Abstract
Half diallel crosses (excluded reciprocal) carried out among the pure lines of maize Agr183, DK, W13R, W17, OH40, IK58, IK8, ZP and SH. Genotypes were planted using RCBDesign with 3 replications, and data collected for plant height, upper ear height, number of rows per ear, number of grains per row, 300 grain weight and grain yield per plant, and statistical analysis conducted to study general and specific combining abilities, gene action and some genetic parameters. The results showed significant mean square for genotypes, general and specific combining ability for all characters. The pure lines W13R, W17, IK58, IK8 and ZP and hybrids W17 x OH40, W17 x IK58 and IK58 x SH shown as a good general and specific combinors for a larger number of characters respectively. The dominance gene action appeared more important than additive one in controlling the inheritance of all studied characters, and the average degree of dominance exceeded one for all characters indicated the presence of over dominance. Broad sense heritability estimates ranged from 72.13% for number of rows per ear to 99.67% for grain yield per plant, and narrow sense heritability shown moderate for 300 grain weight (22.88%) and low for remainder characters, while expected genetic advance as percent of character mean appeared low for all characters (from 0.199% for number of rows per ear to 8.603% for number of grains per row.