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The Central groundnut ALG 06 320 is the cross derivative of (J 11 x CG 52) x ICGV 86015. This variety yielded 2741 kg/ha) and has given higher pod yield over the national check varieties; 33.06 % increase over TAG 24 (2060kg/ha); 29.05 % over R 8808 (2124 kg/ha); 2.16% over RHRG 06021 (2683 kg/ha); 7.15 % over ICGV 00351 (2558 kg/ha) during rabi season from 2008 to 2011 year. The variety ALG 06 320 is early in maturity (115 days) compared to R 8808 (116 days) and; RHRG (117 days). Shelling out turn (70.7%) is comparable with TAG 24(67.7), ICGV 00350 (66%), CTMG 6 (67%), RHRG 06021 (66%); R 8808 (67.7%). Sound mature Kernels are more in ALG 06 320 (90%) compared to TAG 24 (85.3%), R 8808 (84.3%), ICGV 00350 (86%); RHRG (82.7%) Oil content is also high (50.3%) in TAG 24 (49.3%) and R 8808 (49.7%). For the variety ALG 06 320 has shown lesser incidence of Peanut bud necrosis disease, Late leaf spot and rust diseases, compared to zonal check varieties. ALG 06 320 has shown tolerance against Spodoptera litura, leaf miner, leaf hopper and thrips. Thus, the groundnut culture ALG 06 320 was identified for release during 2013 by AICRP (G) and notified as Central groundnut ALG 06 320 during 2017 by CVRC.

Legumes are an integral part of the ecosystem that contributes to sustainable agricultural development across the globe and ensures nutritional security, particularly among the poor segment of the society. Among several legumes cultivated in the world, common bean, chickpea, cowpea, groundnut, lentil, pigeonpea, and soybean are the major seven legumes highly preferred across the globe. The combined production of these major legumes has followed an increasing trend with the global production increase by 548.6% between triennium ending 1961–1963 and 2014–2016 owing to a combined effect of area expansion by 152.6% (128.37 m ha) and productivity enhancement by 85.9% during the same period. The global annual growth rates (AGRs) of total area, production, and yield of these major legumes during the 1961–2016 period are 1.7%, 3.5%, and 1.2%, respectively. The highest AGR for production was observed in the case of soybean (4.5%) followed by cowpea (4.1%), lentil (3.5%), groundnut (2.2%), pigeonpea (1.8%), common bean (1.5%), and chickpea (1.1%), while the highest AGR for productivity was observed in the case of groundnut (1.5%) followed by soybean (1.4%), cowpea (1.4%), lentil (1.4%), common bean (1.1%), chickpea (0.9%), and pigeonpea (0.4%). The global future demand and supply projections of these legumes clearly highlight the importance of developing countries in legume production. The country-wise demand and supply gaps and the changes in pattern of their utilization over time will drive the future research focus on legumes in those countries.

A deep understanding of the genetic control of drought tolerance and iron deficiency tolerance is essential to hasten the process of developing improved varieties with higher tolerance through genomics-assisted breeding. In this context, an improved genetic map with 1205 loci was developed spanning 2598.3&thinsp, cM with an average 2.2&thinsp, cM distance between loci in the recombinant inbred line (TAG 24 &times, ICGV 86031) population using high-density 58K single nucleotide polymorphism (SNP) &ldquo, Axiom_Arachis&rdquo, array. Quantitative trait locus (QTL) analysis was performed using extensive phenotyping data generated for 20 drought tolerance- and two iron deficiency tolerance-related traits from eight seasons (2004&ndash, 2015) at two locations in India, one in Niger, and one in Senegal. The genome-wide QTL discovery analysis identified 19 major main-effect QTLs with 10.0&ndash, 33.9% phenotypic variation explained (PVE) for drought tolerance- and iron deficiency tolerance- related traits. Major main-effect QTLs were detected for haulm weight (20.1% PVE), SCMR (soil plant analytical development (SPAD) chlorophyll meter reading, 22.4% PVE), and visual chlorosis rate (33.9% PVE). Several important candidate genes encoding glycosyl hydrolases, malate dehydrogenases, microtubule-associated proteins, and transcription factors such as MADS-box, basic helix-loop-helix (bHLH), NAM, ATAF, and CUC (NAC), and myeloblastosis (MYB) were identified underlying these QTL regions. The putative function of these genes indicated their possible involvement in plant growth, development of seed and pod, and photosynthesis under drought or iron deficiency conditions in groundnut. These genomic regions and candidate genes, after validation, may be useful to develop molecular markers for deploying genomics-assisted breeding for enhancing groundnut yield under drought stress and iron-deficient soil conditions.

SUMMARYBiofortification (delivery of micronutrients via micronutrient-dense crops) can be achieved through plant breeding and offers a cost-effective and sustainable approach to fighting micronutrient malnutrition. The present study was conducted to facilitate the initiation of a breeding programme to improve the concentration of iron (Fe) and zinc (Zn) in peanut (Arachis hypogaea L.) seeds. The experiment was conducted with 64 diverse peanut genotypes for 2 years in eight different environments at the International Crops Research Institute for the Semi-Arid Tropics, Patancheru, India to assess the genetic variation for Fe and Zn concentrations in peanut seeds and their heritability and correlations with other traits. Significant differences were observed among the genotypes and environments for Fe (33–68 mg/kg), Zn (44–95 mg/kg), protein (150–310 mg/g) and oil (410–610 mg/g) concentration in seeds and their heritability was high, thus indicating the possibility of improving them through breeding. As seen in other plants, a significant positive association between concentrations of Fe and Zn was observed. Trade-offs between pod yield and Fe and Zn concentrations were not observed and the same was also true for oil content. Besides being high yielding, genotypes ICGV 06099 (57 mg/kg Fe and 81 mg/kg Zn) and ICGV 06040 (56 mg/kg Fe and 80 mg/kg Zn) had stable performance for Fe and Zn concentrations across environments. These are the ideal choices for use as parents in a breeding programme and in developing mapping populations.

Late leaf spot (LLS), caused by Phaeoisariopsis personata, is an important foliar fungal disease of groundnut (Arachis hypogaea L.), which causes significant economic losses globally to the crop. Inheritance of resistance to LLS disease was studied in three crosses and their reciprocals involving two resistant interspecific derivatives and a susceptible cultivar to refine strategy for LLS resistance breeding. The traits associated with LLS resistance, measured both in the field and under controlled conditions were studied following generation mean analysis. Results suggested that resistance to LLS is controlled by a combination of both, nuclear and maternal gene effects. Among nuclear gene effects, additive effect controlled majority of the variation. In JL 24 × ICG 11337 cross and its reciprocal only additive effects were important, while in JL 24 × ICG 13919 cross and its reciprocal, both additive and dominance effects contributed to the variation. Among digenic epistatic effects, additive × dominance interactions were significant. Additive–maternal effects were significant in both the crosses, while dominance–maternal effects also contributed to the variation in the crosses between the parents, JL 24 and ICG 13919. Due to significant contribution of additive effects of both nuclear and maternal inheritance to resistance to LLS, the parent, ICG 11337 would be a good donor in breeding programs. It would be worthwhile to use the resistance donor as female parent to tap maternal effects of resistance to LLS. Disease score is the best selection criterion in the field for use in breeding programs because of its high heritability and ease in measurement.

Molecular markers are the most powerful genomic tools to increase the efficiency and precision of breeding practices for crop improvement. Progress in the development of genomic resources in the leading legume crops of the semi-arid tropics (SAT), namely, chickpea (Cicer arietinum), pigeonpea (Cajanus cajan) and groundnut (Arachis hypogaea), as compared to other crop species like cereals, has been very slow. With the advances in next-generation sequencing (NGS) and high-throughput (HTP) genotyping methods, there is a shift in development of genomic resources including molecular markers in these crops. For instance, 2,000 to 3,000 novel simple sequence repeats (SSR) markers have been developed each for chickpea, pigeonpea and groundnut. Based on Sanger, 454/FLX and Illumina transcript reads, transcriptome assemblies have been developed for chickpea (44,845 transcript assembly contigs, or TACs) and pigeonpea (21,434 TACs). Illumina sequencing of some parental genotypes of mapping populations has resulted in the development of 120 million reads for chickpea and 128.9 million reads for pigeonpea. Alignment of these Illumina reads with respective transcriptome assemblies have provided more than 10,000 SNPs each in chickpea and pigeonpea. A variety of SNP genotyping platforms including GoldenGate, VeraCode and Competitive Allele Specific PCR (KASPar) assays have been developed in chickpea and pigeonpea. By using above resources, the first-generation or comprehensive genetic maps have been developed in the three legume speciesmentioned above. Analysis of phenotyping data together with genotyping data has provided candidate markers for drought-tolerance-related root traits in chickpea, resistance to foliar diseases in groundnut and sterility mosaic disease (SMD) and fertility restoration in pigeonpea. Together with these traitassociated markers along with those already available, molecular breeding programmes have been initiated for enhancing drought tolerance, resistance to fusarium wilt and ascochyta blight in chickpea and resistance to foliar diseases in groundnut. These trait-associated robust markers along with other genomic resources including genetic maps and genomic resources will certainly accelerate crop improvement programmes in the SAT legumes.

Late leaf spot (LLS) caused by Phaeoisariopsis personata is the major foliar disease that reduces the pod yield and severely affects the fodder and seed quality in groundnut. Molecular markers linked with LLS can improve the process of identification of resistant genotypes. In the present study, a LLS susceptible genotype (TMV 2) and the LLS resistant genotype (COG 0437) were crossed and their F2 population was used for marker analysis. The phenotypic mean data on F2:3 progenies were used as phenotype. Parents were surveyed with 77 SSR (Simple Sequence Repeat) primers to identify polymorphic markers. Among SSR markers, nine primers were found polymorphic between the parents TMV 2 and COG 0437. These markers were utilized for bulked segregant analysis (BSA). Among the polymorphic SSR markers, three primers viz., PM 375162, pPGPseq5D5220 and PM 384100 were able to distinguish the resistant and susceptible bulks and individuals for LLS. In single marker analysis, the markers PM 375, PM 384, pPGPseq5D5, PM 137, PM 3, PMc 588 and Ah 4-26 were linked with LLS severity score. The phenotypic variation explained by these markers ranged from 32 to 59 %. The markers identified through BSA were also confirmed with single marker analysis. While validating the three primers over a set of resistant and susceptible genotypes, the primer PM 384100 allele had association with resistance. Hence PM 384 could be utilized in the marker assisted breeding programme over a wide range of genetic background.

Intermittent drought is the most important yield limiting factor affecting groundnut (Arachis hypogaea L.) production in rain-fed regions of Sub-Saharan Africa and Asia. Improvement of crop adaptation to drought is needed and this starts by having a thorough assessment of a large and representative set of germplasm. In this study, 247 lines belonging to the reference collection of groundnut were assessed under well-watered (WW) and intermittent water stress (WS) conditions in India and Niger for two years, following similar experimental protocols. The WS treatment reduced pod yield (31–46%), haulm yield (8–55%) and the harvest index (1–10%). Besides a strong treatment effect, yield differences within locations and years, were attributed to both genotypic and genotype-by-treatment interactions. Pod yield under WW and WS conditions were closely related in both years (Patancheru, r2 = 0.42 and r2 = 0.50; Sadore, r2 = 0.22 and r2 = 0.23). By contrast, within location and treatment, pod and haulm yields were affected predominantly by genotype-by-year (G × Y) effects, especially under WS. Within treatment across locations and years, pod and haulm yields were mostly ruled by genotypic effects, which allowed identifying a group of entries with contrasting pod yield across locations under WS. However, genotype and genotype by environment (GGE) biplot analyses distinguished India from Niger, suggesting that the selection remains environment-specific and also revealed dissimilarity between years in Niger. A close relationship was observed between yield and pod growth rate (r2 = 0.51), and partition (r2 = 0.33) under WS conditions, whereas no significant relationship was found between yield under WS and SCMR, or specific leaf area (SLA). These results showing a close interaction between the environmental conditions and the genotypic response to intermittent drought shows the necessity to carefully choose environments that truly represent target environments. This is an important result in the current breeding context of marker-assisted recurrent selection or genome-wide selection. This work opens also new ways for the breeding of drought tolerant groundnut, by bringing new highly contrasting lines currently used for crossing and deciphering drought adaptation traits to better understand G × E interactions, while it challenges the relevance of long-time used surrogates such as SCMR or SLA.

Enabled by land reforms and fuelled by technological change, agricultural production in Vietnam grew tremendously after the mid-1980s. Focusing on groundnut, an export-oriented cash and food crop, this paper provides estimates of potential benefits from the adoption of improved varieties in northern Vietnam. At farm level, switching over to improved varieties generates additional revenue of VND1.8 to 3.9 million per hectare (US$1 is equivalent to about VND15,969). The aggregate benefits for northern Vietnam are huge. With the groundnut area remaining unchanged, the annual value of benefits from the adoption of improved varieties in 80% of the area by 2020 will be VND571,691 million (US$35.8 million) at a real discount rate of 5%. These benefits will be 14% larger if the groundnut area continues to expand at the rate achieved in the recent past.

Groundnut (Arachis hypogaea L.) is an important food and cash crop grown mainly in semi-arid tropics (SAT) regions of the world where drought is the major constraint on productivity. With the aim of understanding the genetic basis and identification of quantitative trait loci (QTL) for drought tolerance, two new recombinant inbred line (RIL) mapping populations, namely ICGS 76 × CSMG 84-1 (RIL-2) and ICGS 44 × ICGS 76 (RIL-3), were used. After screening of 3,215 simple sequence repeat (SSR) markers on the parental genotypes of these populations, two new genetic maps were developed with 119 (RIL-2) and 82 (RIL-3) SSR loci. Together with these maps and the reference map with 191 SSR loci based on TAG 24 × ICGV 86031 (RIL-1), a consensus map was constructed with 293 SSR loci distributed over 20 linkage groups, spanning 2,840.8 cM. As all these three populations segregate for drought-tolerance-related traits, a comprehensive QTL analysis identified 153 main effect QTL (M-QTL) and 25 epistatic QTL (E-QTL) for drought-tolerance-related traits. Localization of these QTL on the consensus map provided 16 genomic regions that contained 125 QTL. A few key genomic regions were selected on the basis of the QTL identified in each region, and their expected role in drought adaptation is also discussed. Given that no major QTL for drought adaptation were identified, novel breeding approaches such as marker-assisted recurrent selection (MARS) and genomic selection (GS) approaches are likely to be the preferred approaches for introgression of a larger number of QTL in order to breed drought-tolerant groundnut genotypes. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11032-011-9660-0) contains supplementary material, which is available to authorized users.

Inheritance of groundnut (Arachis hypogaea L.) seed traits particularly seed weight, seed length, seed width and length:width ratio was explored in this study. Six-generation mean analysis was carried with two groundnut crosses and their reciprocals in 2 years. Groundnut genotypes significantly differing in seed sizes were used as parents. Highly significant reciprocal differences were observed for almost all the traits in F1, F2, and BC generations. Additive genetic effects were highly significant and explained majority of the variation in these traits. Results suggest that the seed size traits studied in this study were controlled both by combination of both maternal and nuclear gene effects. All the four seed traits measured were highly correlated suggesting that they could be simultaneously improved. Significance of additive effect in all the four crosses suggests that effective selection for seed size traits could be practiced in early generations. In breeding program for confectionary traits it is essential to include a large-seeded genotype as the female parent to exploit the maternal effects.

The ability to identify genetic variation is indispensable for effective management and use of genetic resources in crop breeding. Genetic variation among 189 groundnut (Arachis hypogaea L.) accessions comprising landraces, cultivars, a mutant, advanced breeding lines and others (unknown genetic background) representing 29 countries and 10 geographical regions was assessed at 25 microsatellite or simple sequence repeat loci. A high number of alleles (265) were detected in the range of 3 (Ah1TC6G09) to 20 (Ah1TC11H06) with an average of 10.6 alleles per locus. The polymorphism information content value at these loci varied from 0.38 (Ah1TC6G09) to 0.88 (Ah1TC11H06) with an average of 0.70. A total of 59 unique alleles and 127 rare alleles were detected at almost all the loci assayed. Cluster analysis grouped 189 accessions into four clusters. In general, genotypes of South America and South Asia showed high level of diversity. Extraordinary level of natural genetic variation reported here provides opportunities to the groundnut community to make better decisions and define suitable strategies for harnessing the genetic variation in groundnut breeding.

Peanut plays an important role in the livelihoods of poor farmers and in the rural economy of many developing countries. Aflatoxin contamination in peanut seeds, caused by Aspergillus flavus, hampers international trade and adversely affects health of consumers of peanut and its products. It can occur in the field when the crop is growing, during harvesting and curing, and in storage and transportation. Aflatoxin research on peanut at ICRISAT focuses on identification and utilization of genetic resistance to preharvest seed infection and aflatoxin production by A. flavus and pre and post harvest management practices to minimize contamination. Breeding for aflatoxin resistance has been a contentious issue in peanut for nearly four decades since the first report of host resistance to aflatoxin production by A. flavus. Despite global efforts, progress in aflatoxin resistance breeding has been limited due to the low level of resistance to different components of resistance (preharvest seed infection and aflatoxin production, and in vitro seed colonization by A. flavus), their variable performance due to high G × E interaction, lack of reliable screening protocols, and limited understanding of genetics of resistance. Efforts to combine the three independently inherited components of resistance did not produce expected results towards improving the host plant resistance to aflatoxin contamination. Although breeding lines have shown better performance for resistance to aflatoxin contamination at ICRISAT, they need wider evaluation under diverse growing conditions. The search for better sources of resistance in the cultivated and wild Arachis germplasm continues, and recent developments in the area of transgenic research through modification of aflatoxin biosynthesis pathway or use of genes with antifungal and anti-aflatoxin properties appear encouraging. Meanwhile, the available improved breeding lines coupled with pre and post harvest aflatoxin management practices can help to significantly reduce aflatoxin contamination in farmers' fields. It is expected that transgenic resistance against fungal infection and aflatoxin production in combination with conventional breeding efforts may lead to the development of agronomically superior peanuts that are free of aflatoxin contamination.

Groundnut (Arachis hypogaea L.) is an important oilseed and food crop in the world. The crop is predominantly grown in low input production systems in developing countries in Asia and Africa. There are several production constraints, both biotic and abiotic, to groundnut. Some of these are global in nature and the others are either regional or local. Four Arachis gene pools contain 80 species, distributed among nine sections are native to five countries of South America. Section Arachis contains tetraploid cultivated groundnut, divided into two subspecies and six botanical varieties and a number of cross-compatible diploid species with rich genetic diversity. International efforts have made significant progress in collection and conservation of these genetic resources, facilitating genetic improvement. Groundnut is an autogamous crop. The pedigree and bulk selection methods are more commonly used by the groundnut breeders. Conventional breeding, including cytogenetic manipulations introgressing genes from cross-compatible wild diploid species has been effective in some areas, while in others it has been tardy due to lack of proper and effective phenotyping tools and limited understanding of the genomics, genetics/inheritance, and underlying mechanisms influencing targeted traits. A greater diversification of parental resources (both cultivated and wild Arachis species) in breeding programs is required to develop new cultivars with diversified genetic backgrounds, which will enable them to perform better under the changing climatic/adverse conditions. Molecular breeding is in infancy. Infrequent and low polymorphisms have restricted the progress in the development and application of genetic maps, except in cases where polymorphic chromosomal regions have been introgressed from diploid wild Arachis species into A. hypogaea. Both conventional and nonconventional crop improvement efforts in groundnut need to concentrate on bridging the yield gap between the potential yield and the realized yield by alleviating major production constraints particularly in rainfed environment.

Stem necrosis disease caused by Tobacco streak virus (TSV), first recognized in 2000, has emerged as a potential threat to peanut (Arachis hypogaea) in southern states of India. The virus induces severe necrosis of shoots leading to death of the plant, and plants that survive are malformed, with severe reduction in pod yield. All the currently grown peanut cultivars in India are highly susceptible to the virus. Therefore, wild relatives of peanut were evaluated to identify potential sources of resistance to TSV infection. In all, 56 germplasm accessions from 20 wild Arachis spp. in four sections (Arachis, Erectoides, Procumbente, and Rhizomatosae), along with susceptible peanut cultivars (JL 24 and K 1375), were evaluated for resistance to TSV under greenhouse conditions using mechanical sap inoculations. Systemic virus infection, determined by enzyme-linked immunosorbent assay (ELISA), in the test accessions ranged between 0 and 100%. Twenty-four accessions in section Arachis that had 0 to 35% systemically infected plants were retested, and systemic infection was not detected in eight of these accessions in repeated trials in the greenhouse. These are International Crops Research Institute for the Semi-Arid Tropics groundnut (ICG) accession nos. 8139, 8195, 8200, 8203, 8205, and 11550 belonging to A. duranensis; ICG 8144 belonging to A. villosa; and ICG 13210 belonging to A. stenosperma. Even though the resistant accessions had 0 to 100% TSV infection in inoculated leaves, TSV was not detected in the subsequently emerged leaves. This is the first report of TSV resistance in Arachis spp. The eight TSV resistant accessions are cross compatible with A. hypogaea for utilization in breeding for stem necrosis disease resistance.

The complex nature of physiological traits associated with drought tolerance and the difficulties associated with their measurements in segregating populations and large number of genotypes inhibited their use in the past in developing water-use efficient genotypes in breeding programmes. With new knowledge of easily measurable surrogates of transpiration efficiency (TE), a trait associated with drought tolerance—specific leaf area (SLA) and soil plant analytical development (SPAD) chlorophyll meter reading (SCMR), it is now possible to integrate TE through the surrogates in breeding and selection schemes in groundnut (Arachis hypogaea L.). As a noninvasive surrogate of TE, SCMR is easy to operate, reliable, fairly stable and low cost. However, in a large-scale breeding program, it is difficult to complete SCMR observations within a specified time. The present study addressed the issue as to what extent the SCMR measurements can be spread over time by evaluating 18 diverse groundnut genotypes for two physiological traits, SCMR and SLA in two postrainy (Nov–Apr) seasons (2002/2003 and 2003/2004) in India. Observations were recorded at different times during and after the release of moisture deficit stress. There was general agreement in genotype and trait performance in both the seasons. Interaction between SCMR and time of observation was significant in only one season (2002/2003) but its variance relative to genotypes and time of observation was very small. ICGV 99029 and ICR 48, which recorded higher SCMR and lower SLA values in both the seasons, will make good parents for water-use efficiency trait in breeding programmes. Other good parents include ICGS 76, TCGS 647 and TCGP 6. SCMR recorded at three different times under differing soil moisture deficit in each season showed highly significant correlation with each other. Similarly, SLA at different times also correlated significantly with each other. SCMR and SLA were significantly negatively correlated with each other and the relationship was insensitive to time of observation. The results of the present study indicated that SCMR/SLA observations can be recorded at any time after 60 days of crop growth, preferably under moisture deficit conditions. This gives groundnut breeders a large flexibility to record these observations in a large number of segregating populations and breeding lines in the field. Thus, making it easy to incorporate these physiological traits associated with drought tolerance in breeding and selection scheme in groundnut.

Transpiration efficiency (TE) has been recognized as an important source of yield variation under drought stress in groundnut. Here the variation for TE is evaluated in a set of 318 recombinant inbred lines (RILs) of groundnut at F 8 generation, derived from a cross between a high TE (ICGV 86031) and a low TE (TAG 24) parent, and the value of specific leaf area (SLA), SPAD chlorophyll meter readings (SCMR) and carbon isotope discrimination (Δ 13 C) as surrogates of TE are measured. Transpiration efficiency was measured gravimetrically in the 318 RILs and parents under progressive soil drying in a pot culture in two post-rainy seasons. Large and consistent variation for TE existed among the RILs across years. The overall distribution of TE among the RILs indicated that TE was governed by dominant and additive genes. Surrogates SLA and SCMR, were measured prior, during and after completion of the drought period, whereas Δ 13 C was measured on the dried tissue after harvest. Transpiration efficiency was negatively associated with SLA after the completion of stress treatment ( r 2 = 0.15) and Δ 13 C in leaves ( r 2 = 0.13) and positively associated with SCMR during stress ( r 2 = 0.17). These associations, all fairly weak, were significant only in 2004. None of these relationships was found in 2005. Although the heritability of SCMR during 2005 was relatively higher than that of TE, and although SCMR has previously been used to identify contrasting germplasm for TE, the stress-dependence of the relationship with TE, and the poor regression coefficients ( r 2 ) with that RIL population, do not confer that these surrogates are adequately robust enough in that population. Though more time consuming, a direct gravimetric evaluation for TE appeared to be more reliable.

Late leaf spot (LLS) and rust cause substantial yield losses and reduce the fodder and seed quality in groundnut (Arachis hypogaea L.). Adoption of resistant cultivars by the semi-arid tropic farmers is the best option to overcome yield losses. Knowledge on components of resistance to these diseases should facilitate the development of groundnut cultivars with enhanced resistance to LLS and rust. The objectives of the experiments were to study the genetic variability and relationships among components of resistance to LLS and rust, and assess their significance in disease resistance breeding. Fifteen interspecific derivatives for LLS and 14 for rust and a susceptible control, TMV 2, were evaluated in a randomised complete block design with two or three replications under greenhouse conditions. The experiments were repeated twice. Genotypic differences were highly significant for all the traits studied. Resistance to LLS is due to longer incubation and latent periods, lesser lesions per leaf, smaller lesion diameter, lower sporulation index, and lesser leaf area damage and disease score. Selection based on components of resistance to LLS may not lead to plants with higher retained green leaf area. The remaining green leaf area on the plant should, therefore, be the major selection criteria for resistance to LLS in breeding programs. Resistance to rust is due to longer incubation and latent periods, fewer pustules per leaf, smaller pustule diameter, lower sporulation index, and lesser leaf area damage and disease score. Rust resistant components appear to work additively, therefore, selection based on resistance components together with green leaf area retained on the plant should be the basis of selecting for resistance to rust in breeding programs. ICGV 99005, 99003, 99012, and 99015 for rust and ICGV 99006, 99013, 99004, 99003, and 99001 for LLS are the better parents for use in resistance breeding programs.

Groundnut productivity is low in the semiarid tropics mainly because of drought caused by low and erratic rainfall. Genotypes that have ability to use limited available water efficiently are required to enhance productivity of the crop. In groundnut, water use efficiency (WUE) is correlated with specific leaf area (SLA). The latter can be used as a surrogate trait for selecting for WUE. Partitioning of assimilates as measured by the harvest index (HI) has the greatest effect on pod yield. In order to improve SLA and in turn WUE and HI, a good knowledge of genetic systems controlling the expression of these traits is essential for the choice of an efficient breeding procedure. This study was conducted to investigate inheritance of SLA and HI in three crosses involving Chico, TMV 2 NLM, and ICGV 86031 groundnut genotypes. The crosses used were Chico × TMV 2 NLM, Chico × ICGV 86031 and TMV 2 NLM × ICGV 86031. The study included parents, F1, F2, and backcross generations. Generation means analysis indicated that the additive effects were more important than the dominance effects in the expression of SLA and HI. In addition to additive and dominance effects, additive × additive type of epistasis, which can be fixed in groundnut (a self pollinated crop), was also significant for SLA in all the three and for HI, in two crosses (Chico × TMV 2 NLM and Chico × ICGV 86031). The selection for SLA and HI can be effective in early generations in some crosses and to exploit the additive × additive type of interaction, it can be done in large populations of later generations.

Assessment of genetic diversity in a crop species is prerequisite to its improvement. The use of germplasm with distinct DNA profiles will help to generate genetically diversified breeding populations. The aims of the present experiment were to study molecular diversity among selected groundnut accessions and identify those with distinct DNA profiles for mapping and genetic enhancement. Twenty-six accessions and eight primers of a 10-mer were selected for random amplified polymorphic DNA assay. The genetic similarity (Sij) ranged from 59.0% to 98.8%, with an average of 86.2%. Both multidimensional scaling and unweighted pair-group method with arithmetic averages (UPGMA) dendrograms revealed the existence of five distinct clusters. However, this classification could not be related to known biological information about the accessions falling into different clusters. Some accessions with diverse DNA profiles (ICG 1448, 7101, and 1471, and ICGV 99006 and 99014) were identified for mapping and genetic enhancement in groundnut

Peanut (Arachis hypogaea L.) is a rich source of oil, protein, minerals, and vitamins. The chemical and physical seed quality aspects are gaining importance because of increased use of peanut as a food crop; however, little or no investigation has been carried out on the effect of photoperiod on these traits. The objective of this study was to determine the effect of photoperiod on seed quality traits. The experiment was conducted for three seasons in a three replicate split-plot randomized complete block design with three photoperiods (ND = Normal day, 12 h; SD = Short day, 8 h; LD = Long day, 16 h) as main plots and 10 genotypes as subplots. The SD and LD conditions were created artificially. Pooled analysis of variance, based on a mixed linear model with season (S) as random and photoperiod (Ph) and genotype (G) as fixed effects, indicated significant S and G differences for most of the traits studied. Ph differences were significant only for shelling percentage and palmitic and eicosenoic fatty acids. The interactions S x Ph, S x G, Ph x G, and S x Ph x G were significant for several traits. When SD and LD treatments were compared with ND, shelling percentage increased under SD. Oil content, oleic (O) and linolenic (L) fatty acids, and O/L ratio were not affected due to variation in photoperiod. However, palmitic acid increased and eicosenoic acid decreased under SD. The SD conditions were more interactive with seasons and genotypes for fatty acids. High performing and photoperiod insensitive genotypes were identified for various seed quality traits. These genotypes would be useful in breeding programs aimed at developing high yielding genotypes with improved seed quality for edible purposes.

To improve nutritional quality of peanut (Arachis hypogaea L.), it is necessary to know the importance of genetic effects. Epistasis is not considered in most genetic models. In the presence of epistasis, estimates of additive and dominance variation are biased to an unknown extent. This may affect progress of a breeding program by causing inappropriate breeding methods to be chosen. The objectives of this study were to determine the significance of epistasis in inheritance of protein and oil contents and oil quality parameters, and to estimate additive and dominance variances for the traits not influenced by epistasis. Three testers, Chico (L1), ICGV8 6300 (L2), and their F1 hybrid (L3), were each crossed to 15 cultigens. The experiment was conducted in the 1992-1993 postrainy and 1993 rainy environments at the ICRISATC Center, Patancheru, India. Characters studied were protein, oil, eight fatty acid contents, and five derived parameters. The deviations, cultigen × L1 + cultigen × L2 − 2 cultigen × L3, were tested to detect epistasis. Environment interacted mores strongly with epistatic gene action than with additive or dominant gene action. Epistasis affected the expression of 11 traits in both environments. The additive × additive epistasis was detected for oleic acid in both environments. Additive gene action was detected for eicosenoic and polyunsaturated/saturated fatty acids (P/S) ratio in the rainy environment. Dominant gene action was detected for P/S in the rainy and for eicosenoic in both environments indicating incomplete dominance for these traits.

Summary. Photoperiod insensitivity plays a significant role in ensuring wide adaptability of genotypes across environments. The effect of photoperiod in groundnut (Arachis hypogaea L.) is manifested in post-flowering development including partitioning. The partitioning of assimilates, as measured by harvest index (HI), has the greatest effect on pod yield. The Fi progenies (excluding reciprocals) and their parents from a six-parent diallel cross were studied to estimate combining ability for biomass and HI under short (SD)- and long (LD)-day conditions, and to identify good combiners with high biomass and HI for use in breeding programmes. The experiment was conducted for three seasons in a split plot design with two photoperiods as main plots and 21 genotypes as subplots. The two photoperiod treatments were SD defined as normal-day light period and LD defined as normal-day light period extended by 4 h using incandescent lamps. The multi-environment analogue of Griffing's Method 2 - Model 1 was modified to analyse data for combining ability. While biomass was controlled by both GCA and SCA effects, HI was predominantly controlled by GCA effects. GCA and SCA effects for biomass and HI interacted with environments (six factorial combinations of photoperiods and seasons). SCA effects remained insensitive to variation in photoperiod both for biomass and HI. However, GCA effects for HI were sensitive to photoperiod. V6 (ICG 2405) was a good general combiner for both biomass and HI across environments. None of the crosses showed positive and significant SCA effects for both biomass and HI. Photoperiod influenced the sensitivity of GCA effects of V2 (ICGV 86694) and V6 for HI. However, the difference between SCA effects of V2 × V6 was not significant. The results of this study emphasise the need for future experiments with random genotypes over a range of photoperiods.

Most genetic models assume absence of epistasis while estimating components of genetic variation. However, epistasis when present introduces bias. These biased estimates affect the progress in a breeding program since they influence the choice of breeding methodology. The objectives of this study were to determine the significance of epistasis in the inheritance of pod yield and related traits in 15 peanut (Arachis hypogaea L.) cultigens, and to estimate the additive and dominance variances for the traits not influenced by epistasis. Two cultigens and their F, hybrid were each crossed to 15 cultigens from 13 countries, representing three botanical groups. The experiment was conducted in the 1992-1993 post-rainy and 1993 rainy environments at the ICRISAT Asia Center, Patancheru, India. The deviations were analyzed to detect epistasis of 11 traits. Epistasis affected the expression of eight traits in both environments. Environments interacted more strongly with epistatic gene actions than with additive or dominance gene actions. Expression of epistasis was influenced by genotypes and environments, indicating the need for more genotypes and environments for effective detection of epistasis. Evidence for additive genetic variance and lower levels of partial dominance for canopy breadth and additive and dominance variances and complete dominance for shelling outturn was obtained in the post-rainy environment.

Photoperiod insensitivity plays an important role in the adaptation of peanut (Arachis hypogaea L.) genotypes across environments. Howeverl,i ttle is knowno f its genetic control. Theo bjective of this study was to determine the combining ability of response to photoperiod in peanut. The Ft progenies from a six-parent diallel cross excluding reciprocals were studied together with their parents for response to photoperiod under short and long day conditions in the field for three seasons. The experimentw as conductedi n a split plot design with photoperiod as main plots and genotype as subplots. The response to photoperiod (Dst) was computed as the difference in harvest index (adjusted pod weight/adjusted biomass) between short and long day treatments. The mean square for response to photoperiod was highly significant for parents and their crosses. Season by cross interaction was the only significant interaction effect. The response to photoperiod was mainly associated with general combining ability variance. ICG2 405 and ICGV8 6031 were good general combiners for insensitivity to photoperiod. All crosses of sensitive × sensitive and sensitive × insensitive parents were sensitive to photoperiod. However, in several cases, this response was not consistent across seasons and resulted in a significant season × cross interaction. The F1 between insensitive parents was insensitive to photoperiod in the three seasons tested. A comparison of Ft response with parents and midparent value of crosses between photoperiod sensitive and insensitive parents suggested additive gene action in some crosses and partial dominance to dominance in others.

The rainfed groundnut (Arachis hypogaea L.) crop suffers from moisture stress of varying intensity at different growth stages. The effect of drought on oil, protein and fatty acid contents were studied in 12 genotypes that differed in seed quality traits. The genotypes were subjected to mid-season and the end-of-season drought in field experiments at ICRISAT Asia Center (IAC), Patancheru, India, conducted during the 1991/92 and 1992/93 postrainy (November–April) seasons. Mid-season drought was imposed between 40 and 80 days after sowing (DAS). The crop received normal irrigation, 50 mm at 10 day intervals, before and after the imposition of mid-season drought until harvest. Using the line-source sprinkler technique, end-of-season drought of varying intensity was imposed from 80 DAS until harvest. Mid-season drought had no significant effect on the content of oil, protein and fatty acids other than eicosenoic fatty acid. End-of-season drought significantly reduced total oil, and linoleic and behenic fatty acid content, and significantly increased total protein and stearic and oleic fatty acid content. However, genotype by treatment interactions were found. In ICGVs 88369, 88371, 88381, 88382 and 88403, total oil content remained unaffected while oleic fatty acid content increased under end-of-season drought. These were identified as desirable parents for a breeding program to develop cultivars suitable for rainfed cultivation.

Some plants without pods but with gynophores were observed in two F4 progenies of two crosses of goundnut (Arachis hypogaea L.). The flowers on these plants had translucent white anthers with no or a few sterile pollen grains. Three such plants in the succeeding generation were hand pollinated with pollen from a short-duration Indian cv. JL 24. The resulting F1 hybrid plants (male sterile x ‘JL 24’) were normal. Chi-square tests for segregation for male fertile and male sterile plants in F2 and F3 generations indicated that the male sterility in these crosses of groundnut is governed by two recessive genes. We designate these genes as ms1 and ms2 with ms1ms1ms2ms2 being a male sterile genotype.

Growth in large germplasm collections in most important crops has led to the development of the concept of core collection or a smaller set of germplasm representing most spectrum of variability of total collections to facilitate their easy management, evaluation and use in crop improvement. In the last two decades, significant efforts have been made in this direction, following nearly identical sampling or selection strategies in most crops. The present article has tried to analyze critically the selection methodologies followed to assess how far core collections in different crops have succeeded in meeting the objectives, particularly those of crop genetic improvement. An attempt has also been made to address the possible ways for improvement in the selection strategy with additional steps to overcome the lacunas. Groundnut cores have been critically analyzed as a case study. This has revealed that cores have been able to capture only around 70% of variability, which has limited the value of core with non-capture of rare alleles. To overcome present lacunas, a modified stratification method has been suggested based on biogeographical distribution, and integration of gene pools (sets) of various desirable traits in the selection of accessions to formulate the core set. Greater emphasis needs to be given to genomics and characterization of accessions, particularly in relation to desired traits, using molecular markers associated with these traits to avoid masking effect caused by environment factors.

Groundnut (Arachis hypogaea L.) is grown world over for oil and food uses. It is a self-pollinated crop with low genetic diversity. The origin of the crop from single hybridization event followed by chromosome doubling as well as crossing barriers of cultivated species with wild species due to ploidy differences rendered the crop with narrow genetic variability. Developing new varieties with increased yield potential and resistance to biotic and abiotic stresses that meet the needs of the growers, processors and consumers is the primary objective of groundnut breeding. In this chapter, we discuss about phenotyping tools used in groundnut improvement programs for various targeted traits. Both field and laboratory tools are described to screen for resistance to diseases caused by fungi, bacteria, virus and nematodes. Phenotyping based on Cumulative Thermal Time (CTT) is used to select for early maturity. Phenotyping for complex traits can be challenging. Either empirical approach that involves measuring the yield under imposed drought stress or salinity conditions or trait based approach using surrogates or a combination of both are used for phenotyping abiotic stresses. Phenotyping for Aspergillus contamination needs improvement to derive reliable and reproducible results. Estimation of quality and nutritional parameters generally involves use of destructive and laborious chemical or physical procedures. Near infrared reflectance spectroscopy (NIRS), a robust and non-destructive method is gaining popularity for estimation of oil, protein, carbohydrate and fatty acid contents. Methods for estimating oil, protein, sugar and micronutrient concentrations and fatty acid composition of seeds and haulm quality traits are described.

Knowledge of inheritance of early maturity or its components is important to groundnut breeders in developing short-duration cultivars. This study was conducted to determine the inheritance of two components of early maturity: days to first flower from sowing, and days to accumulation of 25 flowers from the appearance of first flower, using three groundnut genotypes. Two early-maturing (Chico and Gangapuri) and one late-maturing (M 13) genotypes were crossed in all possible combinations, including reciprocals. The parents, F1, F2, F3, and backcross populations were evaluated for days to first flower from sowing, and for days to accumulation of 25 flowers. The data suggest that days to first flower in the crosses studied is governed by a single gene with additive gene action. Chico and Gangapuri possess the same allele for this component of earliness. Three independent genes with complete dominance at each locus appear to control the days to accumulation of 25 flowers. In crosses between late (M 13) and early (Chico or Gangapuri) parents, a segregation pattern suggesting dominant-recessive epistasis (13 late:3 early) was observed for this component. Segregation in the F2 generation (1 late:15 early) of both early parents (Chico x Gangapuri) indicated that the genes for early accumulation of flowers in these two parents are at different loci.

Peanut genomics is very challenging due to its inherent problem of genetic architecture. Blockage of gene flow from diploid wild relatives to the tetraploid; cultivated peanut, recent polyploidization combined with self pollination, and the narrow genetic base of the primary genepool have resulted in low genetic diversity that has remained a major bottleneck for genetic improvement of peanut. Harnessing the rich source of wild relatives has been negligible due to differences in ploidy level as well as genetic drag and undesirable alleles for low yield. Lack of appropriate genomic resources has severely hampered molecular breeding activities, and this crop remains among the less-studied crops. The last five years, however, have witnessed accelerated development of genomic resources such as development of molecular markers, genetic and physical maps, generation of expressed sequenced tags (ESTs), development of mutant resources, and functional genomics platforms that facilitate the identification of QTLs and discovery of genes associated with tolerance/resistance to abiotic and biotic stresses and agronomic traits. Molecular breeding has been initiated for several traits for development of superior genotypes. The genome or at least gene space sequence is expected to be available in near future and this will further accelerate use of biotechnological approaches for peanut improvement.

The quality of edible oils is now receiving increasing consideration from consumers and processors. The present study was conducted to investigate the effects of environments on oil content and fatty acid composition in peanut. The correlation between oil content and oil quality parameters was also studied. Thirteen peanut (Arachis hypogaea L.) genotypes were grown in 12 environments for the study. Soils at experiment locations differed significantly for pH, EC, and N, P, Zn, Mn, and Fe contents. Significant genotype, environment, and genotype x environment interaction effects were observed for oil content, individual fatty acid contents, and derived oil quality parameters. The original range of 34-54% of oil content based on one season/location evaluation in these lines was not repeatable, and ranged from 45-50% in multilocation evaluation. Oil content was positively correlated with soil pH and Fe content. The correlation of oleic and linoleic acid content with soil pH and Fe content was positive in the former and negative in the latter. The oil content was positively correlated with O/L ratio. Oliec and linoleic acid contents were negatively correlated. Selection for reduced linoleic acid level in genotypes would also reduce levels of total long chain saturated fatty (TLCSF) acids. Of the thirteen genotypes tested, ICG 5856, ICG 5369, and ICGV 87124 could be used in breeding for improved oil quality.

The effects on pod yield and quality characteristics of using chlorothalonil for foliar disease control were studied in 10 confectionary groundnut genotypes (Arachis hypogaea subsp. hypogaea var. hypogaea) at Patancheru, Andra Pradesh, India, during the rainy seasons of 1991 and 1992. Significant treatment (disease control vs no control) and genotypic effects were observed for pod yield, total biomass, remaining green leaf area, retained leaf area damaged by rust, shelling percentage, 100-seed mass, oil content, fatty acids and oleic (O)/linoleic (L) acid, and polyunsaturated (P)/saturated (S) fatty acid ratios. A significant increase in pod yield and total oil content was observed due to the control of foliar diseases by chlorothalonil, but protein content was unaffected. Control of foliar diseases with chlorothalonil affected 4 fatty acids; linoleic acid content increased but stearic, oleic and behenic acid content decreased. Of the seed quality characteristics, a significant decrease in the O/L ratio and a significant increase in P/S ratio were observed following disease control. Response to disease control for pod yield and quality characteristics was influenced by genotype and year. Correlations between the content of the different fatty acids were generally unaffected by application of chlorothalonil, however, the correlations between content of fatty acids and pod yield, seed mass, oil and protein content changed in their significance and magnitude

Several groundnut (Arachis hypogaea L) cultivars developed by the International Crops Research Institute for the Semi-arid Tropics (ICRISAT), and one local cultivar for use as a control were grown in the post-rainy and rainy seasons at Patancheru, India. Free and bound lipids were extracted and their fatty acid compositions determined. Acid, peroxide, iodine and saponification values were determined. Flavour quality was evaluated using headspace analysis. The quantity of total lipids was significantly higher in the cultivars grown in the rainy season than those grown in the post-rainy season and was higher in the ICRISAT cultivars than in the control in both seasons. Oleic (O) to linoleic (L) acid ratio was lowest in the chioroform-methanol extract and highest in water-saturated butanol extract. One ICRISAT line, ICGS 21, showed the highest O/L ratio in all lipid fractions in both seasons. Among the flavour components, n-methyl pyrrole, associated with an objectionable musty flavour, was present in very high concentration in all the cultivars.

Five groundnut (Aruchis hypogueu L) cultivars developed by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) and two local cultivars as controls were grown in post-rainy and rainy seasons at Patancheru, India. They were analysed for their proximate composition, minerals and trace elements, amino acid composition, true protein digestibility (TD), biological value (BV), net protein utilisation (NPU), and protein efficiency ratio. One-hundred seed mass, protein content and TD were significantly higher in the post-rainy season while starch, sugars, BV and NPU were significantly higher in the rainy season. Post-rainy cultivars exhibited higher concentrations of potassium, calcium, iron and several essential and non-essential amino acids. TD of blanched groundnut was better than that of the whole seeds. The composition and protein quality of ICRISAT cultivars were comparable to those of the controls.

Transpiration efficiency (TE) is an important trait for drought tolerance in peanut (Arachis hypogaea L.). The variation in TE was assessed gravimetrically using a long time interval in nine peanut genotypes (Chico, ICGS 44, ICGV 00350, ICGV 86015, ICGV 86031, ICGV 91114, JL 24, TAG 24 and TMV 2) grown in lysimeters under well-watered or drought conditions. Transpiration was measured by regularly weighing the lysimeters, in which the soil surface was mulched with a 2-cm layer of polythene beads. TE in the nine genotypes used varied from 1.4 to 2.9 g kg(-1) under well-watered and 1.7 to 2.9 g kg(-1) under drought conditions, showing consistent variation in TE among genotypes. A higher TE was found in ICGV 86031 in both well-watered and drought conditions and lower TE was found in TAG-24 under both water regimes. Although total water extraction differed little across genotypes, the pattern of water extraction from the soil profile varied among genotypes. High water extraction within 24 days following stress imposition was negatively related to pod yield (r(2) = 0.36), and negatively related to water extraction during a subsequent period of 32 days (r(2) = 0.73). By contrast, the latter, i.e. water extraction during a period corresponding to grain filling (24 to 56 days after flowering) was positively related to pod yield (r(2) = 0.36). TE was positively correlated with pod weight (r(2) = 0.30) under drought condition. Our data show that under an intermittent drought regime, TE and water extraction from the soil profile during a period corresponding to pod filling were the most important components.

This chapter discusses the target growing environments and sensitivity of pearl millet, sorghum, maize, groundnut, chickpea and pigeon pea to drought; phenotypic screens and natural genetic variations for response to drought; empirical and trait-based breeding methods to enhance drought tolerance; and deployment of emerging biotechnological tools (DNA markers and transgene) to enhance crop adaptation and productivity under drought stress conditions.

Grain legumes are important crops for providing key components in the diets of resource-poor people of the semi-arid tropic (SAT) regions of the world. Although there are several grain legume crops grown in SAT, the present chapter deals with three important legumes i.e. groundnut or peanut (Arachis hypogaea), chickpea (Cicer arietinum) and pigeonpea (Cajanus cajan). Production of these legume crops are challenged by serious abiotic stresses e.g. drought, salinity as well as several fungal, viral and nematode diseases. To tackle these constraints through molecular breeding, some efforts have been initiated to develop genomic resources e.g. molecular markers, molecular genetic maps, expressed sequence tags (ESTs), macro-/micro- arrays, bacterial artificial chromosomes (BACs), etc. These genomic resources together with recently developed genetic and genomics strategies e.g. functional molecular markers, linkage-disequilibrium (LD) based association mapping, functional and comparative genomics offer the possibility of accelerating molecular breeding for abiotic and biotic stress tolerances in the legume crops. However, low level of polymorphism present in the cultivated genepools of these legume crops, imprecise phenotyping of the germplasm and the higher costs of development and application of genomic tools are critical factors in utilizing genomics in breeding of these legume crops.

About 94% of the world groundnut (Arachis hypogaea L.) production comes from the rainfed crop grown largely by resource-poor farmers. Several biotic and abiotic stresses limit groundnut productivity, together causing annual yield losses of over US $ 3.2 billion. The Arachis species harbor genes capable of improving both seed yield and quality in addition to imparting high levels of resistance to diseases and insect pests. Many of the wild Arachis species are not cross compatible with cultivated groundnut. However, efforts to overcome incompatibility in wide crosses have started to liberate resistance genes in interspecific progenies. But these progenies carry a lot of linkage drag. Marker-assisted backcross breeding should minimize the linkage drag as it greatly facilitates monitoring of introgressed chromosome segments carrying beneficial genes from wild Arachis to cultivated groundnut. Transgenic groundnuts with resistance or tolerance to biotic and abiotic stresses have been produced and are in various stages of characterization under containment and/or controlled field conditions. Once favorable genes are introduced into cultivated groundnut through wide crossing and/or genetic transformation techniques, these genes will become ideal candidates for marker-accelerated introgression. DNA marker based genetic linkage map should enable breeders to effectively pyramid genes for good seed quality and resistance to biotic and abiotic stresses into agronomically enhanced breeding populations in a much shorter time than would be possible by conventional techniques. To date 110 SSR markers detected genetic variation in a diverse array of 24 groundnut landraces. However, substantial efforts are still required to develop sufficient PCR-based markers, particularly SSRs and SNPs, for the construction of high-density genetic linkage map and for the routine application in the molecular breeding in groundnut. The use of automated technologies will become increasingly important for large-scale germplasm characterization and realistic scale marker-assisted selection in groundnut. An international legume genomics initiative has been formed between USA Universities and the International Agricultural Research Centers of the Eco-Regional Alliance on legumes to translate the benefits of the "consensus legume genome" for rapid impacts on the genetic improvement of tropical legumes.

SPAD chlorophyll meter reading (SCMR) and specific leaf area (SLA) are important traits associated with water-useefficiency (WUE). Understanding their genetic nature and association with yield parameters enables their deployment in breeding programs for drought tolerance. The results obtained from the study conducted on six generations of four groundnut crosses showed significant additive effects for SCMR and SLA in all the crosses indicating possible gains through selection. Relative contribution of additive effects was high for both, SCMR (58 to 93%) and SLA (63 to 91%). The low heritability of SCMR and SLA indicates environmental influence on these traits. SCMR is positively associated with pod, kernel and haulm yield, while the association of SLA with them was negative. Combining trait-based approach using SCMR and SLA with empirical approach can be rewarding in groundnut breeding for drought tolerance.

Grain legumes are an important source of protein in the diets of humans and livestock, as well as being components of sustainable cropping systems. Poor productivity of legumes on acid soils is a major problem globally. The severity of damage depends on the soil characteristics and sensitivity of plant species. There has been substantial research into and increased understanding of crop management on acid soils, but little progress has been made in characterising genetic variability in grain legume crops in response to acid soil conditions. We propose to explore such genetic variability, primarily for groundnut but also for other grain legumes depending on the interest expressed by potential cooperators. We propose to address this objective by initiating a working group, to integrate global efforts in screening genotypes of grain legumes for tolerance to acid soils. We would like to involve scientists from countries where acid soils are a major constraint, to establish appropriate field screening facilities. We are also seeking support of national and international organisations conducting research on acid soils. We believe that this approach would contribute to development of acid tolerant genotypes, leading to sustainable grain legume production and sustainable cropping systems on acid soils.

ICGV 92267 (Reg. no. GP-116, PI 630947) is an improved Spanish peanut (Arachis hypogaea L. subsp. fastigiata var. vulgaris Harz) germplasm line, bred at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Andhra Pradesh, India. This germplasm line was released by the Plant Materials Identification Committee of ICRISAT in 2000 for its early-maturity, less susceptibility to rust (caused by Puccinia arachidis Speg.) and late leaf spot [caused by Phaeoisariopsis personata (Berk. & M.A. Curtis) Arx; syn. Cercosporidium personatum (Berk & M.A. Curtis) Deighton], and chill tolerance to low temperature at germination.

The groundnut (Arachis hypogaea L.) — groundnut rust (Puccinia arachidis Speg.) pathosystem appears to have coevolved in Peru, South America, where the host is known to have been cultivated for almost 4000 years. The groundnut spreaded to the rest of the world after the Spanish and Portuguese colonization of South America. Prior to 1969 the pathogen which was largely confined to South America, but it got firmly established in all the groundnut growing countries in a short span of time (a ‘re-encounter’ phenomenon). The pathogen is highly host-specific and is known by its uredinial stage. Rust is an economically important disease on groundnut, often causing more than 50% yield losses in most groundnut growing areas. Rust resistant genotypes have been identified. The resistance is of a quantitative nature and its inheritance does not seem to be simple. Rust resistance in most genotypes is stable over a wide range of geographic locations except in a few locations, indicating possible variation in the pathogen, which needs confirmation. Rust resistance in groundnut fits neither typical race-specific nor race-non-specific patterns and appears to be an intermediate type falling in the continuum of these two extreme types.

ICGV 93470 (Reg. no. GP-102, PI 614087) is an improved Spanish peanut (Arachis hypogaea L. subsp. fastigiata var. vulgaris) germplasm, developed at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) Center, Patancheru, Andhra Pradesh, India. This improved germplasm was released by the Plant Materials Identification Committee of ICRISAT in 1999 for its early-maturity and fresh seed dormancy in a Spanish background.

ICGV 87354, a drought tolerant peanut (Arachis hypogaea L. Fabaceae subsp. hypogaea var. vulgaris) germplasm (Reg. no. GP-97, PI 568164) was released in 1999 by the Plant Materials Identification Committee of the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) because of its tolerance to drought, resistance to rust (caused by Puccinia arachidis Speg.), and field resistance to peanut bud necrosis.

ICGV 86015, a spanish-type peanut (Arachis hypogaea L. subsp. fastigiata Waldron var. vulgaris Harz) germplasm (Reg. no. GP-73, P1 585005) was bred at the Asia Center of the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India. It was identified and released as an early-maturing widely adapted high-yielding breeding line (3) by the Plant Materials Identification Committee of ICRISAT in 1993. This improved germplasm has been designated as Hung Loc 25 (HL 25) in Vietnam, where, in 33 field experiments and 6 trials involving 344 farming families, it was found most suitable for intercropping with cassava (Manihot esculenta Crantz) and maize (Zea mays L.) in the southeast coastal and southeastern regions of the country (4). It is proposed for release as BARD 92 in Pakistan for double cropping with wheat (Triiicum aestivum L.) and is particularly adapted to the barani (rainfed) conditions of the Pothwar area in the country.

Four peanut (Arachis hypogaea L.) germplasm lines, ICGV 99001 (Reg. no. GP-118, PI 631072), ICGV 99003 (Reg. no. GP-119, PI 631073), ICGV 99004 (Reg. no. GP-120, PI 631074), and ICGV 99005 (Reg. no. GP-121, PI 631075), were released in 2001 by the Plant Materials Identification Committee of International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, AP, India, for their resistance to foliar fungal diseases. These lines were derived from A. hypogaea and wild Arachis species crosses. ICGV#99001 and 99004 belong to subsp. fastigiata var. vulgaris while ICGV#99003 and 99005 belong to subsp. hypogaea var. hypogaea. ICGV# 99001 and 99004 possess resistance to late leaf spot (LLS) [(caused by Phaeoisariopsis personata (Berk. & Curt.) v. Arx = Cercosporidium personatum (Berk. & Curt.) Deighton], and ICGV# 99003 and 99005 have resistance to rust (caused by Puccinia arachidis Speg.).

ICGS 35 (ICGV 87127) (Reg. no. GP-67, P1577819) Spanish peanut (Arachis hypogaea L. subsp. fastigiata Waldron var. vulgaris Hartz) was developed at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Andhra Pradesh, India. It was introduced into the Republic of Korea in 1981, together with other breeding lines from ICRISAT. After a 4-yr evaluation in multilocation trials, the Crop Experiment Station of the Rural Development Administration, Suweon, Korea, recommended its release under the name 'Jinpungtangkong' in 1986 for cultivation in the country