A half diallel cross between seven inbred lines of maize were evaluated under two different planting dates for yield and its components. The results showed that the mean squares for planting date, genotypes, parental inbred lines, crosses and parent vs crosses were highly significant for all studied traits. The crosses P3xP5, P4xP5, P4xP7 , P5xP7 and P6xP7 in early planting date, P5xP7 in late planting date and P4xP5, P4xP7 and P5xP7 in the combined analysis, had significant out yielded (heterosis) than the best check hybrid (SC Pioneer 30k8). The mean squares associated with general and specific combining ability were significant for all traits, GCA/SCA ratio was less the unity for all traits except No. of rows ear-1, indicating that greatest role of the non-additive type of gene action in the expression of these traits. The parental inbred lines P4 and P7 seemed to be the best general combiners for grain yield plant-1 and some of its components in the combined analysis of both planting dates. The parental combinations P3xP5, P4xP5, P4xP6, P5xP6, P5xP7, P1xP4 and P2xP4 had the best SCA effects for grain yield plant-1 in the combined analysis. The genetic diversity (GD) among seven parental inbred lines was investigated using Random Amplified Polymorphic DNA (RAPD). The genetic diversity among seven parental inbred lines ranged from 0.19 to 0.49. The correlation between GD and mean performance for grain yield which computed for 21 hybrids combination were found positive (r = 0.07). Therefore, this specified tendency could be predicted about the relationship of GD for grain yield plant-1 in this study. |
