The present study was carried out to determine the combining ability for yield and yield associated traits by crossing 8 diverse maize inbred lines in a half diallel mating design. Twenty eight F1 progenies along with their parents were planted in randomized complete block design with four replications in two environments. Combined analysis of variance showed significant mean squares of general combining ability (GCA) and specific combing ability (SCA) for days to ear silking (DS), plant height (PH), 1000-kernel weight (KW), number of kernels in ear row (KR), number of rows in ear (NR), kernel length (KL), cob to ear weight ratio (CR) and kernel yield (KY) indicating the importance of both additive and non additive genetic effects for these traits. However, high narrow-sense heritability estimates, low degree of dominance and the ratio of estimates of GCA to SCA effects for DS, KW, NR and CR indicated that additive genetic effect were more important for these traits. Most of the crosses with significant SCA effects for DS and KY had at least one parent with significant GCA effects for the same traits. Significant positive correlations were detected between KY and other yield components which included; KW, KR and KL. Therefore, these traits can be used as indirect selection criteria for seed yield improvement. The crosses MO17 × L8, MO17 × L12 and MO17 × L24 had high KY and were thus, considered as good combinations for improving the trait.
Key words: Additive, combined analysis, correlation, dominance, heritability.