Combining ability analysis of grain yield and some of its attributes in maize (Zea mays L.)

All X 9 dlallel rombining ability analysis showed the predominant role of nonadditive type of gene action in the inheritance of grain yield, ear diameter and 1000-kernel weight. Ear length, kernel rows per ear and kernels per row indicated equal importance of both additive and nonadditive genes. Greater importanre of gca x environment (E) interadion, than of sca x E interadion, was revealed for ear length and diameter, while only sca x E was important for kernel rows per ear and 1000-kernel weight. G x E interariion was of no importanre for grain yield and kernels per row. Two inbreds (P7 and P9) and two crosses (P2 x P8 and P4 x P7) exhibited signifirant and positive gca and sca of effects, respectively, for grain yield and some of its attributes.