Genetic Studies on Combining Ability for Grain Yield and its Attributes in Bread Wheat (Triticum aestivum L. em Thell)

Selecting suitable parent genotypes to create gene combinations that enhance yield and other advantageous characters is the key goal of wheat improvement programmes. This research investigated the general and specific combining ability and the gene actions associated with yield and yield-attributing traits.

Combining ability for ten parental bread wheat genotypes was analyzed using a 10x10 half-diallel fashion in a randomized block design (RBD) having three replications.

The results disclosed that all genotypes differed significantly in yield and the factors contributing to it. GCA and SCA mean squares were highly significant for days to 75% heading, productive tillers per plant, plant height, grains per spike, 1000-grain weight, biological yield, grain yield and harvest index. Except for days to 75% heading, all traits had GCA: SCA ratios less than unity, suggesting that nonadditive factors were comparatively more significant in the inheritance of these traits. The parents, CAL/NH//H567.71/3/SER1/ 4/CAL/NH/H567.71/5/2*KAU2/6/…, DBW 189 and UP 2901 were good general combiners in terms of yield and a few of their component traits. Eleven crosses presented notable and favourable SCA impacts regarding grain yield. The cross CAL/NH//H567.71/3/SER1/4/ CAL/NH/H567.71/5/2*KAU2/6/…x PBW 692 displayed the maximum SCA effect for grain yield per plant. To improve productivity components and increase yields in wheat breeding programmes, parental wheat genotypes and progenies from these crosses offer the possibility of commercial exploitation either as hybrid varieties or as a base material for selecting potential homozygous lines from transgressive segregants.