Genetic Analysis of Diallel Crosses in F2 Bread Wheat (Triticum aestivum L.)

Six parents (Pandas, Gemeny, Saberbey, 69-S3, 35-S6, and Kvz/Cgn) and their F2 hybrids obtained by the selfing of F1 ,S from half diallel wheat crosses were used to estimate general combining ability for their F2 hybrids, gene effect through variance components and graphical analysis for maturity time, plant height, grain yield ,number of spikes / plant, spike length, 100-grain weight and number of grains spike. Seeds of parental varieties and their f2 generations from diallel crosses were grown at the plant experimental station, College of Education, Mosul University, during the growing season (2003-2004) according to the Randomized complete Block design with four replications, under rainfall conditions. The results showed highly significant variances for both general and specific combining abilities for all studied characters, this indicates the presence of additive and non-additive gene effects for these characters. Narrow sense heritability values ranged from 0.15 for number of grains / spike to 0.73 for 100-grain weight. The average degree of dominance and the graphic analysis revealed the partial dominance for 100-grain weight and over dominance for the remaining characters.