Plant genetic resources are raw materials and their use in breeding is one of the most sustainable ways to conserve biodiversity. The ICRISAT has over 120,000 accessions of its five mandate crops and six small millets. The management and utilization of such large diversity are greatest challenges to germplasm curators and crop breeders. New sources of variations have been discovered using core and minicore collections developed at the ICRISAT. About 1.4 million seed samples have been distributed; some accessions with specific attributes have been requested more frequently. The advances in genomics have led researchers to dissect population structure and diversity and mine allelic variations associated with agronomically beneficial traits. Genome-wide association mapping in sorghum has revealed significant marker–trait associations for many agronomically beneficial traits. Wild relatives harbour genes for resistance to diseases and insect pests. Resistance to pod borer in chickpea and pigeonpea and resistance to rust and late leaf spot in groundnut have been successfully introgressed into a cultivated genetic background. Synthetics in groundnut are available to broaden the cultigen's gene pool. ICRISAT has notified the release of 266 varieties/cultivars, germplasm, and elite genetic stocks with unique traits, with some having a significant impact on breeding programs. Seventy-five germplasm lines have been directly released for cultivation in 39 countries.

The International Crops Research Institute for the Semi-Arid Tropics conserves 335 accessions of Pennisetum glaucum subsp. monodii originated in 13 countries. In the present study, the collection was evaluated and assessed for diversity and geographical gaps. A wide variation was observed in the collection for total tillers per plant (16 to 609), productive tillers per plant (12 to 368), leaf length (21.3 to 58.8 cm) and leaf width (8.1 to 33.1 mm), indicating high fodder yield potential of the collection. The accessions of cluster 3 flowered late, grew tall with thick stems and long and broad leaves, and differed significantly from those of cluster 1 and cluster 2. The accessions of cluster 2 were found to be promising for tillering. The highly significant positive correlation (r= 0.944) between total and productive tillers per plant suggests that the selection for total tillers will result in selection for productive tillers. A total of 354 districts located in 86 provinces of eight countries in the primary centre of origin for pearl millet were identified as geographical gaps. The probability map generated using FloraMap in the present study matched quite closely to the origin of pearl millet, supporting the prediction of P.glaucum subsp. monodii occurrence in the primary centre of diversity for pearl millet. The high fodder yield potential of P.glaucum subsp. monodii germplasm and low intensity of collection in countries under study suggest the need for launching germplasm collection missions, exclusively for pearl millet wild relatives to fill taxonomic and geographical gaps in the collection.

The genebank at ICRISAT, Patancheru, India conserves a total of 19,063 pearl millet landraces from latitudes ranging from 33.00° in the Southern Hemisphere (SH) to 34.37° in the Northern Hemisphere (NH). In the present study, the NH was found to be the major region for growing pearl millet landraces (80.5%). More landraces were found at lower latitudes ( < 20°) in both hemispheres than at higher latitudes. The latitude range of 10°–15° in the NH and 15°–20° in the SH were found to be important source regions for the prevalence of pearl millet, with 39.6% and 13.1% in the world collection of landraces, respectively. Landraces from lower-latitude regions on either side of the equator varied widely for all traits. Landraces from the 5°–10°N latitude region flowered late and grew tall in the rainy and post-rainy seasons and produced more tillers. Landraces from the 10°–15°N latitude region produced few tillers and had long and thick panicles with larger seeds. Long-bristled bird-resistant landraces were considerable at latitudes of 10°–15°S and 20°–25°S. The minimum temperature at the collection sites was found to be one of the important factors for determining the patterns of the prevalence of pearl millet across the latitudes. Late-maturing, tall and high-tillering landraces from lower-latitude regions were better sources for fodder production. Early-maturing landraces producing long and thick panicles with large seeds from mid-latitude regions (15°–20°) in both hemispheres were useful for developing high-yielding cultivars. Using the latitudinal patterns of diversity in pearl millet landraces, missions may be launched to explore high-diversity, under-collected and threatened areas for the collection of materials of interest at latitudes of 15°–20°.

The International Crops Research Institute for the semi-Arid Tropics Genebank at Patancheru, India holds the world's largest collection of 22,211 pearl millet germplasm accessions from 50 countries including 4488 landraces from 16 East and Southern African (ESA) countries. Gap analysis using FloraMap software and 3750 georeferenced pearl millet germplasm accessions from ESA countries revealed 34 districts located in 18 provinces of four East African countries and 76 districts located in 34 provinces of seven Southern African countries as geographical gaps. Analysis of characterization data using DIVA-GIS software showed 11 districts of seven provinces in Sudan and Uganda and 58 districts of 20 provinces of seven countries in Southern Africa as gaps in diversity for important morphoagronomic traits. The following districts were identified as gaps common to geographic area and diversity for some or the other traits: Amuria district in Soroti province of Uganda; Mpwapwa in Dodoma province of Tanzania; Mahalapye in Centre province and Kgatleng in Kgatleng province of Botswana; Lalomo in Southern province of Zambia; and Motoko, Mudzi and Wedza in the province of Mashonaland East; Makoni in Manikaland; Gutu and Chivi in Masvingo; Gwanda and Bulalimamangwe in Metabeland south; Hwange and Nkayi in Metabeland north; and Kwe Kwe in Midlands of Zimbabwe. For a successful germplasm collection mission to fill the gaps identified, planning should be made in advance of collaboration and consultation with National Agricultural Systems, local government officials and extension officers. It is suggested to collect the complete passport data including georeference information while collecting the germplasm.

Foxtail millet (Setaria italica (L.) P. Beauv.) is an ideal crop for changing climate and food habits of peoples due to its short duration, high photosynthetic efficiency, nutritional richness and fair resistance to pest and diseases. However, foxtail millet yields are low mainly due to the lack of effort for its improvement and the lack of proper utilization of existing genetic variability. To enhance the use of diverse germplasm in breeding programmes, a core collection in foxtail millet consisting of 155 accessions was established. Core collection accessions were fingerprinted using 84 markers (81 simple sequence repeats (SSRs) and three Expressed Sequence Tag (EST)-SSRs). Our results showed the presence of greater molecular diversity in the foxtail millet core collection. The 84 markers detected a total of 1356 alleles with an average of 16.14 alleles (4–35) per locus. Of these, 368 were rare alleles, 906 common alleles and 82 the most frequent alleles. Sixty-one unique alleles that were specific to a particular accession and useful for germplasm identification were also detected. In this study, the genetic diversity of foxtail millet was fairly correlated well with racial classification, and the race Indica showed a greater genetic distance from the races Maxima and Moharia. The pairwise estimate of dissimilarity was >0.50 except in 123 out of 11,935 pairs which indicated a greater genetic variability. Two hundred and fifty pairs of genetically most diverse accessions were identified. This large molecular variation observed in the core collection could be utilized effectively by breeders or researchers for the selection of diverse parents for breeding cultivars and the development of mapping populations.

Eighty-six chickpea (Cicer arietinum L.) genotypes, including 44 Kabuli type and 42 Desi type, were evaluated for their phenological, physicochemical and cooking quality traits. There were significant differences among the genotypes for days to 50% flowering (34–81 d), days to maturity (85–122 d), number of pods per plant (13–66), number of seeds per plant (15–85), 100-seed weight (10.5–58.6 g), seed yield (561–1852 kg/ha), hydration capacity (0.11–0.68 g water/seed), hydration index (0.80–1.21), swelling capacity (0.11–0.7 ml/seed), seed volume (0.1–0.52 ml/seed) and cooking time (38–125 min). The Desi and Kabuli types of chickpea differed significantly from each other for all the traits except for hydration index, swelling index and cooking time. High heritability coupled with high genetic advance was recorded for 100-seed weight, hydration capacity, swelling capacity and seed volume in both Desi and Kabuli genotypes. Seed size (100-seed weight and seed volume) showed significant positive correlations with hydration capacity and swelling capacity. Cooking time did not show any significant positive or negative correlation with any of the traits studied, including seed size, indicating that other additional factors may be involved in controlling cooking time. The results of this study indicate that it is possible to develop cultivars with faster cooking time in both Kabuli and Desi types and in all seed size categories.

Chickpea (Cicer arietinum L.) is an important pulse crop grown and consumed all over the world, especially in the Afro-Asian countries. It is a good source of carbohydrates and protein, and protein quality is considered to be better than other pulses. Chickpea has significant amounts of all the essential amino acids except sulphur-containing amino acids, which can be complemented by adding cereals to the daily diet. Starch is the major storage carbohydrate followed by dietary fibre, oligosaccharides and simple sugars such as glucose and sucrose. Although lipids are present in low amounts, chickpea is rich in nutritionally important unsaturated fatty acids such as linoleic and oleic acids. β-Sitosterol, campesterol and stigmasterol are important sterols present in chickpea oil. Ca, Mg, P and, especially, K are also present in chickpea seeds. Chickpea is a good source of important vitamins such as riboflavin, niacin, thiamin, folate and the vitamin A precursor β-carotene. As with other pulses, chickpea seeds also contain anti-nutritional factors which can be reduced or eliminated by different cooking techniques. Chickpea has several potential health benefits, and, in combination with other pulses and cereals, it could have beneficial effects on some of the important human diseases such as CVD, type 2 diabetes, digestive diseases and some cancers. Overall, chickpea is an important pulse crop with a diverse array of potential nutritional and health benefits.

The ICRISAT genebank, Patancheru, India holds 22,211 pearl millet germplasm accessions from 50 countries, including 19,063 landraces. Among these, 15,904 landraces that were geo-referenced are either thermo-sensitive (52.5%), or photoperiod-sensitive (45.6%), or insensitive to both temperature and photoperiod (2%). Latitude ranges of 10–15°N with 39.6% and 15–20°S with 13.1% of total accessions are the important regions for pearl millet germplasm. A study on climate data of the germplasm collection sites revealed that most accessions from latitudes ranging from 10 to 20° on both sides of the equator were highly sensitive to longer photoperiod (>12.5 h) and/or lower temperature ( < 12°C). Accessions that originated in locations at higher latitudes (>20–35°) on both the hemispheres exhibited low sensitivity to both photoperiod and low temperature, as they were exposed to such climates during their evolution. The accessions that are insensitive to both photoperiod and temperature were few but they originated from locations spread across all latitudes, although the highest numbers were from mid-latitudes (15–20°) in both hemispheres. As germplasm accessions are sensitive to climatic variables such as temperature and photoperiod, recording of location-specific geo-reference data while collecting the germplasm, which can help to elucidate the sensitivity of accessions to temperature and photoperiod, is emphasized. Critical evaluation of photoperiod-sensitive accessions that are late flowering for forage production and the photoperiod-insensitive early-maturing accessions for grain production, multiple cropping and development of parental lines with synchronized flowering for the development of hybrids is suggested.

Crop wild relatives are important components of agro-ecosystems as potential gene contributors for crop improvement programmes. Cajanus scarabaeoides (L.) Thou., a pigeonpea wild relative is crossable with cultivated pigeonpea and possesses several beneficial traits. Hundred accessions conserved at the ICRISAT genebank were characterized for 13 quantitative and ten qualitative traits to assess the diversity in the collection. Highly significant genotypic variance for leaflet length, days to 5% maturity, seeds per pod, 100-seed weight, seed protein content and trichome density and length was observed. All C. scarabaeoides accessions used in the present study are the best sources for extra early ( < 80 d to 50% flowering) and early maturity (80–100 d to 50% flowering). Eight accessions (ICP 15692, ICP 15696, ICP 15698, ICP 15699, ICP 15712, ICP 15719, ICP 15732 and ICP 15758) and the control ICP 15695 have produced more than 92% healthy pods per plant and higher number of seed per pod (4–6 seeds). Accessions in cluster 2, 3 and 4 with low mean values for days to 50% flowering were found as the best sources for early flowering and maturity. Accessions in cluster 2 and 3 for seeds per pod and cluster 2 for healthy pods per plant were found as promising sources for use in crop improvement. Mean diversity over all clusters was highest (H= 0.57 ± 0.01) for seeds per pod and lowest for days to 50% flowering (0.48 ± 0.02). Significant negative correlation between pods per raceme and healthy pods per plant ( − 0.213) indicated high pod damage in racemes having more pods. Trichome length had highly significant negative association with healthy pods per plant ( − 0.293). The probability map generated using FloraMap, a GIS tool, revealed the occurrence of C. scarabaeoides quite close to the origin and dispersal of pigeonpea. The probability (>75%) map identified a total of 118 provinces covering 790 districts in Bangladesh, Cambodia, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Papua New Guinea, Philippines, Thailand and Vietnam as geographical gaps in the collection. Complete passport data including location coordinates should be collected while collecting the germplasm to analyze the spatial aspects of species distribution.

Pigeonpea (Cajanus cajan (L.) Millsp. is one of the most important legume crops as major source for proteins, minerals and vitamins, in addition to its multiple uses as food, feed, fuel, soil enricher, or soil binder, and in fencing, roofing and basket making. ICRISAT's genebank conserves 13,632 accessions of pigeonpea. The extensive use of few parents in crop improvement is contrary to the purpose of collecting a large number of germplasm accessions and has resulted in a narrow base of cultivars. ICRISAT, in collaboration with the Generation Challenge Program, has developed a composite collection of pigeonpea consisting of 1000 accessions representing the diversity of the entire germplasm collection. This included 146 accessions of mini core collection and other materials. Genotyping of the composite collection using 20 microsatellite or simple sequence repeat (SSR) markers separated wild and cultivated types in two broad groups. A reference set comprising 300 most diverse accessions has been selected based on SSR genotyping data. Phenotyping of the composite collection for 16 quantitative and 16 qualitative traits resulted in the identification of promising diverse accessions for the four important agronomic traits: early flowering (96 accessions), high number of pods (28), high 100-seed weight (88) and high seed yield/plant (49). These accessions hold potential for their utilization in pigeonpea breeding programmes to develop improved cultivars with a broad genetic base. Pigeonpea germplasm has provided sources of resistance to abiotic and biotic stresses and cytoplasmic-male sterility for utilization in breeding programmes.

Chickpea is the third most important pulse crop worldwide. Changes in cropping system that necessitate late planting, scope for expansion in rice fallows and the global warming are pushing chickpeas to relatively warmer growing environment. Such changes demand identification of varieties resilient to warmer temperature. Therefore, the reference collection of chickpea germplasm, defined based on molecular characterization of global composite collection, was screened for high temperature tolerance at two locations in India (Patancheru and Kanpur) by delayed sowing and synchronizing the reproductive phase of the crop with the occurrence of higher temperatures ( ≥ 35°C). A heat tolerance index (HTI) was calculated using a multiple regression approach where grain yield under heat stress is considered as a function of yield potential and time to 50% flowering. There were large and significant variations for HTI, phenology, yield and yield components at both the locations. There were highly significant genotypic effects and equally significant G × E interactions for all the traits studied. A cluster analysis of the HTI of the two locations yielded five cluster groups as stable tolerant (n = 18), tolerant only at Patancheru (n = 34), tolerant only at Kanpur (n = 23), moderately tolerant (n = 120) and stable sensitive (n = 82). The pod number per plant and the harvest index explained ≥ 60% of the variation in seed yield and ≥ 49% of HTI at Kanpur and ≥ 80% of the seed yield and ≥ 35% of HTI at Patancheru, indicating that partitioning as a consequence of poor pod set is the most affected trait under heat stress. A large number of heat-tolerant genotypes also happened to be drought tolerant.

The International Crops Research Institute for the Semi-Arid Tropics (1CRISAT) genebank in India holds the world's largest collection of 21,594 pearl millet germplasm accessions from 50 countries including 6529 landraces from ten Asian countries. Gap analysis using passport and characterization data and geographical information system tools revealed 134 distinct districts of 14 provinces in India and 12 districts of Punjab province in Pakistan as the major geographical gaps. Different methods of identifying geographical gaps used in the study indicated Chittoor, Karimnagar, Nizamabad, Prakasam and Warangal in Andhra Pradesh; Raigarh in Chattisgarh; Dewas and Rewa in Madhya Pradesh; Buldana and Hingoli in Maharashtra; Malkangiri, Nabarangapur, Naupada and Sundergarh in Orissa; Bhilwara, Chittaurgarh and Kota in Rajasthan; Thiruvallur and Vellore in Tamil Nadu; and Auraiya, Chandauli, Chitrakoot, Gonda, Gorakhpur, Hamirpur, Kushinagar, Mau, Shrawasti and Sonbhadra in Uttar Pradesh as common geographical gaps in India. A total of 208 distinct districts in 12 provinces were identified as gaps in diversity for one or more traits. Among all districts, Beed, Latur and Osmanabad in Maharashtra, India, for all traits; Rajanpur, Muzaffargarh, Multan and Lodhran for panicle length and Chakwal and Sargodha for panicle width in Pakistan; and southern parts of North Yemen and Lahiz provinces in Yemen were identified as gaps in the diversity. In India, Warangal in Andhra Pradesh; Rewa in Madhya Pradesh; Hingoli in Maharashtra; Vellore in Tamil Nadu; and Auraiya, Chandauli, Chitrakut, Gorakhpur and Mau in Uttar Pradesh were identified as gaps in diversity for one or more traits and found common to geographical gaps identified. In Pakistan, Lodhran, Multan and Muzaffargarh were identified as gaps common to probability and diversity methods. Area for exploration should be decided prior to launch of the collection mission in consultation with local government officials and extension officers, who are known to have knowledge in pearl millet cultivation in the identified districts. It is suggested to collect the complete passport data including georeference information while collecting the germplasm.

Pigeonpea (Cajanus cajan (L.) Millsp.) seed harvested while it is immature is a nutritious vegetable and forms a substitute for green pea [Pisum sativum (L.)]. Using the characterization data of more than 12,000 accessions conserved at ICRISAT genebank, Patancheru, India, 105 accessions were selected for important traits of vegetable pigeonpea (mature pod length>6 cm, seeds per pod>5 and 100-seed weight>15 g) and evaluated for these traits during 2007–08. From the initial evaluation, 51 accessions were identified as vegetable type and further evaluated for traits of vegetable pigeonpea during 2008–09 to identify most promising accessions. ICP 13831 produced longest immature pods (10.3 cm), ICP 13828 had maximum number of seeds per pod (5.9) and ICP 12746 produced larger seeds (44.8 g/100 seeds). Highest percentage of total soluble sugars (9.7%) was recorded in immature seeds of ICP 13413. ICP 15143 followed by ICP 15186 recorded more dry pods per plant and seed yield per plant. Performance of ICP 12184, ICP 13413, ICP 14085 and ICP 15169 was better than that of the best control for pod length, seeds per pod, soluble sugars and protein content. Cluster analysis based on scores of first five principal components resulted in three clusters that differed significantly for days to 50% flowering, days to 75% maturity, shelling percentage and soluble sugars. Important traits of vegetable pigeonpea such as immature pod length, seeds per pod, seed soluble sugars and protein content had shown strong positive correlation. Caribbean and Eastern Africa were found as the best source regions for vegetable pigeonpea. Evaluation of selected accessions at potential locations in different countries was suggested to identify vegetable pigeonpeas suitable for different regions and for use in crop improvement programs.

The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) genebank in India holds the world's largest collection of 21,594 pearl millet germplasm accessions including 18,447 landraces from 50 countries. West and Central Africa (WCA) region, which is considered as the centre of diversity for pearl millet, is also an important pearl millet germplasm source for resistance to biotic and abiotic stresses. A total of 7372 landraces were assembled from WCA countries. Out of which, 6434 landraces have the georeference data. The geographic origins of these landraces were analyzed using geographic information system tools to identify gaps in the collection. Geographical distribution of existing collections, type of vegetation, land cover and the high probability (>70%) for the occurrence of pearl millet estimated using the FloraMap software in different countries show that 62 districts in 13 provinces of Nigeria, 50 districts in 16 provinces of Burkina Faso, 9 districts in 6 provinces each of Mali and Mauritania, 8 districts in 8 provinces of Chad and 7 districts in 3 provinces of Ghana as the major geographical gaps in the pearl millet collection at the ICRISAT genebank. In view of this, we suggest that the final areas for exploration in these districts should be decided prior to the launch of the collection missions in consultation with local government officials and extension officers, who have the knowledge of pearl millet cultivation in the districts identified.

Foxtail millet (Setaria italica (L.) Beauv.) is one of the ten small millets and is cultivated in 23 countries. The foxtail millet is valued as a crop of short duration, which is good as food, feed and fodder. In general, grain yield levels of foxtail millet are low in comparison with other staple cereals. The greater use of diverse germplasm in breeding is suggested as a means to improve the productivity of this crop. The International Crops Research Institute for the Semi-Arid Tropics genebank is presently holding 1474 cultivated germplasm accessions from 23 countries. To utilize this diversity in research, a core collection (10% of the entire collection) was established using the taxonomic and qualitative traits data. The germplasm accessions were stratified into three taxonomic races (Indica, Maxima and Moharia). Principal coordinate analysis was performed on 12 qualitative traits for each of the biological races, separately that resulted in the formation of 29 clusters. From each cluster, 10% of the accessions were selected to constitute a core collection of 155 accessions. The composition and diversity of the core collection was validated by the χ2-tests of the frequencies of origin, races, subraces and data on qualitative traits. The analysis of the quantitative traits for mean, range, variance, Shannon–Weaver diversity index and phenotypic associations indicated that the diversity from the entire collection was optimally represented in the core collection. The core subset will be evaluated in replicated trials to make a more precise assessment of diversity and further efforts to identify the sources of agronomic and grain nutritional traits for utilization in breeding programmes.

Grainage parameters, viz. pupal weight, rate of moth emergence, fecundity and hatching were studied among four bivoltine pure races and their five single and four double cross hybrids of silkworm Bombyx mori L. The significant increase in double cross hybrids over pure races was 11.72, 7.43, 19.45 and 12.26% for pupal weight, rate of moth emergence, fecundity and hatching, respectively. The fecundity in double cross hybrids improved significantly over single cross hybrids to the extent of 16.03% whereas pupal weight, rate of moth emergence and hatching increased to the extent of 4.38, 5.90 and 5.76%, respectively.

The extent of standard heterosis and heterobeltiosis was maximum in double cross hybrids and the heterosis was more pronounced for fecundity.