A half-diallel mating system was used to evaluate six wheat cultivars and their F₁ and F₂ populations for inheritance of earliness and morphological and yield traits. These genotypes were crossed in a half-diallel fashion during 2010–2011 to get 15 cross combinations. The 6 × 6 wheat F₁ and F₂ half-diallel populations and their parental cultivars were assessed in a randomized complete block design during 2011–2012 and 2012–2013, respectively. Genotypes revealed significant (P ≤ 0.01) differences for all the traits in both generations. According to scaling tests, an additive–dominance model was partially adequate for all the traits in the F₁ and F₂ generations. Diallel analysis revealed significant values for additive (D) and dominance (H₁ and H₂) genetic components of variance for majority traits in both generations, however, the overdominance type of gene action was predominant for inheritance. Additive gene action was observed for days to heading and plant height in the F₁ generation and tiller per plant and grain yield per plant in the F₂ generation. In the loci (H₂ < H₁), the majority of the traits showed an unequal proportion of positive and negative genes with asymmetrical distribution among parental genotypes (H₂/4H₁ < 0.25). Significance of both additive and nonadditive genetic variations suggested integrated breeding strategies with delayed selection for improvement in wheat populations.