Gene action for pre and post harvest traits in F2 wheat populations

The inheritance mechanism for plant height, days to heading, spike length, grains spike-1 and biological yield traits in 8×8 half diallel F2 wheat populations was studied at Agricultural University, Peshawar, Pakistan, during 2006-07. The experiment was laid out in randomized complete block (RCB) design having four replications. Each experimental unit was assigned a four-row plot of 5m length with row-row space of 30cm. Analyses of variance displayed significant genotypic differences for studied traits. Diallel analyses reflected significance of both additive and non-additive components in the inheritance of these traits, however, genetic components revealed the importance of a non-additive component. The average degree of dominance being greater than unity indicated involvement of over dominance for phenotypic expression of all traits studied. Broad-sense heritability values were much higher than narrow-sense and thus delayed selection till advance generations are suggested.