Spot blotch (SB) disease causes significant yield loss in wheat production in the warm and humid regions of the eastern Gangetic plains (EGP) of South Asia (SA). Most of the cultivated varieties in the eastern part of SA are affected by SB under favorable climatic conditions. To understand the nature of SB resistance and map the underlying resistant loci effective in SA, two bi-parental mapping populations were evaluated for 3 years, i.e., 2013–2015 for the BARTAI × CIANO T79 population (denoted as BC) and 2014–2016 for the CASCABEL × CIANO T79 population (CC), at Varanasi, Uttar Pradesh, India. DArTSeq genotyping-by-sequencing (GBS) platform was used for genotyping of the populations. Distribution of disease reaction of genotypes in both populations was continuous, revealing the quantitative nature of resistance. Significant “genotype,” “year,” and “genotype × year” interactions for SB were observed. Linkage map with the genome coverage of 8,598.3 and 9,024.7 cM in the BC and CC population, respectively, was observed. Two quantitative trait loci (QTLs) were detected on chromosomes 1A and 4D in the BC population with an average contribution of 4.01 and 12.23% of the total phenotypic variation (PV), respectively. Seven stable QTLs were detected on chromosomes 1B, 5A, 5B, 6A, 7A, and 7B in the CC population explaining 2.89–10.32% of PV and collectively 39.91% of the total PV. The QTL detected at the distal end of 5A chromosome contributed 10.32% of the total PV. The QTLs on 6A and 7B in CC could be new, and the one on 5B may represent the Sb2 gene. These QTLs could be used in SB resistance cultivar development for SA.

Flowering time and seed size are the important traits for adaptation in chickpea. Early phenology (time of flowering, podding and maturity) enhance chickpea adaptation to short season environments. Along with a trait of consumer preference, seed size has also been considered as an important factor for subsequent plant growth parameters including germination, seedling vigour and seedling mass. Small seeded kabuli genotype ICC 16644 was crossed with four genotypes (JGK 2, KAK 2, KRIPA and ICC 17109) to study inheritance of flowering time and seed size. The relationships of phenology with seed size, grain yield and its component traits were studied. The study included parents, F 1 , F 2 and F 3 of four crosses. The segregation data of F 2 indicated flowering time in chickpea was governed by two genes with duplicate recessive epistasis and lateness was dominant to earliness. Two genes were controlling 100-seed weight where small seed size was dominant over large seed size. Early phenology had significant negative or no association (ICC 16644 9 ICC 17109) with 100-seed weight. Yield per plant had significant positive association with number of seeds per plant, number of pods per plant, biological yield per plant, 100-seed weight, harvest index and plant height and hence could be considered as factors for seed yield improvement. Phenology had no correlation with yield per se (seed yield per plant) in any of the crosses studied. Thus, present study shows that in certain genetic background it might be possible to breed early flowering genotypes with large seed size in chickpea and selection of early flowering genotypes may not essentially have a yield penalty.

Heat stress is a major production constraint of wheat in South Asia, particularly in the Gangetic plains of India and Bangladesh. The leaf chlorophyll status is a key determinant for a high rate of photosynthesis under stress. The present experiments included 238 genotypes in 2016–2017 and 321 genotypes in 2017–2018 under optimum and under heat stress conditions. Subsequently, a set of 100 genotypes selected on basis of the heat susceptibility index was evaluated in 2018–2019 under heat stress conditions to study the relationship between important physiological traits and yield under stress. A significant correlation of soil plant analysis development (SPAD) value of the two upper leaves with stay-green trait and grain yield indicates the importance of chlorophyll content, both in flag and penultimate leaf, in maintaining leaf areas under greenness (LAUG) and grain yield under heat stress. The SPAD in the flag and penultimate leaf was responsible for 8.8% and 10.9%, respectively, of the variation in grain yield. For the stay-green trait, 8.4% and 7.2 % of the variation was governed by the SPAD value in the flag and penultimate leaf, respectively. These results suggest that, in addition to the flag leaf, the chlorophyll status of the penultimate leaf can be an important criterion for the selection of superior wheat genotypes under heat stress. The genotypes SW-139; SW 108; DWR-F8-35-9-1; NHP-F8-130; DWR-F8-3-1 that maintained a high chlorophyll content in the flag and penultimate leaf can be used further in breeding programmes addressing heat resistance in wheat.

Heat stress is one of the major wheat (Triticum aestivum) production constraints in South Asia (SA), particularly in the Eastern Gangetic Plains (EGP) of India and Bangladesh. Malnutrition is also a severe problem among children and women in SA. Wheat varieties with high grain Zn/Fe are a sustainable, cost-effective solution in the fight against hidden hunger. Thirty wheat genotypes were characterised under the optimum temperature and heat stress conditions in 2016–2017 and 2017–2018 to study the response of the stress on the yield, physiological traits and grain Zn/Fe content. A significant genetic variation was observed for all the traits under the optimum temperature and stress conditions. The yield was reduced by an average of 59.5% under heat stress compared to that of the optimum temperature. A strong positive association of the canopy temperature depression (CTD) with the grain yield (GY) was observed under the heat stress. A negative correlation of the grain Zn/Fe with the yield was observed under the optimum temperature and heat stress conditions, while the association between the grain Zn and Fe was positive. The genotypes BRW 3723, BRW 3759, BRW 3797, BRW 160, HD 2967, HD 2640 were found to be heat-tolerant in both years. Among the tolerant genotypes, BRW 934, BRW 3807 and BRW 3804 showed a high zinc content and BRW 934, BRW 3797, BRW 3788 and BRW 3807 showed a high iron content, respectively. These genotypes can be explored in future breeding programmes to address the problem of nutritional deficiency.

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