Deciphering the genetics of quantitative traits of economic importance provides valuable guidance to plant breeders in choosing appropriate breeding strategies for yield improvement. The objective of this study was to assess the nature and magnitude of gene effects controlling quantitative traits in bread wheat through generation mean analysis to formulate effective breeding strategies for yield improvement. Six generations, P 1 , P 2 , F 1 , F 2 , B 1 , and B 2 , derived from six crosses (HPW 155 × ONS 27, HPW 349 × HSB 6, HPW 368 × ONS 29, HPW 368 × ONS 27, PBW 343 × ONS 29, and HS 562 × ONS 29) were evaluated in a compact family block design during the rabi season of 2018–19. Results demonstrated that the six‐parameter model provided the best‐fit for explaining the inheritance of grain yield, indicating that, alongside additive and dominance effects, epistatic effects (additive × additive, additive × dominance, and dominance × dominance) play a critical role in governing this trait. Significant and positive epistasis, coupled with the predominance of duplicate epistasis, was observed for grain yield per plant in the crosses HPW 155 × ONS 27, HPW 368 × ONS 29, HPW 349 × HSB 6, HPW 368 × ONS 27, and HS 562 × ONS 29. These findings suggest that biparental mating and recurrent selection, with delayed selection in later segregating generations, are the most effective strategies for yield improvement.
Batheja et al. (Thu,) studied this question.