hyderabad, India. D E A K I N , J. R. 1974. Association of seed color w i t h emergence and seed yield of snap beans. J o u r n a l of t h e A m e r i c a n Society f o r Horticultural Science 99(2):110-114.
73
An
M U E H L B A U E R , F. J., and KRAFT, J . M . 1978. Effect of pea
association b e t w e e n p i g m e n t a n d l i g n i n f o r m a t i o n in the seed coat of t h e l i m a bean. Crop Science 4(6):621-622.
seed g e n o t y p e on pre-emergence d a m p i n g off a n d resistance to Fusarium and Pythium root rot. Crop Science 1 8 ( 2 ) : 3 2 1 - 3 2 3 .
M A , Y., and Buss, F. A. 1978. T a n n i n content and inheritance in c o m m o n bean. Crop Science 18(2):201-204.
VAN DER M A E S E N , L. J. G. 1972. Cicer L. A m o n o g r a p h of the g e n u s , w i t h special reference to t h e chickpea Cicer arietinum L., its ecology and c u l t i v a t i o n . Mededelingen Landbouwhogeschool Wageningen, Nederland.
KANNENBERG,
74
L.
W.,
and
ALLARD,
R.
W.
1964.
Kabuli-Desi Introgression and Genesis of New Plant Type in Chickpea P. N. Bahl*
I m p r o v ed plant type has played a very important role in recent years in raising t h e yield plateau in cereals and in certain legumes. In t h e case of cereals, particularly w h e a t and rice, this has been achieved by breeding dwarf varieties capable of favorably responding to such inputs as irrigation and fertilization. In contrast to this, mid-tall genotypes have given higher yields in s o m e of t h e legumes, like broadbeans and soybeans. However, chickpea cultivars cont i n u e to be notoriously l o w in yield in t h e Indian subcontinent. Chickpea has been traditionally g r o w n in this part of the w o r l d under marginal conditions of moisture stress and l o w soil fertility. These stress environments, w h e r e land races of chickpea are even n o w being g r o w n , are not very m u c h different f r o m those of their w i l d habitats (Swaminathan and Jain 1973). Natural selection under these conditions has played a m o r e i m p o r t a nt role than h u m a n selection in d e t e r m i n i n g m o r p h o l o g i c a l and physiological structure. The chickpea genotypes have adapted t h e m selves to these conditions by developing such characteristics as bushy, spreading, and indeterminate g r o w t h habit, nonsynchronous development, and photo- and thermo-insensitive habit (Bahl et al. 1978). Under these conditions, adaptive response must have resulted in the evolution of ecotypes possessing coadaptive gene complexes that are n o w conserved by genetic linkages. Therefore, the f o r e m o s t requirement of a plant breeder is to change the physiological makeup by restructuring the plant type so as to identify early m a t u r i n g photo- and thermo-insensitive determinates and widely adapted genotypes that can be g r o w n under different c r o p p i n g patterns a n d f a r m i n g systems.
* Geneticist (Pulses), Division of Genetics, Indian A g r i c u l t u r a l Research Institute, N e w D e l h i , India.
Correlations and Path Analysis Table 1 (Bahl and Jain 1977) s h o w s s i m p l e phenotypic correlations between different characters, including grain yield and harvest index recorded on 16 chickpea cultivars. Grain yield s h o w e d a highly significant positive correlation w i t h branches per plant, pods per plant, biological y i e l d , and harvest index. The biological y i e l d , pods per plant, and harvest index are practically contributed by the n u m b e r of branches per plant, w i t h w h i c h they all s h o w positive association. As the grain yield is the product of biological yield and harvest index, it is interesting to f i n d that both yield c o m p o n e n t s are positively correlated. An important f i n d i n g is that these yield parameters can be increased simultaneously, in contrast to maize and s o m e other cereals w h e r e dry matter is negatively correlated w i t h harvest index (Jain et al. 1976). Path-analysis studies on 21 cultivars of chickpea revealed that branches per plant contributed substantially and directly t o w a r d pods per plant, w h i c h is always strongly correlated w i t h grain yield in most legumes, including chickpea (Bahl et al. 1976). It was concluded f r o m these observations that plant breeders should look for genotypes that bear m o r e p o d s per branch, so that vegetative yield is reduced and harvest index is increased. This w i l l p e r m i t partitioning the total dry matter in a favorable direction so that higher grain yields are obtained. From these studies, it w a s theorized that an i m p r o v e d plant t y p e in chickpea should be characterized by a large n u m b e r of branches and an erect g r o w t h habit, w i t h m a n y primary and secondary branches. This w o u l d help intercept m o r e sunlight, p e r m i t larger plant p o p u lations to be raised per unit area, and help avoid a wastage of energy in the production of tertiary and late-order branches; such branches do not appear to contribute m u c h to grain f o r m a t i o n .
75
Table
1.
Correlation coefficients b e t w e e n various characters in chickpea, 1 9 7 7 .
Character Plant h e i g h t Branches/plant Pods/plant Seeds/pod 100-seed w e i g h t Biological y i e l d / p l a n t E c o n o m i c y i e l d / p l a nt Harvest i n d e x
Branches/ Pods/ plant plant 0.095
0.124 0.891**
Seeds/ pod
100-seed weight
0.199 0.180 0.280*
0.137 -0.095 -0.237 -0.309*
Biological yield/ plant
Economic yield/ plant
0.303* 0.740** 0.694** 0.263* 0.167
0.200 0.701** 0.726** 0.306* 0.179 0.819**
Harvest index 0.076 0.470** 0.540** 0.283* 0.258* 0.528** 0.870**
* S i g n i f i c a n t at p = 0.05. ** S i g n i f i c a n t at p = 0 . 0 1 . Bahl a n d J a i n (1977).
In this conceptual plant ideotype of chickpea, s o m e of t h e vertical g r o w t h in t a l l , erect, and c o m p a c t types w i l l replace the horizontal spread of traditional types to s o m e extent w i t h out losing on the n u m b e r of p o d - f o r m i n g loci. This w i l l a m o u n t to looking f o r a plant t y p e that is architecturally adapted to h i g h plant density and n a r r o w row-spacing, w h i c h w e think w i l l b e conducive to o p t i m u m yield e n v i r o n m e n t , as visualized in maize by Mock and Pearce (1975).
Genetic Diversity among Kabuli and Desi Cultivars W i t h i n cultivated species of chickpea, kabuli and desi types are t w o distinct g r o u p s of practical i m p o r t a n c e (van der Maesen 1973). Desi types, w i t h yellow to b r o w n testa and a 1 0 - 1 5 g 100-seed w e i g h t , are m o s t l y planted as a w i n t e r crop in the t r o p i c s ; kabuli types, w i t h s a l m o n w h i t e testa and w e i g h i n g m o r e than 26 g per 100-seeds, are generally planted as a s u m m e r crop in t e m p e r a t e climates. However, in t e r m s of seasons and space, there is s o m e a m o u n t of overlap in the distribution of desi and kabuli types. Nevertheless, the inferential criterion of ecogeographical diversity is often used to discriminate between desi and kabuli types as separate g r o u p s w i t h i n the cultivated species. However, i n f o r m a t i o n on the extent of genetic divergence and factors contributing to intraspecific differentiation in chickpea is very meager. Figure 1 (Salimath 1979) s h o w s genetic divergence in a set of 80 genotypes consisting of 39 indigenous desi, 15 exotic desi, 11 i n d i genous kabuli, and 15 exotic kabuli types. Of the
76
80 genotypes, 50 came f r o m India, 14 f r o m Iran, 6 f r o m USSR, 2 each f r o m A f g h a n i s t a n , Egypt, and M o r o c c o , and 1 each f r o m Lebanon, Algeria, Turkey, and the USA (Table 2). In this study a set of nine quantitative characters — plant height, total n u m b e r of branches, p r i m a r y branches, secondary branches, days to 5 0 % f l o w e r i n g , days to maturity, n u m b e r of pods per plant, seeds per p o d , and 100-seed w e i g h t — related to fitness or yield w e r e used for estimating genetic divergence, using t h e D 2 statistic of Mahalanobis (1936) and canonical analysis. On the p r i m a r y axis of differentiation, the potent factors causing divergence w e r e seeds per p o d , n u m b e r of pods per plant, and primary branches. On the secondary axis of differentiation the potent factors w e r e pods per plant, total branches, and p r i m a r y branches per plant. On t h e tertiary axis, the single m o s t potent factor was days to 50% f l o w e r i n g . Another i m p o r t a n t aspect e m e r g i n g f r o m this study is that kabuli and desi types f o r m t w o distinct constellations, w i t h the exception of one g e n o t y p e f r o m each g r o u p having fallen in the other cluster. The study has b r o u g h t out s o m e interesting features of subspecific differentiation in the cultivated species of chickpea. The u n i q u e d i vergence of kabuli f r o m desi m a y indicate that these t w o types represent different g e r m p l a s m pools (intergroup D 2 = 143.30). Second, withing r o u p divergence w a s greater in kabulis (intragroup D 2 = 103.48) than in desi types (intragroup D 2 = 90.31). T h i r d , kabuli as a g r o u p had high mean values for p r i m a r y branches, 100-seed w e i g h t , and plant height, whereas the desi
Indigenous Exotic
desi
Indigenous Exotic
28
desi
kabuli
kabuli
26
K A B U L I
24
22
20
18
16
14
12
10
8
6
D E S I 4
2 8
10
12
14
16
18
20
22
24
26
Vector Z2
Figure
1.
Two-dimensional representation
first two
canonical vectors
of divergence
(Z1andZ2).
of 80 genotypes
Source:
Salimath
of chickpea
using
the
(1979).
77
Table 2.
Particulars of 80 genotypes of chickpea used In Figure 1. Country of o r i g i n
Number, and entry n a m e a Desi 2 (B. g r a m ) , 3 (Radhey), 5 (T3), 6 (P436), 8 (P324), 10 (NEC249), 11 (B110), 13 (P514), 15 (P127), 16 (Annigeri), 18 (P182), 19 (P1243), 20 (P1137), 21 (JG62), 23 (P1132), 24 (B108), 25 (C214), 26 (P47), 28 (P325), 29 (850-3/27), 30 (F378), 32 (P517), 33 (NP50), 34 (P481), 36 (K468), 37 (G130), 38 (H 208), 40 (C235), 41 (BG1), 42 (P326), 43 (Pant. G113), 44 (P70), 45 (P1208), 46 (P1209), 47 (BG206), 74 (BG 203), 75 (F370), 76 (P10), 79 (P1387)
India
Iran
1 (P3552), 4 (P2559), 7 (P496), 14 (P2974), 22 (Kaka), 27 (Pyrouz), 31 (NEC1196) 9 (NEC 240), 71 (P9656), 72 (NEC 136), 78 (P852)
USSR
12 (P4235), 39 (P896)
Afghanistan
17 (P840)
Morocco
35 (USA 613)
USA
Kabuli 48 (L534), 50 (L532), 52 (L550), 54 (K 1071), 56 (K4), 58 (C104), 61 (No. 501), 63 (Hy. 16-3), 67 (GL629), 69 (JG20), 77 (P179)
India
Iran
57 (P3896), 59 (P2264), 62 (P2663), 64 (P2245), 65 (P2221), 66 (P2566), 80 (P3090) 70 (P9847), 73 (K1480)
USSR
53 (Giza), 55 (NEC 1572)
Egypt
49 (Rabat)
Morocco
51 (P 9800)
Turkey
60 (Lebanese local)
Lebanon
68 (NEC 1646)
Algeria
a. N a m e or accession n u m b e r of t h e c u l t i v a r is g i v e n in p a r e n t h e s e s .
g r o u p had high mean values f o r seeds per p o d , pods per plant, and secondary branches (Table 3). Therefore, genes f r o m kabuli can be transferred to desi and vice versa by hybridization and selection f o r several c o m b i n a t i o n s of characters already present in t h e t w o groups. It w i l l be reasonable to assume t h a t — like spring and w i n t e r wheats — kabuli- and desitype chickpeas represent t w o different g e r m p l a s m pools. Kabuli types possess genetic qualities that t h e breeder w a n t s for desi types, such as p r i m a r y branches, 100-seed
78
w e i g h t , and upright compact habit. By contrast, desi types can contribute qualities needed in kabuli types, such as seeds per p o d , pods per plant, and d r o u g h t resistance. In short, kabuli and desi g e r m p l a s m pools — w h i c h have been sparingly crossed in the p a s t — - o f f e r n e w sources of variability for m a n y characters.
Kabuli-Desi Introgression Reviewing t h e i m p r o v e m e n t in y i e l d capabilities of different crop species, Frey (1971) ob-
Table 3.
G r o u p m e a n s f o r six c h a r a c t e r s i n c h i c k p e a . Character
Group Kabuli Desi
Primary branches 100-seed weight (no.) (g) 5.46 4.49
20.46 14.01
Plant height (cm) 67.27 60.65
served that " t h e primary d i l e m m a facing the plant breeder w h o wishes to introduce n e w g e r m p l a s m into his breeding populations to i m p r o v e yields per se is w h e r e to find such genes." He gives examples f r o m different crops to s h o w that valuable genes do exist in rather remote and unexpected material. One of the major problems of chickpea is that traditional cultivars of the Indian subcontinent s h o w a bushy habit w i t h dense vegetative g r o w t h . Major gains in yield can be achieved if selection is done for an i m p r o v e d plant type in t e r m s of high harvest index, response to increased plant population per unit area, and early maturity. The i m p r o v e m e n t in plant type w i t h high harvest index is likely to be associated w i t h determinate and compact g r o w t h habit (Jain 1975). We reviewed our present problems and possible experimental approaches in 1973 and planned an aggressive and diversified breeding program w i t h the clear objective of evolving a plant type as theorized on the basis of correlation and path-analysis studies. As a first step in this direction, we augmented our existing g e r m p l a s m collection by obtaining g e r m p l a s m lines t h r o u g h c o m m u n i c a t i o n and t h r o u g h FAO. In order to lay our hands on valuable genes, we stressed geographical diversity in choosing parents for hybridization. Also, in the majority of our planned cross combinations, we used kabuli as one of the parents. In general, kabuli types tend to be semi-erect but give lower yields under Indian conditions than desi types. However, w h e n we compared desi x desi with desi x kabuli types of crosses, we had the unique experience of recovering a higher percentage of transgressive segregates in terms of various yield c o m p o n e n t s in the later type of cross c o m b i n a t i o n . Also, crosses of desi x kabuli parentage s h o w e d m o r e phenotypic variability in segregating generations.
Seed/pod (no.) 1.23 1.30
Pods/plant (no.) 53.89 88.77
Secondary branches (no.) 16.94 20.42
90 cm) Introduction in 1974 of semi-tall kabuli cultivars f r o m USSR marked the beginning of a new approach in our breeding program. S o m e of the Russian cultivars s h o w an erect g r o w t h h a b i t as they have probably been selected for mechanical harvesting. A distinct weakness of the Russian kabuli talls has been shy p o d d i n g restricted to about the top onefourth of the plant. Another difficulty in kabuli x desi type of crosses is the recovery of recombinants w i t h intermediate types of grain, which are neither kabuli nor desi and, therefore, will not attain consumer preference. We have f o u n d by experience that t w o - w a y and three-way crosses where we topcross desi x kabuli w i t h another desi type gives us better results. We lay m o r e emphasis on transgressive genes f r o m kabuli to desi types as this is a m o r e pressing p r o b l e m at the m o m e n t . Experience in handling cross combinations involving kabuli g e r m p l a s m — particularly semi-tails and c o m pact types f r o m USSR — and desi types has been rewarding in many ways. First, we got transgressive segregates in terms of earliness in f l o w e r i n g time, and some of the F 4 lines are 3 5 - 4 5 days earlier than the parents. We hope to select genotypes in this material that will fit into certain nonconventional seasons. These varieties may be specifically relevant to those areas where rabi s o w i n g s are delayed due to late harvest of paddy. Also, early m a t u r i n g types are likely to escape physiological wilt, w h i c h comes late in the growing season. Second, we recovered combinants that show almost determinate g r o w t h habits. M o v i n g f r o m an indeterminate, w h i c h is a w i l d character, to a determinate type of g r o w t h habit involves an expected type of change in chickpea, as ancestral f o r m s of most of the pulses have been f o u n d to be indeterminate (Smart 1976). T h i r d , remarkably, we could get individual plants in w h i c h the harvest index was better by 10% than the check
79
varieties. Fourth, s o m e of the recombinants f r o m these crosses have relatively erect branches w i t h p o d f o r m a t i o n starting near the base of t h e plant. Thus r e c o m b i n a t i o n breeding i n v o l v i n g Indian desi types, Mediterranean kabulis, and tall Russian cultivars has helped us to reconstruct n e w plant types that correspond w i t h t h e ideotype considered ideal on t h e basis of our studies earlier referred to in this paper. In such recombinants, part of the increased yield is inherent, and part w i l l be d u e to performance under h i g h plant populations. in a f e w p l a n n e d crosses in t h e kabuli-desi introgression p r o g r a m , a p r o p o r t i o n of the desi and kabuli g e r m p l a s m has been so m a n i p u l a t e d that it varies f r o m 12.5 to 87.5% in various cross c o m b i n a t i o n s . Plant populations f r o m these crosses w i t h different percentages of kabuli and desi g e r m p l a s m in F 2 are being studied for individual as well as combination s of characters. On this basis, prediction of the percentage of kabuli g e r m p l a s m in h y b r i d c o m b i n a t i o n s g i v i n g g o o d scope f o r selection w i l l be attempted.
References B A H L , P. N., agronomic pea (Cicer zuechtung
and J A I N , H. K. 1977. Association a m o n g characters and plant i d e o t y p e in chickarietinum L ) . Zeitschrift f u e r Pflanzen79: 154-159.
B A H L , P. N., M E H R A , R. B., and R A J U , D. B. 1976. Path
analysis a n d its i m p l i c a t i o n s f o r chickpea b r e e d i n g . Zeitschrift fuer Pflanzenzuechtung 7 7 : 6 7 - 7 1 . B A H L , P. N., S I N G H , S. P., H A Y A T R A M , R A J U , D. B., and
J A I N , H. K. 1978. Breeding f o r i m p r o v e d plant architecture a n d high protein yields. In FAO/IAEA International S y m p o s i u m o n Seed I m p r o v e m e n t i n Cereals and Grain L e g u m e s . 4 - 8 Sep 1978. FREY, K. J. 1971. I m p r o v i n g crop yields t h r o u g h plant b r e e d i n g . Pages 1 5 - 5 8 in M o v i n g off t h e yield plateau. A S A special publication No. 20. J A I N , H. K. 1975. Breeding f o r yield and other attributes in grain l e g u m e s . Indian J o u r n a l of Genetics 35:169-187. JAIN,
H.
K.,
MUKHERJEE,
B.
K.,
SINGH,
R.
D.,
and
A G A R W A L , K. N. 1976. The present basis and f u t u r e possibilities of b r e e d i n g for y i e l d in maize. Zeitschrift fuer Pflanzenzuechtung 7 6 : 9 0 - 1 0 1 . M AHALANOBIS, P. C. 1936. On t h e generalized distance in statistics. Proceedings of National A c a d e m y of Science (India) 2 : 4 9 - 5 5 . M O C K , J . J . , and PEARCE, R. B. 1975. A n i d e o t y p e i n
maize. Euphytica 2 4 : 6 1 3 - 6 2 3 . S A L I M A T H , P. M. 1979. U n p u b l i s h e d Ph. D. thesis, IARI, N e w Delhi.
Acknowledgments S W A M I N A T H A N , M . S., and J A I N , H.
The author wishes to thank Dr. H. K. J a i n , Director, Indian Agricultural Research Institute, N e w D e l h i , under w h o s e d i r e c t i o n and g u i d a n c e this w o r k was done. Thanks are also d u e to my friend and colleague Mr. R. B. M e h r a , w h o w e n t t h r o u g h t h e manuscript t o offer s o m e very useful suggestions.
80
K.
1973.
Food
l e g u m e s in Indian A g r i c u l t u r e . Pages 6 9 - 8 2 in N u t r i t i o n a l i m p r o v e m e n t o f f o o d l e g u m e s b y breedi n g , (ed. M. M. Milnes). VAN DER M A E S E N , L. J. G. 1973. Chickpea: distribution of variability. Pages 3 0 - 3 4 in S u r v e y of crop genetic resources in their centres of diversity, (ed. 0. H. Frankel), FAO report.
Session 2 — Yield Improvement through Kabuli-Desi Introgression Discussion
Hawtin
and Singh
Paper
S. Chandra There has been considerable interest in desi x kabuli crosses in the late 1950s and 1960s in Punjab (including Haryana). There w e r e three kabuli types (C-104, L-144, L-550) and one desi type (S-33) that w e r e developed and released for cultivation in that region and resulted f r o m desi x kabuli crosses. Other i m p o r t a n t conclusions d r a w n in this line of work are: 1. The early generation advantage exhibited by these crosses was due to unusually high heterosis that characterized t h e m in contrast to desi x desi crosses or kabuli x kabuli crosses. 2. The p o p u l a t i o n sizes required in segregating populations for recovery of transgressive segregants w e r e nearly three to f o u r times the sizes required for desi x desi crosses. 3. The intermediates w e r e highly unstable and took many m o r e generations for fixation tha n the desi or the kabuli-like types. 4. There is an unmanageably large n u m b e r of intermediate seed types e m e r g i n g f r o m these crosses. They had the disadvantage of poor seed coat adherance and poor consumer acceptability. 5. Genetic studies showed a conspicuous presence of epistatic and interallelic interactions. These experiences m i g h t well be kept in v i e w w h i l e pursuing the work on this aspect. M. V. R. Reddy At ICRISAT w h i l e screening for Ascochyta blight, we have seen that kabuli types produce m o r e v i g o r o u s and stronger seedlings than the desis. Because of stronger and v i g o r o u s stems they do not
die so quickly as the desis d o , and w h e n e v e r there is t h e chance they do recover better. G. C. Hawtin Under field conditions in Syria and Leban o n , kabuli types adapted to West Asian conditions certainly exhibit a greater degree of seedling v i g o r than nonadapted desis. I agree that this may be i m p o r t a n t in recovery f o l l o w i n g pest and insect attack. C. L. L. G o w d a I feel that kabulis definitely evolved later, probably by mutation. Hence they have less variability and are m o r e susceptible to disease, pests, and vagaries of nature. The fact that they are m o r e exacting in their needs shows that they u n d e r w e n t a shorter evolution than the hardy desi types. G. C. Hawtin I agree that kabulis probably evolved later t h a n desis. The evidence suggests they have arisen w i t h i n t h e past 2000 years. This does not automatically lead to less v a r i a t i o n ; however, t h e range of e n v i r o n ments in w h i c h kabulis are well adapted is huge. I am not sure we can necessarily assume that kabulis arose at o n e place f r o m a single m u t a t i o n . C. L. L. G o w d a The macrosperma do not contain anthocyanin and are w h i t e f l o w e r e d but do not have colorless vegetative organs. G.C. Hawtin The term colorless was q u o t e d f r o m the paper of M o r c a n o and Cubero. Obviously, the plants have c h l o r o p h y l l . The absence of anthocyanin t h r o u g h o u t the plant seems to be characteristic of kabulis. I have yet to see a pink-flowered kabuli. This can be m a d e
81
use of in breeding to increase t h e proportion of kabuli seeds in segregating p o p u lations t h r o u g h the roguing of pink-flowered plants. M. V. Reddy W h a t could be t h e reason f o r cold tolerance in kabulis and heat tolerance in desi types? Kabulis w h e n c o m p a r e d to desis, have m o r e u n w a n t e d characters, such as m o r e disease and insect susceptibility. W h a t are the probabilities of linkage between g o o d and bad characters? G. C. H a w t i n We certainly do not yet k n o w e n o u g h a b o u t the differences between kabulis and desis, either genetically or physiologically, to give an adequate answer to y o u r question. Until the last f e w years, very little w o r k has been d o n e on kabul i types, c o m p a r e d to t h e work on desis in the Indian subcontinent. It is possible that we will f i n d resistance to m a n y insects and pathogens w i t h i n t h e kabuli g r o u p if we look harder fo r it. This was certainly t h e case w i t h Ascochyta blight resistance. The absence of anthocyanin p i g m e n t a t i o n t h r o u g h o u t the plant in the kabulis may ultimately be s h o w n to be responsible, at least in part, for poor disease and insect characteristics. This, however, has certainly not been adequately p r o v e n yet, and even if it is, can we not envisage t h e existence of other resistance mechanisms that m i g h t be used in i m p r o v i n g kabuli types. A. Q. S a m e t I w o u l d like to d r a w y o u r kind attention to t h e f a c t that the origin of kabuli chickpeas is Kabul, capital of the Democratic Republic of Afghanistan. Fifty years ago, w h e n the great Russian botanist Vavilov was collecting the plants f r o m West Asia, his report clearly m e n t i o n e d that the place of origin of chickpea is Kabul, so kabuli belongs to Kabul. L. J. G. van der Maesen The designation " k a b u l i " w a s given in India w h e n the large-seeded w h i t e chickpeas first came to that country t h r o u g h Kabul. This happened about 3 centuries ago.
82
R. B. Singh 1. L o w recovery of kabuli types in the k a b u l i x desi crosses m a y not be generalized. Certain g e n o t y p e c o m b i n a tions m a y give the expected p r o p o r t i o n of kabuli and desi types in the F 2 p o p u lations. In case you visualize a genetic drift as a c a u s e f o r t h e a b n o r m a l p r o p o r t i o n s , w h a t is y o u r basis of thinking so? 2. I feel crosses a m o n g " n e a r - k a b u l i " segregants of the kabuli x desi crosses c o u p l e d w i t h d i r e c t i o n a l selection should yield the desired results. G. C. Hawtin I do not consider genetic drift to be an i m p o r t a n t factor d e t e r m i n i n g the l o w recovery of kabulis in West Asia. If it is a factor at all, one w o u l d expect the reverse, i.e., a greater recovery of seed characters associated w i t h t h e m o r e adapted parent. Obviously, a large n u m b e r of genes are involved in the d e t e r m i n a t i o n of kabuli and desi characteristics, and it w o u l d appear that the recovery of kabulis may depend to a considerable extent on the interactions between t h e t w o parental genotypes. We at present k n o w nothing about m o d i f y i n g genes, epistatic effects, and so on in regard to the determination of seed characteristics. As s h o w n in my paper, of seven F 2 populations studied, recovery of kabulis ranged f r o m less than 6% to over 2 2 % . Other people have also f o u n d such w i d e variation. D. Sharma W h i l e studying transgressive segregation for yield in kabuli x kabuli, desi x desi, and desi x kabuli crosses, have y o u c o m p a r e d crosses involving parents w i t h comparable seed size in t h e t w o groups? Generally, a kabuli parent used in the crosses is the one w i t h a large seed size. Recovered kabuli w i t h higher yield than the kabuli parent is smaller in seed size than the kabuli parent. G. C. H a w t i n We have not m a d e any detailed studies on seed size. I do not believe, however, that there is a strong negative correlation between yield and seed size within the seed size range of, say 2 0 - 3 5 grams per 100
seeds. M o s t of t h e parents used have fallen w i t h i n this range. J. S. Sindhu W h i c h c o m p o n e n t of yield is likely to be i m p r o v e d in the desi x kabuli crosses, and w h y is it that the advantage of that character c o m p o n e n t goes to the i m p r o v e m e n t of kabuli and not desi chickpea? G. C. Hawtin I d o n ' t think the advantage of kabuli-desi introgression is merely the c o m b i n i n g of c o m p l e m e n t a r y yield components. Different responses to stress conditions, different g r o w t h characters, and possibly different yield-efficiency genes may have developed in the separate gene poois. The introgression of these factors is likely to reflect itself in increased yield per plant, w h i c h presumably will reflect most in seeds per plant or pods per plant, although of course, other c o m p o n e n t s may be affected.
Jambunathan
and
Singh
Paper
M. V. Reddy Is there any i n f o r m a t i o n on the chemical c o m p o s i t i o n of kabuli and desi plants themselves? S o m e of the chemical differences in the plants could be affecting physiological efficacy of these t w o subgroups. R. J a m b u n a t h a n We have not analyzed any kabuli- or desitype plants for p r o x i m a t e c o m p o s i t i o n . U m a i d Singh A considerable a m o u n t of chickpea, particularly in India, is consumed as parched or puffed chickpea. Large variations in the percentage of seed coat exist between kabuli and desi types. There is a point in measuring the thickness of seed coats w h e r e this factor plays a greater role in d e t e r m i n i n g t h e extent of parching or puff i n g that remain consumer preferences. R. J a m b u n a t h a n As m o s t l y desi types are used for parching and puffing, I am not sure whether i n f o r m -
ation on the thickness of seed coat of both desi and kabuli types w o u l d be of m u c h help. U m a i d Singh This is a suggestion regarding t h e chemical analysis of kabuli and desi types. As we have seen, there are s o m e differences in the chemical constituents of kabuli and desi types. From a nutritive point of v i e w , it w o u l d be w o r t h w h i l e to study the levels of antinutritional factors in kabuli and desi types. Further, the biological value and digestibility of kabuli and desi chickpeas should be studied. R. J a m b u n a t h a n I agree that it will be w o r t h w h i l e to have this information. V. P. Gupta It w o u l d be advisable to study the a m i n o acids of kabuli and desi because we are interested in both the consumer quality and the protein quality in kabuli specifically. Our studies have indicated that kabuli (L-144) type has a better essential a m i n o acid index (92%) than does desi (H-208, 80%). This was m a i n l y due to the high amount of lysine (more than 20%) and m e t h i o n i n e in kabuli as compared to desi. R. J a m b u n a t h a n We have analyzed a f e w desi and kabuli cultivars for their a m i n o acid c o m p o s i t i o n and there appear to be no significant differences between these t w o types.
Haware et al. Paper J. S. Sindh u At Kanpur we have worked out the genetics of w i l t resistance in chickpeas. Segregation patterns in F 2 and BC 1 populations in the wilt-sick plot have proved that resistance to this disease is governed by a single recessive gene. M. P. Haware We know about y o u r studies at Kanpur. I feel that to study inheritance of resistance in soilborne pathogens, studies s h o u l d be
83
conducted under controlled conditions. Under field conditions, due to presence of other root rot pathogens, results are sometimes misleading. R. B. Singh In v i e w of the possible occurrence of biotypes or physiological races of Aschochyta blight, the oligogenic inheritance (monogenic) of resistance as suggested by you and others needs to be searched m o r e critically. A detailed study i n v o l v i n g diverse genotypes on genetics of resistance to Aschochyta blight is w a r r a n t e d . M. P. Haware I agree w i t h y o u , as we are getting m o r e evidence about the presence of races in Ascochyta rabiei. International nurseries m a y provide us w i t h m o r e i n f o r m a t i o n on races,. and if so, study i n v o l v i n g diverse genotypes on genetic resistance will be undertaken at ICARDA.
Knights
A. S. Gill W h y w a s g e r m i n a t i o n reduced in the case of desi types w h e n they w e r e treated w i t h Thiram/Captan? E. J. Knights Generally, there was a slight, but nonsignificant increase. The one exception, CPI56315, could be explained by experimental error. Y. S. T o m e r W h y w a s the g e r m i n a t i o n of the blackseeded types reduced w h e n treated w i t h Thiram/Captan? E. J. Knights First, the reduction was m i n i m a l and can most reasonably be explained by experimental error. Alternatively, there may be a c o r r e l a t i o n b e t w e e n concentratio n of phenol and intensity of color.
Paper
M. C. Saxena Your presentation highlights the need for chemical w e e d control in Australia. W o u l d y o u please specify the chemicals and rates r e c o m m e n d e d for use.
E. J. Knights Simazine has been f o u n d to be the most effective herbicide for broad-spectrum weed c o n t r o l , although the level of control is dependent on soil m o i s t u r e at and i m mediately after application. A rate of 1.5 kg active ingredient/ha usually gives excellent c o n t r o l , although toxicity systems s h o w up in s o m e cultivars. Jagdish Kumar In seven desi x kabuli F 2 populations we recovered less than 5% kabulis. The kabuli-type parents used w e r e P-9623, L-550, and Giza. I w o n d e r w h a t w e r e the parents y o u used? E. J. Knights The kabuli parents were: K-1480 (USSR), K-
84
583 (USSR), CPI-56565 (USSR), CPI-56329 (Iran), and CPI-56296-6 (Afghanistan).
C. L. L. G o w d a The black-seeded cultivar CPl-56315 gave a higher percentage of g e r m i n a t i o n in the untreated check. At ICRISAT, the blackseeded cultivars lose most of their viability after 18 m o n t h s of storage at ambient temperature. H o w long was the seed in your study stored, and h o w do y o u relate your results w i t h our experience? E. J. Knights Storage was for 18 m o n t h s . T e m p e r a t u r e and h u m i d i t y are lower at Wagga Wagga than in India. The - 0 . 3 % difference is probably due to natural variation. J. Kannaiyan Do you encounter any serious disease p r o b l e m s in chickpea in Australia? E. J. Knights There is a root rot/aerial blight complex that can reduce yields under l o w temperatures. The major fungal genera are Botrytis, Sclerotinia, Rhizoctonia, and Fusarium. A p p r o p r i a t e seed dressing can substantially reduce disease incidence.
Bahl
Paper
A. S. T i w a r i 1. Experiences of desi-kabuli introgression at Jabalpur reveal that w i d e variations occur not only for seed color but also f o r seed shape and size. 2. Selection for c o m p l e m e n t a r y characters is difficult because of tight linkages resulting in little yield increases. 3. Therefore, a w o r d of caution that in such introgression either a very large F 2 s h o u l d be raised or crossing a m o n g F 2 s m a y be attempted in order to break t i g h t linkages. 4. Besides the desirable characters of kabuli m e n t i o n e d , t w o such types, JG-18 and JG-20, w e r e f o u n d to have a very high positive response to Rhizobium inoculation c o m p a r e d to desi types, such as JG-74.
P. N. Bahl Search f o r both desirable plant t y p e as well as d e t e r m i n a t e type. J. M. Green After m u c h discussion, w h i c h if taken seriously, w o u l d discourage y o u , I trust y o u w i l l persevere in the d e v e l o p m e n t of y o u r target ideotype. Yo u (P. N. Bahl) have m a d e excellent progress to date. J. P. Yadavendra Path coefficient analysis m a y be m o r e precise if c o m p u t e d t h r o u g h genotypic correlations and not t h r o u g h s i m p l e correlation. P. N. Bahl Path coefficient analysis was d o n e on genotypic values. Data g i v e n in t h e paper on simple correlations and path analysis came f r o m different studies.
R. B. Singh Higher genetic diversity revealed by D 2 analysis a m o n g the kabuli types as c o m pared to desi types may not be real. The n u m b e r of strains s a m p l e d , background selection history, and edaphic geoecological parameters w o u l d affect the estimates, and thus before any generalization is m a d e regarding variability as revealed by D 2 analysis, i n f o r m a t i o n on the parameters m e n t i o n e d above s h o u l d be considered.
R. B. Deshmukh What is your experience of crosses bet w e e n genetically diverse parents a m o n g the desi types in respect to heterosis, c o m bining ability, and segregation in early generations? H o w d o they c o m p a r e w i t h crosses between desi x kubuli types? Don't y o u think that kabuli m a y transfer s o m e undesirable characters, such as susceptibility to heat and poor plant stand?
P. N. Bahl Our data does s h o w greater genetic heterogeneity a m o n g kabuli cultivars. l agree, however, that additional data and other studies in this direction may help to elucidate f u r t h e r s o m e points raised by Prof. Singh.
P. N. Bahl M a g n i t u d e and direction of heterosis w i l l differ according to the parents involved in each of the t w o types of crosses. But we have had g o o d success in kabuli x desi crosses. There are g o o d c o m b i n i n g parents in both t h e types. Y o u can get rid of undesirable characters by applying the right type of selection pressure.
T. S. S a n d h u I w o n d e r w h e t h e r we s h o u l d search for a determinate plant type, keeping in v i e w the g r o w t h habit of t h e chickpea plant, or should w e search f o r genotypes w i t h desirable g r o w t h habit less influenced by environmental conditions? The chickpea plant is very sensitive to e n v i r o n m e n t a l c o n d i tions. Its g r o w t h habit is highly influenced by spacing, s o w i n g t i m e , rainfall, and other related factors.
A. R. Sheldrake 1. Branching varies greatly according to spacing. How w o u l d y o u select for this? 2. We have tested upright types at high population density and find they have no advantage over n o r m a l types. 3. W h a t does Dr. Bahl mean by d e t e r m i nate type?
85
P. N. Bahl 1. Selection is d o n e on the pattern of branching. Also branching is c o m p a r e d w i t h check varieties repeated at regular intervals under identical conditions. 2. Y o u r data on upright types relate to unadapted cultivars. I am talking of tall u p r i g h t recombinants that w i l l be adapted to our conditions. We h o p e these w i l l respond to high population density. 3. Determinate types here refer to those plants w i t h a shorter span of f l o w e r i n g duration and w h i c h put up a restricted n u m b e r of branches.
86
S. Lal W h a t is the f l o w e r i n g duration in d e t e r m i nate segregants in kabuli x desi crosses? If it is shorter than in an indeterminate t y p e , it serves t h e m e a n i n g of determinate type. At the same t i m e , w h a t is the sequence of f l o w e r i n g i n the determinate t y p e s — acropetal or basipetal? P. N. Bahl Flowering duration was reduced in a proportion of the segregants in the kabuli x desi crosses. The sequence of f l o w e r i n g is still acropetal, but these determinate types quit f l o w e r i n g early.
Session 3
Chickpea Agronomy and Physiology Chairman : Co-Chairman:
E. H. R o b e r t s M. Abdullah Khan
Rapporteur:
S. C. Sethi
Recent Advances in Chickpea Agronomy M. C. Saxena*
Because of the g r o w i n g awareness of the importance of chickpea as a f o o d legume crop in the semi-arid tropics and the Mediterranean areas of the developing w o r l d , increasing attention is being paid to chickpea i m p r o v e m e n t t h r o u g h national and international efforts. For the full exploitation of the yield potential, chickpea cultivars m u s t be g r o w n w i t h adequate a g r o n o m i c management. Thus, research on production a g r o n o m y is of great significance. The a g r o n o m i c requirements of chickpea and past research on its production a g r o n o m y have been reviewed elsewhere (van der Maesen 1972; Saxena and Yadav 1975). This paper covers s o m e of the m o r e recent work and is heavily dependent u p o n local reports, since m u c h of the i n f o r m a t i o n on a g r o n o m i c research is location specific and does not find its w a y into research journals.
Planting Date Several studies in the various chickpea-growing areas have established the significance of date of planting in influencing crop g r o w t h and yield. As in the past, most of the recent studies on response of newly developed genotypes of chickpea to dates of planting in different parts of India, under the All India Coordinated Project, have indicated that mid-October to m i d November is the ideal period of planting and any deviation f r o m this causes conspicuous reduction in yield (Kaul and Sekhon 1976; Saxena and Singh 1977; Panwar 1978; Sharma 1978). In areas w h e r e the w i n t e r period is rather short, e.g. in the eastern and southern parts of India, the o p t i m u m range f o r planting becomes still narrower. For example, Sen (1978) reported that the first week of N o v e m b e r was the best planting t i m e f o r chickpea in Berhampur, West Ben-
* A g r o n o m i s t , Food A l e p p o , Syria.
Legume
Program,
ICARDA,
gal. Studies on date of planting, w i t h six p r o m i s ing genotypes of chickpea at Debre-Zeit in Ethiopia, revealed that 1 September was the best and delaying the planting any further caused drastic yield reductions (Bezuneh 1975). How date of planting could affect the crop performance t h r o u g h interaction between the altered aerial and edaphic crop e n v i r o n m e n t has been well illustrated by studies of Ageel and A y o u b (1977) at Hudeiba Research Station in Ed-Damer, Sudan. In their study, w h i c h was carried out w i t h irrigated chickpea on alkaline soils of three different textural classes, s o w i n g date affected the yield by influencing not only the g r o w t h and major yield c o m p o n e n ts per plant but also plant stand (Table 1). The best s o w i n g date was f o u n d to be between the end of October and the end of November, w h i c h resulted in m a x i m u m survival of the plants. Seedlings f r o m the plantings m a d e earlier or later than this period showed s y m p t o m s of toxicity associated with excessive s o d i u m accumulation. High mean m a x i m u m temperature and l o w relative h u m i d i t y to w h i c h the seedlings were exposed w h e n planted outside the opt i m u m t i m e range led to excessive s o d i u m accumulation in the shoots and resulted in seedling mortality. Surviving plants showed poor vegetative and reproductive g r o w t h and thus gave low seed yield primarily t h r o u g h reduced pod formation per plant (Table 1). A significant advancement in the a g r o n o m y of chickpea in West Asia is the possibility of a complete change of the traditional s o w i n g season f r o m spring to early winter (Kostrinski 1974). Throughout most of t h e Mediterranean and the Near East where major rainfall occurs in winter, chickpea is g r o w n on conserved soil moisture in the early spring. A rapid rise in temperature and t h e desiccative power of the atmosphere cuts short the vegetative and reproductive g r o w t h period of the crop, thus resulting in l o w yield. Studies initiated in the Arid Land Agricultural Development (ALAD) Program in Lebanon, in 1974-75, revealed that
89
Table
1.
Effect of sowing date on plant survival, crop g r o w t h rata (CGR), total plant dry w e i g h t at m a t u r i t y , and pods par plant in local chickpea at the Hudelba Research S t a t i o n, S u d a n .
Date of planting
No. of plants/m 2 a
CGRb (g/m 2 /week)
Dry w e i g h t (g/plant)
No. of pods/plant
Oct 1 Oct 15 Oct 29 N o v 12 N o v 26
0 4 9 11 13
NA 0.7 12.1 34.7 32.1
NA 3.1 10.8 24.5 23.8
NA 10 39 77 72
Dec 10 Dec 24 Jan 7 J a n 21 S.E. ±
11 10 8 6 0.3
26.1 18.4 11.4 12.1 4.9
11.9 9.5 6.9 10.6 1.02
31 25 24 34 4.6
a. O r i g i n a l p o p u l a t i o n e s t a b l i s h e d 16.7 p l a n t s / m 2 . b. B e t w e e n t h e p e r i o d f r o m 4 w e e k s after p l a n t i n g to onset of f l o w e r i n g . NA = N o t available. S o u r c e : A g e e b a n d A y o u g (1977).
the existing chickpea lines have e n o u g h cold tolerance to survive the w i n t e r in the low- and m e d i u m - e l e v a t i o n areas of the region. But there is greatly increased risk of severe c r o p losses f r o m Ascochyta blight. This was well demonstrated in a yield trial during the 1976-77 w i n t e r season in northern Syria, w h e r e all entries except one w e r e destroyed by the disease (Hawtin et al. 1978). That planting in w i n t e r could give a considerable yield advantage was also established by this study as the single surviving entry (NEC-2305) in the trial w i t h moderate resistance to Ascochyta blight yielded m o r e than 3 tonnes/ha, c o m p a r e d w i t h 950 kg/ha in spring planting. T h e best variety in t h e s a m e trial in s p r i n g produced o n l y 1621 kg/ha. W i t h t h e establishment of t h e ICARDA research station at Tel Hadia, Syria (36°N, 37°E, 392 m above sea level) in 1977, systematic dates of planting studies w e r e initiated using local cultivars and s o m e p r o m i s i n g genetic stocks under fungicidal protection f r o m Ascochyta blight. In one such study, eight genotypes were planted on six different dates covering t h e range f r o m early winter to spring. Seedling establishment in the last date of planting (March 26) w a s extremely poor, and t h e crop failed. The yield p e r f o r m a n c e of the crop f r o m t h e first f o u r dates is s h o w n in Table 2. Aver-
90
aged over all genotypes, t h e y i e l d f r o m spring planting (March 6) was about 3 8 % of that obtained f r o m t h e December 4 planting. Genotypes differed in the m a g n i t u d e of their response; NEC-1656 s h o w e d m u c h m o r e reduct i o n in the yield w i t h delay in planting than the Syrian local. The reduction in the yield was mainly because of reduction in p o d n u m b e r per plant (Table 3). Similar response to date of planting was observed in another trial w h e r e t h e effect of r o w spacings and plant population levels on the performance of Syrian local and NEC-2300 cultivars planted on different dates was studied (Table 4). Thus, substantial increases in yield are possible by w i n t e r planting if the crop is protected f r o m Ascochyta blight either by increasing crop tolerance or by chemical c o n t r o l . At higher elevations, e.g. on the A n a t o l i a n plateau, w h e r e w i n t e r temperatures can bec o m e extremely low, s o m e t i m e s reaching - 3 0 ° C w i t h o u t a protective s n o w cover, the planting has to be d o n e in s p r i n g , and tolerance to these extreme conditions will have to be introduced in the varieties before they can be g r o w n successfully there in winter. Studies on irrigated and rainfed kabuli and desi chickpea in Tabriz, Iran, have s h o w n that the end of A p r i l to the beginning of May is the best period for planting (Anon. 1976).
Table 2.
Effect of date of planting on the grain yield (kg/ha) of eight genotypes of chickpea at Tel Hadla, Syria, 1 9 7 7 - 7 8 . Date of planting
Genotype NEC-30 NEC-144 NEC-266 NEC-239 NEC-1540 NEC-1656 NEC-2305 Syrian local LSD (0.05) Mean LSD (0.05) CV%
Table
3.
Dec 4
Dec 29
Feb 2
Mar 6
Mean
1820 1409 1468 1954 1907 2142 1744 1689
1662 1576 1576 1900 1868 1918 1487 1804
1639 1031 1294 1531 1618 1542 1241 1422
787 572 954 809 768 741 698 955
1477 1147 1323 1548 1541 1586 1292 1467
1767
1724
1415
215.6
438.8 666 211.7 18.5
Effect of date of planting on m e a n height, number of branches, and number of pods per plant of eight genotypes of chickpea at Tel Hadia, Syria, 1977—78. Date of planting
Attribute Plant height (cm) N u m b e r of branches/plant N u m b e r of pods/plant
Table 4.
Dec 4
Dec 29
Feb 2
Mar 6
34.0 6.5 22.0
32.3 6.5 19.4
26.7 5.6 13.9
22.3 5.0 10.9
T h e effect of date of planting and plant population on the grain yield ( k g / h a ) of Syrian local and N E C - 2 3 0 0 cultivars of chickpea at Tel Hadla, Syria, 1 9 7 7 - 7 8 . Date of planting
Cultivar/population level Cultivar Syrian local NEC-2300
Dec 4
1732 1412
1004 928
1487 1657
947 984
1572
966
LSD ( 0 . 0 5 ) CV%
1132 997 138.4
1022 1107
632 681 49.4
85.6
LSD (0.05) Mean
Mean
661 652 239.6
LSD (0.05) Population per ha 185 000 278 000
Mar 6
Feb 2
657 169.5 14.3
91
Plant Population and Planting Geometry The o p t i m u m level of plant p o p u l a t i o n seems to differ d e p e n d i n g upon the e n v i r o n m e n t a l conditions and the plant type. In a congenial envir o n m e n t that permits an adequate period for vegetative and reproductive g r o w t h , m o s t of the g e n o t y p e s s h o w little change in yield w i t h large variations in p o p u l a t i o n , as has b e c o m e evident f r o m studies carried out in north India (Panwar 1978; Saxena and Sheldrake 1977; Saxena and Singh 1977). Most of these and earlier studies suggest that a population level of about 33 plants/m 2 is adequate. If plant g r o w t h is restricted by an unfavorable aerial e n v i r o n m e n t the response to plant population varies w i t h the availability of soil moisture. Studies at Tabriz s h o w e d that yield increased w i t h increasing plant population up to 50 plants/m 2 for irrigated chickpea, whereas for unirrigated chickpea the o p t i m u m level was 24.8 plants/m 2 (Anon. 1976). Kostrinski (1974) observed a 5 2 % increase in yield w h e n the population level of winter chickpea in Israel was doubled by reducing the r o w spacing to 30 cm f r o m the usual 60 cm spacing. Significant increase in yield of rainfed chickpea at Tel Hadia, Syria, d u r i n g 1977-78 was obtained as the population was raised f r o m 18.5-27.8 plants/m 2 only in t h e winter planted crop (4 Dec 1977) and not in the March planting (Table 4).
Table 5.
The response of winter and spring planted chickpea, raised w i t h supplemental irrigation, was studied to increasing plant density in a fan-type design at Tel Hadia in 1977-78 using genotypes of differing g r o w t h habit. The yield generally increased as the population level was raised f r o m 4.4 to 71.7 plants/m 2 (Table 5). Genotypic differences in response to plant population have been frequently observed (Panwar 1978; Saxena and Sheldrake 1977; Saxena and Singh 1977). Studies at the ICARDA site in Tel Hadia (Table 5) indicated that an increase in yield due to increased plant p o p u lation was of greater magnitude in NEC-141, a relatively compact and upright-growing genotype, than in the Syrian local cultivar, which had a spreading g r o w t h habit. In a separate study at the same site w i t h spring planted chickpea raised w i t h supplemental irrigation, the yield increased by 28 and 6 2 % in NEC-249 and NEC-138 chickpea respectively, as the population was raised f r o m 16.6 to 50 plants/m 2 . Both these genotypes had a s o m e w h a t compact and upright g r o w t h habit. In contrast to this, NEC-1540 and Syrian local, t h e t w o spreading types, s h o w e d relatively less increase in yield w i t h the increase in p o p u l a t i o n . Planting geometry does not seem to have a conspicuous effect on crop performance at an adequate level of plant population. Studies at ICRISAT (Saxena and Sheldrake 1976) c o m pared rectangularity ranging f r o m 1 to 12 during
Yield of Syrian local and NEC-141 chickpea, g r o w n at Tel Hadia, 1 9 7 7 - 7 8 , supplemental irrigationa, as affected by plant population varied in a fan-type design. Grain y i e l d (kg/ha) Winter
Plant p o p u l a t i o n (plants/m 2 )
Syrian local
NEC-141
Syrian local
NEC-141
784 1051 1294 1023 1357 1721 2535 2811 3041
495 729 840 1076 1133 1616 2143 2773 2868
629 764 673 772 991 1295 1158 1707 2223
292 311 617 758 637 778 1020 1471 2008
4.4 6.3 9.2 13.4 23.6 28.4 41.3 48.9 71.7 a . Crop w a s i r r i g a t e d t w o t i m e s i n t h e s p r i n g .
92
Spring
the 1 9 7 5 - 7 6 crop season. Based on this and previous studies, it was concluded that there was no need for square planting of chickpea in Hyderabad. Studies at ICARDA during 1977-78 w i t h rectangularity ranging f r o m 1.6 to 6.66 at 18.5 plants/m 2 and 2.5 to 6.0 at 27.8 plants/m 2 plant p o p u l a t i o n level revealed that there was no significant effect of this on t h e yield of Syrian local and NEC-2300 chickpea. Effect of variations in the seed size w i t h i n a cultivar and the r o w direction was studied at Hyderabad and Hissar by Saxena and Sheldrake (1976). The yield was not affected by these variables in all the genotypes studied.
Fertilizer Use Total uptake of nitrogen by a chickpea crop has been estimated to vary f r o m 6 0 - 1 4 3 kg/ha, depending u p o n the g r o w i n g conditions of the crop (Saxena and Sheldrake 1977). These estimates are very near to the ones m a d e earlier (Saxena and Yadav 1975). Positive response to starter nitrogen dressing of about 1 5 - 2 5 kg N/ha has been reported by several workers on the sandy and sandy loam soils poor in organic matter (Tripathi et al. 1975; Sharma et al. 1975; Chundawat et al. 1976; Rathi and Singh 1976). No such response, however, has been obtained on soils of relatively better fertility status (Chowdhury et al. 1975; Raikhelkar et al. 1977; Saxena and Singh 1977; Dhingra et al. 1978). Symbiotic N fixation apparently seems to be effective enough in most of these areas to meet the major nitrogen need of the crop. Studies by Saxena and Sheldrake (1976) on the effect of starter N dressing (20 kg N/ha) on nodulation and crop g r o w t h revealed that there w a s no adverse effect on the former and the early crop g r o w t h was slightly i m proved. The positive effects, however, became less and less conspicuous w i t h the advancement in age and, therefore, no yield advantage was obtained. In areas w h e r e n o d u l a t i o n has been either very poor or has completely failed, significant response to increasing rates of N application have been obtained. Experiments at Hudeiba Research Station in Sudan, f r o m 1973-1976, w i t h irrigated chickpea have s h o w n such positive responses up to 120 kg N/ha. Split application (1/2 at seeding and 1/2 at flowering) was f o u n d to be better than a complete, single
application, particularly w h e n an intermediate a m o u n t of N (80 kg N/ha) was used. During the 1977-78 crop season, chickpea nurseries at ICARDA in Tel Hadia had to be topdressed w i t h nitrogen as they had poor nodulation and showed nitrogen deficiency s y m p t o m s . No chickpea had been g r o w n on that site in the recent past, and the nursery seeds w e r e not inoculated w i t h Rhizobium culture. Phosphorus uptake has been reported to range f r o m 5 to 10 kg/ha, depending u p o n t h e crop g r o w t h conditions (Saxena and Sheldrake 1977). The latter also affected the course of P accumulation. Considerable attention has been paid to the response of chickpea to phosphate fertilization. Positive response to phosphate application (up to 50-75 kg P2O5/ha) has been obtained at Delhi (Chowdhury et al. 1975), at Kanpur (Rathi and Singh 1976; Panwar et al. 1977), in Rajasthan (Chundawat et al. 1976), and at Jabalpur (Sharma et al. 1975) in India. The soils used were reported to be l o w in available phosphorus content. Panwar et al. (1977) analyzed the phosphate response for 2 years at Kanpur and 1 year at Bareilly and f o u n d that the response was quadratic. The mean yield equation was given as Y = 2090.7 + 17.182X- 0.1488X2 where Y is yield (kg/ha) and X is kg of P 2 O 5 /ha. In contrast to these observations, several other investigators have f o u n d no positive response to phosphorus application even in soils testing m e d i u m to l o w in available phosphorus (Srivastava and Singh 1975; A n o n . 1976; Saxena and Sheldrake 1976,1977; Raikhelkar et al. 1977; Saxena and Singh 1977; Dhingra et al. 1978). Lack of response to phosphate application could not be attributed to reduced soil moisture availability, as even under irrigated conditions no response was obtained (Saxena and Sheldrake, 1976, 1977; Raikhelkar et al. 1977; Saxena and Singh 1977). Even different methods of application, including soil incorporation of phosphate in a preceding rainy season or just before planting, or deep placement, had no effect on chickpea g r o w n on soil testing l o w in available phosphate ( 2 - 5 ppm) during 1 9 7 5 76 at Hyderabad in the studies carried out by Saxena and Sheldrake (1976). Analysis of the soil at the end of the crop season in their 1975-76 and 1976-77 studies revealed that the p h o s p h a t e fertilization d i d not increase the available phosphate status of t h e soil.
93
Therefore, it was concluded that the high phosphate-fixing capacity of the soil was responsible f o r lack of crop response to applied phosphate. It may be m e n t i o n e d , however, that d u s t i n g t h e crop w i t h finely g r o u n d rock phosphate and single superphosphate also had no s t i m u l a t o r y effect under similar soil conditions (Saxena and Sheldrake 1977). At t h e same t i m e , in none of these studies w e r e any apparent s y m p t o m s of phosphate deficiency noted on t h e crop. Studies at ICARDA have revealed that chickpea failed to respond to phosphate fertilization on the same soil on w h i c h lentil and b r o a d b e a n s h o w e d p h o s p h a t e deficiency s y m p t o m s w i t h o u t P and g r o w t h p r o m o t i o n w i t h P fertilization. All this points to the possibility that chickpea might be mor e efficient in uptake and utilization of soil phosphorus. Lately, considerable interest has been s h o w n in the use of foliar spray of N, P, K, and S solution at the t i m e of p o d filling in f o o d legumes f o l l o w i n g t h e observations of Hanway (1976) that such spray could increase the yields of a w e l l - m a n a g e d crop of soybean. Studies carried out at Pantnagar (India) during 1976-77, as a part of the Coordinated Research Program of the International A t o m i c Energy Agency and FAO J o i n t Division, revealed that there was no i m p r o v e m e n t in the yield of chickpeas f r o m
Table 6.
foliar spraying of Hanway solution (Table 6). Labelling of fertilizer nitrogen w i t h N 1 5 and using a n o n n o d u l a t i n g crop of linseed, we estimated the symbiotic N fixation of the chickpea crop receiving 20 kg N/ha as starter dressing to be 63 kg N/ha, w h i c h was 9 2 % of total N yield in the crop. Soil and foliar application of m o r e N reduced the symbiotic N fixation. A n u m b e r of cultivars of chickpea, w h e n g r o w n on high pH soils rich in calcium carbonate, s h o w typical s y m p t o m s of iron deficiency. The deficiency has been observed at Hyderabad (Saxena and Sheldrake 1977) and at various ICARDA sites in Syria and Lebanon. Local kabuli cultivars f r o m Syria and Lebanon do not s h o w any such deficiency, whereas s o m e of the desi cultivars, particularly NEC-2300, NEC-2304, and NEC-2305, s h o w very conspicuous s y m p t o m s early in the season. Saxena and Sheldrake (1977) obtained a 4 2 % increase in the yield of susceptible cultivars (ICC-1685 and ICC-10157) f r o m spraying a 0.5% w/v ferrous sulfate solution near t h e b e g i n n i n g of reproductive g r o w t h and a f o r t n i g h t later. No further advantage was obtained w i t h repeated spraying. On soils testing l o w in available zinc, s y m p t o m s of zinc deficiency have been observed early in the crop season. Conspicuous varietal differences have been observed in the
Chickpea response to soil-applied N and ( 8 0 N + 8P + 2 4 K + 4S) at Pantnagar, 1 9 7 6 - 7 7 .
foliar
spray
of
Hanway
solutiona
Treatment Yield (kg/ha)
At p o d filling At seeding
T o p dress
0 0 20 kg Nb 20 kg Nb 20 kg Nb 20 kg Nb 20 kg N 20 kg N F test S.E.M. ± C.V. (%)
0 0 0 0 20 kg Nb 20 kg Nb 20 kg Nb 80 kg Nb
Foliar spray
Grain
Total dry matter
0 + (N)b 0 + (N)b 0 + 0 +
1725 1581 1865 1514 1610 1520 1490 1347 NS 150 24
2815 2594 2989 2466 2780 2504 2466 2249 NS 265 21
a. Foliar spray of H a n w a y s o l u t i o n w a s a p p l i e d f o u r t i m e s to p r o v i d e a t o t a l of 80 kg N, 8 kg P, 24 kg K, a n d 4 kg S/ha. b. N labelle d w i t h N 1 5 .
94
susceptibility to zinc deficiency. The deficiency can be corrected by a foliar spray of 0.5% w/v zinc sulfate solution (Saxena and Singh 1977). Positive yield response to soil application of 25 kg zinc sulfate/ha has been observed at Ludhiana, India (Dhingra et al. 1978). Recent studies at Kanpur, India (Panwar 1978), have s h o w n that soil application of 1 kg s o d i u m molybdate/ha increased the seed yield of T-3 chickpea by 19% over t h e d i a m m o n i u m phosphate-applied check and by 3 8 % over the absolute control.
Water Requirement and Irrigation The potential evapotranspiration of a chickpea crop, as c o m p u t e d by the T h o r n t h w a i t e formula, under the conditions of Hissar (India), ranged f r o m 204 to 280 m m , depending on the crop season (Sharma et al. 1974). Studies m a d e by Gupta and A g r a w a l (1976) at Jabalpur (India) indicated that c o n s u m p t i v e use of water based on water balance in the root zone was 247, 257, and 290 mm for the JG-62 variety of chickpea under 0, 1, and 2 irrigations, respectively. A l t h o u g h most of the chickpea crop in the w o r l d is g r o w n on moisture conserved in the soil f r o m the rain received prior to planting, the crop responds favorably to supplemental irrigation (Sharma et al. 1974; Kaul 1976; Koinov and Vitkov 1976; Raikhelkar et al. 1977; Panwar 1978; Sharma 1978). Irrigation d u r i n g the preflowering period (at the early stage of vegetative g r o w t h on soils having l o w waterholding capacity and at the late vegetative phase on heavier and deeper soils) and at early pod filling stage has consistently resulted in increased yields at several locations in India (Kaul 1976; Raikhelkar et al. 1977; Saxena and Singh 1977; Panwar 1978; Sharma 1978). Irrigation improved the nodulation and increased the per plant yield by increasing the pod number (Kaul 1976).
after planting has been very effective in c o n t r o l ling weeds, several herbicides have also given p r o m i s i n g results. Laptiev (1976) reported that the application of 1 - 3 kg Gesagard 50 (prometryne) or A 3623 (terbuthylazine + terbutryne) per ha decreased the population of annual weeds b y 7 0 - 8 0 % and increased seed y i e l d . Preemergence application of 1.5 kg a.i./ha of nitrofen or 0.5 kg a.i./ha of p r o m e t r y n e w e r e found to be very effective at Kanpur (Panwar and Pandey 1977). Pre-plant incorporation of 1 kg a.i./ha of Basalin gave g o o d weed control on silty-clay loam soils of Pantnagar (Singh et al. 1978). Pre-plant application of Basalin (48 EC) at the rate of 1 kg product/per ha was f o u n d effective on the sandy loam soils of Ludhiana (Sandhu et al. 1978). Preemergence application of 1 kg product of either terbutryne (80% WP) or Lorox (50% WP) also proved highly p r o m i s i n g . It is apparent f r o m the foregoing that no single herbicide is effective for all conditions and the choice of herbicide as well as its rate of applicat i o n w i l l vary depending upon the nature of weed infestation and the soil type.
References A G E E B , O. A. A., and A Y O U B , A. T. 1977. Effect o f
s o w i n g date and soil t y p e on plant survival and grain yield of chickpea (Cicer arietinum L ) . J o u r n a l of Agricultural Science U.K. 8 8 ( 3 ) : 5 2 1 - 5 2 7 . A N O N Y M O U S . 1976. A n n u a l Report of 1975 on grain legumes, Tehran University School of A g r i c u l t u r e , Karaj, Iran. B E Z U N E H , T. 1975. Status of chickpea p r o d u c t i o n and research in Ethiopia. Pages 9 5 - 1 0 1 in International W o r k s h o p on Grain Legumes, ICRISAT, H y d e r a b a d , India. C H O W D H U R Y , S. L., R A M , S., and GIRI, G. 1975. Effect of
P, N and i n o c u l u m on root, n o d u l a t i o n a n d yield of g r a m . Indian J o u r n a l o f A g r o n o m y 2 0 ( 3 ) : 2 9 0 - 2 9 1 . C H U N D A W A T , G. S., S H A R M A , R. G., S H E K H A W A T , G. S.
Weed Control Crop yield losses due to weeds have been estimated to range f r o m 30 to 50% (Panwar and Pandey 1977; Sandhu et al. 1978; Singh et al. 1978). Whereas hand w e e d i n g at 30 and 60 days
1976. Effect of N, P and bacterial fertilization of g r o w t h and yield of g r a m in Rajasthan. Indian Journal of A g r o n o m y 21(2):127-130. D H I N G R A , K. K., S E K H O N , H. S., and T R I P A T H I , H. P. 1978.
Pages 2 9 - 3 1 in Pulses a g r o n o m y progress report 1977-78, Departmen t of Plant Breeding, P A U , Ludhiana: 2 9 - 3 1 .
95
G U P T A , R. K., and A G R A W A L , G . G. 1976. C o n s u m p t i v e
use of w a t e r by g r a m and linseed. Indian J o u r n a l of A g r i c u l t u r a l Science 4 7 ( 1 ) : 2 2 - 2 6 . H A W T I N , G.
C.,
S I N G H , K. B., and S A X E N A , M. C.
1978.
S o m e recent d e v e l o p m e n t s in t h e u n d e r s t a n d i n g and i m p r o v e m e n t of chickpea and lentil. International L e g u m e Conference, Royal Botanical Gardens, Kew, England, 31 J u l y - 5 A u g 1978. K A U L , J. N. 1976. Pulses a g r o n o m y report of 1 9 7 5 - 7 6 , Plant Breeding D e p a r t m e n t , P A U , Ludhiana. K A U L , J . N., and S E K H O N , H. S. 1976. P e r f o r m a n c e of
three chickpea (gram) g e n o t y p e s , as affected by t h e dates of s o w i n g and r o w spacing. Crop I m p r o v e ment 3(1/2):22-26. KOINOV,
G.,
and
VITKOV,
M.
1976.
Investigation
of
irrigation r e g i m e f o r chickpea on podzolized chernozem soils in northeastern Bulgaria. R a s t e n i e v " d n i Nauki 1 3 ( 8 ) : 5 9 - 6 2 . K O S T R I N S K I , J. 1974. P r o b l e m s in chickpea cultivation and g r a i n crop r o t a t i o n in Israel. Special Pubin., Agric. Res. O r g . , Volcani Centre, N o . 34, 51 pp. LAPTIEV, A. 1976. Chemical c o n t r o l of w e e d s in chickpea. T u r d y , N a u c h n o - i s s l e d o v a t e l ' s k i t . Institut Zashchity Rastenii N o . 1 2 : 1 5 0 - 1 5 8 . P A N W A R , K. S. 1978. Latest t e c h n o l o g y f o r cultivation of g r a m . All-India Subject Matter S e m i n a r on Pulse Production T e c h n o l o g y (Rabi Pulses) held at C.S.A. Univ. of A g r i c . Tech., Kanpur, 2 8 - 3 0 A u g u s t 1978. P A N W A R , K. S., and PANDEY, K. 1977. W e e d control studies in Bengal g r a m . Indian J o u r n a l of A g r o n o m y 22(4):257-259. P A N W A R , K. S., S I N G H , Y. P., S I N G H , U. V., and M I S R A ,
S A X E N A , N. P., and SHELDRAKE, A. R.
1976. Pulses
p h y s i o l o g y annual report 1 9 7 5 - 7 6 , Part II: Chickpea p h y s i o l o g y , ICRISAT, H y d e r a b a d , 176 pp. S A X E N A , N. P., and SHELDRAKE, A. R.
1977. Pulses
p h y s i o l o g y annual report 1 9 7 6 - 7 7 , Part II: Chickpea p h y s i o l o g y , ICRISAT, H y d e r a b a d , 179 pp. S A X E N A , M . C., and S I N G H , H. P.
1977. S t u d i e s o n
a g r o n o m i c r e q u i r e m e n t s of w i n t e r pulses. Pages 2 3 - 4 2 in Research on W i n t e r Pulses, G.B.P. U n i v . of Agric. and Tech., Exp. Sta. Bull. 101. 2 3 - 4 2 . S A X E N A , M . C., and Y A D A V , D. S.
1975. S o m e a g -
ronomic considerations of pigeonpea and chickpeas. Pages 3 1 - 6 1 in International W o r k s h o p on Grain L e g u m e , ICRISAT, H y d e r a b a d , India. S E N , S. N. 1978. Studies on suitability of t h e different i m p r o v e d t y p e s of g r a m under early and late s o w i n g c o n d i t i o n s . 1977-78 A g r o n o m y report of pulses a n d oil seeds research station, B e r h a m p u r , W. Bengal. S H A R M A , J. 1978. Report of the a g r o n o m y section of the pulses i m p r o v e m e n t project at University of A g r i c , U d a i p u r Research Station, D u r g a p u r a , 1977-78. S H A R M A , H.
C.,
T E J S I N G H , and M O H A N , D. S.
R.
1974.
Response of g r a m varieties to irrigation.Haryana Agricultural University Journal of Research 4(4):255-260. SHARMA,
P.
P.,
SINGH,
P.,
and
SINGH,
P.
P.
1975.
Response of N a n d P in relation to m e t h o d of application on the yield of g r a m (Cicer arietinum). JNKVV Research J o u r n a l 9 ( 1 / 2 ) : 2 1 - 2 3 . S I N G H , N.
P., S I N G H , H.
P., S A H U , J.
P., and S H A R M A ,
B. B. 1978. 1977-78 Report on the a g r o n o m y of rabi pulses, G. B. Pant University of Agric. a n d Tech., Pantnagar.
A. S. 1977. Response of g r a m , lentil, and field peas to inoculation a n d levels of n i t r o g e n a n d p h o s p h o r u s . Indian J o u r n a l o f A g r o n o m y 2 2 ( 3 ) : 1 4 5 - 1 4 8 .
S R I V A S T A V A , S. P., and S I N G H , A. P. 1975. P h o s p h o r u s
RAIKHELKAR, S. V., Q U A D R I , S. J . , and B A G A D E , D. N.
fertilization in g r a m under d r y l a n d c o n d i t i o n s . Science a n d Culture 4 1 ( 1 1 ) : 5 2 7 - 5 2 8 .
1977. Irrigation and fertilizer r e q u i r e m e n t of g r a m . J o u r n a l of M a h a r a s h t r a A g r i c u l t u r a l Universities 2(2): 1 4 4 - 1 4 7 . R A T H I , S. S., and S I N G H , D. 1976. Effect of nitrogen and p h o s p h a t e fertilization on the g r o w t h a n d y i e l d of g r a m . Indian J o u r n a l o f A g r o n o m y 2 1 ( 3 ) : 3 0 5 - 3 0 6 . S A N D H U , K. S., K O L A R , J. S., K A L S I , N. S., and S I N G H , S.
1978. Chemical w e e d c o n t r o l in irrigated g r a m . J o u r n a l of Research, PAU 15.
96
TRIPATHI,
R.
S.,
DUBEY,
C.
S.,
KHAN,
A.
W.,
and
A G R A W A L , K. B. 1975. Effect of application of Rhizobium i n o c u l u m on t h e yield of g r a m varieties in C h a m b a l C o m m a n d area of Rajasthan. Science and Culture 4 6 ( 6 ) : 2 6 6 - 2 6 9 .
VAN DER M A E S E N , L. J. G. 1972. Cicer L. A m o n o g r a p h of the g e n u s w i t h special reference to chickpea (Cicer arietinum), W a g e n i n g e n , T h e Netherlands.
Effect of Edaphic Factors on Chickpea S. Chandra*
In nature's agricultural e n v i r o n m e n t soils play the vital role of a m e d i u m for plant nutrition and productivity. Productivity can be tremendously enhanced by addition of inputs such as fertilizers, water, and soil amendments. Alternatively, and preferable to such inputs is the development, utilization, and perpetuation of i m p r o v e d plant types. Unfortunately, such a simple and straightforward application of technology is often not possible. This is the case w i t h saltaffected soils or w h e r e only saline water is available for irrigation to crops. Soil salinity occurs w h e n the soil solution contains salts in such proportions or quantities that plant g r o w t h is adversely affected. The lower limit for a saline soil is conventionally set at an electrical conductivity of 4 m m h o s / c m in the saturated soil extract (USDA Handbook 60, 1954). Alkali soils, the other type of salt-affected soils, are those characterized by high pH, and exchangeable sodium that occupies m o r e than 15% of the cation-exchange sites. In the so-called salinesod ic soils, where a high salt content in soil solution is associated w i t h a high s o d i u m absorption ratio, the effects of salinity pred o m i n a t e over those of sodicity. Thus, soils may be described as saline or sodic, depending on the t y p e of p r o b l e m created. In brief, salinity causes nutritional imbalances and specific ion deficiencies, especially w i t h regard to Ca, M g , and K, w h i l e excessive uptake of Na causes toxic effects on plants. Sodicity, on the other hand, is associated w i t h poor physical soil conditions that cause p r o b l e m s of root aeration, hydraulic permeability, high bulk density, and physical i m p e d i m e n t to root g r o w t h and its activity. Both salinity and sodicity cause problems w i t h w a t e r availability and water transport in plants, a condition that is sometimes referred to as physiological drought. In India and Pakistan, w h e r e the bulk of the * Central Soil Salinity Research Institute, Karnal, India.
World's chickpea (Cicer arietinum L.) is cultivated, there is a history of domestication of this crop under adverse edaphic environments. Indeed, the crop has earned such titles as "risk insurance c r o p , " " f a r m e r s ' friend in adversity,'' and so f o r t h . M o r e recently in this subcontinent, it has been pushed further into cultivation under increasingly adverse conditions w h e r e b y its productivity has been adversely affected. In the present discussion, an effort has been m a d e to present s o m e effects of soil salinity, sodicity, and soil-water deficit on the chickpea plant. In my treatment of the edaphic factors of chickpea, I m i g h t be expected to deal w i t h the situation as a soil scientist or a physiologist. Since I am a plant breeder, however, my treatment will be characterized by the limitations inherent in such an approach.
Methods of Determining Response to Salinity Field conditions representing typically adverse environments m i g h t be ideal to study plant response, but field experimentation is not always the best way because of the inherent heterogeneity in the field. Moreover, control over s o m e of the contributing side factors may not be possible in the field. Thus, there is a vast variety of techniques used by different workers to evaluate plant response to salinity and water deficit, using nutrient media, culture, lysimeters, pots, even blotting papers and petri dishes, and they also look at different g r o w t h stages w h i c h are apparently differentially sensitive to stress. Efforts are therefore required to standardize the techniques employed so that data obtained f r o m different sources may be intercorrelated and c o m p a r e d . Our Institute has been emphasizing this aspect of work related to studying plant responses; however, much of the w o r k d o n e in this direction pertains to cereals. We feel there may be a useful application of this work to legumes.
97
Plant yield is recognized as t h e m o s t w o r t h w h i l e attribute for deducing relative tolerances of crop species and cultivars w i t h i n a crop. Using t h i s approach, chickpea (gram) has been classified as one of t h e m o s t sensitive crops to both alkali (Table 1) and saline soils (Table 2). In this context, it m a y be desirable to describe briefly t h e standard measures of tolerance based on y i e l d w h i c h are being used by us to ascribe a relative level of salt tolerance to a test material. It is interesting that, if necessary, besides y i e l d , other test criteria could be utilized in a similar approach to c o m p a r e test materials. For instance, t h e relative level of saltaffectedness w h i c h causes 5 0 % reduction in
Table 1.
Tolerant
Relative tolerance of crops to exchangeable s o d i u m (alkali soils). Semi-tolerant
Sensitive
Rice
Barley
Dhaincha Sugar beet Spinach Turnip
Wheat Sugarcane Raya Cotton
Cotton (at g e r m i n a t i o n ) Maize Groundnut Peas Cowpeas
Paragrass
Berseem Senji Bajra Sorghum Potato Watermelon
Mung Mash Lentils Sunflower Guar Gram
yield as c o m p a r e d to n o r m a l soil in t h e y i e l d test may be d e t e r m i n e d using graded levels of salt-affectedness in the soil. Thus, in Figure 1, the g e n o t y p e A w h i c h reaches 50% of its yield in a n o r m a l soil, at a lower level of saltaffectedness than either B or C, is less tolerant t h a n the latter, t h e order of descending tolerance being C, B, A. A n o t h e r m e t h o d is to determine the slope of t h e response curve in the additive response range. Thus in Figure 2, g e n o t y p e B is m u c h less tolerant t h a n A or C. However, A is m o r e tolerant t h a n B at l o w salt levels by virtue of a peak s h o w i n g favorable response to l o w or moderate salt-affectedness. Maas and Hoffman (quoted by Framji 1976) used these slopes to quantify relative crop tolerances to salinity (Table 3) and even worked out an equation that can be called the Maas and Hoffman equation to obtain yield for a given soil salinity exceeding the threshold level. Thus, Y = 100-B (ECe - A) w h e r e Y is the predicted yield at threshold level A, measured as ECe (mmhos/cm), and B represents the percentage of decrease in yield per unit of salinity increase. In certain cases w h e r e economic yield levels
A
B S o u r c e : A b r o l et a l . (1973).
Table
2.
C
Relative tolerance of crops to salinity (saline soils).
Tolerant
Semi-tolerant
Sensitive
Date p a l m Barley Sugar beet Spinach
Pomegranate Wheat Oats Rice Sorghum Maize Sunflower Potato
Citrus Cowpeas Gram Peas Groundnut Guar Lentils Mung
Rape Cotton
S o u r c e : A b r o l et al. (1977).
98
Salt-affectedness Figure
1.
The inging yield
extent about
as
tolerance
a
of salt a
means
among
affectedness
50%
reduction of
relative
genotypes.
brin salt
under graded soil conditions d r o p off rather sharply beyond a threshold value, it m a y be advisable to test yield performance at the saltaffect threshold value. The lines representing above-average performance w o u l d be relatively m o r e tolerant t h a n the average ones, and
A
likewise, the below-average lines w o u l d be intolerant ones. A character such as g e r m i n a t i o n percentage could be used in the above measures to classify test cultivars. It has been f o u n d that the above three parameters are rather independent and do not necessarily give the same picture of relative tolerances. They w o u l d perhaps represent different categories of tolerance and thus help to attribute diversity of tolerance.
B
Determining Biochemical Parameters
C
Salt level Figure
2.
Slope sure different
Table 3.
of
of response curve as relative
salt
a
tolerance
meaof
genotypes.
We have s h o w n interest in identifying s o m e biochemical parameters w h i c h quantify relative tolerance to salinity. It was indicated that the f o l l o w i n g w o u l d constitute relative tolerance in cereals: (1) high accumulation of free proline, an amino acid, in the seedling leaves; (2) high K/Na uptake ratio in leaves at the tillering stage; and (3) high inorganic P status in leaves at the rank g r o w t h stage. A l t h o u g h evidence in favor of the above conclusions has been recorded on previously classified representative tolerant, semi-tolerant, and intolerant genotypes, their use in defining variability for tolerance has been rather limited, especially as regards items (1) and (3) above.
C r o p y i e l d r e s p o n s e s t o soil s a l i n i t y .
Crop
Salinity level at initial yield decline (mmhos/cm)
% Yield decrease per unit increase in salinity b e y o n d threshold level (mmhos/cm) 5.0 7.1
Salinity tolerance rating a
Barley (Hordeum vulgare) W h e a t (Triticum aestivum) Rice (Oryza sativa) Maize (Zea mays) Bean (Phaseolus vulgaris)
8.0 6.0 3.0 1.7 1.0
12.0 12.0 19.0
T MT MS MS S
Cotton (Gossypium hirsutum) Sugarcane (Saccharum officinarum) Sugar beet (Beta vulgaris) Alfalfa (Medicago sativa) Berseem (Trifolium alexandrinum) B e r m u d a grass (Cynodon dactylon)
7.7 1.7 7.0 2.0 1.5 6.9
5.2 5.9 5.9 7.3 5.7 6.4
T MS T MS MS T
S o u r c e : M a s s a n d H o f f m a n a s q u o t e d b y F r a m j i (1976). a. T = T o l e r a n t ; MT = M e d i u m t o l e r a n t ; MS = M e d i u m sensitive; S = Sensitive.
99
Pot Studies of Genotypes Since chickpea is o n e of t h e m o s t sensitive of t h e crops, even a m o n g legumes (Fig. 3), it does not offer itself as a suitable material to study variability based on yield-based criteria. Thus, a m o r e p r e l i m i n a r y level of evaluation has had to be e m p l o y e d in looking at its response pattern. Field conditions are not t h e best w a y to examine these responses because of heterogeneity. T h u s porcelain pots have been u s e d , w h e r e t h e soil w a s b r o u g h t up to a desired level of salinity and seeding w a s d o n e in t h e pots. Irrigation w a s not applied as usual (from the top) because of its adverse effects on soil c o n d i t i o n . Rather, t h e pots w e r e allowed to stand in water m a d e up to a calculated salinity value that w o u l d not substantially alter t h e salt-affectedness of t h e soil. Different genotypes had a differential response to a soil salinity of 5.8 ± 0.2 ECe (mmhos/cm). In the case of G-24, t h e g e r m i n a t i o n w a s n o r m a l but the g r o w t h w a s arrested almost s o o n after. In the variety E-100Y (ICRISAT source), stem elongation was not very
m u c h affected t h o u g h g e r m i n a t i o n w a s c o m paratively less. In the case of C-235, there was succulence and greening coupled w i t h a reduct i o n in g r o w t h under saline conditions. The g e n o t y p e H 75-36 appeared to be relatively less affected. M o r e frequent irrigation had to be given to saline pots w h e r e the general w i l t i n g appeared rather soon compared to normal pots. Also, the b o t t o m p o r t i o n of t h e stem in saline soil appeared to s h o w a degree of d e c o m p o s i t i o n , w h i c h w a s generally related to sensitivity of genotype. During the progress of g r o w t h , different genotypes became progressively affected and mortality began to rise w i t h advancement of age. Even in lines that registered g o o d g e r m i nation and good survival, many failed to flower or set seed (Table 4). Only seven varieties set any seed at all, of w h i c h H 75-36, L-550, and RG-2 may be considered w o r t h m e n t i o n i n g because others put up only one or t w o seeds. Singh et al. (1974) and Singh (1975) tried to establish that in cereals the ability to accumulate free proline in leaves w a s correlated w i t h
2.0
Indian
clover
Gram
Lentil
1.5
Shaftal
clover
Berseem
clover
1.0
0.5
0
Figure
10
3.
Dry-matter percentage.
100
20
yield
of
30 40 50 Exchangeable sodium percentage some
winter
legumes
as
affected
by
60
soil
exchangeable
70
sodium
Table 4.
N a t u r e o f r e s p o n s e o f c e r t a i n c h i c k p e a v a r i e t i e s t o soil s a l i n i t y ( E C e cm).
Response
5.8 ± 0.2 m m h o s /
G e n o t y p e (s)
l.
Germination: delayed, poor Survival : very poor
BG-211, BEG-482, Bengal g r a m , F-378, GG-550, GL-629, JG-1254, KE-30, L-345, Pant G-121, WF-WG
II.
G e r m i n a t i o n : not m u c h d e l a y e d , extent g o o d Survival : low
850-3/27, P-1353, P 1358-3, P-9800
III.
Germination: good Survival : good
NEC-240, NEC-50, P-416, P-257, P-662, P 1305-1, USA-613 ( + g e n o t y p e s in IV, V)
IV.
Reproductive ability not a t t a i n e d
C-235*, JG-35, P-6625 ( + g e n o t y p e s in III)
V.
Reproductive ability attained
C-214, E-100, H-208, H 75-35, H 75-36, L-550. RG-2
* Classification d o u b t f u l .
salt tolerance. In t r y i n g to obtain similar data on chickpea (Table 5), we f o u n d variable trends in the genotypic behavior of certain genotypes. A m o n g the genotypes which could be carefully evaluated, H 75-36 and L-550, the most tolerant ones (Table 4), s h o w e d this ability. However, w i t h regard to other genotypes, the situation was reverse, i.e., the proline content was lower under salt stress than in unstressed. Other genotypes w h i c h indicated a tendency to accumulate proline did not belong to the m o r e tolerant category. However, under the d r o u g h t stress, increase in proline was very c o m m o n and only three varieties, i.e., Annigeri, P-1148, and BEG-482 failed to record a rise in free proline content under drought stress. Apparently the level of salinity at w h i c h these genotypes w e r e tested did not cause a p r o b l e m of water potential in the plant and the expression of most genotypes was in response to ion imbalance or toxicity. However, detailed observations in this direction are necessary.
Chickpea in Sodic Soils Sodic soils are widespread in the area w h e r e chickpea enjoys large acreages in India. Because of the p r o b l e m s of root aeration and physical soil properties, these soils are very
Table 5.
A c c u m u l a t i o n of free proline in certain chickpea varieties under d r o u g h t and salinity stress. Leaf p r o l i n e (μg/g d r y weight)
Variety
Without stress
Salinity stress (ECe 5.5-6.2)
C-235 C-214 G-24 G-130 H-208 E-100Y
7680 2315 2775 6357 4985 6905
9308 2458 4630 2402 2400 1850
JG-221 BG-203 BG-109 L-550 P-6625 P-4356 H 75-35 H 75-36
2535 3567 2763 2340 900 6910 2647 2558
727 3323 4568 5091 9262 1855 2600 4203
4 422 6817 5913 11 370 11867 7 861 3 778 11471
Annigeri Jyoti P-1148 P-1231 P-692 BEG-408
7868 2674 3725 4832 5016 7055
3656 2315 7365 5211 4775 2773
4 3 3 12 10 3
Drought stress ( > 1 5 bars) 9 3 9 4 4 1
876 759 657 462 973 680
568 559 547 133 357 105
101
inhospitable to chickpea. During the early years of work at CSSRI, attempts w e r e made to raise a n u m b e r of crops on such soils by first t r y i n g to i m p r o v e their physical and chemical properties in the t o p 15 cm t h r o u g h the application of g y p s u m . Results of the experiment (Table 6) to study the behavior of this crop after continuous and discontinuous use of g y p s u m coupled w i t h a rice crop d u r i n g kharif and a w h e a t crop d u r i n g rabi revealed that only in t h e t h i r d year of reclamation is it possible to obtain any economic yield of chickpea, w h e n the pH of the surface soil is well b e l o w 9.0. The yield differences a m o n g different treatments w e r e not significant because of a high coefficient of variation, resulting f r o m field variation, large enough to cause d a m a g e to chickpeas. The type of sensitive reaction s h o w n by chickpea under these conditions was a s h a l l o w root system, poor branching, b r o w n i n g and d r o p p i n g of leaflets, and poor nodulation. It m a y be seen f r o m Table 7 that the chickpea rhizobia isolated f r o m n o r m a l soil for attempts at multiplication in saline-sodic soil failed to reproduce at all. N o d u l a t i o n of chickpea under sodic soil was either t o o poor to allow isolation of bacteria or the bacterial strain was t o o inefficient to be cultured under a high level of saline-sodic soils. By c o m p a r i s o n , certain other legumes developed rhizobia w h i c h could be
Table 6.
subjected to studies in alkali soils. However, the m o s t interesting feature of the data in Table 7 is that bacterial g r o w t h patterns are quantitatively associated w i t h relative tolerances of these crops under sodic soil conditions, as the data in Table 8 also indicate. It is therefore very desirable that w o r k on rhizobial studies be associated as a c o m p o n e n t of the tolerance studies.
Rooting Patterns of Chickpea in S a l t - A f f e c t e d Soils Shallow rooting or perhaps poor rooting has been t h o u g h t to be associated w i t h the poor p e r f o r m a n c e of chickpea under salt-affected soil conditions. Studies on rooting pattern under these situations are therefore of significance. However, of necessity, such studies must be conducted w i t h great caution. Under field conditions, there are a very large number of uncontrollable factors. As an initial step, therefore, we m a d e efforts in porcelain pots to identify the effect of salt-affected soils on root g r o w t h . In spite of the problems inherent in a direct comparison between affected and normal soil, we w e r e encouraged by our data. Using a steel plate, we divided porcelain pots into t w o halves and filled the pots w i t h n o r m a l soil in one half and sodic or saline soil in the
E f f e c t o f g y p s u m d o s e s a p p l i e d o v e r y e a r s o n t h e soil p H a n d y i e l d o f g r a m I n 1 9 7 4 - 7 5 (variety C-235).
G y p s u m (t/ha) pH after g r a m
p H before g r a m 1st year
2nd year
3rd year
0-15 cm
6.5 6.5 6.5 13.0
0 6.5 6.5 0
0 0 6.5 0
13.0 13.0 19.5 19.5
6.5 6.5 0 6.5
19.5 26.0 26.0 26.0
6.5 0 6.5 6.5
C D . at 5 %
102
15-30 cm
Grain yield of g r a m (g/ha)
0-15 cm
15-30 cm
8.7 8.5 8.4 9.1
9.0 8.9 9.3 9.4
11.4 9.6 11.2 11.0
8.6 8.6 8.5 8.6
8.8 9.0 9.3 9.0
0 6.5 0 0
8.5 8.4 9.0 8.5
9.2 9.0 9.5 9.5
9.6 12.6 11.5 12.6
8.6 8.7 8.5 8.6
9.1 9.1 8.9 9.4
6.5 0 0 6.5
8.6 8.5 8.5 8.5
9.0 9.2 9.2 8.9
11.4 11.6 12.2 13.7
8.5 8.5 8.6 8.8
8.9 9.6 9.1 8.9
N.S.
Table 7.
G r o w t h a n d survival of various Rhizobium species in saline-sodic and n o r m a l soil. Nature of soil
N o . of bacteria x 104/g soil
Pea (Pisum sativum) Soybean (Glycine max) Gram (Cicer arietinum) Indian clover (Melilotus parviflora) Indian clover ( M e l i l o t u s parviflora)
Normal Normal Normal Normal Saline-sodic
0 0 0 80 0
Berseem (Trifolium alexandrinum) Berseem (Trifolium alexandrinum) Guar (Cyamopsis tetragonoloba) Guar ( C y a m o p s i s tetragonoloba) U r d (Vigna mungo)
Normal Saline-sodic Normal Saline-sodic Normal
12 35 0 21 0
Daincha (Sesbania aculeata) Daincha (Sesbania aculeata) Cowpea (Vigna sinensis) Cowpea (Vigna sinensis)
Normal Saline-sodic Normal Saline-sodic
45 116 30 38
Rhizobium
sp
of
Source: A d a p t e d f r o m A n n u a l Report of CSSRI 1971.
Table 8.
Occurrence and effectiveness of t h e rhizobia in saline-sodic soil.
No. of nodules per plant
Host
Dry w e i g h t (g) per 4 plants 1.00 0.45 0.90 0.56 0.85
Glycine max Vigna mungo Pisum sativum Cicer arietinum Vigna sinensis Trifoiium Cyamopsis Medicago Melilotus Sesbania
% increase over uninoculate d control (%)
a/exandrinum tetragonoloba sativa parviflora aculeata
23.0 21.0 36.0 43.0 46.0
0.42 0.38 0.50 0.50 1.40
6 4 19 29 31
Source: A d a p t e d f r o m A n n u a l Report of CSSRI 1973.
other half. In a w a y , this represented t h e hori-
both soils affect r o o t i n g to a great degree.
zontal variation that may be encountered in
However, t h e s o d i c - n o r m a l borders of patches
nature u n d e r field conditions. Likewise, vertical
are not likely to be as d e t r i m e n t a l to root g r o w t h
v a r i a t i o n was created by f i l l i n g the b o t t o m half
as saline-normal patches.
and t h e t o p half of a p o t w i t h different kinds of soil. Even c o n d i t i o n s representing a p o i n t surr o u n d e d by different kinds of soil w e r e created, but it d i d not y i e l d
Monitoring Water Status
i n f o r m a t i o n of t h e k i n d
s h o w n in Table 9. The conclusions that can be
The physiological d r o u g h t that m a y s o m e t i m e s
d r a w n f r o m this table are that t h e roots are
be associated w i t h salt stress makes it impor-
shallower in a sodic soil t h a n in a saline s o i l , but
tant
to
monitor
internal
plant
water
status
103
Table 9.
E f f e c t of saline a n d sodic soils on r o o t g r o w t h a n d dry m a t t e r yield in c h l c k p e a a Root Length (cm)
Vol. (ml)
Wt.
Dry plant weight
(g)
(g)
Normal Saline Sodic
55.3 35.1 30.4
38.2 18.6 16.4
5.8 3.3 3.0
25.3 10.8 8.7
Normal Brownish Whitish
Horizontal variation Nor/Sal Nor/Sod Sal/Sod
35.9 42.6 27.5
16.0 18.9 12.3
5.2 5.5 3.0
20.1
Normal Normal Whitishb
Nor/Sal
33.8
16.5
3.1
18.6
Nor/Sod
40.4
19.9
3.7
19.4
Soil type
18.5 9.2
Root color
Vertical v a r i a t i o n Upper normal, lower brownish Upper normal, lower whitish
a . T h r e e varieties w e r e t e s t e d , b u t t h e i r g e n o t y p i c differences w e r e s m a l l . b. Some brownish discoloration occurred.
in different varieties to understand the m e c h a n i s m of tolerance. This line of w o r k is g o i n g to be handled by us in futur e studies.
3.
Conclusions
4.
Salinity as well as sodicity can adversely affect g e r m i n a t i o n , g r o w t h , and yield of chickpea. Chickpea has a very l o w level of tolerance against salinity and, indeed, we cannot yet make any r e c o m m e n d a t i o n s f o r cultivation even in soils marginally affected by salts. Under saline conditions, toxicity of ions and/or ion imbalance appears to be associated w i t h chickpea's susceptibility. In sodic soils, n o d u l a t i o n and root g r o w t h and also p o o r soil aggregation seem to be the m a j o r reasons for chickpea's subeconomic p r o d u c t i o n potential. Genotypic differences can be identified for salt tolerance, but the extent to w h i c h salts can be tolerated does not seem to be high e n o u g h . Future approaches to screening chickpea for tolerance to salinity are as f o l l o w s : 1. Rapid rejection of susceptible w o r l d collections on t h e basis of g e r m i n a t i o n and survival tests in microplots or pots d u r i n g 5.5. th e first 3 weeks at ECe 2. Carry f o r w a r d only p r o m i s i n g lines for
104
5.
6.
m o r e critical testing based on dry-matter 5.5. p r o d u c t i o n at ECe Identification of lines possessing satisfact o r y reproductive ability under saline conditions as sources of relative tolerance. Intensification of gene frequencies for salt tolerance by developing a r a n d o m m a t i n g population a m o n g salinity-tolerant lines and selection f o r progressively greater tolerance. S u p p l e m e n t i n g tolerance studies by n o d u lation and rooting pattern studies of genotypes. If feasible, t a p p i n g the unselected indigenous bulk mixture s in India and other parts of the w o r l d for latent genetic diversity for salinity tolerance, w h i c h may be still existing in t h e m in v i e w of a lack of conscious or unconscious selection for this attribute in the untouched native land races.
References A B R O L , I. P., and F I R E M A N , M . 1977. A l k a l i a n d saline
soils. CSSRI Bull. No. 4, Central Soils Salinity Research Inst., ICAR, K a m a l , India. 32 pp.
A B R O L , I. P., D A R G A N , K. S., and B H U M B L A , D. R. 1973.
Reclaiming alkali soils. CSSRI Bull. No. 2, Central Soils Salinity Research Institute, ICAR, Karnal, India. 58 pp. F R A M J I , K. K. (ed.) 1976. Irrigation and salinity: a w o r l d - w i d e survey. Internat. C o m m . Irrgn. Drng., N e w Delhi. 671 p p . S I N G H , T. N. 1973. Page 61 in A n n u a l Report CSSRI.
SINGH,
T.
N., A S P I N A I L ,
D.,
and
PALEG,
L.
G.
1974.
Proline accumulating ability as a criterion of d r o u g h t resistance, in Breeding researches in Asia a n d Oceania. Indian J o u r n a l of Genetics 34 A: 1 0 7 4 1083.
USDA. 1954. United States Salinity Laboratory Staff: Diagnosis and i m p r o v e m e n t of saline a n d alkali soils. USDA Handbook 60, 1954, 185 pp.
105
Physiology of Growth, Development, and Yield of Chickpeas in India N. P. Saxena and A. R. Sheldrake*
Crop p h y s i o l o g y research on chickpea started o n l y recently in India, and th e i n f o r m a t i o n available on this pulse is therefore rather limited t h a n on other crops, such as cereals and cotton. However, a n u m b e r of papers have been published on s o m e physiological aspects, including the effect of certain treatments on enzyme activities and the effect of g r o w t h regulators; in a d d i t i o n , a f e w papers have appeared on p h o t o synthesis and translocation of assimilates. Saxena and Yadav (1975) reviewed previous w o r k on t h e a g r o n o m y and p h y s i o l o g y of chickpea; s o m e g r o w t h and d e v e l o p m e n t a l aspects have also been discussed by Argikar (1970). The purpose of this paper is to report ICRISAT research on crop g r o w t h processes, t h e p h y s i o l o g y of y i e l d , and the influence of env i r o n m e n t a l and cultural practices. I n f o r m a t i o n is being sought for a better understanding of the c o m p l e x p h e n o m e n o n of y i e l d d e t e r m i n a t i o n . In India, chickpea is g r o w n as a winter crop f r o m as far south as Karnataka (14°N) to as far north as Palampur (32°N). However, 5 3 % of the chickpea production area is in the Indo-Gangetic plains of northern India, and 3 0 % is in central India between latitudes 23° and 26°N; the rest of t h e chickpea-producing area is in peninsular India. Average yields in North India are around 800 kg/ha as c o m p a r e d to only 400 kg/ha in peninsular India. The crop is usually s o w n w i t h the onset of cooler temperatu res in October and N o v e m b e r , utilizing m o i s t u r e f r o m the preceding m o n s o o n rains in fields that w e r e f a l l o w e d d u r i n g the rainy season. W h e n a rainy-season crop has been taken (in northern India), chickpea is planted after a p r e s o w i n g irrigation. Soil m o i s t u r e is gradually depleted d o w n w a r d in t h e profile as crop growth proceeds. Toward the end of the g r o w i n g season, the evaporative d e m a n d * Plant Physiologist, ICRISAT; and p r e v i o u s ly Plant Physiologist, ICRISAT.
106
of the atmosphere is on t h e increase (Sheldrake and Saxena 1979a). Limited moisture availability finally terminates g r o w t h and forces the plants to mature. Thus, the period in which chickpea can be g r o w n is l i m i t e d , and is determ i n e d at a given location by climatic conditions. Climate is an important determinant of yield. Data are collected on crop g r o w t h , development, and yield aspects at ICRISAT Center near Hyderabad (a s h o r t - g r o w t h duration location, representative of peninsular India) and at Hissar (a longer g r o w t h duration location, representative of northern parts of India).
Climatic Conditions at the T w o Locations Climatic c o n d i t i o n s d u r i n g the chickpeag r o w i n g period at Hissar and at ICRISAT Center are summarized in Figure 1. M i n i m u m temperatures at Hissar decline f r o m late October o n w a r d and remain l o w d u r i n g December and J a n u a r y ; the temperature starts rising again in late M a r c h . On t h e other hand, at ICRISAT Center, temperatures decline around the end of N o v e m b e r or early December and start to increase again in mid-February. Open-pan evaporation d u r i n g the g r o w i n g period f o l l o w s t h e same pattern. Thus, t h e fall of temperature w i t h the onset of w i n t e r and the rise at t h e beg i n n i n g of s u m m e r determines the duration of crop g r o w t h . This period is shorter in peninsular India than in the northern parts of India, and so are the g r o w t h durations. Early-duration cultivars perform better than late-duration cultivars at ICRISAT Center, as t h e y are better adapted to the short-growth duration conditions. The a m o u n t of rain received in t h e preceding rainy season as well as that received during the c r o p - g r o w i n g period at ICRISAT Center is a little less than
40 Maximum temperature 30 20 Hissar ICRISAT
10
Center
0 30 Hissar ICRISAT Center
20
Minimum
temperature
10 0 100
40
42
44
46
48
50
52
2
4
6
8
10
12
14
16
8
10
12
14
16
8
10
12
14
16
M o r n i n g RH ( 0 8 0 0 )
80 Hissar 60 ICRISAT
40
ICRISAT Center
Center
Hissar W e e k l y r a i n f a l l (mm)
20 0 80
Hissar ICRISAT Center
A f t e r n o o n RH (1400)
60 40 20 0 40
42
44
46
48
50
52
2
4
6
16 E v a p o r a t i o n (mm)
Hissar ICRISAT Center
12 8 4 0 40
42
44
46
48
50
52
2
Standard Oct Figure
1.
Weekly mornings 1977-78
and at
Dec
Nov mean
maximum
afternoons, Hissar
and
and ICRISAT
Jan
and
minimum
open
pan
4
6
weeks Feb temperature, evaporation
Apr
Mar rainfall, throughout
relative the
humidity
monsoon
in
season
Center.
107
t w i c e that received at Hissar (Table 1). The soils f r o m b o t h locations are l o w in available P and high in pH (Table 2). The soils at ICRISAT Center are Vertisols (fine, clayey, deep black cotton soils, typic chromustert); Entisols (sandy, typic cambarthids, alluvial) are f o u n d at Hissar. The cation-exchange capacity of the f o r m e r is higher t h a n that of t h e latter. The soils, fairly representative of the chickpea-growing areas of central and peninsular India, are rich in potash.
Table
1.
Average monthly rainfall (mm) at Hissar a n d H y d e r a b a d (average o f 3 0 years, 1 9 3 1 - 1 9 6 0 ) a .
Period
Hyderabad
Hissar
612.6 70.8 24.9 5.5 1.7 11.4 13.4 24.1 151.8
368.6 14.6 7.5 4.5 19.1 14.7 17.0 6.2 83.6
May-Sep Oct Nov Dec Jan Feb Mar Apr Oct-Apr
a. C l i m a t o l o g i c a l t a b l e s of o b s e r v a t o r i e s in India. Meteorological Department.
Table 2.
Hissar
Available nutrients (ppm)
pH
EC (mmhos/ cm)
N
P
K
CEC (me/100 g)
0-15 15-30 30-45 45-60 60-75 75-90
8.0 8.0 8.1 8.1 8.0 8.2
0.45 0.30 0.30 0.35 0.40 0.35
52.0 57.0 49.0 49.0 48.0 41.0
2.0 1.0 Traces " 1.0 Traces
163 144 128 119 169 145
40.9 40.8 40.8 40.2 NA NA
0-15 15-30 30-60 60-90
8.1 8.3 8.3 8.3
0.23 0.15 0.13 0.17
87.1 63.0 63.0 54.6
7 2.7 2.7 3.2
203 176 149 95
8.1 9.5 10.6 10.7
N A = N o t available.
108
Sheldrake and Saxena (1979a) studied the root system of chickpea at ICRISAT Center by taking soil cores w i t h a mechanical auger t w o t i m e s before and t w o times after f l o w e r i n g . They f o u n d that as the soil in the surface zone dried, there was little or no development of roots in this zone, but the roots continued to develop in deeper soil layers d o w n to 120 c m ; w h e r e there was e n o u g h water, d e v e l o p m e n t continued until harvest. M o s t of the nodules w e r e f o u n d to be confined to the 0 - 1 5 cm depth. Nodule mass increased d u r i n g the vegetative period and declined in the later part of the reproductive period. T o w a r d the end of the reproductive phase, m o r e than half of the roots lay in the region b e l o w 4 5 - 6 0 cm. Subramania Iyer and Saxena (1975) also described the rooting pattern in nine varieties of g r a m d u r i n g pod d e v e l o p m e n t using p 32 . The soils are rich in organic matter and have a relatively high water table. They reported that 5 0 - 6 5 % of the root spread occurred in a radius of 7.5 cm around the plant. Root penetration was studied only up to a depth of 30 c m , w h i c h revealed that 4 0 - 5 0 % of the extractable roots w e r e f o u n d in the t o p 1 0 c m of the soil. Perhaps this is the case w h e n moisture is not l i m i t i n g in the surface layers.
Soil characteristics a t ICRISAT C e n t e r a n d a t Hissar.
Location ICRISAT Center
India
Root G r o w t h , Development of Leaf-Area Index, and Dry-Matter Accumulation
Depth (cm)
The dry-matter accumulation pattern in a short- (adapted to peninsular Indian conditions) and a long-duration cultivar g r o w n at ICRISAT Center has been described by Sheldrake and Saxena (1979a). T h e pattern of dry-matter acc u m u l a t i o n at Hissar is described here. Development of leaf area and addition of dry matter continued even after f l o w e r i n g in both cultivars (Fig. 2). Since chickpea is indeterminate, addit i o n of dry matter in the vegetative structures continues even after the onset of reproductive g r o w t h . Pod n u m b e r increased as dry matter and leaf area increased, but once the leaf area started to decline, there was no further increase in p o d number. There w e r e big differences in f l o w e r i n g dates of the cultivars, both at ICRISAT Center and at Hissar. Pod set c o m m e n c e d w i t h the onset of f l o w e r i n g at ICRISAT Center, but at Hissar the f l o w e r s on early cultivars and some on late cultivars did not bear fruit w h i l e temperatures were low. At Hissar, in both cultivars, pod set
c o m m e n c e d at the same t i m e (when temperatures w e r e high enough), irrespective of t h e t i m e of flower initiation. At ICRISAT Center, senescence of t h e lower leaves generally begins before f l o w e r i n g in late cultivars and m u c h after f l o w e r i n g in early cultivars. Data for 1974-75 are s h o w n in Figure 3. At the t i m e w h e n senescence c o m m e n c e d , m a x i m u m and m i n i m u m temperatures had remained unchanged, but m o i s t u r e was being progressively depleted f r o m the upper soil profile. This suggests that soil moisture is an important factor in triggering senescence. Senescence occurred later in t h e border r o w s of plots, w h i c h had access to a better moisture supply; senescence is also delayed by irrigation. At Hissar, both in early and late cultivars, considerable addition in leaf area occurred after 50% f l o w e r i n g , and the m a x i m u m leaf-area index was generally m o r e than twice that at ICRISAT Center. Barring this exception, the
5
5 G - 130
4
JG - 6 2 4 F lowering
3 2 1 0 36
0
20
40
60
80
120
3
80
2
40
1
80 -40
0
0 100 120 140 160 180
0 0
G - 130
32
120 Flowering
20 40
60
80 100 120 140 160 180
32 JG - 6 2
28
28
24
24
Pods
20
20
16
16
Pods
Flowering
12
Stem
12
8 Leaves
4 0 0
Figure
Stem Flowering
8
20
40
4
Roots
0
Development two
chickpea
of leaf area, cultivars
at
Leaves
increase Hissar
Yellow leaves Roots
0
60 80 100 120 140 160180 Days after s o w i n g
2. in
Yellow leaves
in
20
40
60 80 100 120 140 160 180 Days after s o w i n g
pod number,
and dry-matter partitioning
overtime
(1977-78).
109
pattern of d e v e l o p m e n t of leaf area and its relation to p o d d e v e l o p m e n t w a s similar at both locations. The a c c u m u l a t i on of dry matter at Hissar continued f o r a protracted p e r i o d , o w i n g to longer g r o w t h d u r a t i o n . In the early cultivar, JG-62, f l o w e r i n g c o m m e n c e d early in the season w h e n t e m p e r a t u r e s w e r e l o w and f l o w e r s p r o d u c e d d u r i n g this period d i d not set pods. Even t h o u g h t h e plant w a s physiologically in t h e reproductive g r o w t h stage, g r o w t h in t h e vegetative structures continued vigorously, and t h e n o d e n u m b e r at harvest w a s not m u c h different f r o m that of late cultivars. The senescing pinnae d r o p off the plant, and at harvest only the rachis remains attached to t h e plant. A considerable part of total biological yield is sloughed off in the d r o p p e d pinnae, resulting in underestimates of total biological y i e l d . The effect of this on harvest index (HI) is discussed later.
Pod Development
Seed Pod w a l l
1000
600
200 0 500
400
300
200
Pod d e v e l o p m e n t was studied in f l o w e r s tagged soon after they opened. S a m p l i n g of pods was d o n e periodically until they matured at harvest. The p o d wall was the first to develop, and m o r e d r y w e i g h t accumulated here than in t h e seeds d u r i n g the first 1 5 - 1 7 days after anthesis. There was a rapid addition of dry matter in t h e seeds starting about the t i m e g r o w t h of the p o d wall ceased (Fig. 4). In the
100
0 7 6
100
G-130
5
850-3/27 80
4
JG-62
3
60
2 40 1 20
0 0
20
40
60
80
Days after anthesis -10
0
10
20
30
40
50
60 Figure
Days after flowering
4.
Fresh nitrogen
Figure
3.
Time (1974-75).
110
course
of
leaf
senescence
developing (1974-75).
and
dry
weight
of seed and pod
in
pod CV
and
percent
wall
of
a
850-3127
early cultivars, w h i c h w e r e suited to peninsular India, the addition of dry matter in the seed continued up to 35 to 40 days, whereas in cultivars of longer duration, w h i c h w e r e subject to forced maturity, dry matter addition ceased after 25 to 30 days. This period may be considered as the t i m e required for the individual pods to reach physiological maturity. Cultivars differed in rate of pod d e v e l o p m e n t and the t i m e of m a x i m u m dry-matter accumulation. Pods of smaller-seeded cultivars tended to reach physiological maturity earlier. In both t h e seed and p o d w a l l , the percentage N w a s highest at first and declined w i t h the g r o w t h of the p o d . It remained unchanged after 24 days in the seed and after 31 days in the p o d wall. Thus, d u r i n g the period of most rapid g r o w t h of seeds, accumulations of dry matter and nitrogen take place in parallel. Pods in chickpea are capable of photosynthesis. Kumari and Sinha (1972) reported variation in fruit-wall photosynthesis in Bengal g r a m ; however, they m a d e no assessment of the contribution to seed yield of fruit-wall photosynthesis. Sinha (1974) suggested that selection of genotypes in w h i c h fruits c o m e out of the plant canopy m i g h t be m o r e useful in legumes because of greater photosynthetic activity in the pod walls. Such cultivars are k n o w n to occur in cowpea and m u n g bean. At ICRISAT Center, such cultivars have also been identified in chickpea. Chickpea pods normally hang below the leaves and are consequently shaded. In a field experiment, pods w e r e exposed to sunlight by hooking t h e m onto the upper surface of the leaves to eliminate any possible limitation by light on their photosynthesis (Saxena and Sheldrake 1980a). No significant effect of pod exposure on yield was observed. Sheldrake and Saxena (1979b) reported that at ICRISAT Center and at Hissar there was a decline in p o d n u m b e r per node, weight per p o d , seed n u m b e r per p o d , and/or w e i g h t per seed in later-formed pods. The percentage of nitrogen in the seeds was the same in earlierand later-formed pods at ICRISAT Center; at Hissar, the later-formed seeds contained a higher percentage of N. The decline in yield c o m p o n e n t s suggests that pod filling was limited by the supply of assimilates or of nutrients. In one small-seeded cultivar, there was
no decline in the number or w e i g h t of seeds in later-formed pods, indicating that yield was limited by sink size.
Analysis of Yield at Hissar and at Hyderabad The g r o w t h duration at Hissar, as discussed earlier, is almost twice that at ICRISAT Center. Yield at Hissar is also about t w i c e that at Hyderabad (Table 3). Differences in yield between early and late cultivars are qu ite evident at ICRISAT Center but are less pronounced at Hissar (Saxena and Sheldrake, unpublished data). The reason seems to be the less marked differences in g r o w t h duration of early and late cultivars at Hissar. Productivity per day, in total dry matter and to some extent in y i e l d , was higher at Hissar than at Hyderabad. The response to longer g r o w t h duration was relatively more in total dry-matter production than in y i e l d , and resulted in a lower harvest index at Hissar than at Hyderabad. The fall of pinnae, as mentioned earlier, results in underestimation of total biological yield and overestimation of harvest index. The fallen pinnae were collected in the field to correct the total biological yield at harvest. Harvest indices were calculated sepa-
Table 3.
Differences In growth duration, g r o w t h , yield, and yield components of chickpea (average of two cultivars, 8 6 0 - 3 / 2 7 a n d J G - 6 2 ) a t ICRISAT Center and at Hissar (1977-78). ICRISAT Center
Character Vegetative period (days) Period of ineffective f l o w e r i n g (days) Reproductive period (days) Total g r o w t h duration (days) Total nodes/plant (number) Total dry matter (kg/ha) Yield (kg/ha) Harvest index (%) Total dry matter (kg/day) Yield (kg/day)
(Hyderabad) Hissar 49
76
0 41 90 167
48 48 172 346
2072 1166 50 22 12
6176 2495 40 36 14
111
rately, using biological yield corrected and not corrected f o r pinnae fall (Table 4). On an average, the harvest index was overestimated by 10%, bot h in the desi and kabuli cultivars. The ranking of cultivars f o r harvest index changed only slightly, w h i c h suggests that the uncorrected harvest indices give a reasonably reliable indication of varietal differences. High harvest index and high yield are t w o different things. The efficiency of partitioning of total dry matter into seeds was higher at ICRISAT Center; even t h e n , t h e y i e l d was about half that harvested at Hissar. The harvest index (HI) thus seems to be greatly influenced by climatic conditions. At a given location, the high-yielding cultivars generally have higher harvest indices. Dahiya et al. (1976) suggested selection of early m a t u r i n g , high-HI cultivars for North Indian locations. H o w these cultivars c o m p a r e in yield w i t h cultivars of later d u r a t i o n was not discussed in their paper. The harvest indices of around 50 for chickpea in peninsular India (Tables 3 and 4) are comparable w i t h those reported for wheat and rice.
chickpea; w h e n the leaves senesce, the content d r o p s to a r o u n d 1 % . Stems In early stages of g r o w t h contain about 1.5-1.8% nitrogen w h i c h drops to about 0 . 6 - 0 . 8 % at harvest. The corresponding values for P in leaves in early stages and at harvest are 0.7 and 0.2%, whereas in stems they w e r e around 0.5 and 0.3%, respectively. A considerable a m o u n t of nitrogen and phosphorus seems to be remobilized f r o m older plant parts to seed and other y o u n g er tissues. The a m o u n t of nitrogen and phosphorus in the above-ground parts and in the roots and nodules that could be recovered at ICRISAT Center and at Hissar are presented in Table 5.
Tabl e 5.
Seed yield, t o t a l dry m a t t e r , N, and P content at ICRISAT Center and at Hissar ( k g / h a ) o f a t t a c h e d p l a n t parts of chickpea. In neither location w a s N fertilizer supplied to t h e crop (1976-77).
Character
Uptake of Nitrogen and Phosphorus The content of nitrogen is very high (about 5% of total dry matter) in the green leaves of
Table 4.
Hyderabad
Hissar
1500 2600 58 5
3400 7000 143 10
Seed yield Total d r y m a t t e r N removed P removed
E f f e c t o f l e a f f a l l o n h a r v e s t I n d e x (HI) a n d i t s r a n k i n g i n c h i c k p e a c u l t i v a r s ( 1 9 7 5 - 7 6 ) a . Ranking
Harvest index (HI)
Mean
Increase (uncorrected/corrected)
44 50 42 41 44
39 44 38 35 38
29 31 23 41 31
6 4 6 8
5.5 4 7 8
44 61 54 55 53
39 57 50 49 48
29 15 17 28 22
6 1 2 3
5.5 1 3 2
Corrected
Uncorrected
Leb. local 1-550 K-16-3 Rabat Mean
34 38 34 29 34
BEG-482 Chafa JG-62 850-3/27 Mean
34 53 46 43 44
Type
Cultivar
Kabuli
Desi
Corrected
Uncorrected
%
a. LSD (0.05); cultlvar m e a n s , 3.7; t r e a t m e n t m e a n s , 1.2; t r e a t m e n t s w i t h i n a c u l t i v a r , 3.5; cultlvar w i t h i n a t r e a t m e n t , 4.4.
112
The tota l N r e m o v e d at ICRISAT Center is less t h a n half, and P removed is half that at Hissar, a relationship similar to dry-matter production and y i e l d . Since nitrogen fertilizer was not supplied to t h e crops and the soils w e r e l o w in available N, m o s t of the nitrogen was presumably fixed by t h e nodules.
Source-Sink Relationships The t w o i m p o r t a nt factors that determine yield are the photo-assimilate supply (source size and activity) and the storage capacity — i.e., n u m b e r and size of pods (sink size). To evaluate w h i c h is a greater limitation to yield in chickpeas, shading, defoliation, and flower removal experiments were conducted.
Effect of Shading Sheldrake and Saxena (1979a) reported the effects of shading w i t h horizontal shades over th e crop canopies d u r i n g t h e reproductive period of g r o w t h at ICRISAT Center. W h e n photosynthetically active radiation (PAR) was reduced by 5 0 % , senescence was delayed and yield significantly increased up to 15%. This was ascribed to the fact that shading reduced the stresses that were accelerating the senescence process. It was assumed that, in spite of 50% PAR reduction, light intensity might still be near saturation. Further reduction in light intensity delayed senescence even more, but also reduced yield. The studies on shading were extended to Hissar in the 1976 postrainy season using hori-
Table 6.
zontal shades of cloth, w h i c h transmitted the f o l l o w i n g percentage of light t h r o u g h to t h e canopy: Control (no shade) = 100% Mosquito net cloth = 77% transmission Thin cloth = 45% transmission Thick cloth = 16% transmission The shades w e r e placed on the canopy w h e n pod set c o m m e n c e d , rather that at f l o w e r i n g , because the crop virtually continues g r o w i n g vegetatively until temperatures rise. Pod set, as it is determined by temperature, began in all cultivars at about the same time. Yield progressively declined w i t h the increase in thickness of the shade (Table 6). There was a significant reduction in yield in all the cultivars, even w i t h shades intercepting only 25% of the sunlight. Drastic reduction in total dry matter, harvest index, pods/m 2 , and seeds per pod occurred at 8 4 % light interception, i.e., 16% transmission (Tables 7, 8). At Hissar, temperatures were not really very high at the t i m e of p o d set, w h e n shading was started. Therefore, in the winter of 1977, shading at Hissar was delayed until the temperature began to rise. Even then, shading did not produce increases in yield and dry matter (Table 9), as was reported for ICRISAT Center, w h e r e reduction in yield occurred only under the thickest shade that transmitted only 16% sunlight. Senescence was delayed in all the shade treatments at Hissar, as was observed at ICRISAT Center. Light becomes a limiting factor to dry-matter production and yield at Hissar, even at levels only 15% below full sunlight. This does not seem surprising in view of the high leaf area
E f f e c t o f s h a d i n g t r e a t m e n t s o n g r a i n y i e l d ( k g / h a ) o f f o u r c h i c k p e a c u l t i v a r s a t Hissar, postrainy season 1 9 7 6 - 7 7 .
Cultivar
Control
Mosquito net
Thi n cloth
Thick cloth
Mean
P-173 850-3/27 L-550 G-130
3422 3539 3879 3353
2479 2848 3190 2356
2344 2579 2701 1992
679 1229 1237 705
2231 2547 2752 2102
3548
2718
2404
960
170.1 2408
LSD (0.05) Mean LSD (0.05) CV%
315.5 126.1 6.5
9.8
113
Table
7.
Effect of shading treatments on total dry w e i g h t , harvest index and yield components of c h i c k p e a (means f o r 4 cultlvars), postralny season, Hissar, 1 9 7 6 - 7 7 .
Shading treatment
Total d r y w e i g h t (kg/ha)
Harvest index (%)
Pod number/m2
100-seed w e i g h t (g)
7980 6590 6494 4067
45 42 38 24
2547 2331 1789 984
19.2 18.9 17.9 19.6
Control M o s q u i t o net Thin cloth Thick cloth LSD
Table
754.1
8.
749.0
5.2
1.39
E f f e c t o f s h a d i n g t r e a t m e n t s o n s e e d n u m b e r p e r p o d o f 4 c h i c k p e a c u l t l v a r s a t Hissar, postralny season, 1 9 7 6 - 7 7 . Seed n u m b e r per p o d
Cultivar
Control
Mosquito net
P-173 850-3/27 L-550 G-130
1.19 0.79 1.07 1.25
0.98 0.87 0.87 1.21
1.07
0.98
LSD Mean LSD CV%
Table 9.
Thin cloth
Thick cloth
Mean
0.99 0.89 1.24 1.02
0.82 0.84 0.94 0.95
0.99 0.85 1.03 1.11
1.03
0.88
1.107 0.99
0.229 0.150 18.9
15.0
Effect of shading t r e a t m e n t s on t o t a l dry w e i g h t , yield, harvest Index and yield c o m p o n e n t s , postralny season, Hissar, 1 9 7 7 — 7 8 .
Shading treatment Control M o s q u i t o net Thin cloth Thick cloth LSD
Total d r y weight (kg/ha)
Yield (kg/ha)
Harvest index (%)
Seeds/ pod
100-seed w e i g h t (g)
5550 5161 5393 4636
1990 1956 1933 1112
37.2 38.8 36.8 24.7
0.97 1.00 0.95 0.86
19.7 19.0 19.7 14.7
444.5
238.2
index (LAI) values ( a r o u n d 5.0, Fig. 2) reached in
0.06
0.15
1.59
Effect of Leaf Removal
t h i s c r o p a t Hissar, w h e r e m u t u a l s h a d i n g a n d light p e n e t r a t i o n in t h e c a n o p y c o u l d be an
Different degrees of partial d e f o l i a t i o n w e r e
i m p o r t a n t factor. On t h e o t h e r h a n d , at ICRISAT
carried o u t at ICRISAT Center and at Hissar,
Center w i t h a LAI of a r o u n d 2.0 (35 days after
starting a t t h e t i m e o f f l o w e r i n g and c o n t i n u i n g
flowering), the
until harvest. T h e r e w a s practically no effect of
40-50%.
114
light transmission
ratio w a s
25, 33, or 5 0 % d e f o l i a t i o n , on t o t a l d r y - m a t t e r
p r o d u c t i o n , but these treatments had a small effect on y i e l d , although not in p r o p o r t i o n to degree of defoliation. A 50% reduction in leaf area reduced yield only 2 0 % , whereas 100% defoliation reduced yield by 7 0 - 8 0 % . This suggests either that leaf area is not a primary factor in limiting yield or that the remaining leaves are able to compensate for the removal of leaves by an increased photosynthetic rate. There is a possibility that such treatments modify th e water balance of plants. To investigate this, the defoliation treatments w e r e repeated w i t h and w i t h o u t irrigation. Treatment effects w e r e not modified by irrigation. Changes in plant water potential in response to defoliation w e r e also monitored soon after defoliation and continued t h r o u g h o u t the day. The water potential of defoliated and nondefoliated plants did not differ. These experiments suggest that the compensation was not because of changes in water status of plants after defoliation, but because of other factors. The effects of defoliation were mor e severe at ICRISAT Center. Comparison of results at the t w o locations suggest that leaf area is not a serious constraint to total dry-matter product i o n , but yield was relatively m o r e sensitive than was total dry-matter production to defoliation.
plant. Such an observation is also reported in soybean (Lindoo and N o o d e n 1977). There was no significant decline in yield w h e n one-third of t h e flowers w e r e r e m o v e d t h r o u g h o u t the g r o w i n g p e r i o d . Similarly, removal of all flowers for 1 4 - 2 8 days resulted in no significant reduction in total dry matter and yield. Both experiments on partial flower removal and flower removal for a specified period of t i m e suggest that chickpea plants have some ability to compensate for t h e loss of potential sinks. Extension of the g r o w i n g period in response to flower removal provided one opportunity for yield compensation. Continued g r o w t h causes addition of flowering nodes, and m o r e pods can be f o r m e d . Indeed, this activity was observed. The second means of compensation was the increase in the number of seeds per pod. The increase in seeds per pod was in a range of 2 4 - 2 6 % of the plants in w h i c h flowers w e r e r e m o v e d , w h e n compared to the controls. The third and final type of compensation involved increase in seed weight. The compensation in seed w e i g h t generally occurred in small-seeded cultivars, and was relatively small — ranging from 8 - 2 0 % . In bold-seeded cultivars, the 100seed weight declined in response to flower removal.
Effect of Flower Removal
Response of Chickpea to Cultural Practices
Flower removal experiments were conducted at ICRISAT Center and at Hissar to study the effect of altered sink size on dry matter production and its partitioning. T w o kinds of experiments were conducted at the t i m e of 50% f l o w e r i n g : (1) removal of all flowers for different periods of t i m e ; and (2) flower removal to different degrees (partial flower removal) until harvest. Both f l o w e r removal treatments extended the g r o w i n g period. The prevention of pod set by different f l o w e r removal treatments resulted in mor e g r o w t h of roots and nodules (tenfold increase in nodule weight) and delayed senescence of the plant. Removal of flowers on s o m e branches and not on others of the same plant resulted in delayed senescence of the branches on w h i c h pod set was prevented. This suggests that the stimulus or signal that initiates senescence is related to pod set and is localized w i t h i n the
Saxena and Yadav (1975) reviewed the work on a g r o n o m y in the International Workshop on Grain Legumes. Additional aspects are included in this paper.
Response to Irrigation Saxena and Yadav (1975) summarized w o r k on response to irrigation, suggesting a positive response to irrigation in areas w h e r e winter rainfall is negligible. We obtained positive responses to irrigation ranging between 3 and 94% on Vertisols and a threefold increase on an Alfisol at ICRISAT Center.
Response to Nitrogenous Fertilizer Nitrogen is not generally applied to legumes, as it is symbiotically fixed by the plants. In t h e deep
115
black soils at ICRISAT Center (Table 2), chickpea cv JG-62 (a high-yielding cultivar of that region) d i d not respond to nitrogenous fertilizer applications up to 100 kg N/ha nor to m a n u r i n g w i t h f a r m y a r d manure. C o m b i n e d nitrogen at the rate of 100 kg N/ha reduced the nodule mass. Response to applied nitrogen was observed in greater vegetative g r o w t h and LAI development. This advantage was not reflected in total dry-matter p r o d u c t i o n or yield at harvest. Sinha (1977) reported an increase in yield in s o m e cultivars and a decrease in others w h e n nitrogen was applied at the rate of 75 kg N/ha. Singh (1971) and Singh and Yadav(1971) reported an increase in yield of cickpea w i t h nitrogen application at the rate of 22.5 kg N/ha on soils l o w in total nitrogen (0.042%). Singh et al. (1972) and Rathi and Singh (1976) also reported positive response to soil applied N at the rate of 30.2 and 20.0 kg N/ha, respectively. No significant increase in yield in response to nitrogen application was reported by M a n j h i and C h o w d h u r y (1971) and Rao et al. (1973). The latter authors attributed it to l o w or total absence of rainfall d u r i n g the crop season.
Response to Phosphatic Fertilizer Saxena and Yadav (1975) summarized well the responses to phosphatic fertilizers reporting conspicuous responses to soil-applied P. At ICRISAT Center on deep black soil l o w in available P and high in pH (Table 1), no positive response to soil-applied P was obtained in broadcast application w i t h and w i t h o u t irrigation or w i t h placement. T h o u g h placement increased t h e y i e l d , t h e increase was not statistically significant. it w a s felt that interference in t h e uptake of soil-applied nutrients, especially under d r y l a n d conditions w h e r e the moisture in receding, m a y be a factor in the lack of response to soil-applied nutrients. We therefore investigated different methods of foliar fertilization. The presence of a very acidic exudate p r o m p ted us to use rock phosphate or superphosphate as dust on chickpea foliage; P w o u l d t h e n become available for g r o w t h of t h e plants. The experiment was conducted over 2 years, and there was a significant but small increase in one year and not in t h e other. Response to foliar applications of N, P, and N + P in liquid solutions w a s also investigated.
116
Interestingly, individually N and P and the t w o together in t h e spray increased yield significantly (21.6%). Singh et al. (1971) f o u n d that a three-fourth dose of the p h o s p h o r u s applied as spray w a s equivalent to the full dose of P t h r o u g h t h e soil and concluded that P uptake efficiency in foliar applications was high. Srivastava and Singh (1975) did not f i n d a response to foliarly applied P up to 60 kg P 2 O 5 /ha.
Intercropping of Chickpea Cultivars of Different Durations Observations at ICRISAT Center indicate that considerable m o i s t u r e is left behind in the soil profile, even after harvest. To make better utilization of moisture in the profile, intercropping of chickpea cultivars varying in g r o w t h duration (early, m e d i u m late, and late), either as alternate r o w s or as a m i x t u r e , was investigated at ICRISAT Center and at Hissar. No marked beneficial or detrimental effect of intercropping w i t h cultivars of the same species w a s observed. However, w h e n cultivars of varying duration were g r o w n in alternate rows, there was a tendency for yield to be about 6% greater at ICRISAT Center a n d 4% greater at Hissar.
Effect of "Nipping" on Yield In northern India and Pakistan, n i p p i n g of the y o u n g shoots d u r i n g vegetative g r o w t h and grazing of the y o u n g plants by sheep in Rajasthan causes an increase in auxiliary branches, w h i c h s o m e t i m e s leads to increased yields. The effect of n i p p i n g in shorter g r o w t h duration c o n d i t i o n at ICRISAT Center (peninsular India) w a s investigated. N i p p i n g treatments tended t o reduce y i e l d , but the reduction was not statistically significant.
Effect of Row Direction Orientation of rows in s o m e crops has been s h o w n to increase yields, w h i l e in others it has no effect. Trials w e r e conducted at ICRISAT Center and at Hissar to f i n d the effect of eastwest or north-south r o w directions on yield of chickpea. There w a s no effect on yield at either location.
Effect of Planting Geometry Geometry of planting has been s h o w n to influence the yield of many crops. Under conditions w h e r e water is l i m i t i n g , square planting of dryland crops such as sunflower (Krishnamoorthy 1972) results in earlier development of moisture stress than does rectangular planting. This was investigated w i t h chickpea at ICRISAT Center. Three rectangularities w e r e studied at t w o densities of p o p u l a t i o n , 33 and 50 plants/m 2 . At normal p o p u l a t i o n densities (33 plants/m 2 ), square planting yielded less than rectangular planting. At higher population densities (50 plants/m 2 ), the difference between square and rectangular planting was statistically insignificancy although the square planting tended to produce higher yields.
Saxena et al. (in press) investigated the effect of graded seed size w i t h i n a given cultivar on yield of chickpea at three locations in India. Large seed gave larger seedlings, but there was no significant effect on final yields.
Physiological Aspects of Yield Improvements For directed efforts to i m p r o v e yield levels t h r o u g h plant breeding, yield enhancing factors and genetic sources of these need to be identified. On the other hand, yield-reducing factors need to be identified and sources of tolerance f o u n d so they can be utilized by breeders to increase yields under g r o w t h - l i m i t i n g conditions.
Response to Plant Population
Double-Podded Character
Response to increasing plant density was investigated at ICRISAT Center and at Hissar. Opt i m u m plant population depended u p o n the location and choice of cultivar. In general, yields of chickpea at both locations were fairly plastic over a range of plant densities. Total dry-matter production and yield did not reach a plateau at ICRISAT Center at p o p u l a t i o n densities of less than 80 and 20 plants/m 2 , respectively, compared to 20 and 4 plants/m 2 at Hissar. The idea of increasing yield by increasing the plant density of nonbranching erect cultivars was also investigated and f o u n d to be not p r o m i s i n g . Branching of a normal cultivar is automatically suppressed w h e n it is g r o w n at high p o p u l a t i o n densities, and a normal branching t y p e tailors itself into a nonbranching type.
In chickpea, the dominant component of yield is the number of pods produced per unit area. Where g r o w t h duration is short — as at ICRISAT Center (peninsular India) — there is a great limitation imposed on the production of pods a n d , consequently, on yield. Sheldrake et al. (1979) reported that the double-podded character (cultivars with more than one pod per node) can confer an advantage in yield, ranging between 6 and 1 1 % under conditions in w h i c h the character is well expressed. The character is well expressed under n o r m a l short g r o w t h duration at ICRISAT Center and in late plantings at Hissar. The double-podded character can be exploited to make yield gains under such conditions.
Effect of Seed Size In s o m e crops, larger seeds have been s h o w n to produce v i g o r o u s plants and high yield. This was investigated in chickpea. Narayanan et al. (in press) reported that there is a close relationship between the w e i g h t of seeds and seedlings in graded seeds of a given cultivar, w h i c h may result in better seedling vigor. The greater seedling v i g o r of larger seeds may be related to greater seed reserves. This could be of practical i m p o r t a n c e in o v e r c o m i n g p r o b l e m s of emergence f r o m crusted soils.
Cultivaral Difference in Plasticity Ability of cultivars to yield nearly the s a m e at suboptimal populations as at normal plant population is a measure of plasticity of cultivars. Chickpea cultivars in general are very plastic, but cultivaral differences have been noted in yield reduction b e l o w a critical plant population (Saxena and Sheldrake, unpublished data). Those with reduced yield at low populations were considered to be nonplastic. The yielding ability of these nonplastic cultivars was similar to that of the plastic cultivars at normal plant populations. Plastic cultivars could be very important in stabilizing and i m p r o v i n g
117
yields in f a r m e r s ' fields w h e r e the p o p u l a t i o n s are often n o n u n i f o r m and s u b o p t i m a l . A s i m p l e screening procedure has been developed in w h i c h plants are g r o w n at a s u b o p t i m a l p o p u lation and at the recommended normal population (actual populations depending upon the location). The ratio of s u b o p t i m a l / n o r m a l p o p u lation in yields indicates the plasticity of t h e cultivar.
Cultivaral Differences in Germination with Limited Water Cultivaral differences in g e r m i n a t i o n of chickpea w i t h l i m i t e d available water w e r e noted in laboratory studies on soils brought to different m o i s t u r e tensions and in osmotic solutions (Saxena and Sheldrake, unpublished data). Germination studies were also carried out under field conditions where emergence is influenced by variation in soil moisture, depth of sowing, soil compaction, and so on. Seed size within a cultivar seems to influence g e r m i n a t i o n to s o m e e x t e n t Under limited soil m o i s t u r e conditions, small seed (withi n and between cultivars) had some advantage, w h i c h m i g h t be expected because of a larger surface/volume ratio and requirement of smaller a m o u n t s of water per seed. The reverse was observed w h e n water was not l i m i t i n g .
Cultivaral Differences in Susceptibility to Iron Chlorosis S o m e of the chickpea cultivars exhibited iron chlorosis on Vertisols high in pH (Table 1) at ICRISAT Center. The s y m p t o m s are y e l l o w i n g of the y o u n g e r leaves w i t h severe deficiency, reduction of size of y o u n g e r leaves and d r o p ping of pinnae. Agarwala et al. (1971) reported differences in cultivar reaction to iron deficiency in sand culture experiments. In our studies, we f o u n d that iron chlorosis in the field can be easily corrected by a single spray of 0.5% FeSO4 The recovery is very u n i f o r m , probably because of the presence of acid exudate on t h e foliage, w h i c h keeps the iron in an available and m o b i l e f o r m . The yield of n o n s p r a y e d susceptible cultivars w a s 4 1 - 4 4 % lower t h a n the sprayed cultivars (Saxena and Sheldrake 1980b). Expression of t h e s y m p t o m s appears to be under genetic cont r o l , and susceptible plants can be picked out and discarded f r o m segregating populations.
118
Cultivaral Differences in Susceptibility to Salinity S o m e of the chickpea-growing areas in India are saline. T h o u g h chickpea is m o r e susceptible tha n wheat, barley, or other cereals to salinity, cultivar differences in response to salinity, as it affects g e r m i n a t i o n and g r o w t h , w e r e noticed in artificially salinized soil. Salinity tolerance at g e r m i n a t i o n is i m p o r t a n t in ensuring plant stand, w h i c h also is an i m p o r t a n t factor in d e t e r m i n i n g yield. Susceptibility to salinity may change d e p e n d i n g u p o n the stage of plant d e v e l o p m e n t Brick chambers (above ground) have been constructed and are being used to g r o w chickpea at different salinity levels until harvest to identify cultivaral differences in yield.
Cultivaral Differences in Heat Tolerance Early planting soon after the end of the rainy season should ensure better g e r m i n a t i o n and plant stands, as the moisture supply is good. However, temperatures are higher at this t i m e and have been reported to affect early g r o w t h (Sheldrake and Saxena 1979a). N u m e r o u s studies have s h o w n reduced yields result f r o m planting t o o early (Saxena and Yadav 1975). Plants planted early are also affected by disease. We investigated cultivaral differences in heat tolerance at ICRISAT Center by planting at the n o r m a l t i m e (October) and in February w h e n temperatures are rising. We planted late, w h e n t h e season was dry, rather than early at the end of the rainy season, to avoid the effect of differential disease pressure f r o m year to year. Relative g r o w t h rates (RGR) and net assimilation rates (NAR) were calculated. Significant differences a m o n g cultivars w e r e noted both w i t h respect to NAR and RGR, and there was a significant interaction between RGR s o w i n g date (Table 10). The significant interaction bet w e e n cultivar and s o w i n g date suggests that s o m e cultivars may be m o r e heat tolerant than others. Bengal g r a m , A n n i g e r i , 850-3/27, H-208, and Radhey are s o m e of the cultivars that had high RGR values in the February planting.
Screening for Cultivaral Differences on Limited Water By w i t h h o l d i n g irrigation, severe water stress
Table
10.
Variance ratios for relative g r o w t h r a t e (RGR) a n d n e t a s s i m i l a t i o n rate (NAR) f r o m heat stress trial at ICRISAT Center ( 1 9 7 7 - 7 8 ) . RGR
NAR
10.03 3.33** 3.33**
446 177.2 4.98** 2.8
Source of variation S o w i n g dates Cultivars Interaction **Significant
genotypes in chickpeas (Cicer arietnum L ) . Pages 1 9 - 2 0 in Tropical Grain L e g u m e Bull. No. 4. KRISHNAMOORTHY, C. H. 1972. Discussion in S o r g h u m in seventies. N. G. P. Rao and L. R. House (ed.), Oxford and IBH Publishing Co., N e w Delhi. 370 pp. K U M A R I , P. S., and S I N H A , S. K.
1972. V a r i a t i o n in
chlorophylls and photosynthetic rate in cultivars of Bengal g r a m (Cicer arietinum L.). Photosynthetica 6: 189-194.
a t 1 % level.
LINDOO, S. J . , and N O O D E N , L. D. 1977. S t u d i e s o n t h e
behavior of senescence signal in Anoka soybeans. Plant p h y s i o l o g y 59: 1136-1140. can be created in Alfisols (red soils), w h i c h are p o o r in w a t e r h o l d i n g capacity. A s i m p l e field screening t e c h n i q u e w a s d e v e l o p e d t o c o m p a r e relative y i e l d p e r f o r m a n c e of cultivars under stress
and
irrigation
nonstress
treatments
treatments. included
T h e three
no
irrigation,
once a m o n t h i r r i g a t i o n and once every 15 days i r r i g a t i o n . Cultivars differed tolerance
(avoidance
in their d r o u g h t
and/or
tolerance).
A
M A N J H I , S., and C H O W D H U R Y , S. L. 1971. Response of
Bengal g r a m (Cicer arietinum L.) to four levels of phosphorus applied alone and in c o m b i n a t i o n w i t h nitrogen and potassium. Indian J o u r n a l of A g r o n o m y 16: 247-249. N A R A Y A N A N , A., S A X E N A , N. P., and SHELDRAKE, A. R.
1980. CuItivaral differences in seed size and seedling g r o w t h of pigeonpeas and chickpeas. Indian J o u r n a l of Agricultural Sciences (in press).
d r o u g h t tolerance index (DTI) w a s calculated as follows:
RAO,
DTI =
n o n i r r i g a t e d yield/irrigated y i e l d
On the basis of t h e d r o u g h t tolerance index, d r o u g h t tolerant cultivars w e r e early, but not all early cultivars w e r e d r o u g h t tolerant. D r o u g h t tolerance index w a s positively correlated w i t h yield
of
nonirrigated
plants
(r = + 0 . 4 0 * * ,
n = 70). S o m e degree of d r o u g h t tolerance also
S.
B.
P.,
RAMNATH,
B.,
and
SAM,
M.
J.
1973.
Response of g r a m to fertilizer application in the black cotton soils of Bellary under dryland f a r m i n g . M y s o r e J o u r n a l of Agricultural Science7: 3 6 0 - 3 6 5 . RATHI, S. S., and S I N G H , D. 1976. Effect of nitrogen and phosphate fertilization on the g r o w t h and yield of g r a m (Ev). Indian Journal of A g r o n o m y 21(3):305-306.
appeared in cultivars of m e d i u m m a t u r i t y . The ranking of cultivars in irrigated and n o n i r r i g a t e d t r e a t m e n t s c h a n g e d , suggesting that it may not be possible to select cultivars for n o n i r r i g a t e d conditions b y g r o w i n g t h e m w i t h irrigation.
S.
C.,
C.,
and Y A D A V , D.
S.
1975.
S o m e ag-
r o n o m i c c o n s i d e r a t i o n s of p i g e o n p e a s and chickpeas. Pages 3 1 - 6 2 in Proceedings of the International Workshop on Grain Legumes ( 1 3 - 1 5 Jan 1975), ICRISAT, Hyderabad, India. S A X E N A , N. P., and SHELDRAKE, A. R. 1980a. Effect of pod exposure on the yield of chickpeas (Cicer arietinum L ) . Field Crops Research 3: 1 8 9 - 1 9 1 .
References AGARWALA,
S A X E N A , M.
SHARMA,
C.
M E H R O T R A , S. C., and AFZAL , A.
P.,
BISHT,
S.
S.,
1971. G e n o t y p i c
S A X E N A , N. P., and SHELDRAKE, A. R. 1980b. Iron chlorosis in chickpea (Cicer arietinum L) g r o w n in high pH calcareous Vertisol. Field Crops Research 3: 211-214.
differences in susceptibility of s o m e l e g u m e s t o iron chlorosis, in Abstract of papers presented at t h e Second International S y m p o s i u m on Plant Patholo g y , 27 J a n - 3 Feb 1971, N e w D e l h i , India.
S A X E N A , N. P., N A R A Y A N A N , A., and SHELDRAKE, A. R.
ARGIKAR, G. P. 1970. G r a m . Pages 5 4 - 1 3 6 in Pulse Crops of India. ICAR, N e w Delhi, India.
1980. Effect of seed grading on yield of chickpea and pigeonpea. Indian J o u r n a l of A g r i c u l t u r a l Sciences (in press).
D A H I Y A , B. S., S I N G H , K. B., BRAR, H. S., and BRAR, J. S.
1976.
Identification
of
physiologically
efficient
SHELDRAKE, A. R., and S A X E N A , N. P. 1979a. The g r o w t h and d e v e l o p m e n t of chickpeas under progressive
119
m o i s t u r e stress. Pages 4 6 5 - 4 8 3 in Stress Physiology in Crop Plants, by H. Mussel and R. C. Staples, J. Wiley, N e w York, 1979. SHELDRAKE, A. R., and S A X E N A , N. P. 1979b. C o m p a r i s o n of earlier a n d later f o r m e d chickpeas (Cicer arietinum L.). A n n a l s of Botany 4 3 : 4 6 7 - 4 7 4 . SHELDRAKE, A. R., S A X E N A , N. P., and K R I S H N A M U R T H Y ,
L 1979. T h e expression a n d influence on yield of t h e d o u b l e - p o d d e d character in chickpeas (Cicer arietinum L.). Field Crops Research 1: 2 4 3 - 2 5 3 . S I N G H , K. B., T O M E R , P. J . , and J A I N , M . K. 1971. Effect
of spray fertilization of p h o s p h o r u s in g r a m . A n n a l s of A r i d Zone 10(2/3):199-202.
Indian Journal 41(2):101-106.
of
Agricultural
Sciences
S I N G H , R.S., and Y A D A V , S . C . 1971. Effect of n u m b e r of cultivation a n d increasing levels of N and P on yield and quality of g r a m (Cicer arietinum L ) . Indian J o u r n a l o f A g r i c u l t u r a l Research 5 ( 1 ) : 5 1 - 5 4 . S I N H A , S. K. 1974. Yield of grain legumes. P r o b l e m s and prospects. Indian Journal of Genetics 34A:988-994. S I N H A , S. K. 1977. Food legume s d i s t r i b u t i o n , adaptability a n d b i o l o g y of y i e l d . FAO. Plant Production and Protection, Paper 3.
1972.
S R I V A S T A V A , S. P., and S I N G H , A. P. 1975. P h o s p h o r u s
Response of g r a m (Cicer arietinum L.) to n i t r o g e n ous and p h o s p h a t i c fertilization under different crop rotations. Haryana A g r i c u l t u r a l University J o u r n a l o f Research 2 ( 1 ) : 1 9 - 2 4 .
fertilization in g r a m under dry-land c o n d i t i o n s . Science and Culture 4 1 ( 1 1 ) : 5 2 7 - 5 2 8 .
SINGH,
K.,
TRIPATHI,
H.
P.,
and
RAHEJA,
H.
R.
S I N G H , R. G. 1971. Response of g r a m (Cicer arietinum L ) t o t h e application o f n i t r o g e n a n d phosphate.
120
S U B R A M A N I A IYER, P.
R. V., and
S A X E N A , M.
C.
1975.
Preliminary studies on root d i s t r i b u t i o n pattern of s o m e g r a m varieties. J o u r n a l o f Nuclear A g r i c u l t u r e and B i o l o g y 4 ( 2 ) : 4 6 - 4 8 .
The Effects of Photoperiod and Air Temperature on Growth and Yield of Chickpea (Cicer arietinum L.) R. J. Summerfield, F. R. Minchin, E. H. Roberts, and P. Hadley*
From a cultivated area w h i c h exceeds ten m i l lion hectares, the average seed yield of chickpea (Cicerarietinum L) is small, probably about 700 kg/ha, and varies greatly between both sites and seasons, f r o m about 190 to 1600 kg/ha. Most crops are of ancient land races g r o w n on poor fertility soils in rainfed conditions (Auckland and Singh 1976). Chickpeas are grouped into 2 basic types — the small-seeded desi varieties g r o w n mainly as a w i n t e r crop planted in October or N o v e m b e r f r o m Pakistan eastward, and the large-seeded kabuli varieties characteristically g r o w n as a s u m m e r crop planted in March or April f r o m Afghanistan to the M i d d l e East. Clearly, crops of this species w h i c h cover such a w i d e range of latitude, longitude, and altitude are subject to a tremendous variety of e n v i r o n m e n t s ; w i t h our present knowledge, however, it is impossible to assess reliably the significance of various environmental factors or of g e n o t y p e x e n v i r o n m e n t interactions in varietal adaptability. For example, chickpea breeding at ICRISAT is divided between field sites at Hyderabad (17°N) and at Hissar (29°N); crops generally matur e w i t h i n 110 days after sowing in the w a r m e r (southernmost) environment and w i t h i n 160 days in the cooler environment. Crosses between cultivars " a d a p t e d " to south* Lecturer, Department of A g r i c u l t u r e and Horticult u r e , University of Reading; Senior Scientific Officer, Department of Plant and Crop Physiology, Grassland Research Institute, Hurley, M a i d e n h e a d , Berkshire; Professor, Crop P r o d u c t i o n , Department of A g r i c u l t u r e and Horticulture, University of Readi n g ; Research Fellow, Department of A g r i c u l t u r e and H o r t i c u l t u r e , University of Reading, U.K., respectively. N o t e : This review w a s prepared d u r i n g the course of a collaborative research p r o g r a m sponsored by t h e UK M i n i s t r y of Overseas Development.
ern India produce short-duration segregants, which produce greater yields at Hyderabad than at Hissar, whereas crosses between cultivars " a d a p t e d " to northern India produce longduration segregants, w h i c h yield best at Hissar (Auckland, personal c o m m u n i c a t i o n 1977). Clearly, the different aerial environments in these localities are likely to contribute markedly to variations in phenotypic expression. As w i t h other grain legumes, physiological data on chickpea are rife w i t h confusion and contradiction, and conclusions are often based on unreliable methodology. As a consequence, the chickpea breeder, w i t h o u t clear guidelines f r o m the plant physiologist, primarily uses final seed yield as a criterion for selection in t h e f i e l d . Even if components of yield are also used (traditionally, the number of pods per plant and seeds per pod and the w e i g h t of individual seeds), there is little, if any, information available as to the phenological or physiological bases for their variations. Seed yield in grain legumes depends upon both vegetative and reproductive components, which are markedly affected by environmental factors (Summerfield and M i n c h i n 1976). As is true of other species, the n u m b e r of pods that reach maturity has a major effect on seed yield in chickpea (Sandhu and Singh 1972), but we know little of either h o w or at w h i c h stage during development variations in this yield component arise. W i t h o u t doubt, the environment in w h i c h chickpea g r o w s and matures has a major effect on the realization of yield potential, as many time-of-planting studies have s h o w n (Eshel 1968). In order to elucidate the environmentalfactors that s h o w these effects, it is usually necessary to use controlled environments. A l t h o u g h some work has been d o n e in controlled-environment conditions, however, we still k n o w little about the effects of environ-
121
mental factors or their interactions on chickpea g r o w t h because orthogonal treatment c o m b i nations have not been used, and e n v i r o n m e n t a l factors have been poorly controlled or have been studied in isolation (Sandhu and Hodges 1971; van der Maesen 1972). An essential prerequisite to the use of controlled e n v i r o n m e n t s as an adjunct to field research is that plants g r o w n to reproductive maturity in artificial conditions should resemble, as closely as possible, plants of the same genotype g r o w n as spaced individuals in the field ( S u m m e r f i e l d 1976). We have n o w successfully adapted plant husbandry and culture techniques developed for other potential tropic-adapted grain legumes and s h o w n that this prerequisite can be satisfied for chickpea ( S u m m e r f i e l d et al. 1978). W i t h experiments on grain legumes, it is imperative to take the widest possible viewpoint of the s y m b i o t i c association w i t h Rhizobium, o t h e r w i s e it becomes increasingly difficult to ascribe experimental treatment effects to responses of the host plant, the micros y m b i o n t , or both. For e x a m p l e, just as a selection objective such as increased net photosynthesis rate in chickpea (e.g., Kumari and Sinha 1972) may be irrelevant unless the reproductive behavior of a l e g u m e crop is well adapted to t h e local e n v i r o n m e n t (Evans and King 1975), so is t h e evaluation of e n v i r o n m e n tal adaptability if the role of the m i c r o s y m b i o n t in the realization of yield potential is ignored ( S u m m e r f i e l d et al. 1978).
Seasonal means M a x . ° C =23.9° C M i n . ° C =10.2° C Day length 13.02hr 15.3 hr in June
40
14
Teheran (36°N) 30
-13
20
12
10
11
0
10 O
N D J F M A M J J A S Seasonal means Max. °C =27.8° C Min. °C =14.7° C Day length 11.95hr
40
14
Delhi (29°N) 30
13
20
12
10
11
0
10 O N D J F M A M J J A S Seasonal means Max. °C =28-8° C Min. ° C 16.2° C Day length 12.33hr
40
Growth, Phenology, and Yield Seasonal changes in p h o t o p e r i o d and in day (mean m a x i m u m ) and night (mean m i n i m u m ) t e m p e r a t u r e b e c o m e progressively m o r e pronounced as latitude increases, a n d although changes in air t e m p e r a t u r e lag behind those in p h o t o p e r i o d , the t w o measurements also tend to be closely correlated. The correlation between temperature and photoperiod, however, is not inevitable since t e m p e r a t u r e varies markedly w i t h altitude. The relative m a g n i t u d e of these changes in selected localities w i t h i n i m portant areas of chickpea cultivation are s h o w n in Figure 1. Not o n l y do average absolute values differ markedly between p h o t o t h e r m a l regimes, but also there are m a j o r chronological
122
14 Dire dawa (9°N)
30
13
20
12
10
11 10
0 O N D J F ' M A ' M J Ca lendar month Figure
1.
J
A
S
Seasonal changes in mean monthly maximum
and
minimum
air
photoperiod within
at
important
cultivation Francis
mean
monthly
temperature three areas (photoperiods
1972).
and
in
locations of
chickpea from
variations in both the rates and direction of change in these climatic factors. M a n y studies w i t h chickpea are severely limited because it is assumed or inferred that a single c o m b i n a t i o n of values of e n v i r o n m e n t a l factors is o p t i m a l for all stages of g r o w t h . Such an a s s u m p t i o n may be erroneous since the effects of w a r m e r temperatures on g r o w t h , at least in the temperate range, may be positive during vegetative d e v e l o p m e n t because the effects on a plant organ (e.g., t h e initiation and expansion of leaves) can reasonably be expected to be positive; but the effect may well be n e g a t i v e w h e n t h e s a m e o r g a n i s a g i n g because w a r m e r temperatures accelerate aging and shorten useful life. In the field, the effects of air temperature and h u m i d i t y are often conf o u n d e d . In temperate conditions the separate effects may well be in opposition because w a r m air (which accelerates growth) is usually dry air (which retards growth) and vice versa. On the other hand, in tropical environments, hot and dry atmospheric conditions may c o m b i n e to limit plant g r o w t h . Response to differences in p h o t o p e r i o d , associated w i t h season as well as latitude, are important c o m p o n e n t s in the adaptation of traditional legume cultivars to their native environments (Wien and Summerfield 1979). Alt h o u g h this climatic factor changes in an exactly predictable manner t h r o u g h o u t the calendar year at any one location, climatologists pay little attention to it. Temperature affects not only the rates but also the durations of m a n y processes that affect g r o w t h . The adaptations of local populations of grain legumes and their progeny to e n v i r o n m e n t depend on differences between genotypes in the separate effects of day and night temperature and of p h o t o p e r i o d , and in the interactions between t h e m , all of w h i c h may vary w i t h the phenological and developmental stage of the genotype. Understanding these effects and interactions makes it possible to predict reliably the times of phenological features such as onset of flower initiation, appearance of first flowers, duration of f l o w e r i n g , physiological maturity, and harvest ripeness (Nix et al. 1977). Such knowledge is a necessary basis for constructing realistic predictive m o d els of crop g r o w t h and yield (Monteith 1972), models w h i c h at present become less reliable as f l o w e r i n g and reproductive g r o w t h become preponderant over vegetative g r o w t h , since we
k n o w relatively little about t h e t i m e course of fruit-to-total g r o w t h ratios and the effects on t h e m of e n v i r o n m e n t and genotype. A plant species can realize its full genetic g r o w t h potential or complete its genetically p r o g r a m m e d phasic d e v e l o p m e n t only w i t h i n certain ranges of e n v i r o n m e n t a l factors. G r o w t h and d e v e l o p m e n t apply to c o m p o n e n t s as well as w h o l e plants and involve i m p o r t a n t changes in m o r p h o l o g y and reproductive state. In n o n l e g u m i n o u s plants, phenotypic variations are the consequence of a c o m b i n a t i o n of genetic differences, the effects of e n v i r o n m e n t on the rate or duration of vegetative g r o w t h and reproductive development, and of genotype x e n v i r o n m e n t interactions. H o w ever, in marked contrast, a nodulated l e g u m e can obtain at least part of its nitrogen requirem e n t s f r o m s y m b i o t i c f i x a t i o n , and its economic yield (leaves and seeds) is c o m p o s e d not only of carbohydrate but also of protein and sometimes of oil. Studies of phenotypic variability in legumes should therefore consider the additional contribution of the Rhizobium genotype u p o n w h i c h plants may partly depend for their nitrogen supply, and the likelihood of Rhizobium x h o s t , Rhizobium x environment, or indeed second-order interactions (Fig. 2A). The more a legume depends upon symbiotically fixed rather than inorganic nitrogen, the most c o m m o n situation in chickpea cultivation (Table 8 van der Maesen 1972), the m o r e significant these potential sources of variation become. The chickpea-Rhizobium symbiosis is extremely specific (Vaishya and Sanoria 1972), and Rhizobium strain differences in efficacy of nitrogen fixation are c o m m o n (Okon et al. 1972). Strains differ in their ability to tolerate salinity and w a r m soil temperatures and significant host x strain interactions can occur (Dart et al. 1976). Significant correlations have been established between effective inoculation and seed yield of chickpea in locations where the crop has not been previously g r o w n (Corbin et al. 1977). In view of these observations, it is unfortunate that the symbiotic relationship has all too frequently been ignored in studies of interactions between genotypes and environment in this species (Gupta et al. 1972; Malhotra and Singh 1973). It is convenient to consider the g r o w t h and development of an annual legume as a n u m b e r of consecutive phases: vegetative (which in-
123
cludes juvenility), m a t u r e (ripeness to flower), reproductive (flowering and setting of fruits), and senescent (which includes m a t u r a t i o n of fruits). The quantitative performance of plants throughout each stage of development (Fig. 2B) is often d e t e r m i n e d or limited by those env i r o n m e n t a l factors w h i c h also initiate phase changes. A traditional components-of-yield analysis equates l e g u m e seed yields to t h e product of three c o m p o n e n t s only, that is, the n u m b e r of pods that reach maturity, the average n u m b e r of seeds in t h e m , and the mean w e i g h t of individual seeds (Fig. 2C). However, as we have argued before ( S u m m e r f i e l d et al. 1978), these aggregated data alone are of limited value in furthering our comprehension of the physiological limitations to l e g u m e seed p r o d u c t i o n . W e cannot hope t o identify w i t h confidence t h e m a i n effects and interactions of climatic factors on the m o r e responsive c o m ponents that c o n t r i b u t e to significant variations in yield until these relations have been studied m o r e carefully.
Growth: Increase in Size and Formation of New Vegetative Organs Variation in both t h e n u m b e r and size of a particular plant organ can be analyzed in terms of t w o variables, w h i c h m a y or may not be independent, i.e., the rate and the d u r a t i o n of g r o w t h ( M o n t e i t h 1977). W h e n the size or n u m b e r of organs is fixed genetically, a change in g r o w t h rate associated w i t h w a r m e r or cooler temperatures may be offset by a proportional change in d u r a t i o n , so that t h e net effect may be small. However, if the rate of g r o w t h is limited by s o m e nongenetical factor(s), such as the supply of carbon or nitrogen, a change in growth rate in association with change in temperature may not be compensated for by differences in g r o w t h duration. Indeed, it is difficult and d a n g e r o u s to make general statements f r o m ''first p r i n c i p l e s " about the effects of p h o t o p e r i o d and air t e m p e r a t u r e on t h e g r o w t h (and development) of legumes, and m a n y data cannot be sensibly interpreted because of the poor experimental designs and cultural practices that have been adopted. W i t h i n chickpea cultivars, individual seed size depends on pod location (mean seed w e i g h t decreases acropetally), the n u m b e r of seeds
124
produced by m o t h e r plants (seed size and n u m b e r per plant are often inversely related), and m a t u r a t i o n environment. For e x a m p l e , w h e n parent plants m a t u r e in t h e hot and dry e n v i r o n m e n t of Hyderabad, m e d i u m - and late-maturity cultivars (e.g., 850-3/27 and G-130, respectively) produce fewer but individually heavier seeds w i t h smaller nitrogen, and presumably protein concentrations than in the cooler climate of Hissar (Saxena and Sheldrake 1977). These differences could influence crop performance not only in the current but also in t h e s u b s e q u e n t g e n e r a t i o n , since small seeds of a given cultivar may germinate m o r e rapidly and result in better stand establishment than larger seeds w h e n soil water status is poor. However, in contrast to s o m e other legumes, (e.g., the sensitivity of large-seeded Virginia g r o u n d n u t s t o d r o u g h t during embryogenesis and the associated loss of germ inability (Palls et al. 1977), the agronomic significance of " e n v i r o n m e n t a l p r e c o n d i t i o n i n g " of chickpea seeds on mother plants remains to be demonstrated. After planting, the rates of g e r m i n a t i o n , emergence (hypocotyl elongation), and seedling g r o w t h are very temperature-dependent w i t h marked differences between genotypes. Chickpea seeds can germinate over a w i d e range of temperatures (10-45°C), but they do so most rapidly at either a constant temperature of 20°C or in diurnally fluctuating regimes of 1 5 25°C (van der Maesen 1972) or 20-30°C (ISTA 1966). S o m e cultivars are responsive to coldtemperature vernalization (Pal and Murty 1941). It is claimed that the vernalized plants have m o r e rapid anatomical d e v e l o p m e n t — e.g., vascular differentiation and cessation of cambial activity (Chakravarti 1 9 5 3 ) — and f l o w e r earlier, and at lower nodes, than plants produced f r o m nonvernalized seeds (Pillay 1944; Chakravarti 1964). Vernalization can also influence chickpea m o r p h o l o g y by hastening stem elongation and suppression of branch f o r m a t i o n , although there are complex interactions between vernalization treatment and the photoperiodic regimes to w h i c h plants are subsequently exposed (Nanda and Chinoy 1960a, 1960b); however, s o m e cultivars do not respond b y f l o w e r i n g earlier w h e n g r o w n f r o m vernalized seed (Kar 1940), and M a t h o n (1969) has classified Cicer arietinum as " h a v i n g no obligate cold r e q u i r e m e n t . "
Cereal
A Phenotypic expression of character = (e.g. y i e l d )
A
General population mean
=
μ
General Yield = population
+
Genotypic effect
±
[Gh
±
Legume
crop
Host effect
±
crop
+
Environmental effect
E
+
±
h
Rhizobium effects
+
+
Interaction effect
(Gh Eh)]
Second order interaction effects
mean
A
=
[ G h ± E h ± ( G h Eh)] ± [ G r ± E r ± ( G r E r ) ] ± [ G h G r E h r ]
±
μ
B
Store
C r o p d u r a t i o n (60 - > 2 5 0 d a y s ) Emer-
Vegetative
gence
Vegetative
Reproductive Veg.+
Reproductive
Reproductive
Vernalization and/or Temp, p r e c o n d i t i o n i n g
Juvenility or Vernalization Floral
induction Flower expansion First anthesis: Duration of flowering Pod p r o d u c t i o n Seed f i l l i n g D e s i c c a t i o n and r i p e n i n g Senescence
Infection
Rapid
Nodulation
Degeneration Residual fixation
Degeneration Reinfection
fixation
o. (N0) 1. Number of n o d e s / p l a n t 2. % of N0 that becomes r e p r o d u c t i v e (1 x 2) = P h e n o l o g i c a l p o t e n t i a l
V e g e t a t i v e growth rate x Duration of p r e f l o w e r i n g period
3. Number of f l o w e r s pe r r e p r o d u c t i v e 4 . % of F t h a t s e t p o d s 5. % of P t h a t a r e r e t a i n e d
node
(F) N u m b e r o f p o d s p e r r e p r o d u c t i v e n o d e ( P )
6 . N u m b e r of s e e d s p e r p o d (S) (3 x 4 x 5 x 6) = R e p r o d u c t i v e e f f i c a c y Carbon supply Nitrogen supply
7. % of S t h a t a t t a i n m a t u r i t y
Mean seed growth rate 8. Mean seed w e i g h t (7 x 8 ) = Y i e l d c u l m i n a t i o n . ' . Y i e l d / p l a n t s (1
Figure
2.
(A)
x 2)
Factors
(B) Diagrammatic (C)
Components
x
that
(3 x 4 x 5 x 6)
contribute
to
representation of
seed
yield
variations
x Duration of p o d - f i l l
x
(7 x 8)
in
seed
of
growth
in
determinate
yield
and
of a
cereal and a
development
in
legume
annual
crop;
legumes;
legumes.
125
Vernalization response in plants is c o m m o n l y controlled by a single or f e w genes and can be readily m o d i f i e d by selection (Evans and King 1975); h o w e v e r , a m o d e s t vernalization requirement m a y be advantageous in Mediterranean climates in order to prevent the appearance of f l o w e r s before winter. Likewise, for crops g r o w n t h r o u g h o u t the Indian winter, requirement for vernalization may enhance yields by delaying flower initiation until plants are well established. Then again, in southern Australia such a cold requirement may p e r m i t early a u t u m n s o w i n g s w i t h o u t the risk of late w i n t e r f l o w e r i n g (Corbin 1976). Many different cultivars have been used in experiments on seed vernalization. Even if genetic diversity for " c o l d r e q u i r e m e n t " exists in cultivated chickpea, it may n o r m a l l y be masked in areas to w h i c h particular cultivars are adapted because of the frequent occurrence of cool temperatures. This illustrates a f u n d a m e n tal principle — the chance of detecting genetic differences is increased w h e n plants are g r o w n in environmental conditions that m a x i m i z e the difference in response between genotypes (Murfet 1977). Y o u n g plants of chickpea cultivars c o m m o n l y g r o w n in Mediterranean climates aretolerant of cool s p r i n g t i m e temperatures, and genotypic differences in seedling g r o w t h rate in cool conditions have been identified in Australia (Corbin 1976). Y o u n g seedlings can w i t h s t a n d temperatures as cold as - 8 ° C (Ivanov 1933) or even - 13°C (Koinov 1968), and cultivar differences in frost tolerance have been reported (Whyte et al. 1953; FAO 1959). At the other climatic extreme, ensuring adequate stand establishment is a major problem in s o m e legume p r o d u c t i o n systems (e.g., soybean) in the tropics. However, chickpea seeds seem able to tolerate w a r m soils at planting, at least w h e n adequate water is available. For example, van der Maesen (1972) recorded 8 4 % g e r m i n a t i o n after 9 days at 35°C in laboratory tests. Nevertheless, chickpea stands in f a r m e r s ' fields are often poor, a n d , w h i l e limited availability of w a t e r in t h e seed bed may be a major factor (Saxena and Sheldrake 1977), other factors may interact w i t h this, such as seed m a t u r a t i o n e n v i r o n m e n t , storage conditions, depth of p l a n t i n g , soil c o m p a c t i o n , and soil temperature. It seems logical to consider nodule initiation
126
and d e v e l o p m e n t at the seedling stage, but unfortunately, this is seldom d o n e even t h o u g h in chickpea significant differences are k n o w n in t h e ability of Rhizobium strains to establish an effective symbiosis and, in the subsequent rate of nitrogen f i x a t i o n , in different t h e r m a l regimes. For example, the f o r m a t i o n and f u n c t i o n of nodules by Cicer rhizobium can be restricted in w a r m soils (Sen 1966). A t e m p e r a t u r e of 30-33°C had drastic effects even w h e n imposed for only a f e w hours each day (Dart et al. 1976). W h e n chickpea is g r o w n as a s u m m e r crop at latitudes between 30 and 40°N in Lebanon, Italy, Spain, Iran, and Turkey, the vegetative plants w i l l experience long days (to m o r e than 14 hours) and average m a x i m u m and m i n i m u m air temperatures of about 25° and 8-10°C, respectively. For winter crops in India and Pakistan, however, the daylengths at this stage of development will be only 1 0 - 1 2 hours, and mean m a x i m u m air temperature will be about 18°C while nights can be as cool as 0-2°C (Sinha 1977). We have used c o n t r o l l e d - e n v i r o n m e n t g r o w t h cabinets to investigate the effects on chickpea g r o w t h and d e v e l o p m e n t of factorial combinations of long and short days, w h i c h are either w a r m or cool and w h i c h are f o l l o w e d in each diurnal cycle by w a r m or cool nights. The temperatures chosen w e r e selected to typify the range of each climatic factor experienced by chickpea crops t h r o u g h o u t their geographical distribution. Evidence to date (Summerfield et al. in press) for three cultivars (Chafa, Rabat, and G-130) has established that the rate of seedling emergence f r o m a h o m o g e n e o u s and hydrated rooting m e d i u m is m o r e obviously positively correlated w i t h w e i g h t e d mean temperatures throughout the range 14.5-24.5°C than any other aspect of temperature ( w h e n treatments comprised nights of 10° or 18°C alternating w i t h days of 22° or 30°C). Seedlings emerged w i t h i n 4 - 6 days after sowing at 24.5°C, compared w i t h 6 . 5 - 9 days at 14.5X (Fig. 3). The subsequent vegetative p e r f o r m a n c e of y o u n g plants, h o w ever, is far m o r e dependent on the separate effects of day and night t e m p e r a t u r e than on the mean value of the diurnal fluctuation. These responses are typified by Chafa plants harvested after 28 days f r o m s o w i n g (Figs. 4, 5). In daylengths characteristic of the Indian g r o w i n g season ( 1 1 - 1 2 hours), the dry weight of vegetative plants (Fig. 4A) depends largely on whether
9 8 Y = 13.46-0.33 x r2 = 0 . 6 1
7
6 5 4 Rabat Chafa
3
Y = 10.12-0.26 x r2 r 0 . 7 9
0 14
15
16
17
18
19
20
21
22
Figure
3.
Relationship chickpea to
between
cultivars
Chafa
and
has
A. Total shoot, root, a n d n o d u l e dry w t (g/plant)
days
Rabat been
to and
omitted
50%
emergence
Chafa.
Cultivar
for
23
and
weighted
mean
G-130 showed a
25
26
air
temperature
for
response
almost identical
clarity.
B. (Root + n o d u l e ) : s h o o t dry w t r a t i o
D. Total N 2 f i x a t i o n (μmol C 2 H 4 / p l a n t per hour)
C . N o d u l e : r o o t dry wt ratio
2.4
0.6
12
2.0
0.5
10
0.4
8
1.6
24
(xoC)
Weighted mean air temperature
Total 1.2
Shoot
0.8
0.4
0.3
0.3
0.2
0.2
0.1
0.1
6
4 2
Root + Nodules 0
1
2
0
1
2
0
1
2
0
1
2
Treatments 0=cool
d a y s and n i g h t s ;
1= cool d a y s / w a r m n i g h t s or warm n i g h t s / c o o l d a y s ;
2 = w a r m days and n i g h t s ; in day t e m p e r a t u r e (22-33° C). Figure
4.
Richards' production plants replicates six
and grown per
replicates
diagrams
(1941)
distribution
of
in
illustrating dry
matter,
controlled-environment
treatment in
= increase in night temperature (10-18°C);
total).
combination Plants
in
harvested
the
effects
and
on
growth 1128
and days
of day and night nitrogenase cabinets.
12-hour after
activity, Mean
day
lengths,
=increase
temperature of values
on
the
young
Chafa
of
three
respectively
(i.e.,
sowing.
127
the nights are w a r m (18°C) or cool (10°C), and neither above- nor b e l o w - g r o u n d dry-matter production is significantly affected by w h e t h e r or not days are w a r m (30°C) or cool (22°C). W a r m nights p r o m o t e shoot g r o w t h m o r e s o than b e l o w g r o u n d dry-matter p r o d u c t i o n , w h i c h in all treatments, represents at least 2 8 % of the total dry w e i g h t produced at this stage of development. While they do not affect drymatter production per se, w a r m days do favor dry-matter allocation to organs b e l o w rather than above the g r o u n d (Fig. 4B), and w a r m nights favor n o d u l e production and g r o w t h rather than root g r o w t h (Fig. 4C). Hence, vegetative plants g r o w n in cool days and w a r m nights (22-18°C) are equally the largest, and they invest about one-half of their total dry matter into root plus n o d u l e g r o w t h and about 20% of this to the nodules themselves. Indeed, the nodules (formed by Rhizobium strain CC 1192) in this r e g i m e are especially active, whereas a night t e m p e r a t u r e of 10°C and (as
A . Dry w t
(g/plant)
2.4
2.0
also s h o w n by Dart et al. 1970) a day temperatur e of 30°C are clearly sub- and s u p r a o p t i m a l , respectively (Fig. 4D). In a 15-hour daylength regime characteristic of the g r o w i n g season in m o r e northerly latitudes, w a r m days and cool nights or cool days and w a r m nights (30-10°C or 2 2 - 18°C) are best f o r dry-matter production (Fig. 5A). W a r m nights favor dry-matter allocation b e l o w the g r o u n d (Fig. 5B) and again, to nodules rather than to roots (Fig. 5C), and they stimulate symbiotic activity if day temperatures are not supraoptimal (Fig. 5D). Since many chickpea crops are g r o w n w i t h o u t addition of large a m o u n t s of nitrogenous fertilizer and, in India and Pakistan, on m o i s t u r e conserved in the soil after preceding rains, a c o m b i n a t i o n of cool days and w a r m nights ( 2 2 - 18°C) seems likely to produce plants best equipped to tolerate such practices. It may prove w o r t h w h i l e however, to screen genotypes for their ability to g r o w and nodulate in cool nights (10°C) —a site at high
B. ( R o o t + n o d u l e ) : s h o o t dry wt ratio
D. Total N2 f i x a t i o n (μmol C 2 H 4 / p l a n t per hour)
C. N o d u l e : root dry wt ratio
0.6
12
0.5
10
0.4
8
Total 1.6
Shoot
1.2
0.3
0.3
6
0.2
0.2
4
Root + Nodules
0.1
0.1
2
1
2
0.8
0.4
0
0
1
0
2
1
2
0
1
2
Treatments 0 = c o o l days and nights; 1= cool d a y s / w a r m n i g h t s or warm n i g h t s / c o o l days; 2 = warm days and n i g h t s ; = i n c r e a s e in n i g h t t e m p e r a t u r e ( 1 0 - 1 8 ° C ) ; = increase in day temperature ( 2 2 - 3 0 ° C ) .
Figure
5.
Same as for Figure 4 except that each combination
128
and
in
a
day
length
of
15
value is the mean hours.
Plants
of three replicates per treatment
harvested
28
days
for
sowing.
altitude m a y suffice — and f o r n o d u l a t i o n and
treatment
fixation activity in warm days (30°C).
h o w easily erroneous conclusions c o u l d
Figure 6 s h o w s t h e diurnal d i s t r i b u t i o n of
combinations
and
highlights
just be
d r a w n if plant responses w e r e related o n l y to
t e m p e r a t u r e s u m (centigrade hours a b o v e a
mean t e m p e r a t u r e or, as is c o m m o n l y d o n e
base t e m p e r a t u r e of 0°C) w i t h i n the various
w i t h grain legumes, t o average day t e m p e r a -
A . Mean o f 1 1 - a n d 12-hr day l e n g t h s
B. 15-hr day l e n g t h
600
TTS 500 TTS
400
DTS DTS
300
NTS
200
NTS
100
0
1
0
2
1
2
Treatments 0= cool days and n i g h t s ; 1= cool d a y s / w a r m n i g h t s or warm n i g h t s / c o o l d a y s ; 2= warm d a y s and n i g h t s ; = increase in night temperature (10-18°C); = i n c r e a s e i n day temperature (22-30°C). Figure
6.
Distribution tions:
DTS,
Note
especially
of temperatures
NTS,
and
that
temperature
sum
to
drastically
different
temperature
sum
TTS
sum
within
denote
day,
treatment plants
combinations
each
diurnal
consequences,
between
hours
various night, which cycle
depending of
daylight
and
day
and
and
provide
(e.g., on
night
temperature
total temperature more
22-18°C the
darkness
and
relative (see
Figs.
sum,
or
combinarespectively.
less
the
same
30-10°C)
can
have
distribution 4
and
of
the
5).
129
ture. These data are presented and discussed m o r e f u l l y elsewhere ( S u m m e r f i e l d et al., in press). Others have investigated the effects on vegetative attributes of chickpea w h e n plants are g r o w n in a range of nonfactorial c o m b i n a t i o n s of t e m p e r a t u r e (van der Maesen 1972) or even constant temperatures (Sandhu and Hodges 1971). A plethora of responses have been described (Table 1), usually f o r plants dependent on inorganic nitrogen rather t h a n s y m b i o t i c fixation but w h i c h may or may not have been nodulated. It is difficult to relate these data either to each other or to extrapolate f r o m t h e m to predict field performance. It is also difficult to anticipate h o w such data will relate to the p e r f o r m a n c e of nodule-dependent plants in different aerial environments. However, it is n o t e w o r t h y that t w o of the t e m p e r a t u r e c o m b i nations that others have described as ' ' o p t i m a l " for dry-matter production have a mean value close to that of the cool day, w a r m night env i r o n m e n t (19.56°C), w h i c h was so favorable to the early vegetative g r o w t h and symbiotic activity of cv Chafa (Figs. 4 and 5). The longevity of individual chickpea leaves is m o r e p r o l o n g e d in areas of cool temperatures (18°-19°C) t h a n in w a r m e r regimes (26°C), a fact w h i c h , in t i m e , could counteract their slower
Table
1.
rates of photosynthesis (23.2 and 26.1 mg CO 2 d m - 2 , per hour, v a n der Maesen 1972). Furtherm o r e , t h e rate of dry-matter productio n of a cultivar does not necessarily closely reflect t h e rate of foliar photosynthesis of the s a m e cultivar in other trials (van der Maesen 1972). The photosynthetic capacity of chickpea leaves seems neither greater nor less than other grain legumes, is equally variable (Table 2), and presents the same problems w i t h respect to measurement and interpretation of comparative data (Evans 1975). Others have suggested or inferred, that selection fo r photosynthetic rate per se or s o m e related attribute, such as RuDP carboxylase activity or chlorophyll content (Kumari and Singh 1972; and Sinha 1977), may be a w o r t h w h i l e objective. This seems unlikely: selection for photosynthetic rate presents very great p r o b l e m s w i t h little surety of return. One major p r o b l e m is immediately apparent in Table 2 w h e r e it can be seen that an e n o r m o u s range of values has been reported even for t h e s a m e cultivars of soybean. The average dry w e i g h t of y o u n g Chafa plants (28 days after sowing) g r o w n in a 15 hour daylength of intense fluorescent light (Fig. 5) was exactly 30% larger than the average of plants g r o w n in 11 or 12 hour days (1.96 and 1.51 g r a m s p l a n t - 1 , respectively). Plants in the
S o m e effects of air t e m p e r a t u r e and photoperlod on vegetative attributes of several cultivars of chickpea. Optimum environmental combination P h o t o p e r i o d (hr)
T e m p e r a t u r e (°C) Vegetative attribute
Day
Night
Length
Light s o u r c e
Leaf + s t e m d r y w e i g h t (g) Total d r y w e i g h t (g)
22.5 18.0 24.0 21.0 30.0 10.0 15.0 27.0
12 12 14 14 16 16 14 14
Fluorescent + incandescent Fluorescent HPL b u l b s f o r 12 hr + 2 hr l o w intensity Fluorescent + incandescent Fluorescent
Leaf no. on m a i n s t e m
22.5 26.0 32.0 29.0 30.0 10.0 23.0 35.0
Area l e a f - 1 (cm 2 ) Leaf area p l a n t - 1
26.0 26.0
18.0 18.0
14 14
No. p r i m a r y and secondary branches p l a n t - 1
HPL bulbs f o r 12 hr + 2 hr l o w Intensity
Light intensity (lux) 28 063 ? ? 28 063 4|000
?
C o m p i l e d f r o m H u g o n (1967); S a n d h u a n d H o d g e s (1971); a n d v a n der M a e s e n (1972). A l l p l a n t s p r o b a b l y d e p e n d e n t o n i n o r g a n i c N ; m a y o r m a y n o t h a v e b e e n n o d u l a t e d . Insufficient data p r e s e n t e d t o calculate N concentration applied.
130
Table
2 . R a t e s o f f o l i a r p h o t o s y n t h e s i s ( m g C O 2 d m - 2 p e r hr) r e p o r t e d f o r g r a i n l a g u m a s .
Legume Lupin P. vulgaris Chickpea Cowpea Groundnut Soybean Soybean cv cv cv cv
Wayne Chippewa Hark Lee
Net photosynthetic rate of f u l l y expanded leaves at saturating light intensity
N o . of m e a s u r e m e n t s on different lines/ cultivars/genotypes
29.4-34.9 13.5-32.0 19.0-42.5 23.0-50.0 29.0-41.0 12.0-41.6
3 10 8 2 24 63
18.0-50.0 22.0-35.0 20.0-38.3 15.0-34.7
5 3 3 3
Data extracted f r o m 23 p u b l i c a t i o n s , w h i c h i n v o l v e a total of 113 species, g e n o t y p e s , cultivars, and breeders' lines.
longer daylength received 30% m o r e total short wave radiation (300-3000 nm) than the average of 11 and 12 hour regimes (15.60 and 11.95 MJ m - 2 , respectively). Clearly, there is no photoperiodic effect and differences in dry-matter production reflect those in light-energy receipt. Others have studied photoperiodic effects on chickpea, either on plants g r o w n in pots in poorly designed experiments in controlled env i r o n m e n t s or in natural daylengths, w h i c h are either shortened by screening plants fo r a n u m b e r of hours in each diurnal cycle or extended w i t h d i m incandescent light. Incandescent lighting was used to extend a c o m m o n photosynthetic period of 11 hour duration to 20 hours (Dart et al. 1976), and three varieties were tested. The plants g r o w n in 11 hour daylengths produced many m o r e branches but were only slightly (13.5%) heavier, nodulated better, and fixed between 24 and 27% m o r e nitrogen than those g r o w n in the 20 hour regime. The better branched plants had m a n y m o r e leaves, w h i c h probably supplied m o r e photosynthate to the roots. Singh (1958) also recorded a decline in nodulation of chickpea plants in daylengths longer than 12 hours, w h i c h t o o was associated w i t h a decrease in leaf n u m b e r per plant. These data, coupled w i t h those observations of van der Maesen (1972), w h i c h are consistent and can be interpreted logically, lend support to a hypothesis that p h o t o p e r i o d per se has little effect on vegetative attributes of chickpea, except w h e r e the duration of the vegetative period
is drastically influenced by photoperiodic effects on flower initiation and development (see below). We caution against the sole use of incandescent lighting to provide contrasting photoperiods in controlled conditions, not only because of unwanted photomorphogenetic responses to light quality by the host plant but also because of the complex effects of red/farred light on nodulation that are already k n o w n for other legumes, e.g., Lie (1971). Chickpea is indeterminate and can continue vegetative g r o w t h into the reproductive period. A l t h o u g h relatively f e w cultivars have been studied in detail, those examined reveal marked differences in the rate of dry matter production and the relative distribution of dry-matter between vegetative and reproductive c o m p o nents, when grown at the same or in different locations. Such differences may well reflect appropriate adaptation to the environment experienced t h r o u g h o u t crop duration. For example, Table 3 contrasts the average performance of each of four desi and kabuli types g r o w n at Hyderabad (Fig. 7). Kabuli cultivars seem far better adapted to the environmental conditions that prevail during the early g r o w i n g season: they first flower slightly later but by then they have produced m o r e than d o u b l e the dry weight (and presumably a correspondingly larger number of nodes) of desi cultivars. However, the earlier f l o w e r i n g desi types produce most of their vegetative dry matter (68%) after f l o w e r i n g , so that by final harvest (100 days
131
Table 3.
C o m p a r i s o n o f t h e p r o d u c t i o n ( 9 p l a n t - 1 ) a n d d i s t r i b u t i o n (%) o f d r y m a t t e r b y f o u r cultivars of each deal and kabuli typos at Hyderabad.
M e a n values o f
Desi (D)
Days f r o m s o w i n g t o first f l o w e r Plant d r y w e i g h t at first f l o w e r Total dry w e i g h t at harvest (100 days) Fruit dry w e i g h t at harvest Vegetative dry w e i g h t at harvest P r o p o r t i o n (%) of total d r y w e i g h t p r o d u c e d b y first f l o w e r P r o p o r t i o n (%) of v e g e t a t i v e d r y w e i g h t p r o d u c e d b y first f l o w e r P r o p o r t i o n (%) of d r y w e i g h t p r o d u c e d after first f l o w e r in (a) Fruits (b) V e g e t a t i v e Fruit w e i g h t ratio
Kabuli (K)
Relative difference (%) b e t w e e n kabuli a n d desi (100 [K-D]/D)
44.3 1.46 10.73 6.14 4.59
53.8
14
27
+93
32
55
+72
66 34 0.57
70 30 0.51
+6 -12 -10
3.15 11.74 5.98 5.76
+21 + 116 +9 -3 +25
Calculate d f r o m S a x e n a a n d S h e l d r a k e (1976).
f r o m sowing) both types have similar biological and almost identical economic yields. Both types allocate remarkably similar p r o p o r t i o n s of their dry-matte r accumulation after first f l o w e r i n g into fruits (about t w o thirds), but the i m p r o v e d dry-matter production of desi cultivars t h r o u g h o u t t h e latter half of the g r o w i n g season overcomes the early advantage of kabuli types. This trial (Saxena and Sheldrake 1976) w a s s o w n between N o v e m b e r 6 a n d 12 and experienced average m a x i m u m and m i n i m u m air temperatures of 30 and 10°C, respectively, t h r o u g h o u t the first 6 0 - 7 0 days. This c o m b i n a t i o n of temperatures has already been s h o w n not to favor vegetative g r o w t h of cv Chafa (a desi type) in Indian d a y l e n g t h c o n d i tions (Fig. 4). A Compariso n of the p e r f o r m a n c e of shortand long-duration cultivars in different env i r o n m e n t s can p r o v i d e i n f o r m a t i o n on t h e adaptability of these types to time and to the env i r o n m e n t a l conditions that prevail (Table 4). In both Hyderabad and Hissar, t h e onset of flowering in t h e long-duration cultivar (G-130) was delayed to the same relative extent (54-59%) as was the short-duration cultivar (JG-62), and this resulted in a dramatic, m o r e than t h r e e f o l d , increase in dry-matter p r o d u c t i o n . However, in t h e w a r m e r e n v i r o n m e n t at Hyderabad this
132
represents almost all the vegetative dry matter produced by the crop (83%) and m o r e than half (62%) of the total dry-matter p r o d u c t i o n . At Hissar, these values correspond to less t h a n half and less than 2 0 % , respectively (Table 4). Even t h o u g h t h e durations of the reproductive period and overall crop g r o w t h are significantly longer in G-130 than in JG-62 at Hyderabad, the long-duration cultivar produces slightly less total dry matter and only about one-third the fruit yield than the short-duration type does. Clearly, the long-duration cultivar is poorly adapted to t h e e n v i r o n m e n t a l conditions that prevail t h r o u g h o u t the latter part of crop d u ration at Hyderabad. In contrast, a delay in the onset of f l o w e r i n g between sites, again to t h e s a m e relativedegree in both cultivars (a delay of 3 3 - 3 7 % at Hissar), reduces plant d r y w e i g h t at this stage of dev e l o p m e n t by an identical p o r p o r t i o n (19%) in both cultivars. The d u r a t i o n of the reproductive period and overall crop g r o w t h ( s o w i n g to harvest) is drastically extended in the short- but not t h e long-duration cultivar w h e n g r o w n at Hissar, and by m a t u r i t y , both cultivars have produced m o r e or less the s a m e total dry matter — about three t i m e s m o r e than at Hyderabad (Table4). Fruit yields are also similar but represent a six- and threefold increase in t h e
A. Hyderabad (17°N) Mean maximum Mean minimum
35
25
15
5
Mean seasonal diurnal variation
13.5 ± 1 6 ° C
0 Oct
Nov
Dec
Jan
Feb
Mar
B. H i s s a r ( 2 9 ° N ) 35
Mean maximum Mean minimum
25
15
5
Mean seasonal diurnal variation
17.6 ± 1.3° C
0 Oct
Nov
Dec
Jan
Feb
Mar
16 Hyderabad (Mean 11 hr 54 mm) H i s s a r (Mean 11 hr 26 min) 14
12
10 Oct
Figure
7.
Nov
Dec Jan Feb Calendar month
Mean
monthly
minimum and tions main
at
Hissar
monthly
day (hr
maximum
meteorological
temperatures
≥
and
screen
Hyderabad
(29°N), length 1
Mar
air (17°N)
and in
Ft-c)
chickpea-growing
both
mean loca-
throughout
the
seasons.
long- and short-duration cultivars over their respective performances at Hyderabad. It seems likely that the cold nights at Hissar are s u b o p t i m a l for vegetative g r o w t h of these t w o desi cultivars (Figs. 4, 7). Both cultivars had produced only a m i n o r p r o p o r t i o n of their
vegetative (and total) dry matter by t h e onset of flowering at Hissar, but the later flowering of G130 allowed four times greater dry-matter production (and presumably i m p r o v e d n o d e production and nitrogen accretion) than did JG-62. At Hyderabad, t h e short-duration cultivar allocated about three times m o r e dry matter into fruits than into vegetative components than d i d G-130, and this ratio was identical at Hissar (Table 4). Clearly, the short-duration cultivar is less well adapted to Hyderabad conditions during vegetative g r o w t h than is G-130 (at least w i t h respect to dry-matter production), but early f l o w e r i n g , rapid maturation and a mor e efficient distribution of dry matter into fruits ensure far greater economic yields at harvest. The long-duration cultivar g r o w s little after flowering, produces fruits w h e n air temperatures are w a r m i n g rapidly (see below), and has an abysmal harvest index. It is inappropriately adapted to both t i m e and environment; the short-duration cultivar, w h i l e better adapted in t i m e , is poorly adapted to the environment that prevails during early g r o w t h . At Hissar, adaptation in time is less critical, but both cultivars are poorly adapted to cold nights. It is pertinent to note the contrasting "strategies" of the shortand long-duration cultivars at Hissar: they have identical crop durations, which however, result f r o m relatively long vegetative and short reproductive periods in G-130 and vice versa in JG-62; dry matter is produced mainly after the first f l o w e r i n g by JG-62, but a far larger proportion is generated during the vegetative period of G-130, w h i c h then allocates a larger proportion (of the relatively smaller amount) of dry matter produced after flowering into fruits than does JG-62 (Table 4). Overall, these data pose the f o l l o w i n g questions that merit investigation: (1) w h a t is the potential value of kabuli germplasm to the i m p r o v e m e n t of chickpea adaptability to cold nights?; (2) what is the potential fo r earlier sowing of long-duration cultivars in southerly locations?; (3) w h a t is the potential value of long-duration g e r m p l a s m to the i m p r o v e m e n t of vegetative g r o w t h rates of progeny material (dry-matter production being far greater than expected if t i m e to f l o w e r i n g and dry w e i g h t at f l o w e r i n g were linearly related)?; (4) w h a t is the potential value of short-duration parents to the improvement of harvest index of longer duration cultivars?
133
The translocation of photosynthates accumu-
m e r f i e l d a n d W i e n 1979). O n t h e other h a n d , t h e
lated b e f o r e f l o w e r i n g f r o m v e g e t a t i v e o r g a n s
n i t r o g e n n u t r i t i o n of v e g e t a t i v e plants is often
to seeds is p r o b a b l y s m a l l in chickpeas (inferred
neglected
f r o m d e f o l i a t i o n e x p e r i m e n t s ) ; t y p i c a l values i n
adequate n i t r o g e n a c c u m u l a t i o n b e f o r e f l o w e r -
other grain legumes range f r o m 8 to 15% (Sum-
ing is of critical i m p o r t a n c e to final seed y i e l d .
Table 4.
even
though
the
probability
C o m p a r i s o n o f t h e p r o d u c t i o n ( g p l a n t - 1 ) a n d d i s t r i b u t i o n (%) o f d r y m a t t e r b y a s h o r t (JG-62) a n d long-duration ( G - 1 3 0 ) d e s i cultivar a t H y d e r a b a d a n d a t Hissar.
Mean values of Days f r o m s o w i n g t o first f l o w e r
Cultivar (desi) JG62 G130
Relative difference b e t w e e n c u l t i v a r s *
Hyderabad (A)
Hissar (B)
46 73
63 97
+ 59
+54
Relative difference (%) b e t w e e n sites (100[B-A]/A) +37 +33
Plant d r y w e i g h t at first f l o w e r
JG62 G130
1.6 5.3
1.3 4.3
-19 -19
Relative difference Crop d u r a t i o n (days)
JG62 G130
+231 107 150
+231 172 172
+61 + 15
61 77
109 75
+79 -3
+26
-31
+40
Relative difference Duration reproductive p e r i o d (days)
JG62 G130
Relative difference Total dry w e i g h t at maturity
JG62 G130
9.3 8.5
27.5 22.9
+ 196 + 169
Relative difference Fruit d r y w e i g h t at maturity
JG62 G130
-9 5.9 2.1
-17 14.9 12.3
+ 152 +486
Relative difference Vegetative d r y w e i g h t at maturity
JG62 G130
-64 3.4 6.4
-17 12.6 10.6
+271 +65
Relative difference P r o p o r t i o n (%) of total d r y w e i g h t p r o d u c e d b y first f l o w e r
JG62 G130
+88 17 62
-16 5 19
P r o p o r t i o n (%) of vegetative d r y w e i g h t produced by firstflower
JG62 G130
47 83
10 41
JG62
77 23 66 34
57 43 66 34
0.63 0.24
0.54 0.54
P r o p o r t i o n (%) of d r y w e i g h t p r o d u c e d after first f l o w e r in a) Fruiting stage b) Vegetative stage a) Fruiting stage b) V e g e t a t i v e stage Fruit w e i g h t ratio
Calculated f r o m Saxena a n d Sheldrake (1977). *For all I t e m s , r e l a t i v e d i f f e r e n c e Is 100(b-a)/a.
134
of
G130
JG62 G130
Indeed, large quantities of nitrogen are mobilized f r o m vegetative organs as chickpea seeds fill (Table 5). We urgently require m o r e detailed quantitat i v e data on environmental regimes that significantly influence the a m o u n t of nitrogen accumulated by different symbiotic associations before the onset of reproductive g r o w t h . It is surprising that the majority of studies on vegetative growth in chickpea have concentrated exclusively on carbon m e t a b o l i s m and that only in a small m i n o r i t y of investigations has attent i o n been focused on the f o r m a t i o n of potential reproductive sites or on nitrogen nutrition. Clearly, such studies should receive research priority. An example of symbiotic response to e n v i r o n m e n t is s h o w n by s o m e preliminary data in Figure 8. For symbiotic associations w h i c h involve Rhizobium strain CC 1192, there are marked differences in average symbiotic performance w i t h different hosts and subtle differences in response to environmental factors. The most obvious, consistent, and dramatic effect on symbiotic N 2 fixation, however, is the adverse consequences of w a r m (30°C) days (Dart et al. 1976). These symbiotic combinations are ill adapted to w a r m days and cool nights (30-10°C) and to the warmest diurnal regime (30-18°C) — conditions that prevail at the beginning and end of crop duration in m a n y Indian locations (e.g. see Fig. 7). The o p t i m u m environment for fixation (22-18°C) was also optimal for vegetative g r o w t h (Figs. 4, 5), but the t e m p o r a l relationships between i m p r o v e d g r o w t h and m o r e rapid fixation have yet to be resolved. For the t w o desi cultivars, the longer the daylength, the m o r e adverse are w a r m days; however, it may be significant that, although symbiotically inferior, the kabuli cultivar Rabat (strain CC 1192 association) s h o w s identical absolute responses in long (15 hour) and short (11-12 hour) days (Fig. 8). These preliminary data indicate the magnitude of the effects of environmental factors on symbiotic potential and demonstrate to the plant breeder that not only does the host genotype contribute to symbiotic performance but also responses to environmental factors differ between symbiotic partnerships. Attempts should be made to select not only the host but also the Rhizobium genotypes, and the agronomic management of breeders' plots will require careful regulation.
Table 5.
Sources of N to seeds In chickpea. ( A l l v a l u e s e x p r e s s e d as a p e r c e n t a g e of total seed N c o n t e n t at harvest.)
Source Mobilization f r o m : Leaves + petioles M a i n stem + lateral axes Root + nodules Pod w a l l s Total Assimilation of N2 and/or NO 3 uptake d u r i n g seed fill
Contribution to seed N
31.8 8.0 3.0 NDa 42.8 57.2
Calculated f r o m Saxena a n d Sheldrake (1977). a. N o t d e t e r m i n e d .
Clearly, the rates at w h i c h nodes, leaf initials, and branches are differentiated and expand, the pattern of branching, and the height of plants depend on temperature, but, unless there is a marked effect on the duration of vegetative g r o w t h , differences in photoperiod seem generally iess important. Leaf area per plant, or per unit area (leaf area index), however, depends not only on the rate of leaf g r o w t h but also on the rate of leaf death, about w h i c h little is k n o w n in chickpea. The rate of foliar senescence w i l l change during the ontogeny of the crop, and the effects of temperature (frequently progressively w a r m e r in many natural g r o w i n g conditions) are likely to become m o r e acute as individual leaves age. Furthermore, the rate of senescence will certainly depend on the number and size of the fruits, and the rate at which they grow, and on nitrogen nutrition both before and after f l o w e r i n g begins. We should not pretend to have m o r e than a cursory knowledge of these relationships in chickpea. Only in a few studies have the separate effects of day and night temperature been investigated. Already, we f i n d that night rather t h a n day temperature determines the vegetative dry-matter production of cultivars examined in factorial experiments. In other legumes, cool nights can limit water uptake b u t they may favor root rather than shoot g r o w t h , and they may lessen dark respiration of w h o l e plants and so p r o m o t e vegetative g r o w t h . Alternatively, w i t h warmer temperature ranges than those investi-
135
Chafa
G-130
Rabat
140
120
100
80
60
40
20
0
1
2
0
1
2
0
1
2
Treatments 0 = C o o l d a y s and n i g h t s ; 1= cool d a y s / w a r m n i g h t s or warm n i g h t s / c o o l days; 2 = warm days and n i g h t s ; = i n c r e a s e in n i g h t t e m p e r a t u r e ( 1 0 - 1 8 ° C ) ; = increase in day t e m p e r a t u r e ( 2 2 - 3 0 ° C ) .
Figure
8.
Richards' length
on
diagrams
total
plant
controlled-environment are
differentiated
by
(1941)
illustrating
nitrogenase
growth relatively
cabinets. thick
effects of
Mean (15
gated w i t h chickpea, leaf expansion, b r a n c h i n g , and the a c c u m u l a t i o n of vegetative dry matter in cowpea and soybean are p r o m o t e d in w a r m nights (24° c o m p a r e d w i t h 19°C) but are little affected by day t e m p e r a t u r e (33° and 27°C). Then again, m o r e nodules may be f o r m e d in w a r m nights and they m a y also fix n i t r o g e n m o r e rapidly than in cool nights ( S u m m e r f i e l d and W i e n 1979). Clearly, we are far f r o m being able to classify chickpea g e n o t y p e s as to their adaptability to relatively w a r m e r or cooler c o n ditons: field observations at this t i m e can offer no m o r e than tentative proposals.
136
the
activity hr)
or
45-day
of day and night old
values
of
thin
(11-12
chickpea three hr)
temperature cultivars
replicates. solid
lines
and
day
grown
in
Day and
lengths dashes.
Reproductive Development Our current approach to and c o m p r e h e n s i o n of e n v i r o n m e n t a l adaptation in all grain legumes has been largely influenced by the discovery, more than 50 years ago, that photoperiod markedly affects t h e induction of f l o w e r i n g in soybean. The effects of other e n v i r o n m e n t a l factors, and especially of their interactions w i t h p h o t o p e r i o d , on reproductive d e v e l o p m e n t have been seriously neglected even t h o u g h it w a s observed 40 years ago that cool t e m p e r a tures, particularly at night, can m o d i f y the
response of soybean to inductive photoperiods (Steinberg and Garner 1936). Chickpea provides the classic example of the m y o p i c preoccupat i o n w i t h photoperiodic effects on reproductive development.
Juvenility and Vernalization A pronounced juvenile phase, during w h i c h plants are insensitive to normally inductive conditions, has not been reported in chickpea. Cultivars responsive to cool temperature vernalization are k n o w n but, in general, only relatively small positive and negative effects have been reported, as we discussed earlier in this review.
Floral Initiation and Flower Development Air temperature and p h o t o p e r i o d and their interaction markedly affect the t i m e of initiation of flower buds in legumes and their subsequent expansion into open flowers. In contrast to many n o n l e g u m i n o u s species, w h e r e t h e initiation of flowers is the reproductive stage most sensitive to environmental regulation, in legumes the expansion of flower initials seems equally, if not m o r e sensitive to external control. It is very difficult to generalize f r o m published data because so f e w experiments on the effects of these environmental factors have been designed factorially or have continued t h r o u g h successive periods of reproductive development. Chickpea has been variously described as a long-day plant (Pal and M u r t y 1941; Singh 1958; Nanda and Chinoy 1960a, 1960b; Moursi and Gawad 1963; Eshel 1968; M a t h o n 1969; Pandey et al. 1977), quantitative long-day plants (Sandhu and Hodges 1971; van der Maesen 1972), day-neutral plants (Allard and Zaumeyer 1944; Mateo Box 1961), and in one case, as short-day plants (Bhardwaj 1955). Evidence has been summarized as s h o w i n g "chickpeas are only moderately sensitive to p h o t o p e r i o d " (van der Maesen 1972) whereas others have described cultivars of this species that " d i s p l a y t r e m e n d o u s variation in photoperiodical res p o n s e " (Ladizinski and Adler 1975). Several workers report that long days suppress branching but increase dry-matter production, w h i l e others report that early f l o w e r i n g leads to small
yields. Cultivars may flower earlier in w a r m days, in w a r m nights, w i t h w a r m e r average temperatures, or with warmer constant temperatures; but they can also flower later w i t h w a r m e r average or constant temperatures (Summerfield and Wien 1979). Collectively, these conflicting data p r o v i d e little information to enable the prediction of cultivar responses in t h e field, to identify potentially broad or narrow adaptation to climate, or to arrange that the durations of vegetative and reproductive g r o w t h coincide w i t h t h e most efficient utilization of the available g r o w i n g season. We have discussed earlier some of the reasons w h y this unsatisfactory situation has arisen, but a number of other reasons need to be borne in mind in the future. For instance, there are likely to be important differences a m o n g chickpea cultivars w i t h respect t o : 1. The o p t i m u m photoperiod (that at w h i c h the course of events at a particular stage of reproductive ontogeny is most rapid); 2. Photoperiod sensitivity (the delay in a particular developmental sequence per unit change of photoperiod); 3. The critical photoperiod (that above or below w h i c h a given developmental sequence is arrested); 4. Separate effects of day and night temperature on successive stages of d e v e l o p m e n t ; and 5. Temperature effects on (1), (2), and (3) above. Furthermore, f r o m experience gained f r o m other legumes, we should n o w attempt to quantify for chickpea: 1. Whether cool temperatures, particularly at night, can substitute for longer photoperiods; 2. The effects of temperature on t h e shape of daylength response surfaces; 3. Whether genetic indifference (neutrality) to daylength w i t h respect to the onset of flowering is available: 4. Whether daylength requirements become progressively mor e stringent after f l o w e r initiation; and 5. The separate temperature effects on successive stages of reproductive ontogeny. To illustrate the care that is needed if controlled environment studies are to be used effectively to resolve s o m e of these problems, we
137
that both day and night temperature and p h o t o p e r i o d can have large effects on chickpea behavior such t h a t as Table 6 s h o w s , a cultivar classified as early f l o w e r i n g is not necessarily destined to mature early and to enjoy only a short reproductive period. Conversely, cultivars taking t w i c e as long to c o m e into f l o w e r can have shorter reproductive periods and so c o m e to m a t u r i t y in m o r e or less t h e s a m e t i m e , depending u p o n e n v i r o n m e n t a l conditions. The shorter the daylength and the cooler t h e air
have replotted s o m e data f r o m van der Maesen (1972), w h i c h indicate that large differences between occasions m a y occur w h e n t h e environment is not closely controlled. Four photoperiodic regimes (simulated s o w i n g dates) w e r e imposed in each of 2 years in a glasshouse in w h i c h air t e m p e r a t u r e was not closely controlled. A l t h o u g h t h e differences w e r e not discussed, t h e t w o cultivars tested responded markedly differently in each year (Fig. 9). From our results in controlled e n v i r o n m e n t s it is clear
Year 1
80
Year 2
80
70
70 Vilmorin DZ 1 0 - 2 60
60
50
50
40
40
30
30
20
20
Vi Imorin DZ
10
10-2
10
0
0 1
2
3
4
1
2
3
4
Photoperiodic treatment regimes Year 2
Year 1 Mean 43 36
Vilmorin DZ 10-2 Figure
9.
The large differences in flowers ments. (replotted
138
that These from
were
obtained
differences van
der
Range 39-46 35-37
two
consecutive
in were
Maesen
identical probably 1972).
Mean 70 41
years in
Range 62-77 32-48
days
photoperiodic the
result
to
the appearance of first perfect
regimes of
in poor
glasshouse
experi-
temperature
control
Table
6.
Bangs of durations (days) of vegetative g r o w t h (sowing to the appearance of first p e r f e c t f l o w e r ) , reproductive period (first p s r f s c t f l o w s r t o final harvest), a n d c r o p d u r a t i o n (sowing to final harvast) of chickpea cultivars classlflsd according to their relative m a t u r i t y in the field at H y d e r a b a d . Cultivar
Attribute Duration o f vegetative g r o w t h Duration of reproductive period Crop d u r a t i o n
Chafa (early-maturing)
Rabat (medium)
G-130 (late-maturing)
26-48 67-130 98-181
46-81 49-111 113-181
42-89 46-95 99-181
Data f r o m c o n t r o l l e d e n v i r o n m e n t studies of S u m m e r f i e l d et al. (1979a).
temperature (over the range tested; see text), the m o r e protracted and equable are the overall crop durations. Conversely, In longer days and in w a r m temperatures, all plants mature equally rapidly ( 9 8 - 1 1 3 days f r o m sowing), but the earliest f l o w e r i n g cv Chafa had by then enjoyed a reproductive period far longer than did cvs Rabat and G-130 (67 and 4 6 - 4 9 days, respectively). A l t h o u g h p h o t o p e r i o d has a major effect on the duration of vegetative g r o w t h (defined here as " t h e period f r o m s o w i n g to the appearance of t h e first perfect f l o w e r w i t h clearly visible corolla c o l o r a t i o n " ) , plants can be induced to flower after exactly the same t i m e in different p h o t o p e r i o d s by changes in air t e m p e r a t u r e (e.g., for cv Chafa, see Fig. 10). Pseudoflowers (Aziz et al. 1960) a p p e a r e d f i r s t a n d w e r e produced for the longest period in less inductive conditions (for 9 and 4 days in 11 and 12 hour daylengths, respectively). None w e r e recorded in the 15 hour daylength. In any given temperature regime, Chafa plants produced their first perfect flowers progressively earlier as daylengths increased f r o m 11 to 15 hours. W a r m e r day and/or night temperatures also p r o m o t e d earlier f l o w e r i n g ; hence, t h e earliest plants to f l o w e r w e r e those g r o w n under 15 hour, 30° to 18°C conditions (26.5 days) and the latest ones w e r e g r o w n under 11 hour 22° to 10°C conditions (48.0 days). Short days contributed about one-half to this delay (12 days), and cooler day and night temperatures each delayed f l o w e r i n g by an average of 3 to 4 days (Fig. 10). Clearly, the o p p o s i ng effects of longer days, w h i c h hasten f l o w e r i n g , and of cooler
temperatures, w h i c h delay it, can exactly offset each other! Longer days and w a r m e r temperatures also reduced t h e length of the reproductive p e r i o d , and hence overall crop duration, especially in s u b o p t i m a l photoperiods. Of the 12 treatment combinations tested, t h e 12 hour, 30° to 18°C regime most closely approximates the average of seasonal changes in the climatic factors at Hyderabad (Fig. 7A). Indeed, the durations recorded f o r cv Chafa in controlled e n v i r o n m e n t s (Fig. 10) and those reported f r o m the field studies of Saxena and Sheldrake (1977) are remarkably similar (Table 7). Plants of the long-duration cultivar G-130 also had cropping " t i m e t a b l e s " very similar to those recorded in the field. Seasonal profiles of the activity of nodules in fixing nitrogen suggest that " f l o w e r i n g " is a critical period for the symbiotic system. In several l e g u m e species, symbiotic nitrogenf i x i n g activity reaches a peak t o w a r d the end of vegetative g r o w t h , and then it declines very sharply s o m e t i m e during the f l o w e r i n g period. In s o m e chickpeas, bacteroids degenerate, and leghaemoglobin content declines after flowering (Chopra and Subba Rao 1967), whereas in other cultivars, the onset of f l o w e r i n g has no i m m e d i a t e effect on symbiotic p e r f o r m a n c e (Fig. 13, Dart et al. 1976). There are also marked variations in other grain legumes in the effects of f l o w e r i n g on nodule functionin g and longevity of bacteroid tissue (e.g., for soybean, compare Brun 1976 w i t h Hardy et al. 1971). We k n o w of f e w data (Dart 1973; Dart et al. 1976) f r o m studies designed to evaluate the effects of
139
A.
1 1 - h r day
C. 1 5 - h r day l e n g t h s
B. 1 2 - h r day l e n g t h s
lengths
180
160
140
120
CD 100
CD CD
80
LRP
LRP
LRP
60
FF 40
FF
FPs F
FPs F
20
0
1
0
2
1
FF
0
2
1
2
Treatments 0 = Cool days and n i g h t s ; 1= cool d a y s / w a r m n i g h t s or warm n i g h t s / c o o l days; = increase in n i g h t temperature ( 1 0 - 1 8 ° C ) ; 2 = warm days and n i g h t s ; = i n c r e a s e in day temperature ( 2 2 - 3 0 ° C ) . Figure
10.
Effects to
the
of photo period and day and night temperatures
appearance
reproductive
period
controlled-environment
of
first
(LHP), growth
pseudoflowers
and
crop
duration
cabinets.
(See
day length and t e m p e r a t u r e on t h e consequences of f l o w e r i n g for symbiotic nitrogen fixation. However, the potential i m p o r t a n c e of these e n v i r o n m e n t a l factors has been demonstrated in other legumes (e.g., S u m m e r field et al. 1978), and diurnal variations in fixation activity are k n o w n to be markedly affected by air temperature, w i t h c o m p l e x interactions between solar radiation, atmospheric h u m i d i t y , and t h e water status of host plants.
140
(FPsF), (CD)
first for
Summerfield
on
the
perfect chickpea et
time flower cv
al.
from
sowing
(days)
(FF),
length
of
Chafa
grown
in
1979a.)
Anthesis and Seed Set Economically important grain legumes are pred o m i n a n t l y self-pollinated; perhaps obligatorily so in chickpea since pollination is effected at t h e h o o d e d - b u d stage (van der Maesen 1972). Chickpea seems atypical a m o n g the grain legumes in that s o m e cultivars produce abnorm a l , poorly developed flowers that become y e l l o w and desiccate w i t h o u t o p e n i n g , that is, pseudoflowers (Aziz et al. 1960). They are
Table
7.
D u r a t i o n (days) of v e g e t a t i v e g r o w t h ( s o w i n g to the a p p e a r a n c e of first p e r f e c t f l o w e r ) , reproductive period (first p e r f e c t f l o w e r t o final harvest), a n d c r o p longevity ( s o w i n g t o f i n a l h a r v e s t ) f o r s e l e c t e d c h i c k p e a c u l t i v a r s in the f i e l d a n d in g r o w t h cabinets.
Cultivar/location
Vegetative p e r i o d
Reproductive p e r i o d
Crop d u r a t i o n
36
71
107
35 73
71 77
108 150
73 97
61 75
134 172
89
91
180
Chafa at Hyderabad a Chafa in 12 hour, 30-18°C controlled e n v i r o n m e n t G-130 at Hyderabad b G-130 in 12 h o u r , 30-18°C controlled e n v i r o n m e n t G-130 at Hissar G-130 in 11 hour, 30-10°C or 22-10°C controlled environment a. Data f r o m Saxena a n d Sheldrake (1977).
produced before perfect f l o w e r s ; but the t i m e f r o m s o w i n g to their appearance, and the duration for which they are produced, depends not only on the cultivar but also on the air t e m perature and the daylength (e.g., Fig. 10). Whether this floral abnormality is a f o r m of cleistogamy or partial sterility is a topic for debate. Floral biology and phenology have been reviewed for chickpea (Meimandi-Nejad 1977); seed set is reduced in poor light intensities (Howard et al. 1915; Aziz et al. 1960), but contrary to popular belief, seems little affected by atmospheric h u m i d i t y (van der Maesen 1972). Pollen is equally viable at 20° and 30°C but germinates and produces longer pollen tubes m o r e rapidly in the w a r m e r regime (van der Maesen 1972). It is not u n c o m m o n for between 55 and 95% of flowers and i m m a t u r e chickpea p o d s to abort. The extent of f l o w e r i n g and seed set varies not only w i t h i n inflorescences but also between the nodes on a parent plant: f l o w e r s produced early in reproductive d e v e l o p m e n t are m o r e likely to produce pods (containing m o r e and individually heavier seeds) than those produced later (Saxena and Sheldrake 1975). The sequestering of a large p r o p o r t i o n of available assimilates f r o m m o t h e r plants and an increased p r o d u c t i o n of endogenous h o r m o n e s (e.g., ABA) by f l o w e r s or fruits, w h i c h p r o m o t e s the abortion of distal reproductive structures, have both been i m p l i cated as the m a i n causes of p r e m a t u r e abscission. However, Sinha (1977) lists 8 possible
factors and their n u m e r o u s combinations w h i c h could be significant and the role of ABA as a p r i m a r y controlling factor of f l o w e r abscission (in lupin) has been questioned (Porter 1977). Genotypes of m o s t species examined in detail differ markedly in their ability to retain flowers and y o u n g pods, and chickpea genotypes should be screened in these respects also. We obviously require detailed studies of both the effects of climate on flower and podsetting in chickpea and the mechanisms involved before the major limitations to reproductive efficacy, and their major effects on yield, can be alleviated.
Fruit Development Embryogenesis has been studied in relatively f e w grain legumes, the seeds of w h i c h c o m m o n l y attain their m a x i m u m dry w e i g h t bet w e en 30 and 70 days after anthesis (e.g., Phaseolus vulgaris, Pisum sativum and P. arvense, Glycine max, and Vicia faba). T h e developmental pattern of seed f o r m a t i o n is so similar a m o n g these species that it is possible to generalize about many m a j o r events. For example, final cell n u m b e r in the e m b r y o is attained early in its ontogeny, the subsequent increase in e m b r y o w e i g h t being t h e result of cell expansion and the concomitant synthesis and deposition of starch and thereafter, storage proteins Furthermore, in each of these species,
141
t h e seeds derive a large p r o p o r t i o n of their carbon f r o m photosynthesis by foliar organs at t h e parent node (Dure 1975; S u m m e r f i e l d and W i e n 1979). Furthermore, provided that certain conditions are satisfied (Gallagher et al. 1976), as they are for those legumes w h i c h have been studied in detail (Dure 1975), mean m a x i m u m seed w e i g h t can be equated to the product of mean g r o w t h rate per seed d u r i n g the linear phase of g r o w t h and the duration of this phase. From the l i m i t e d data available (Sinha 1977), we can postulate that chickpea too w i l l s h o w similarities w i t h those species m e n t i o n e d above: the fruit wall g r o w s to a large extent before seed development proceeds. A lag period that lasts about 15 days after anthesis is f o l l o w e d by a linear period of g r o w t h of about 20 days d u r a t i o n , d u r i n g w h i c h the individual seeds accumulate the vast p r o p o r t i o n of their dry matter. Indeed, m a x i m u m seed g r o w t h rates for chickpeas are a m o n g the fastest recorded for grain legumes (Table 3, in Summerfield and W i e n 1979). However, in contrast w i t h the species mentione d above, chickpea seeds seem to sequester assimilates effectively f r o m nodes w i t h i n a branch (whether reproductive or vegetative nodes), and pods at nodes w i t h leaves have no preferential advantage to those at nodes w i t h o u t leaves. On the other hand translocation of assimilates between branches seems less effective (Saxena and Sheldrake 1976). Moreover, we k n o w little f o r chickpea of t h e effects of e n v i r o n m e n t a l factors on the rate or d u r a t i o n of seed f i l l ; w h e n , d u r i n g fruit ontogeny, seed n u m b e r is d e t e r m i n e d ; at w h i c h loci w i t h i n fruits and at w h a t age abortion is most prevalent; or the consequences of maturation e n v i r o n m e n t on the biochemical c o m position of ripe seeds.
f r o m s o w i n g average about 35°C at Hyderabad and may have i m p o r t a n t effects on t h e realization of yield potential, especially in l o n g duration cultivars. In order to investigate w h e t h e r or not chickpea is affected by heat stress w h e n vapor pressure d e f i c i t — a better indication of the d r y i n g p o w e r of t h e air than relative h u m i d i t y (Hughes 1962) — and soil-water status are maintained at values equivalent to those at cooler temperatures (i.e., in t h e absence of water stress), we have screened 15 cultivars of contrasting crop durations in controlled env i r o n m e n t glasshouses. Plants w e r e g r o w n in factorial combinations of t w o daylengths (11 and 12 hours of natural light), w a r m and cool nights (18° and 10°C), and w a r m and hot days (30°C t h r o u g h o u t or 30°C for the first 90 days and 35°C thereafter). These data are reported fully elsewhere ( S u m m e r f i e l d et al., in press). The average yield of all cultivars in all eight e n v i r o n m e n t s (the p o p u l a t i o n mean) was 5.2 grams seed p l a n t - 1 , and the environments can be ranked according to their suitability for expression of yield potential in chickpea on the basis of average yield of all genotypes in each situation (Fig. 11). Differences in daylength and night t e m p e r a t u r e had little effect on the average yield of all cultivars, but hot days (35°C after 90 days) w e r e deleterious and reduced average yields by 33% (Fig. 11). Clearly, plants that experience diurnal variations of either hot days (35°C) and cool nights (10°C) or hot days and w a r m nights (35-18°C) d u r i n g reproductive d e v e l o p m e n t produce only small yields. However, not all cultivars respond in a similar manner, and it is possible to classify cultivars according to whether they yielded greater or less than the average in each environment.
A l t h o u g h the ontogeny of field crops was predicted w i t h remarkable accuracy f r o m controlled e n v i r o n m e n t experiments (Table 7), the seed yields of both cv Chafa and G-130 w e r e increased in w a r m days typical of average seasonal values at Hyderabad (30°C) as c o m pared w i t h cool (22°C) days. These responses do not reflect a g r o n o m i c reality at this site (cf. Table 4). Indeed, t h e late-muturing G-130 responded particularly favorably, and yields were increased by 183% (from 9.2 grams plant -1 at 22°C to 26 g r a m s at 30°C): yields of cv Chafa increased by 8 6 % ( f r o m 7.2 to 11.4 grams). However, day temperatures after about 90 days
The scatter diagrams presented in Figures 12 and 13 s h o w the relationships between seed yield of individual c u l t i v a r s t o each c o m b i n a t i o n of day and night temperature and each p h o t o period, and the mean responses over the range of conditions tested of both the individual cultivar and the population of cultivars f r o m w h i c h it was d r a w n . Thus, it is possible to deduce for each cultivar: first, its relative stability (or variability) in yield over a w i d e range of temperature c o n d i t i o n s ; and second, in the case of a variable response, to w h i c h temperature condition it is best suited (Finlay and Wilkinson 1973). A l t h o u g h there are s o m e statistical disadvan-
142
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
2
1
0
Treatments O = Cool d a y s and n i g h t s ; 1 = cool d a y s / w a r m nights or warm n i g h t s / c o o l days; 2 = warm days and n i g h t s ; = increase in night temperature (10-18°C); = i n c r e a s e in day temperature (30-35°C).
Figure
11.
Richards' diagram the
effect
atures
on
chickpea
average cultivars
lengths growing
(1941)
of day and night seed
Summerfield
yield
grown
characteristic seasons
in of
(11-12 et al.
showing temper-
hr).
of
15 day
Indian (See
1979b.)
tages in this approach (Freeman 1973), the m e t h o d produces simple visual displays w h i c h , if they are interpreted w i t h care, provide the best preliminary c o m p a r i s o n of the data.
The difference in response of any pair of genotypes to a given change in e n v i r o n m e n t measures GE, t h e g e n o t y p e x e n v i r o n m e n t interaction (Figs. 12, 13). The s u m of the responses measures E, the overall effect of e n v i r o n m e n t as revealed by the genotypes as a g r o u p (Fig. 11). Since GE depends on differences in response, it must reflect the properties of only those genes by w h i c h the genotypes differ. On the other hand, E, t h e s u m m e d response of genotypes as a g r o u p , reflects not only those genes by w h i c h the genotypes differ but also other genes that affect response to e n v i r o n m e n t but w h i c h are alike in m a n y , if not all, genotypes. The long-duration cultivar G-130 yields best w h e n day temperature is m a i n t a i n e d at 30°C t h r o u g h o u t g r o w t h , but it is poorly adapted to hot days during the reproductive period (Fig. 12A). The short-duration cultivar A n n i g e r i has a similar response, but, by m a t u r i n g m o s t of its pods before the days become really hot, it produces larger-than-average yields by escaping the potentially adverse conditions (Fig. 12B). Cultivars L-550, Rabat, and RS-11 s h o w very similar responses to G-130, whereas cvs 850-3/27 and P 222-1 are very similar to Annigeri. Other short- and intermediateduration cultivars are less responsive to m o r e ideal environments but m o r e tolerant of adverse climates (Fig. 13, and see the response of cv Chafa in Table 4). A l t h o u g h these t w o examples produce average yields slightly less than the population mean, others (e.g., C-235) have similar trends but produce above-average yields. These responses support the general principle that early-maturing genotypes are least susceptible to environmental influence (Murfet 1977). Of course, these cultivars are selected f r o m a very small n u m b e r of the total chickpea g e r m p l a s m n o w available and represent data f r o m just one trial. However, they demonstrate to t h e chickpea breeder s o m e of the responses of his material w h i c h m a y influence his selection of parents in seeking progeny adapted to given environmental situations.
Prospect for the Future A l t h o u g h economic yields in chickpea are poor in farmer's plots, and vary widely between sites
143
10 A. G-130: e x t e n d e d crop d u r a t i o n (150 days) at H y d e r a b a d
8
6 Population mean Individual
mean
4
2
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
10 B. A n n i g e r i : s h o r t crop d u r a t i o n (107 d a y s ) at H y d e r a b a d
8 Individual
mean
6 Population mean
4
2
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
Site mean y i e l d ( g / p l a n t )
Figure
12.
Scatter diagrams cultivar
in
a
range
illustrating
of aerial
the
yield of a
environments;
long-duration
average
of
15
and a cultivars
short-duration (Summerfield
chickpea et
al.
1979b.)
and seasons, the plants g r o w n are usually of p r i m i t i ve land races selected (probably u n c o n sciously) for performance in conditions of agr o n o m i c neglect and e n v i r o n m e n t a l stress. Only recently have extensive g e r m p l a s m resources b e c o m e available, and multiple selec-
144
tion criteria have been applied to progeny material. W i t h o u t doubt , seed yields in this l e g u m e are largely dependent on pod and seed n u m b e r per unit area a n d , as we have argued before (Summerfield et al. 1978), m u l t i p l e c o m ponents, whether m o r p h o l o g i c a l , physiologi-
8
A . CPS - 1 : i n t e r m e d i a t e c r o p d u r a t i o n ( 1 2 6 d a y s ) a t H y d e r a b a d
6 Population mean Individual
mean
4
2
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8 B. C h a f a : s h o r t crop d u r a t i o n (107 d a y s ) at H y d e r a b a d
6 Population mean I n d i v i d u a l mean 4
2
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
Site mean y i e l d ( g / p l a n t ) Figure
13.
Same that more
both stable
as of
for Figure these
in
12
examples
adverse
for an are
intermediate and a less
responsive
short-duration to
favorable
chickpea
cultivar.
environments
but
Note are
climates.
cal, or t e m p o r a l , contribute to variations in yield. Certainly, chickpea is capable of large yields; 4800 kg/ha is a c o m m o n l y quoted m a x i m u m value, w h i c h was produced at Karaj in Iran (36°N, 1220 m; RPIP 1968) in conditions drastically different f r o m those in India and Pakistan (Sinha 1977). Adaptation in chickpea w i l l , of course, involve appropriate resistance to disease and insect pests (particularly to w i l t and Heliothis, respectively). Then again, water stress is undoubtedly a significant selection force and w i l l be affected by air t e m p e r a t u r e and vapor pressure deficit. However, there is little evidence that it has any
direct regulatory effect on f l o w e r initiation (Murfet 1975), although flower abscission seems especially sensitive to water stress — a pertinent example of the response of yield c o m p o n e n t s to a stress factor (adaptability). Plant breeders have usually selected for adaptation to particular sites, chosen to represent particular regions, rather t h a n to specific combinations of temperature and p h o t o p e r i o d . This traditional approach requires that selections be g r o w n and tested for a n u m b e r of seasons at a particular site (to take account of climatic variations between seasons) a n d , ideally, also at a number of other sites. However,
145
b o t h researchers in t h e field and t h o s e e m p l o y ing
controlled
environments
must
become
and g r a m . Page 256 in Proceedings of t h e Indian Scientific Congress 42.
m o r e a w a r e o f t h e critical aspects o f t h e climates to w h i c h chickpea crops m u s t a d a p t if breeders are t o b e p r o v i d e d w i t h m o r e critical selection criteria and so ensure t h a t t h e reproductive
behavior of
improved
genotypes
is
appropriately adapted t o the e n v i r o n m e n t s f o r w h i c h t h e y are i n t e n d e d .
B R U N , W. A. 1976. T h e relation of N 2 fixation to photosynthesis. Pages 1 3 5 - 1 4 3 in W o r l d Soybean Research, L. D. Hill, ed. Interstate Press, Illinois, USA. B U N T I N G , A. H. 1975. T i m e , p h e n o l o g y and the yields of crops. Weather 30: 3 1 2 - 3 2 5 .
Up to n o w , research on chickpea has c o n c e n trated o n d r y - m a t t e r p r o d u c t i o n a n d has neglected m o r p h o l o g y and p h e n o l o g y ; researchers have also looked into c a r b o n m e t a b o l i s m b u t
CHAKRAVORTI, S. C. 1953. A n a t o m i c a l studies in relation to vernalization. Indian J o u r n a l of A g r i c u l t u r a l Science 23: 2 8 9 - 3 0 0 .
have neglected n i t r o g e n n u t r i t i o n . In a d d i t i o n , t h e r e has been m u c h research on e n v i r o n m e n tal r e g i m e s that bear little relevance to t h e seasonal
changes
and
complex
interactions
between factors, w h i c h are so characteristic of natural situations. W h e r e a species s u c h as chickpea has colonized a range of habitats, we
CHAKRAVORTI, S. C. 1964. Vernalization and g r o w t h . Indian A g r i c u l t u r e 8 : 6 8 - 7 0 . CHOPRA, C. L. and S U B B A R A O , N. S. 1967. M u t u a l
relationships a m o n g bacteroid, l e g h a e m o g l o b i n and N content of Egyptian clover and g r a m . Archives M i k r o b i o l o g i e 58: 7 1 - 7 6 .
m i g h t expect to f i n d a range of genetic adaptations t o t h o s e e n v i r o n m e n t s . H o w e v e r , these adaptive responses have yet to be q u a n t i f i e d in chickpea, let alone exploited by breeders. We s h o u l d seek t o e x p l a in h o w e n v i r o n m e n t a l v a r i ations in t i m e affect p h y s i o l o g i c a l a n d m o r phological
processes — and
hence,
growth,
d e v e l o p m e n t , and y i e l d — rather t h a n merely to describe t h e cedures such
as
outcome
by
correlation
statistical
pro-
C O R B I N , E. J. 1976. Present status of chickpea research in Australia. Pages 8 7 - 9 4 in Proceedings of t h e International W o r k s h o p on Grain Legumes, ICRISAT, H y d e r a b a d , India. C O R B I N , E. J., BROCKWELL, J . , and G A U L T , R. R.
1977.
N o d u l a t i o n studies on chickpea (Cicer arietinum). Australian J o u r n a l of Experimental A g r i c u l t u r e and A n i m a l H u s b a n d r y 17: 1 2 6 - 1 3 4 .
or c u r v e - f i t t i n g
( B u n t i n g 1975).
D A R T , P. J. 1973. Root n o d u l e s y m b i o s i s and tropical grain l e g u m e p r o d u c t i o n . Pages 1 8 5 - 1 9 7 in Proceedings of t h e first IITA Grain L e g u m e I m p r o v e m e n t W o r k s h o p , IITA, Ibadan, Nigeria.
References D A R T , P. J . , I S L A M , R., and E A G L E S H A M , A. R. J. A L L A R D , H. A., and Z A U M E Y E R , W . J . 1944. R e s p o n s e of
beans (Phaseolus) and other l e g u m e s to length of day. U n i t e d States Department of A g r i c u l t u r e (USDA), Technical Bulletin 867. 24 pp. A N O N . 1968. Page 6 in U n i t e d States Regional Pulse I m p r o v e m e n t Project Progress Report (Iran a n d India). U S D A - U S A I D , W a s h i n g t o n , USA. 232 pp. A U C K L A N D , A. K., and S I N G H , K. B.
1976. C h i c k p e a
b r e e d i n g . In ICRISAT A n n u a l Report, 1 9 7 5 - 1 9 7 6 . ICRISAT, H y d e r a b a d , India. 18 p p . Aziz, M. A., K H A N , M. A., and S H A H , S. 1960. Causes of l o w seed setting in g r a m ( C . a r i e t i n u m ) . A g r i c u l t u r e Pakistan 1 1 : 3 7 - 4 8 . B H A R D W A J , S. N. 1955. Effect of l o n g a n d short p h o t o p e r i o d s on incidence of f l o w e r i n g in w h e a t
146
1976.
The root n o d u l e s y m b i o s i s of chickpea and pigeonpea. Pages 6 3 - 8 3 in Proceedings of the International W o r k s h o p on Grain Legumes, ICRISAT, H y d e r a b a d , India. D U R E , L. S. 1975. Seed f o r m a t i o n . A n n u a l Review of Plant Physiology 26: 2 5 9 - 2 7 8 . ESHEL, Y. 1968. Flower d e v e l o p m e n t and pollen viability of chickpea {Cicer arietinum L.). Israel J o u r n a l of A g r i c u l t u r a l Research 18: 3 1 - 3 3 . E V A N S , L. T. 1975. The physiological basis of crop yield. Pages 3 2 7 - 3 5 5 in Crop P h y s i o l o g y : s o m e case histories, L. T. Evans, e d . C a m b r i d g e University Press, L o n d o n and N e w York. E V A N S , L T., and K I N G , R. W . 1975. R e p o r t o n t h e T A C
w o r k i n g g r o u p o n t h e b i o l o g y and yield o f grain
l e g u m e s . Publication n u m b e r DDDR: IAR/75/2, F o o d a n d A g r i c u l t u r e Organisation o f t h e United Nations, Rome. FAO (Food and Agriculture Organisation of the United Nations). 1959. Pages 7 8 - 8 7 in Tabulated i n f o r m a t i o n o n tropical a n d sub-tropical grain legumes. Food and A g r i c u l t u r e Organisation of the U n i t e d Nations, Rome. FINLAY, K. W . , and W I L K I N S O N , G. N. 1963. T h e a n a l y s i s
of adaptation in a plant breeding p r o g r a m m e . Australian J o u r n a l of A g r i c u l t u r a l Research 17: 269-280.
Association 3 1 . IVANOV, N. N. 1933. The causes of chemical variability in the seeds of chickpea in different geographical areas (in Russian). T r u d y po Prikladnoi Botanike, Genetike i Selektsii 3: 3 - 1 1 . KAR, B. K. 1940. Vernalization. Current Science 9: 2 3 3 - 2 3 4 . K O I N O V , G. 1968. O p t i m u m s o w i n g rates f o r chickpea (In Bulgarian). N a u c h n i T r u d o n e . Vissh Selskostopanski Institute Vasil Kolarov 17: 6 5 - 6 9 . K U M A R I , P. S., and S I N H A , S. K.
FRANCIS, C. A. 1972. Natural daylengths f o r p h o t o period .sensitive plants. Centro Internacional de A g r i c u l t u r a Tropical (CIAT), Technical Bulletin 2. 32 pp.
LADIZINSKI,
FREEMAN, G. H. 1973. Statistical m e t h o d s f o r t h e analysis of g e n o t y p e - e n v i r o n m e n t interactions. Heredity 3 1 : 3 3 9 - 3 5 4 . GALLAGHER, J. E., BISCOE, P. V., and SCOTT, R. K.
1976.
Barley and its e n v i r o n m e n t . VI. G r o w t h a n d dev e l o p m e n t in relation to y i e l d . J o u r n a l of A p p l i e d Ecology 13: 5 6 3 - 5 8 3 . G U P T A , S. P., LUTHRA, R. C., G I L L , A. S., and P H U L , P. S.
1972. Variability and correlation studies on yield and its c o m p o n e n t s in g r a m . J o u r n a l of Research of the Punjab A g r i c u l t u r a l University 9: 4 0 5 - 4 0 9 . H A R D Y , R. W. F., B U R N S , R. C., HEBERT, R. R., H O L S T E N ,
R. D., and JACKSON, E. 1971. Biological nitrogen fixat i o n : a key to w o r l d p r o t e i n . Pages 5 6 1 - 5 9 0 in Biological Nitrogen Fixation in Natural and A g r i c u l tural Habitats, T. A. Lie and E. G. M u l d e r , ed. Plant and S o i l , Special V o l u m e . H O W A R D , A., H O W A R D , G. L. C, and K H A N , A. R.
1972. V a r i a t i o n in
chlorophylls and p h o t o s y n t h e t i c rate in cultivars of Bengal g r a m (Cicer arietinum L ) . Photosynthetica 6: 1 8 9 - 1 9 4 . G., and A D L E R , A.
1976. T h e o r i g i n
chickpea Cicer arietinum L. Euphytica 35:
of
211-217.
LIE, T. A. 1971. S y m b i o t i c n i t r o g e n f i x a t i o n under stress conditions. Pages 1 1 7 - 1 2 8 / in Biological Nitrogen Fixation in Natural and A g r i c u l t u r a l Habitats, T. A. Lie and E. G. M u l d e r , ed. Plant and Soil (Special Volume). VAN DER M AESEN, L. J. G. 1972. Cicer L., a m o n o g r a p h of the genus, w i t h special reference to t h e chickpea (Cicer arietinum L.), its ecology and cultivation. Mededelingen Landbouwhogeschool Wageningen. 342 pp. MALHOTRA,
R.
S., and
S I N G H , K.
B.
1973.
Genetic
variability and g e n o t y p e - e n v i r o n m e n t interaction in Bengal g r a m . Indian J o u r n a l of Agricultural Science 43: 9 1 4 - 9 1 7 . M A T E O Box, J . M . 1961. Pages 6 9 - 8 4 / i n L e g u m i n o s u s del G r a n o , I. Era, ed. Barcelona, Salvat.
1915.
S o m e varieties of Indian g r a m (Cicer arietinum L ) . M e m o i r s of the Department of A g r i c u l t u r e in India. Botanical Series 7: 2 1 3 - 2 3 5 . HUGHES, A. P. 1962. The interpretation of thermoh y g o g r a p h s . J o u r n a l of the Australian Institute of A g r i c u l t u r a l Science 28: 5 2 - 5 5 .
M A T H O N , C. C. 1969. Photoperiodic reactions and sensitivity to vernalization in f o u r h u n d r e d species of S p e r m a t o p h y t a : eight years of research i n t o the ecological analysis of d e v e l o p m e n t (In French). Bulletin de la Societe Botanique de France 116: 3 1 1 - 3 2 1 .
H U G O N , E. 1967. Observations on branching and inhibitory correlations between buds in chickpeas, Cicer arietinum (In French). Revue Generale de Botanique 74: 2 5 1 - 2 7 2 .
M E I M A R D I - N E J A D , M. J. 1977. Crop Botany. Pages 2 7 - 6 2 in Food L e g u m e Crops: I m p r o v e m e n t and Production. E. S. B u n t i n g , ed. Food and A g r i c u l t u r e Organization of the United N a t i o n s , Plant Product i o n and Protection Paper N u m b e r 9, FAO, Rome.
ISTA (International Seed Testing Association). 1966. Page 57 in International rules f o r seed t e s t i n g . Proceedings of the International Seed Testing
M O N T E I T H , J. L. 1972. Solar radiation and productivity in tropical ecosystems. J o u r n a l of A p p l i e d Ecology 9: 7 4 7 - 7 6 6 .
147
M O N T E I T H , J. L. 1977. Climate and t h e efficiency of crop p r o d u c t i o n in Britain. Philosophical Transact i o n s of t h e Royal Society of L o n d o n , Series B 281: 277-294. M O U R S I , M . A., and ABDELGAWED, A. A. 1965. L e g u m e
p h o t o p e r i o d i s m . 2 . F o r m a t i v e and p h o t o p e r i o d i c reaction to light d u r a t i o n . A n n a l s o f A g r i c u l t u r a l Science of t h e University of A i n S h a m s (1963) 8: 297-304. M U R F E T , I.C. 1977. E n v i r o n m e n t a l interactions a n d t h e genetics o f f l o w e r i n g . A n n u a l Review of Plant Physiology 28: 2 5 3 - 2 7 8 . N A R D A , K. K., and C H I N O Y , J. J. 1960. Effect of vernalization a n d p h o t o p e r i o d i c t r e a t m e n t s on Cicer arietinum. 1. Phasic d e v e l o p m e n t in relation to its p h o t o and t h e r m i c q u a n t a . Indian J o u r n a l of Plant Physiology 3 : 3 2 - 4 4 . N A R D A , K. K., and C H I N O Y , J . J . 1960. Effect of vernalization a n d p h o t o p e r i o d i c t r e a t m e n t s on Cicer arietinum. 2. S t e m e l o n g a t i o n and branching of Cicer arietinum and t h e i r correlation w i t h f l o w e r i n g under v a r y i n g p h o t o p e r i o d i c t r e a t m e n t s . Indian J o u r n a l o f Plant P h y s i o l o g y 3 : 4 5 - 5 5 . Nix, H., M C M A H O N , J . , and M A C K E N Z I E , D . 1977. Poten-
tial areas of p r o d u c t i o n and t h e f u t u r e of p i g e o n p e a a n d other grain l e g u m e s i n Australia. Pages 5 0 - 6 2 in T h e Potential f o r Pigeonea in Australia, E. S. Wallis a n d P. C. W h i t e m a n , ed. U n i v e r s i t y of Queensland , Australia. Special Publication.
abscission of Lupinuslutens. Physiologia P l a n t a r u m 40:50-54. RICHARDS, F, J. 1941. T h e d i a g r a m m a t i c represent a t i o n of t h e results of p h y s i o l o g i c a l and other exp e r i m e n t s d e s i g n e d factorially. Annals o f B o t a n y 5:249-261. S A N D H U , S. S., and H O D G E S , H. F.
1971. Effect o f
p h o t o p e r i o d , light intensity a n d t e m p e r a t u r e o n v e g e t a t i v e g r o w t h , f l o w e r i n g a n d seed p r o d u c t i o n in Cicer arietinum L. A g r o n o m y J o u r n a l 6 3 : 9 1 3 914. S A N D H U , T. S., and S I N G H , N. B. 1972. Correlation, path coefficient analysis a n d d i s c r i m i n a n t f u n c t i o n select i o n in Cicer arietinum. J o u r n a l of Research, Punjab A g r i c u l t u r a l University 9 : 4 1 7 - 4 2 1 . S A X E N A , N. P., and SHELDRAKE, A. R. 1975. Chickpea
p h y s i o l o g y . In Pulse P h y s i o l o g y A n n u a l Report 1 9 7 4 - 7 5 , Part II. ICRISAT, H y d e r a b a d , India. 51 pp. S A X E N A , N. P., and SHELDRAKE, A. R. 1976. Chickpea
p h y s i o l o g y . In Pulse Physiology A n n u a l Report 1 9 7 5 - 7 6 , Part II. ICRISAT, H y d e r a b a d , India. 176 p p . S A X E N A , N. P., and SHELDRAKE, A. R. 1977. C h i c k p e a
p h y s i o l o g y . In Pulse P h y s i o l o g y A n n u a l Report 1 9 7 6 - 7 7 , Part II. ICRISAT, H y d e r a b a d , India. 179 pp. S E N , A. N. 1966. Inoculation of l e g u m e s as i n f l u e n c e d by soil a n d climatic conditions. Indian J o u r n a l of A g r i c u l t u r a l Science 3 6 : 1 - 7 .
O K O N , Y., ESHEL, Y., and H E N I S , Y. 1972. C u l t u r a l a n d
s y m b i o t i c properties of Rhizobium strains isolated f r o m n o d u l e s of Cicer arietinum L. Soil Biology a n d Biochemistry 4 : 1 6 5 - 1 7 0 . PAL, B. P., and M U R T Y , G. A. 1941. Vernalization of Indian crops. 1 . P r e l i m i n a r y e x p e r i m e n t s o n g r a m , w h e a t , chilli and s o y b e a n . Indian J o u r n a l of Genetics and Plate Breeding 1 : 6 1 - 8 5 . PALLAS, J. E., S T A N S E L L , J. R., and B R U C E , R. R. 1977.
Peanut seed g e r m i n a t i o n as related to s o i l w a t e r r e g i m e d u r i n g p o d d e v e l o p m e n t . A g r o n o m y Journal 6 9 : 381-383. PANDEY, R.
K., SAXENA,
M.
C.,
and
S I N G H , V.
B.
1977.
Genotypic differences in p h o t o p e r i o d i c response in chickpea (Cicer arietinum L.). Pantnagar J o u r n a l of Research 2 : 1 2 3 - 1 2 6 .
S I N G H , A. 1958. T h e effect of clipping s h o o t t i p s on n o d u l a t i o n in Cicer arietinum. Proceedings National A c a d e m y of Sciences of India, Series B 28: 2 3 1 241. S I N H A , S. K. 1977. Food l e g u m e s : d i s t r i b u t i o n , adaptability a n d b i o l o g y o f yield. F o o d and A g r i c u l t u r e Organisation of t h e U n i t e d Nations, Plant Product i o n and Protection Paper N u m b e r 3, FAO, R o m e . 124 p p . S T E I N B E R G , R. A., and G A R N E R , W . W . 1936. R e s p o n s e
of certain p l a n t s to length of day and t e m p e r a t u r e under c o n t r o l l e d c o n d i t i o n s . J o u r n a l o f A g r i c u l t u r a l Research 52: 9 4 3 - 9 6 0 .
PILLAY, K. P. 1944. A short note on vernalization of g r a m . Current Science 1 3 : 1 8 5 .
S U M M E R F I E L D , R. J. 1976. Vegetative g r o w t h , reprod u c t i v e o n t o g e n y a n d seed y i e l d of selected t r o p i c a l grain l e g u m e s . Pages 251-271 in Crop Protection A g e n t s : Their Biological Evaluation, N. R. McFarlane, e d . A c a d e m i c Press, L o n d o n .
PORTER, U. G. 1977. T h e role of abscisic acid in f l o w e r
SUMMERFIELD,
148
R.
J.,
and
MINCHIN,
F.
R.
1976.
An
integrated strategy f o r d a y l e n g t h and t e m p e r a t u r e sensitive screening of potentially tropic-adapted soyabeans. Pages 186-191 in Expanding the use of soyabeans in Asia and Oceania, R. M. G o o d m a n , ed. INTSOY, Illinois, U.S.A.
temperature on g r o w t h , reproductive development and seed yield of chickpea {Cicer arietinum L.). University of Reading — ICRISAT, Internal C o m m u n i c a t i o n N u m b e r 2. 29 p p . S U M M E R F I E L D , R. J . , M I N C H I N , F. R., ROBERTS, E. H . , a n d
S U M M E R F I E L D , R. J . , and W I E N , H. C. 1980. Effects o f
p h o t o p e r i o d and air t e m p e r a t u r e o n g r o w t h and yield of e c o n o m i c l e g u m e s . Pages 1 7 - 3 6 in A d vances in L e g u m e Science, R. J. S u m m e r f i e l d a n d A. H. B u n t i n g , ed. Her M a j e s t y ' s Stationery Office, London. S U M M E R F I E L D , R. J . , M I N C H I N , F. R., and ROBERTS, E. H.
1977. G r o w i n g chickpeas (Cicer arietinum L.) in c o n t r o l l e d e n v i r o n m e n t g r o w t h cabinets. U n i v e r s i t y of Reading — I C R I S A T , Internal C o m m u n i c a t i o n N u m b e r 1. 20 p p . S U M M E R F I E L D , R. J., M I N C H I N , F. R., R O B E R T S , E. H. 1978.
Realisation of yield potential in soyabean (Glycine max (L.) Merr.) and c o w p e a (Vigna unguiculata (L..) Walp.). Pages 1 2 5 - 1 3 4 in O p p o r t u n i t e s f o r Chemical Plant G r o w t h Regulation. British Crop Protection Council, M o n o g r a p h N u m b e r 2 1 , BCPC, L o n d o n . S U M M E R F I E L D , R. J . , M I N C H I N , F. R., ROBERTS, E. H., and
HADLEY , P. 1979. Effects of d a y l e n g t h , day and n i g h t
HADLEY, P. 1979. Variation in adaptation to contrasting aerial e n v i r o n m e n t s a m o n g selected cultivars of chickpea. University of Reading — ICRISAT, Internal C o m m u n i c a t i o n N u m b e r 3. 20 pp. V A I S H Y A , U. K., and S A N O R I A , C. L. 1972. S p e c i f i c i t y a n d
efficiency of Rhizobium cultures of Bengal g r a m (Cicer arietinum L.), Indian J o u r n a l of M i c r o b i o l o g y 12: 133-144. W H Y T E , R. O., NILSSON-LEISSNER, G., and TRUMBLE, H. C.
1953. L e g u m es in Agriculture. Food and A g r i c u l t u r e Organization of t h e United Nations, A g r i c u l t u r a l Study N u m b e r 2 1 , FAO, R o m e . 367 p p .
W I E N , H. C., and S U M M E R F I E L D , R. J . 1980. A d a p t a t i o n
of cowpeas in West A f r i c a : effects of p h o t o p e r i o d and t e m p e r a t u r e responses in cultivars of diverse o r i g i n . Pages 4 0 5 - 4 1 7 in advances in L e g u m e Science, R. J. S u m m e r f i e l d a n d A. H. B u n t i n g , ed. Her Majesty's Stationery Office, L o n d o n .
149
Session 3 — Chickpea Agronomy and Physiology Discussion
Saxena
Paper
B. M. Sharma W h y are there g o o d responses to t h e foliar application of DAP in comparison to single superphosphate? In DAP, is the response mainly d u e to the P c o m p o n e n t or to both N and P? M. C. Saxena Studies in the A l l India Coordinated Research Project on Pulse I m p r o v e m e n t at various locations w h e r e N and P sprays w e r e applied separately, along w i t h treatments involving DAP spray, reveal that whenever increases have occurred, they are generally because of the phosphate component. Spray of single superphosphate has the problems associated w i t h the dissolution of phosphate in the spray solution. R. B. Singh 1. It is often said that legumes are hard on soils, particularly the micronutrients. You showed varietal differences for tolerance to l o w Zn and Fe availability. Are the cultivars that are unaffected by l o w Zn and Fe levels m o r e efficient nitrogen fixers than those that are affected by l o w Zn-Fe conditions? 2. You m a d e a case fo r one to t w o irrigations. This may be a location-specific recommendation. In the All India Coordinated Varietal Chickpea Trials in North India, under irrigated and unirrigated conditions, the average yields w h e n rainfed w e r e higher than w h e n irrigation was applied, and based on this, the coordinated irrigated trial has been d r o p p e d . As a matter of fact, it is the soil m o i s t u r e (at varying profiles) available that w o u l d determine whether or not to irrigate.
150
M. C. Saxena 1. No studies have been conducted by us on N fixation of the genotypes tested for differential susceptibility to Zn and Fe deficiency. We do know, however, that they make excellent g r o w t h under normal conditions w i t h sufficient zinc supply. Good g r o w t h is a reflection that N fixation w a s going on well in all these genotypes. Reduction in nodulation and vegetative g r o w t h w i t h zinc deficiency has been observed by us. 2. Irrigation recommendations are by no means universal. In fact, the response to irrigation is entirely dependent on the soil moisture available to the crop in the season. Depending upon the a m o u n t of moisture present in t h e profile, there may or may not be any response. However, in many areas in North India w h e r e the water-holding capacity is low, the atmospheric conditions are conducive to increased evapotranspiration, and thus good responses have been obtained to supplemental water supply early or late in the vegetative g r o w t h stage and at early pod filling. R. B. Singh Please clarify the relationships a m o n g Zn and Fe deficiency and nodulation and N 2 fixation. P. J. Dart There are differences between cultivars of legumes (e.g., soybean) in ability to use zinc, and their yields could reflect N 2 fixation rates . In large tracts of southern Australia, legumes respond to zinc applicat i o n , but this does not appear to have a specific effect on the nodulation process. Increased N 2 fixation probably results f r o m increased photosynthesis in t h e plants w i t h better Zn nutrition. Zinc is not a c o m p o n e n t
of the nitrogenase enzyme complex, m o l y b d e n u m and iron are, and there is a specific requirement of m o l y b d e n u m for N 2 fixation over and above that required by the plant for g r o w t h on an inorganic nitrogen source. There are no reports on the effect of iron chlorosis on nodulation, but obviously, decreased yields almost certainly mirror a decrease in N 2 fixation. Chickpeas w i t h iron chlorosis have nodules containing leghaemoglobin (Lb), so that nodules are able to sequester some of the limited iron supply for Lb synthesis. As the chlorotic plants age, there is an apparent decrease in the a m o u n t of Lb, probably because the reduced photosynthate supply to the nodules induces premature nodule senescence. The turnover t i m e for iron in Lb in lupin nodules is relatively slow. K. G. S h a m b u l i n g a p p a Was there any relationship between date of planting and pest infestation? M. C. Saxena The susceptibility to foliar diseases, as well as to root rot and w i l t pathogens, seems to be related to some extent, to date of planting. Because of the effect of date of planting on canopy development, susceptibility to foliar diseases changes. Higher temperatures in early plantings in some location have been associated w i t h higher wilt damage. The insect infestation of the crop is also related to planting date. Dr. H. P. Saxena m i g h t like to c o m m e n t on this. H. P. Saxena 1. The trials carried out at some centers of the All India Project on Pulses have revealed that there w e r e m o r e caterpillars of Heliothis armigera Hubn. in the irrigated chickpea crop. 2. Early-sown crops of chickpea attract pod borers, and m o r e caterpillars are seen. The pest builds up, and later the pod borer severely damages the latematuring crops. D. C. Erwin Is there any information on the mycorrhizal fungal flora on chickpea and the response of the crop to phosphorus and zinc uptake?
M. C. Saxena Mycorrhizal associations have been observed by Dr. Sheldrake at ICRISAT. He m i g h t like to c o m m e n t on this. But we have hardly any information on the effect of this association on the phosphorus and zinc uptake in chickpea. S. C. Sethi Dr. M. C. Saxena's data on planting density show continuous increase in yield w i t h increase in density, whereas Dr. N. P. Saxena's data show that there is an appreciable compensating mechanism because of plasticity. It w o u l d be w o r t h w h i l e to resolve this difference. M. C. Saxena As was mentioned by me during the course of my presentation, the effect of population density seems to be related to g r o w t h conditions (both aerial and edaphic). In situations w h e r e conditions are ideal, there is apparently no conspicuous yield difference over a w i d e range of population density as has occurred in Pantnagar, in Hissar, and in some trials in Kanpur. When the aerial environment is such that the vegetative period is rather short, the population response is observed w h e n moisture supply is not limiting. If the moisture supply is limiting, again the population responses become limited. S. S. Lateef 1. What are the c o m m o n pests on chickpea that bring about great losses in yield at Aleppo? 2. Have you observed any delay or earliness in maturity of chickpea plants, because of pesticide sprayings on the crop? M. C. Saxena 1. Chickpea is not damaged much by insects at Aleppo, except for the damage f r o m leaf miners to some extent in the vegetative and early r e p r o d u c t i v e g r o w t h and from Heliothis spp in the podding stage. 2. We have not observed any conspicuous earliness because of the endosulfan spray.
151
A. S. Gil! 1. The histogram s h o w e d t h e f o l l o w i n g varieties fo r y o u r studies: G-130, C-235, K-468, P-61, and PB-7. Please confirm t h a t the cultivar used is P-61, not F-61. I am of the o p i n i o n that it is F-61 and not P-61. 2. Dr. Saxena has chosen five cultivars for his studies, but four of t h e m belong to o n e region, Punjab. It w o u l d have been better if he selected cultivars f r o m five different regions or zones to depict a g o o d picture of zinc uptake. M o s t of these cultivars have c o m m o n parents, as in the case of G-130 and F-61. M. C. Saxena 1. Y o u may perhaps be right; but we h a d this line w i t h us under the n u m b e r P-61, at Pantnagar. 2. No, we had 18 cultivars in this study. Only the ones w i t h large contrast w e r e s h o w n in the histogram. There are eight of these (T-2, G-130, NP-100, P-61, C-235, 742-7, BEG-482, and Pb-7) and represent a fairly w i d e range. M. V. Reddy W h a t is the possibility of date of planting interrelating w i t h s o m e root rot diseases at Hudeiba, w h i c h could also be responsible for l o w stands in addition to the factors y o u have mentioned? M. C. Saxena The authors did check fo r this possibility, and we w e r e of the o p i n i o n that the mortality was primarily due to accumulation of salts. We did isolate Fusarium orthoceras var ciceri f r o m the affected plants, but the pathogenicity of the isolated organism was not c o n f i r m e d . Jagadish Kumar W h e n we irrigate chickpeas at ICRISAT Center after f l o w e r i n g , we get quite a bit of f l o w e r d r o p and the plants look sick, alt h o u g h they recover later on. M. C. Saxena This is a c o m m o n observation, particularly on heavy soils having high pH. Several
152
t i m e s , such plants s h o w induced iron deficiency also. It seems that soil-packing associated w i t h irrigation leads to a t e m porary situation of restricted aeration, w h i c h results in this type of response. Irrigation d u r i n g f l o w e r i n g encourages vegetative g r o w t h and thus should increase competition between the reproduction and vegetative sink for the assimilates, resulting in flower drop. Irrigation during f l o w e r i n g is therefore not r e c o m m e n d e d . Instead, the pod-filling stage is considered good for irrigation to get g o o d response.
S. Sithanantham You have indicated that there have been instances of irrigation during f l o w e r i n g leading to reduced yields. Could we have additional information on t h e t y p e of irrigation and whether the observed reduction in yield was due to flower drop or to other components? M. C. Saxena The studies at Pantnagar and Ludhiana have s h o w n that irrigation at f l o w e r i n g stage encourages vegetative g r o w t h at the expense of reproductive g r o w t h , w h i c h results in reduced yield. Part of this is because of the flower d r o p that occurs due to this type of competition. C. L. L. Gowda In your radial planting experiments, the plant g r o w t h near the base (high density) is better than l o w density (end). This is in contrast to experiments conducted at ICRISAT w h e r e better g r o w t h and branching is observed at the lower densities. Could y o u comment? M. C. Saxena I did m e n t i o n in my talk that there seems to be s o m e synergistic effect of increased plant population on the early vegetative g r o w t h of the winter-planted chickpeas, w h i c h are exposed to long periods of l o w temperature. We do not k n o w w h i c h factors are involved, but there is the possibility that local temperature effects in the microenvir o n m e n t in t h e canopy m i g h t be playing a role.
S. Chandra Paper J.S. Kanwar 1. W h a t critical limit of salinity did y o u use for screening the genotypes? 2. What salt did y o u use to create salinity conditions? S. Chandra 1. The level of salinity used was 5.8±0.2 m m h o s / c m of the saturation extract for screening genotypes. These genotypes w e r e not used for screening under sodic soils. 2. The salts used were NaCI, Na 2 SO 4 , CaCl2 in the ratio of 7:1:2 to build up the desired level of salinity.
Rajat De In North India we encounter t w o types of salinity — one confined to the soil surface and the other in w h i c h the salinity permeates the profile to some depth. Will y o u clarify as to w h i c h type of salinity you referred in y o u r paper and w i t h w h i c h y o u have screened your cultivars. S. Chandra The salinity status of the profile is a dynamic one and w o u l d undergo changes w i t h rainfall or irrigation. Ourconcern at the m o m e n t is to try to i m p r o v e chickpea w i t h regard to a level of salinity since this crop has a very low salt tolerance. We screened varieties in pots having a u n i f o r m salinity of 5.8 ± 0.2 m m h o s / c m . Y. S. Tomer 1. What is the mechanism of salt tolerance in chickpea? 2. Is there any relationship between salt tolerance and agronomic characters or morphological characters? S. Chandra 1. We cannot say anything at this m o m e n t about this mechanism because we are still identifying tolerant ones. However, it may not be possible to identify a simple mechanism because salt tolerance is a complex response. 2. A g a i n , we have no definite answer yet.
J. S. Sidhu In the Indo-Gangetic plains of India, chickpea crops cannot be g r o w n successfully u n d e r assured i r r i g a t i o n c o n d i t i o n s , whereas chickpea could be g r o w n under rainfed conditions before the irrigation facilities were m a d e available. What could be the possible edaphic factors for this failure? S. Chandra It w o u l d be necessary to examine local conditions before a reason could be assigned. However, generally speaking, the availability of irrigation in certain conditions in the Indo-Gangetic plains has led to development of salinity and sodicity. This might be one of the possible reasons. M. V. Reddy 1. W h a t are the external s y m p t o m s of salinity and s o d i u m in soil on chickpea? Do they cause any vascular s y m p t o m s also? 2. Is there any information on temperature on salinity-sodium interaction? S. Chandra 1. There are different types of responses by different genotypes. However, leaf b r o w n i n g and leaflet shedding of older leaves w i t h progressive g r o w t h are associated w i t h saline as well as sodic soils and w o u l d vary in extent w i t h the degree of soil affectedness. Vascular s y m p t o m s w e r e not studied over the range of varieties. 2. Higher temperatures are m o r e conducive to the adverse effects of salinity, but detailed information on chickpea is not yet available in this regard. S. Sithanantham In one of your illustration slides, you showed a picture of a field crop of chickpea in w h i c h y o u suggested that b r o w n leaves indicated response to sodic soils. Could y o u eliminate the involvement of " s t u n t " disease, w h i c h m i g h t also end up in " r e d d i s h " - b r o w n foliage. S. Chandra The s y m p t o m s indicated were f o u n d in
153
k n o w n sodic conditions and n o w h e r e else in adjacent i m p r o v e d fields or n o r m a l fields. This makes us believe that stunt w a s not involved because that w o u l d occur irrespective of type of soil. However, w e d i d not proceed to establish that stunt was not involved.
E. J. Knights W h i c h genotypes s h o w t h e least effect of salinity on establishment and final yield? W h a t are the main s y m p t o m s attributable to sal inity? S. Chandra Of t h e genotypes tested by us, H-75-36 appeared to do well on these scores. The main s y m p t o m s attributable, in the absence of other effects, are b r o w n i n g of leaflet tips, w h i c h moves d o w n t h r o u g h the leaflet progressively, culminating in leaflet d r o p after b r o w n i n g has completed. While this is happening to the older leaves, n e w leaves are being put up and appear n o r m a l except for some restricted elongation and sometimes even g r o w t h . M e a n w h i l e , plant mortality continues at a s l o w to rapid pace, depending on relative tolerance. H. S. Nagaraj Are nodules present in t h e chickpea plant in sodic soils? If so, w h a t is the number? Is it not possible to isolate Rhizobium strains f r o m these nodules? What is t h e c o l o r of the nodules inside? S. Chandra The n o d u l a t i o n studies are important in sodic soils, and s o m e data have been presented in the paper. Further studies, w h i c h are n o w being done by us, w i l l give us data to answer y o u r questions. At the m o m e n t , it is difficult to provide quantitative data.
C. L. L. G o w d a A m o n g the sensitive crops, chickpea is highly sensitive to salinity. Is this because chickpea is g r o w n in the postrainy season w h e n salt begins to seep up and thus affects rabi crops such as chickpea (with its deep root system) m o r e than others?
154
S. Chandra The relative tolerances of crops generally reflect h o w m u c h accumulation of salts in the soil they could withstand. Those that withstand increasing levels are progressively m o r e tolerant. Chickpea s h o w s sensitivity at very l o w levels of salt in soils. Thus, their sensitivity w o u l d not appear to be related to changes in the soil profile before the crop is planted. That w o u l d , however, determine t h e performance of t h e particular cultivar of chickpea that is g r o w n in such soils. Jagdish Kumar I w o n d e r if y o u have anything to say about the effect of salinity on protein content of chickpea or any other crop. S. Chandra Nitrogen content in leaves of salt-stressed plants has been reported to go up on a per-unit dry matter basis and, in certain cases, on a per-unit grain weight basis. In chickpea, however, these data have not yet been estimated by us.
Saxena and
Sheldrake
Paper
K. B. Singh Production and area statistics on chickpeas have been circulated. I am interested to k n o w (1) what is the p r o p o r t i o n of kabuli chickpea in w h o l e chickpea p r o d u c t i o n ; (2) w h a t p r o p o r t i o n of the area under chickpea receives irrigation; and (3) w h a t are the reasons for year-to-year fluctuations in production and area? B. M. Sharma 1. There are no separate statistics available on the area of kabuli chickpea, but kabulis are g r o w n on a restricted area in Punjab, in Haryana, in the Ganganagar area of Rajasthan. 2. A b o u t 10% of the chickpea area is irrigated. 3. The area under chickpea m a i n l y depends u p o n t h e late rains d u r i n g the end of September or early October, w h i l e production depends upon the winter rains. Again, heavy winter rains invite
diseases and stimulate insect infestation and thereby lower yields. B. M. Sharm a If b o l d seeds produce healthier plants, w h a t is their effect on grain yield? N. P. Saxena Bold-seeded cultivars produce larger seedling, but w i t h t i m e , the effect fades away and there is no advantage in yield. In fact, very bold-seeded cultivars tend to be l o w yielding. A. S. T i w a r i Which cultivars responded best to irrigation application in the experiment on cultivaral differences on limited water? N. P. Saxena The results on cultivaral responses to irrigation are available in the Pulse Physiology Progress Report 1977-78. These are data based on 1 year's experience, w h i c h need to be confirmed. Rajat De In screening genotypes of chickpea to d r o u g h t tolerance, will it not be better to take into consideration the leaf water potential at various phenological stages of the crop? N. P. Saxena We are measuring water potential in a set of cultivars varying in g r o w t h duration. The objective of the field screening is to keep it as simple as possible so that it is an effective and useful technique. Measurement of water potential is a c u m b e r s o m e process and is unlikely to be as useful in yield as a criterion for d r o u g h t tolerance. However, it may be used in a limited way for the identification of drought-tolerant parents. K. G. Shambulingappa Have any laboratory studies been initiated to screen the varieties against d r o u g h t conditions. N. P. Saxena No, we have so far not c o m m e n c e d any laboratory studies on d r o u g h t tolerance.
M o h a m e d Bouslama Do y o u think that cultivars w i t h high carbohydrate content perform better under drought-stress conditions? N. P. Saxena We have no information on this aspect. It is k n o w n in other crops that carbohydrate accumulates w h e n plants are under stress. Y. S. T o m e r Please c o m m e n t on whether production of dry matter is more important after or before flowering. N. P. Saxena Chickpeas are indeterminate in nature and consequently dry-matter production continues after flowering. Dry matter at flowering and continued dry-matter production after flowering both seem to be important in determining yield. J. M. Green Did y o u not think it necessary to conduct a balanced test on the effect of double pods? You should have added a second pod to the single-podded cultivar in addition to rem o v i n g one f r o m the double-podded cultivar. N. P. Saxena A balanced test w o u l d be desirable, but the absence of isogenic lines presents certain technical problems. A d d i n g flowers by grafting does not w o r k ; adding alreadyfilled second pods increases yield, but is perhaps somewhat unphysiological. Doubling the pod numbers by means of mirrors has so far failed to influence yields significantly under Hyderabad conditions. V. P. Gupta How do you feel about screening the germplasm for root g r o w t h and root dry matter and relating the data on root dry matter w i t h g r o w t h and the phenological and yield components. What I feel is that most of the studies have been conducted above the g r o u n d , but there is a need to study in detail what is happening below the g r o u n d . We have found genotypic differences for root dry matter and strong as-
155
sociation w i t h t h e physiological attributes. N. P. Saxena Quantitative studies on root g r o w t h are difficult. Also, they are greatly influenced by soil e n v i r o n m e n t factors, such as availability of water, c o m p a c t i o n , and nutrient availability. As we are interested in the differences in biological productivity, and m o r e so in y i e l d , a better root system should be reflected in t h e cultivar's drymatter p r o d u c t i o n in above-ground parts, w h i c h are easy to monitor. S. S. Lateef We k n o w that chickpea plants mature early (2-3 weeks) under sprayed conditions. Have y o u taken this factor into consideration w h e n interpreting your results on delay and earliness in maturity of chickpea because of three other factors, as y o u mentioned in y o u r talk? N. P. Saxena The results on flower removal indicate delay in senescence w h e n pod set is prevented. Insect damage to pods and flowers could be analogous to this in a nonsprayed condition and could delay senescence. I do not k n o w if the early senescence in sprayed plants is in response to an internal signal in response to pod set that triggers senescence or w h e t h e r it is a sole effect of the chemical used as an insecticide. H. S. Nagaraj W h a t is the state of nodulation w h e n the f l o w e r buds are removed and the plants remain green. Do the nodules senesce or continue to be active.
At l o w plant stands the yield of cultivars is reduced, d e p e n d i n g u p o n the plasticity of the cultivar; there seem to be distinct cultivaral differences in this respect. B. M. Sharma In the States of Madhya Pradesh, Uttar Pradesh, and Gujarat, chickpea plants s h o w a bronzing of leaf color and s y m p t o m s of forced maturity. W h a t is the reason for this type of appearance? N. P. Saxena We observe in desi cultivars that the bronzing of leaves occurs in response to any stress, such as water and salt. Disease or insect stress could also be involved. R. C. Misra You mentioned that providing shade cuts off sunlight and temperature to s o m e extent. Dr. M. C. Saxena of ICARDA, w h i l e presenting the slides, mentioned that in late s o w i n g the yield is lower than that of early s o w i n g , probably due to high temperature and full sunlight. Will it not be possible to increase the yield of chickpea in late s o w i n g by using it as an intercrop w i t h safflower or sugarcane to provide shade to cut off sunlight and temperature? Please comment. N. P. Saxena In f a c t in the cropping system g r o u p , an intercrop of chickpea and safflower has led to an increase in yields of chickpeas. The intercrop advantage is suggested to be due to the partial shading effect.
Summerfield et al. N. P. Saxena Nodule regression is delayed in response to flower removal. The nodules continue to g r o w and accumulate a greater mass. M. V. Redey W h a t could be the effect of l o w and high plant stands on t h e stability of yields? N. P. Saxena Chickpeas are fairly plastic and give stable yields over a range of population densities.
156
Paper
K. B. Singh 1. You mentione d that long days and w a r m temperatures induce early f l o w e r i n g and probably result in high yields. Exactly similar conditions exist at Aleppo and result in lower yields. Probably moisture and heat stress are quite important. Could y o u c o m m e n t on this? 2. Your literature review indicated that chickpea has been reported variously as
day-neutral, long-day, and short-day. W h a t is y o u r o w n experience? R. J. S u m m e r f i e l d 1. For the f e w cultivars for w h i c h we have data, longer days and w a r m e r day and night temperatures are m o r e inductive. I was at pains to point out that w a r m e r days to 30°C increase yield, compared w i t h cooler days (22°C), but that 35°C is supraoptimal even w h e n experienced for only the latter part of the reproductive period. 2. Chickpeas are probably mainly quantitative long-day plants; genotypes differ in degree of sensitivity; s o m e may be insensitive, the single report in the literature of a short-day response is unreliable. L. J. G. van der Maesen 1. There is only a single aberrant report extant on chickpea as a short-day plant. 2. Obviously there exists a range of responsiveness to daylength between chickpea cultivars. We w o u l d learn m o r e if many representatives of geographical groups were screened together. W i t h breeding, germplasm gets m i x e d , and w h i c h probably also mixes this response. R. J. S u m m e r f i e l d 1. I k n o w of this single reference and do not believe it. 2. I entirely agree w i t h these sentiments. We have made only a small start. G e n o t y p e s c o u l d f a i r l y easily be screened for photoperiod sensitivity in the f i e l d , but materials of interest to the breeder should subsequently be tested for the effect of day and night temperature on successive stages of reproductive development. N. P. Saxena The shoot g r o w t h in the environmental cabinet was similar to the field-grown plant. D o y o u expect similar results in roots. R. J. S u m m e r f i e l d d o u b t it! Rooting depth is restricted in
pots, and the m e d i u m is defined and mainly inorganic rather than heterogenous and m o r e organic as in natural soils. Different shapes and sizes of containers could be used, but w o u l d we need to recreate the soil profile (e.g., bulk density) to produce realistic data? I can foresee many problems. N. P. Saxena As senescence seems to be governed m o r e by internal physiological factors, early planting of early cultivars may not get the advantage of extending growth duration. The plants will mature in response to internal signals, even though the conditions continue to be conducive for continued growth. R. J. Summerfield On the basis of studies so far completed, we cannot assess reliably which internal factors are involved or w h i c h environmental stimuli trigger or modify their manifestations. Undoubtedly, it may prove to be a combination of endogenous and external control, and it will be pertinent to note the " s t r a t e g y " of cultivars that do not conform . A. R. Sheldrake In the field, sensescence is affected by three main factors: water stress, heat stress, and internal physiological factors. I find it very interesting that in the g r o w t h chambers w h e n the plants were well watered and g r o w n at constant temperatures they matured normally in comparable times to those in the field, emphasizing the role of internal factors in senescence. R. J. Summerfield These nodule-dependent plants completed their phasic development in times (days f r o m sowing) closely similar to those in the field. Certainly, the role of internal factors (such as the mobilization of nitrogen f r o m vegetative to reproductive structures and, perhaps, changes in endogenous h o r m o n e balances) must be important in this respect. There is likely to be a progressively larger effect of water stress on longer duration cultivars in t h e f i e l d , and y o u will notice that predictions are less precise (Table 7) for this line. Furthermore, these plants w e r e har-
157
vested w h e n m o r e than 9 5 % of the fruits w e r e m a t u r e , although all their leaves had not senesced. Crop duration in cultivar Chafa corresponds to all fruits m a t u r e and all leaves senesced. M. C. Saxena You seem to maintain the relative h u m i d i t y in y o u r cabinets at a constant level, whereas in the field t h e r e is not only a diurnal fluctuation in this but also a seasonal pattern. W o u l d y o u care t o c o m m e n t on the effect of relative h u m i d i t y on flower
158
retention and yield build up. R. J. S u m m e r f i e l d To establish a " b a s e l i n e " f r o m w h i c h to build, we control at single values (CO2) V p d , (vapor pressure deficit), light intensity, and quality, frequency of irrigation, nodulation, and v o l u m e of nutrient solution applied. We can then elect " k e y " combinations of daylength and air temperature and vary also V p d or any other factor. We are likely to investigate factorial combinations of Vpd and temperature in future experiments.
Session 4 Chickpea Microbiology Chairman : M. C. Amirshahi C o - C h a i r m a n : D. F. Beech
R a p p o r t e u r : O. P. R u p e l a
Research on Symbiotic Nitrogen Fixation by Chickpea at ICRISAT O. P. Rupela and P. J. Dart* N o d u l a t i o n in Farmers' Fields The Rhizobium strains nodulating chickpea (Cicer arietinum) are very specific, nodulating only Cicer species readily (Raju 1936) and rarely and non-reciprocally w i t h Sesbania bispinosa and S. sesban (Gaur and Sen 1979). Surveys of nodulation of chickpea in farmers' fields in India, Syria, and Lebanon indicate a w i d e range in the extent of nodulation. W i t h i n India, fields w e r e f o u n d in the states of A n d h r a Pradesh, Maharashtra, and Madhya Pradesh where chickpea plants w e r e not n o d u l a t e d ; in other fields in Haryana and Rajasthan nodulation and plant g r o w t h w e r e poor. This may reflect l o w chickpea Rhizobium populations in the soils or poor soil moisture conditions. Large differences in g r o w t h between plants w e r e associated w i t h differences in nodulation. The increase in the area of wheat and rice cultivation in the northern States of India (Punjab, Haryana, Uttar Pradesh, Bihar, West Bengal) since the introduction in 1965 of new, fertilizer-responsive cereal varieties has resulted in a decreased area of chickpea cultivated in these states, f r o m 52.89 to 34.3% in 1972-75, and decreased yields per hectare, probably because the better land was taken out of chickpea production and there was an associated m o v e m e n t of production to m o r e marginal areas w h e r e chickpea may previously have been g r o w n infrequently, if at all. Chickpea production has increased in the states of Rajast h a n , Gujarat, Madhya Pradesh, Maharashtra, Andhra Pradesh suggesting that some product i o n is being taken up in new areas for chickpea g r o w t h ( M . v o n Oppen, personal c o m m u n i c a tion). In such new lands for chickpea, one w o u l d expect l o w populations of chickpea Rhizobium to occur naturally in the soil and responses to
* M i c r o b i o l o g i s t and Principal M i c r o b i o l o g i s t , respectively, ICRISAT.
inoculation w i t h Rhizobium w o u l d also be expected. At ICRISAT Center, there is a sharp transition f r o m a Vertisol field, where chickpea is g r o w n , to an Alfisol field where chickpea is not normally g r o w n . Chickpea nodulates readily in the Vertisol field, but poorly, if at all, 150 metres away in t h e Alfisol field, where marked responses to inoculation occur. The prevailing winds b l o w f r o m the Vertisol to the Alfisol field so that transfer of Rhizobium w o u l d have occurred t h r o u g h the dust. The poor saprophytic development of chickpea Rhizobium in this Alfisol soil is intriguing.
C o u n t i n g Rhizobium
in
Soil
We have n o w developed a suitable technique using a most-probable number m e t h o d based on g r o w i n g chickpea plants axenically in 22 x 200 mm test tubes, and inoculating t h e m w i t h an aliquot of solution f r o m a dilution series. The plant will nodulate if chickpea rhizobia are present in the aliquot. We have achieved consistent nodulation of chickpea in test tubes by transplanting seedlings in w h i c h the cotyledons were excised 3 days f o l l o w i n g germination. The rooting m e d i u m can be either sand or a sand/ vermiculite mixture. Nodules appear at about 20 days after inoculation. The plants will nodulate in natural light if the temperature inside the test tube is kept below 30° C, but nodulate m o r e reliably w h e n they are g r o w n w i t h lateral illumination f r o m fluorescent tubes in a temperature controlled r o o m (Toomsan et al. 1980 in press). This counting technique n o w enables us to determine chickpea Rhizobium populations in soil and in Rhizobium inoculants containing contaminating organisms. This will be helpful in understanding nodulation patterns in the field, and in monitoring the quality of inoculants used in field experiments.
161
Response to Inoculation
Table 2 s h o w s the response in one such trial in a Vertisol field at ICRISAT Center. The previous cultivation history of the field w a s not k n o w n , but t h e uninoculated control plants f o r m e d s o m e nodules (Fig. 1). Nodulation, nitrogenase activity, dry-matter p r o d u c t i o n , and yield w e r e significantly increased by inoculation w i t h no advantage of the multistrain over the single strain inoculm. At ICRISAT Center in the dry winter season of 1977, interactions between Rhizobium strains and host cultivars w e r e f o u n d for nodule f o r m a t i o n in a Vertisol field w i t h a l o w population of native rhizobia. Inoculation increased nodulat i o n w i t h most nodules f o r m e d by strain
We have a collection of several h u n d r e d Rhizobium strains isolated f r o m chickpea nodules collected m a i n l y in India, but also s o m e f r o m Bangladesh, Iran, Syria, J o r d a n , Turkey and w i l d Cicer species f r o m Israel. There is a w i d e range of symbiotic characteristics a m o n g the strains (Table 1). Strains f r o m this collection are available for research workers and inoculant manufacturers; ICRISAT offers to maintain characterized chickpea strains in its collection for any w h o w i s h t o deposit t h e m . Responses to inoculation have been obtained w i t h s o m e of these strains in field experiments.
Table
1.
Range of symbiotic characteristicsa for ICRISAT Center, 1977.
Character
Cicer
Rhizobium
strains screened on cv J G - 6 2 ,
Overall m e a n
Range 7-48 13-74 0.2-3.25
N o d u l e (no./plant) N o d u l e d r y w t (mg/plant) Nitrogenase activity: ( µ m o l C 2 H 4 /plant per hour) µ m o l C 2 H 4 /g n o d u l e dry w t per hour Root d r y w t (g/plant) T o p d r y w t (g/plant) Colony g r o w t h rate b
3-100
21 30 1.2
25 32 1.3
36
41 0.14 0.42 ND
0.15 0.37 9.3
0.08-0.29 0.15-0.92 3-15
Median
a . T e s t i n g d o n e d u r i n g t h e r e i n y season w h e n t h e a m b i e n t t e m p e r a t u r e r a n g e w a s a b o v e o p t i m u m f o r chickpea g r o w t h . Plants g r o w n i n L e o n a r d jars w a t e r e d w i t h N-free n u t r i e n t s o l u t i o n , h a r v e s t e d a r o u n d 4 5 d a y s after p l a n t i n g . Values are m e a n s o f f o u r replications w i t h t h r e e plants. b. Days t a k e n for an Isolated c o l o n y to reach 2 mm d i a m e t e r on yeast extract, m a n n i t o l agar plate. N D = N o data
Table 2.
Effect of Rhizobium Inoculation on nod illation and yield of chickpea. Nodulation/plant
Treatment Uninoculated Strain CC 1192 a Multistrainb SE ± CV (%)
No.
Dry w t (mg)
Nitrogenace activity (µ m o l C 2 h 4 /plant per hr)
Dry matter (kg/ha)
(kg/ha)
4 17 15
11 42 53
0.3 2.2 2.6
2890 3740 3440
1560 2140 2010
2.7 21
13 29
1.1 67
390 12
252 13
Yield
a. S i n g l e s t r a i n I n o c u l u m in peat carrier. b . M u l t i s t r a i n i n o c u l u m p r e p a r e d f r o m 2 0 strains g r o w n separately o n large agar slants a n d s u s p e n s i o n o f t h i s g r o w t h used t o I n o c u l a t e t h e pea t carrier. Cultlvar u s e d — A n n i g e r l .
162
Figure1.
Response inoculant
of chickpea to inoculation with Few nodules are formed on
DNRa-1. A m o n g the five cultivars, 850-3/27 was best nodulated, f o l l o w e d by JG-62, w i t h significantly fewer nodules f o r m e d on Rabat and C-235, and the fewest were f o r m e d on G-130. Inoculation significantly increased grain yields for s o m e strain-cultivar combinations. Nitrogen fertilizer application (150 kg N/ha) produced the highest yields indicating that the symbiotic system was unable to provide enough nitrogen for m a x i m u m yields. No response to inoculation was obtained in another trial in a Vertisol field w h e r e chickpea nodulated readily w i t h o u t inoculation. A similar, rainy-season trial was planted in an Alfisol field (also w i t h l o w numbers of Cicer Rhizobium) to examine the possibility for field screening Rhizobium strains in the off-season. There was again a significant response to inoculation in nodulation and plant g r o w t h w i t h a cultivar x strain interaction in nodulation. Mean nodule number and weight per plant
R h i z o b i u m strain CC noninoculated plants.
1192
or
a
multistrain
were generally greater than for similar treatments planted in a Vertisol in the dry winter (postrainy) season. This experiment indicated that chickpea can be g r o w n in the rainy seasonalthough Colletotrichum blight disease did kill some plants. The temperature regime was not unfavorable for chickpea g r o w t h . A large response to inoculation has also been obtained w h e n chickpea f o l l o w e d paddy (Table 3). It is estimated that in India s o m e 2 million ha of pulses are g r o w n after a rainy season crop of paddy, and much of this is sown to chickpea. We are studying the survival of chickpea Rhizobium in paddy soil. Another trial was conducted in a saline field containing no native chickpea Rhizobium at Hudeiba Research Station in the Sudan by Dr. M o h a m m e d El Habib and Dr F. A. Salih. Strain IC 53 isolated f r o m a saline field at ICRISAT produced three times as many nodules per plant, more than double the nodule weight and
163
a 6 3 % increase in grain y i e l d over another inoculum strain CC 1192, of similar effectiveness in nitrogen fixation under non-saline conditions (Table 4). This experiment suggests that selecting specific strains for saline conditions w o u l d be rewarding. Our experiments suggest that there are situations w h e r e responses to inoculation can be obtained w i t h chickpea, but little response may be obtained w h e r e the soil already contains a large population of chickpea rhizobia. Our w o r k is n o w directed t o w a r d s developing methods of identifying Rhizobium strains so that we can f o l l o w the competitiveness of our i n o c u l u m strains in f o r m i n g nodules in different environments.
Nitrogen Fixation There are large effects of location on nodule longevity on chickpea. At Hyderabad in the Table 3.
Yield of chickpea after paddy.
Treatment Control Inoculated + Na Inoculated SE ± cv% a.
Dry matter (kg/ha)
Grain yield (kg/ha)
1480 2390 2680
1090 1760 1800
161 7
123 8
Fertilizer (Calcium a m m o n i u m nitrate) a d d e d at rate of 150 kg N/ha).
Table 4.
postrainy season, using residual stored w a t e r in the soil, the nitrogen-fixing activity of chickpea nodules virtually ceases by 89 days after planting w i t h final grain harvest at 110-130 days. At Hissar in North India, nodules remain active m u c h longer, even up to 145 days after planting or 3 weeks before final harvest. Nodulation, nitrogenase activity and yield w e r e f o l l o w e d for five cultivars g r o w n in a Vertisol soil at ICRISAT. Highly significant correlations w e r e f o u n d between grain yield and nodulation parameters, particularly for nodule number and nodule weight at 61 days after planting w h e n there were large differences between cultivars, and nodule developmen t and nitrogenase activity w e r e greatest (Tables 5, 6; Fig. 2). At 89 days after planting, only cultivar 850-3/27 retained some nitrogenase activity as measured by acetylene reduction (5μ moles/C 2 H 4 /plant per hr) while less than 0.2μ moles/C 2 H 4 /plant per hr was measured for other cultivars. Differences between cultivars in their pattern of nodulation w e r e apparent at 17 days after planting (Fig. 2). The cultivar 850-3/27 f o r m e d m o r e nodules per plant, a greater mass of nodule tissue and had m u c h greater nitrogenase activity per plant than any of the other cultivars. Nodule tissue developed rapidly between 27 and 61 days, w i t h big differences in g r o w t h rate between cultivars. The specific nitrogenase activity (per g dry weight nodule) was most for the youngest nodules (17 days after planting) and declined similarly and rapidly for all cultivars except 850-3/27 w h e r e the nodule tissue retained its activity until 61 days after planting.
Effect of Rhizobium i n o c u l a t i o n on yield of chickpea in a saline field at Hudelba Research S t a t i o n , Sudan a .
Rhizobium strain Uninoculated CC 1192 IC 53
Nodule no/plant 0.3 45 143
LSD a. E x p e r i m e n t c o n d u c t e d by M o h a m e d El H a b l b I b r a h i m & F. A. Salih. b. N o d u l a t i o n m e a s u r e d 57 days after p l a n t i n g .
164
Nodule dry wt/plant (mg)
Seed yield (kg/ha)
8 149 34
680 860 1400 480
K 850-3/27 L-550 P-2610 80
BEG-482 G-130
(A) Nodule number per plant
(B) Nodule weight per plant 0.5
60
0.4
0.3
SEM
SEM
40 0.2
0.1
20
10
0
10
30
50
70
90
10
30
50-
50
70
90
Days after p l a n t i n g
Days after p l a n t i n g (C) N i t r o g e n a s e a c t i v i t y per plant per hour
(D) Nitrogenase a c t i v i t y per gram dry weight nodule per hour
300
40
200 30-
SEM 20 100
10-
SEM 0
0 10
Figure
30
2.
50
70
Symbiotic performance Center, standard
dry
winter
error
activity, μ moles nodule
per
of
of five
season the
C2H4I
mean
10
90
Days after p l a n t i n g
(SEM);
plant per hr;
(D)
50
70
90
Days after p l a n t i n g
chickpea
1976-77;
30
cultivars
(A)
Nodule
(B)
Nodule
grown
in
a
Vertisoi field at
number per plant weight
per
plant;
Nitrogenase activity, μ moles
Bars
ICRISAT
represent
the
(C)
Nitrogenase
C2H4lg
dry weight
hr.
165
This experiment indicates that there are lagre differences in nodule d e v e l o p m e n t and nitrogen fixation between cultivars, and that this may influence final yield.
even m o r e reduced. Nodules continued t o f o r m between 30 and 50 days in 1976-77 but not in 1977-78 at Hyderabad. The decline in nodule n u m b e r between t h e 50 and 75 day harvests in 1977-78 reflects both nodule senescence and difficulty in recovering nodules f r o m this heavy clay soil as it dries out. In both seasons and at both locations, nodule tissue g r o w t h continued after 50 days so that nodule w e i g h t per plant was greatest at the 7 0 - 7 5 days harvest. Nodule g r o w t h at Hissar was m u c h greater than at Hyderabad w i t h m o r e than double the nodule mass per plant at 70 days. Plant top g r o w t h reflected these differences i n n o d u l e d e v e l o p m e n t b e t w e e n Hyderabad and Hissar, but not between seasons at Hyderabad suggesting that other factors than nitrogen supply may be d e t e r m i n i n g plant development at Hyderabad. Even t h o u g h the entries w e r e variable in plant type, fo r the Hyderabad s o w i n g in 1977-78 there w a s a significant correlation between nodule w e i g h t and t o p weight at the 4 5 - 5 0 day harvest (r 2 = 0.313, p
