Estimation of Combining Ability and Gene Action in Half Diallel Crosses of Bread Wheat (Triticum aestivum L.) Genotypes

The study evaluated 55 wheat treatments, including 46 F1 hybrids, 10 parental lines, and one standard check variety, using a diallel mating design during the 2019-2020 rabi season at the Research Farm of BRD PG College, Deoria, Uttar Pradesh. The parental lines included LAWL-1, HUW-206, Allahabad local, Shriram-303, RAJ 4120, PUSA 2733, RAJ 4037, PBW 243, DH 3171, and PBW 502. Analysis of variance (ANOVA) revealed significant differences among the genotypes for all traits except the harvest index. Key traits such as plant height, flowering days, maturity days, grains per spike, and seed germination varied significantly among parents and hybrids, indicating hybrid vigor. General Combining Ability (GCA) analysis highlighted LAWL-1 as a strong combiner for biological yield, harvest index, and gluten content, while PBW 502 was effective in reducing plant height. Specific Combining Ability (SCA) analysis identified promising hybrids like LAWL-1 x DH 3171 and RAJ 4120 x PBW 502, which showed significant improvements in grain yield, plant height, and harvest index. These findings emphasize the importance of selecting appropriate parents and hybrid combinations to enhance specific traits and support wheat breeding programs focused on improved yield, early flowering, and efficient threshability.