The study utilised a line × tester mating design, crossing twelve diverse female lines with 3 male testers to develop 36 F1 hybrids, evaluated along with three check varieties. The experiment was laid out in a randomized block design with three replications across two sowing environments: timely (E1) and late (E2) sown, for the study of 12 quantitative traits under sodicity conditions. Analysis of variance revealed highly significant genetic variability among genotypes for all traits in both environments. Combining ability analysis indicated the predominance of non-additive gene action for all studied traits, as specific combining ability (SCA) variance consistently exceeded general combining ability (GCA) variance, supported by high estimates of dominance variance and low narrow-sense heritability. Among parents, lines MP-1358 (for early maturity), UP-3043 (for plant height and grain yield) and DBW-302 (for spike length) were identified as superior general combiners. Tester LBRIL-102 also exhibited positive GCA effects for multiple yield components. Several crosses, notably PBW-821 × LBRIL-102 and GW-509 × LBRIL-102, demonstrated highly significant positive SCA effects for critical yield traits like grain yield per plant and harvest index. The study concludes that genetic expression, particularly of non-additive gene effects, was amplified under late-sown conditions (E2). The overwhelming predominance of non-additive gene action strongly suggests that heterosis breeding is the most promising strategy for genetic improvement of wheat for cultivation in sodic soils. The identified superior general combiners and specific cross combinations provide valuable genetic resources for developing high-yielding, stress-tolerant wheat hybrids.
Ajeet et al. (Wed,) studied this question.