Fusarium wilt (FW) and Ascochyta blight (AB) are two major constraints to chickpea (Cicer arietinum L.) production. Therefore, two parallel marker-assisted backcrossing (MABC) programs by targeting foc1 locus and two quantitative trait loci (QTL) regions, ABQTL-I and ABQTL-II, were undertaken to introgress resistance to FW and AB, respectively, in C 214, an elite cultivar of chickpea. In the case of FW, foreground selection (FGS) was conducted with six markers (TR19, TA194, TAA60, GA16, TA110, and TS82) linked to foc1 in the cross C 214 × WR 315 (FWresistant). On the other hand, eight markers (TA194, TR58, TS82, GA16, SCY17, TA130, TA2, and GAA47) linked with ABQTL-I and ABQTL-II were used in the case of AB by deploying C 214 × ILC 3279 (AB-resistant) cross. Background selection (BGS) in both crosses was employed with evenly distributed 40 (C 214 × WR 315) to 43 (C 214 × ILC 3279) SSR markers in the chickpea genome to select plant(s) with higher recurrent parent genome (RPG) recovery. By using three backcrosses and three rounds of selfing, 22 BC 3 F 4 lines were generated for C 214 × WR 315 cross and 14 MABC lines for C 214 × ILC 3279 cross. Phenotyping of these lines has identified three resistant lines (with 92.7-95.2% RPG) to race 1 of FW, and seven resistant lines to AB that may be tested for yield and other agronomic traits under multilocation trials for possible release and cultivation.

Fusarium wilt (FW) and Ascochyta blight (AB) are two important diseases of chickpea which cause 100 % yield losses under favorable conditions. With an objective to validate and/or to identify novel quantitative trait loci (QTLs) for resistance to race 1 of FW caused by Fusarium oxysporum f. sp. ciceris and AB caused by Ascochyta rabiei in chickpea, two new mapping populations (F 2:3) namely 'C 214' (FW susceptible) 9 'WR 315' (FW resistant) and 'C 214' (AB susceptible) 9 'ILC 3279' (AB resistant) were developed. After screening 371 SSR markers on parental lines and genotyping the mapping populations with polymorphic markers, two new genetic maps comprising 57 (C 214 9 WR 315) and 58 (C 214 9 ILC 3279) loci were developed. Analysis of genotyping data together with phenotyping data collected on mapping population for resistance to FW in field conditions identified two novel QTLs which explained 10.4-18.8 % of phenotypic variation. Similarly, analysis of phenotyping data for resistance to seedling resistance and adult plant resistance for AB under controlled and field conditions together with genotyping data identified a total of 6 QTLs explaining up to 31.9 % of phenotypic variation. One major QTL, explaining 31.9 % phenotypic variation for AB resistance was identified in both field and controlled conditions and was also reported from different resistant lines in many earlier studies. This major QTL for AB resistance and two novel QTLs identified for FW resistance are the most promising QTLs for molecular breeding separately or pyramiding for resistance to FW and AB for chickpea improvement.

Abstract. Effective controlled-environment and field screening techniques were developed and refined to identify resistance to Ascochyta blight (AB), caused by Ascochyta rabiei (Pass.) Labr. in chickpea. A controlled environment plant growth room facility developed for AB evaluation at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India was modified to evaluate chickpea genotypes for resistance to AB. Controlled environment screening techniques, such as a seedling screening technique using 10-day-old seedlings and cut-twig screening techniques using excised twigs (10-15cm long) were developed. Components of the screening techniques were optimized in the controlled environment-plant growth room. The controlled environment screening techniques were found to be rapid, reliable and reproducible and a positive correlation was found between the seedling and cut-twig screening techniques (r=0.94).The cut-twig screening technique was quicker than the seedling screening technique and is particularly useful in screening segregating breeding lines derived from wild Cicer spp.Results of the controlled environment screening techniques were compared with results of field screening trials carried out at Dhaulakuan and Ludhiana in India, where the pathogen is endemic. A significant positive correlation was found between results from the controlled environment and field screening techniques (r=0.88). Using these resistance screening techniques, 150 elite chickpea breeding lines were evaluated and 29 lines with high and stable resistance to AB were identified.

Chickpea wilt incited by Fusarium oxysporum f. sp. ciceris is one of the most important constraints to chickpea production worldwide and best managed through host plant resistance. The aim of this work was to find new sources of resistance to wilt disease and validate their stability across different environments. One-hundred and twenty three lines with wilt incidence <10% were selected from preliminary evaluation of 948 lines including germplasm and breeding lines from the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) for wilt resistance in the sick plot during 2003/2004 crop season at ICRISAT, Patancheru, India. Sixty lines were selected for second round of evaluation (2005/2006) and from those 57 lines were selected for third round of evaluation (2006/2007). In order to validate resistance stability, a Chickpea Wilt Nursery was constituted with 27 lines (7 germplasm accessions, 19 breeding lines and a highly susceptible check) and further tested in multi-location experiment for wilt resistance at 9 locations in India for three years (2007/2008-2009/2010). Variability in wilt incidence due to genetic differences among the genotypes, among the environments, and that due to genotype × environment interaction was highly significant (P < 0.001). Although complete resistance across the locations was not found, the genotype and genotype × environment (GGE) biplot analyses allowed the selection of three breeding lines (ICCV 05527, ICCV 05528 and ICCV 96818) and one germplasm accession (ICC 11322) with moderate level of disease resistance and stable performance across the environments. Genotype × environment (G × E) interaction contributed 36.7% of total variation of the multi-environment evaluation, revealing instability of the phenotypic expression across environments. The identified resistant sources should be useful to chickpea disease resistance breeding programs.

Yellow mosaic disease (YMD) is one of the major diseases affecting mungbean (Vigna radiata (L.) Wilczek). In this study, we report the mapping of the quantitative trait locus (QTL) for mungbean yellow mosaic India virus (MYMIV) resistance in mungbean. An F8 recombinant inbred line (RIL) mapping population was generated in Thailand from a cross between NM10-12-1 (MYMIV resistance) and KPS2 (MYMIV susceptible). One hundred and twenty-two RILs and their parents were evaluated for MYMIV resistance in infested fields in India and Pakistan. A genetic linkage map was developed for the RIL population using simple sequence repeat (SSR) markers. Composite interval mapping identified five QTLs for MYMIV resistance: three QTLs for India (qYMIV1, qYMIV2 and qYMIV3) and two QTLs for Pakistan (qYMIV4 and qYMIV5). qYMIV1, qYMIV2, qYMIV3, qYMIV4 and qYMIV5 explained 9.33%, 10.61%, 12.55%, 21.93% and 6.24% of variation in disease responses, respectively. qYMIV1 and qYMIV4 appeared to be the same locus and were common to a major QTL for MYMIV resistance in India identified previously using a different resistant mungbean.