Inheritance in inter-generic crosses between cajanus and atylosia species

Inheritance of six oligogenic traits, namely, leaflet shape, twining nature, pod hairiness, growth habit, seed strophiole and seed colour, were studied in four intergeneric crosses involving two cultivars of C. cajan and three species of Atylosia. The genes responsible for leaflet shape, growth habit and seed colour showed incomplete dominance. For the remaining characters, dominant gene expression was recorded. The F, segregation revealed that lealet shape, pod hairiness and seed colour were governed by a single gene. The twining nature, seed strophiole, and growth habit were governed by two gene

Possibility of genetic improvement of pigeonpea (Cajanus cajan (L.)Millsp.) utilizing wild gene sources

Various wild relatives of pigeonpea,Cajanus cajan, namely some species ofAtylosia andRhynchosia, possess desirable characteristics that could be utilized for effecting genetic improvement of this crop. In total 73 cross combinations among two cultivars ofC. cajan and one accession each of eightAtylosia species and one ofRhynchosia were attempted. Twelve hybrids were obtained. Seven of these were analysed for F1 fertility and their utility for agronomic improvement of theC. cajan. Fertility behaviour of the different F1 hybrids varied and indicated that potential of gene transfer between the two genera,Atylosia andCajanus, was as good as within the genusAtylosia. From F2 and F3 families ofC. cajan × A. scarabaeoides andC. cajan × A. albicans, plants were selected with greater physiological efficiency and agronomic superiority. The prospects of transferring pod borer resistance and higher seed protein content from someAtylosia species to pigeonpea are discusse

Screening of Cicer Species and Chickpea Genotypes for Resistance to Meloidogyne Javanica

Twenty-five accessions of Cicer bijugum, C. chorassanicum, C. cuneatum, C, judaicum, C, pinnatifidum, and C. reticulatum, 173 chickpea advanced breeding lines and five cultivars were evaluated for resistance to Meloidogyne jauanica in a greenhouse. Resistance evaluation was on a 1-9 damage index (l=highly resistant; 9=highly susceptible) based on gall number, gall size, and galled area of root. Numbers of egg sacs were also counted. None of the tested lines was free of nematode damage. Damage indices of Cicer spp. ranged between 5.2 and 8.8. ICCW 47, an accession of C. cuneatum was less susceptible than other accessions. Variation in gall size was greater than that for gall number and galled area. Most of the tested lines showed symptoms of stress in terms of premature drying of leaves, chlorosis, and stunting of plants. Plant growth of two breeding lines (ICCV 90043 and 90243) and a cultivar (ICCC 42) was not affected by nematode parasitism, foliage of these genotypes remaining dark green and without premature leaf drop

Use of core and mini core collections in preservation and utilization of genetic resources in crop improvement

Plant genetic resources are the most valuable and essential basic raw material to meet the current and future needs of crop improvement programmes and the demands of increasing populations. The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT, established in 1972) responded to this need by establishing a Genetic Resources Unit (GRU) for assembling, characterizing, evaluating, maintaining, conserving, documenting and distributing germplasm of the mandate crops (sorghum, pearl millet, chickpea, pigeonpea and groundnut) and their wild relatives, and six small millets (finger millet, foxtail millet, barnyard millet, kodo millet, little millet and proso millet). The efforts have yielded the assembly of 113 849 germplasm accessions in the ICRISAT genebank and over 5.5 million accessions globally. Unfortunately, only a small proportion of this large collection has been used in improving crops. Developing core collection (about 10% of the entire collection) has been suggested as a method of enhancing the use of the germplasm. However, even this number could be large and unmanageable if the entire accession is several thousands. A methodology to reduce the size further and select a mini-core that is about 1% of the entire collection, yet represents full diversity of the species has been developed. Core collections of sorghum, pearl millet, chickpea, pigeonpea, groundnut, and finger millet and mini-core collection of groundnut and chickpea have also been developed. The core and mini-core collections of chickpea and groundnut have been evaluated and diverse sources for early maturity, traits related to drought tolerance and large seed size in kabuli chickpea, and early maturity, tolerance to low temperature, and traits related to drought tolerance in groundnut have been identified. Their use in breeding will broaden the genetic base of the cultivar

Collecfion of chickpea germplasm in Madhya Pradesh, India and their agronomic evaldation

Three-hundred-and-fifty-one seed samples of local chickpeas (Cicer arietinum L.) were collected in Madhya Pradesh, India, during 1986 and 1987 for the world germplasm collection maintained at ICRISAT Centre. These missions were joint efforts of the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Jawaharlal Nehru Krishi Vishwa Vidyalaya(JNKVV), Jabalpur, and the National Bureau of Plant Genetic Resources (NBPGR), New Delhi. Vast variability was noticed for several morphoagronomic traits of chickpea during these missions. The collected samples were sorted out into relatively homogenous samples and later grouped into five homogenous sets for easy evaluation. These sets were evaluated for eight agronomic traits at ICR/SAT Centre (18°N) and Gwalior (26°N). The performance of accessions for seeds per pod and 100-seed mass were almost similar at both locations whereas other agronomic characters varied with locations. The accessions with superior performance in five sets and two locations were identified

Phenotyping Chickpeas and Pigeonpeas for Adaptation to Drought

The chickpea and pigeonpea are protein-rich grain legumes used for human consumption in many countries. Grain yield of these crops is low to moderate in the semi-arid tropics with large variation due to high GxE interaction. In the Indian subcontinent chickpea is grown in the post-rainy winter season on receding soil moisture, and in other countries during the cool and dry post winter or spring seasons. The pigeonpea is sown during rainy season which flowers and matures in post-rainy season. The rainy months are hot and humid with diurnal temperature varying between 25 and 35°C (maximum) and 20 and 25°C (minimum) with an erratic rainfall. The available soil water during post-rainy season is about 200–250 mm which is bare minimum to meet the normal evapotranspiration. Thus occurrence of drought is frequent and at varying degrees. To enhance productivity of these crops cultivars tolerant to drought need to be developed. ICRISAT conserves a large number of accessions of chickpea (>20,000) and pigeonpea (>15,000). However only a small proportion (<1%) has been used in crop improvement programs mainly due to non-availability of reliable information on traits of economic importance. To overcome this, core and mini core collections (10% of core, 1% of entire collection) have been developed. Using the mini core approach, trait-specific donor lines were identified for agronomic, quality, and stress related traits in both crops. Composite collections were developed both in chickpea (3000 accessions) and pigeonpea (1000 accessions), genotyped using SSR markers and genotype based reference sets of 300 accessions selected for each crop. Screening methods for different drought-tolerant traits such as early maturity (drought escape), large and deep root system, high water-use efficiency, smaller leaflets, reduced canopy temperature, carbon isotope discrimination, high leaf chlorophyll content (drought avoidance), and breeding strategies for improving drought tolerance have been discussed

Biodiversity Management in Chickpea

This chapter focuses on the management of biodiversity in chickpea. The morphological diversity; germplasm collections and enhancement; core and minicore collections and their use for diversity studies and new breeding goals; and the conservation and documentation of chickpea genetic resources are describe