Generation mean analysis was used to study the type of gene action and heritability estimates for grain yield per paint, mean panicle weight and lenghth, Plant height, and number of days to flowering. Seventeen families, as the main plots, consisting of parental line, Fl and F2 generations, as the subplots, were evaluated in a randomized complete block design with 5 replications. The mean squares for family and generation within family were statistically significant for all of the traits studied. Therefore, high genetic potentials and variances were existed amongst the materials. Generation mean analysis as described by Mather and Jinks showed that for most of the families, the traits were genetically controlled by additive and dominant gene effects, although nonallelic interactions were revealed for some of them. In most of the families the additive and dominant gene effects were in the direction to increase most of the trits, except number of days to flowering. The degree of dominance in most of the families indicated the predominance of dominant gene effects. Different heritability estimates were observed in different families, and their averages ranged from 50. 99%, for panicle lengh, to 77.54%, for plant height. The estimates of narrow-sense heritability based on regression of F2 means on Fl, ranged from 19:55% for grain yield per plant, to 64.71% for plant height, indicating the effectiveness of selection for some of the traits studied.
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