Heterosis and Combining Ability Analysis for Yield and Its Component Traits in Bread Wheat (Triticum aestivum L.): Experimental Investigation

The study was done on 36 treatments of wheat 25 F1, 10 parental lines and 1 check (GW- 451) in Randomized Block Design (RBD) with three replications during Rabi season 2021-2022, 2022- 2023. The observations were recorded on twelve characters, namely, Days to 50% heading, Days to maturity, Number of effective tillers per plant, Plant height (cm), Length of main spike (cm), Grain filling period, Number of spikelets per main spike, Number of grains per main spike, 100-grain weight (g), Grain yield per plant (g), Biological yield per plant (g), Harvest index (%). The analysis of variance (ANOVA) conducted for both the experimental design and line x tester mating design revealed the presence of sufficient genetic variability among genotypes. Combining ability analysis elucidated higher magnitude of σ2s (estimated variance due to sca) than σ2g (estimated variance due to gca) indicating presence of non-additive gene action for all the characters. A significant GCA effects for grain yield per plant and other crucial traits was exhibited by two lines and two tester which were PBW677, HD3226 for line and C-306, CHIRYA 3 in F1 generation. These specific lines possess valuable qualities as promising parental candidates for hybridization programs. Positive sca effects for grain yield per plant and some other yield components was exhibited by Eleven crosses showed significance. A wide range of variation in the estimates of heterobeltiosis and standard heterosis in positive and negative direction was observed for grain yield per plant in F1. In case of grain yield per plant ten crosses showed positive and significant heterosis over BP and the best among them were DBW222 X HD2967 (68.59), PBW677 X WH711 (55.63), DBW187 X CHIRYA3 (54.03) and HD3226 X CHIRYA3 (44.90). Ten crosses exhibited positive and significant heterosis over standard variety were HD3226 X C-306 (61.68), PBW677 X WH1105 (55.36), DBW187 X CHIRYA3 (31.03), PBW677 X C-306 (30.43) and HD3226 X CHIRYA3 (21.12). However, the number of crosses exhibiting significant estimates and the range of heterosis varied across different traits.