Genetic analysis for yield and its components in doubled haploid wheat

The inheritance of grain yield and its components (number of spikelets per spike, number of tillers, number of grains per spike, plant height) has been studied through a full diallel cross of eight doubled haploid bread wheat. Generation mean and variance analysis was carried out on P-1, P-2, F-1, F-2, BC1 and BC2 generation of two crosses to complement the genetic information from the diallel analysis. Regression analysis, average of dominance and narrow sense heritability in both experiments revealed additive type of gene action for number of grains per spike and plant height and over dominant type of gene effects for the rest of traits. Although different types of epistasis interaction were found for different trait and cross combination, duplicate dominant epistasis only observed for number of spikelets per spike, number of tillers and grain yield per plant. Correlation analysis of dominant genes with the phenotype of the parents revealed recessive gene control for number of tillers, while dominant gene control proved to account for the rest of the traits studied.