Ten corn (Zea mays L.) inbred lines were crossed in a complete diallele fashion in 2001. Parental lines along with their Fl crosses were evaluated in a lattice design of three replications. Twelve agronomic traits, including grain yield and some of the yield components were evaluated. Variation among genotypes were highly significant for all the traits. Therefore, variations were partitioned into additive and non additive components according to Hayman and Hayman & Jinks methods.It was observed that a and b components which are due to additive and dominant gene effects respectively, were significant( p<0.01) for all studied characteristics. Also, the maternal effects were
significant for all traits, except number of leaf/plot. The highest average of dominance (1.78 1) was found for kernel depth and the lowest (0.68) detected for number of leaf/plant. Broadsence heritability estimates ranged from 98% for cob percentage to 85% for number of days from planting to maturity. The highest narrowsence heritability estimate was found for date of tassel emergence (75%) while its lowest value (0.11%) was observed for cob percentage. Based on graphical analyses and regression line of array variance — covariances, and the distribution of parent along the regression line, it was concluded that K86/8 inbred line carried the most dominant genes for grain yield, ear height, and ear diameter with K1264/1 inbred line having the most recessive genes for grain yield , ear diameter and number of days from planting to maturity.
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