| Abstract: |
Eight white maize inbreds and their twenty eight F1 maize crosses derived from a half diallel cross were evaluated under artificial infection with each of corn leaf aphid caused by Rhopalosiphum maydis (Fitch) resistance, common smut caused by Ustilago maydis resistance, earliness, as well as, yield and its attributes under two sowing dates (May, 29 and June, 19).Mean performance; Phenotypic, genotypeic and environmental correlation coefficients between either of number of aphids / plant or disease severity % and each of earliness i.e. days to 50% tasseling and days to 50% silking, number of ears /plant, number of grains /row, total phenol content and grain yield (ard. / fad.); also, heterosis, magnitudes and significancy of both general and specific combining ability, components of genetic variances and heritability of the studied characters were estimated.The results indicated that the inbred lines L120, L74, L144 and L173 (and their single crosses) were the best combiners for corn leaf aphid resistance, common smut resistance, earliness, grain yield and most of its attributes.The additive gene effects were larger in its magnitude than dominance ones for corn leaf aphid resistance, common smut resistance, earliness, and number of rows/ear. However, both additive and dominance gene effects were important in the inheritance of ear height, ear diameter, number of ears/plant and l00-grain weight. Moreover, the dominance was more pronounced in the inheritance of T.S.S.%, plant height, ear leaf area, ear length and grain yield.
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