Diallel analysis undertakes the adequate capture of the interaction of genes contributing to traits’ variation by the general (GCA) and specific combining ability (SCA) effects. However, in reality, the genes’ interaction can be more complex, involving epistatic interactions and pleiotropy, which are unaccounted for in the traditional diallel analysis. Therefore, the presented work sought to study the combining ability in wheat genotypes widely planted in Uzbekistan. The mode of inheritance as studied through combining ability included the vegetation period, plant height, vitreousity, grain weight per ear, 1000-kernel weight, grain yield, and productive accumulation in 4 × 4 F₁ diallel hybrids of wheat. The analysis of variance indicated significant differences among the parental genotypes and their F₁ hybrids in the GCA, SCA, and reciprocal effect of the previously mentioned characters on grain size. Consequently, it helped determine the grain and cultivar quality, as well as the genetic strength of the grain. For management of the grain yield, the GCA and reciprocal effects played major roles compared with the SCA effects. Significant variances due to GCA and SCA showed the predominance of additive, epistatic, and dominant gene effects in controlling the inheritance of the wheat’s studied traits.

Keywords: Bread wheat (T. aestivum L.), F₁ hybrids, diallel analysis, combining ability, additive, epistatic, dominant gene effects, morphological and yield traits

Key findings: Significant variances due to GCA and SCA showed greater genetic variability in the F₁ populations and the predominance of additive, epistatic, and dominant gene effects in managing the inheritance of morphological and yield traits in bread wheat (T. aestivum L.).