Genetic Characterization in 5 × 5 Diallel Crosses for Yield Traits in Bread Wheat

The seed of five parental cultivars alongwith their 10 F1 hybrids of wheat were sown in a randomized complete block design with four replications during 2010 at Sindh Agriculture University, Tandojam, Pakistan. Genetic analysis of yield traits from half diallel crosses was carried-out. Mean squares due to GCA and SCA were significant for days to 75% maturity, tillers plant^-1, spike length, spike density, grains spike^-1, grain yield plant^-1, seed index and harvest index. Significance of GCA and SCA variances suggested that both additive and non-additive genes were controlling these characters. The magnitude of SCA variances were higher than GCA indicating pre-dominance of non-additive gene effects for spike length, spike density, seeds spike^-1, grain yield plant- and harvest index, while GCA variances were greater for days to 75% maturity, tillers per plant. Parental cultivar TD-1 expressed maximum GCA effects for tillers plant^-1, spike length, grain yield plant^-1, seed index and harvest index; while negative and desirable GCA for days to 75% maturity. The SCA estimates revealed that F1 hybrid TD-1 × TJ-83 manifested maximum SCA effects for tillers plant-1, spike length, grains spike-1 and negative yet desirable for days to 75% maturity. The cross TJ-83 × Sarsabz recorded with higher estimates for grains spike^-1, grain yield plant^-1, seed index and harvest index. Thus both the F1 hybrids may be choice breeding material for hybrid crop development to improve the yield traits.