Estimation of Combining Abilities for Yield and its Components in Soybean

Combining ability is mostly used by breeders to select appropriate parental cultivars to produce the larger progeny of new combinations through their hybridization. The objectives of this research were to estimate the general combining ability of parents and specific combining abilities of F1 hybrids, to identify suitable parents and hybrids for yield and its contributing traits. In this study, materials comprising 8 F1s derived by crossing 2 lines with 4 testers following the Line x Tester mating design. The F1s and the parental genotypes were grown at the ‘Research Farm’ of the Tagore University's, Department of Genetics & Plant Breeding during the autumn 2021 using Randomized Block Design (RBD) with three replications. The popular soybean variety JS 335 was found as the best overall performer (good general combiner) for most traits, while the cross-combination JS 93-05 X RVS 2001-4 showed particular promise for specific traits. The cross RVS-24 X JS 95-60 showed desirable traits like high plant height, pod number, and yield, making it a potential candidate for breeding higher-yielding and biomass-rich varieties. Additionally, crosses RVS-24 X JS 95-60, RVS-24 X JS 335, JS 93-05 X RVS 2001-4, and RVS-24 X JS 97-52 exhibited high heterotic responses for seed yield, making them valuable for developing high-yielding lines. The cross JS 93-05 X RVS 2001-4 showed the best potential for genetic improvement in the pod number/plant, seed number per pod, yield/plant, and the harvest index, making it a valuable resource for isolating high-yielding genotypes.