الفهرس 
Introduction
Mode of gene action and heritabilityOnly 14 pages are availabe for public view
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Abstract
This study has been done for partitioning the genetic variance to its components for fodder traits through studies on different generations of the promising hybrids of teosinte and study the possible association existed between some pairs of fodder traits as well as to study the diversity among teosinte entries using protein electrophoresis. The genetic materials used in this investigation included four teosinte races, Rayana and Balsas, Central Plateau and Guatemala. All possible combinations excluding reciprocal among these four races were made. Six populations; P1, P2, F1, F2, BC1 and BC2 for each cross were obtained. In 2000 and 2001 summer seasons, these entries were evaluated. The results of this study could be summarized in the following : ??Highly significant differences among populations within crosses as well as among populations were found within each cross with respect to all studied traits in three cuts. These results reflected the diversity and the different genetic constitution of parents for these traits in the studied crosses. ??The best combination for fodder yield components was Guatemala <U+00D7> Balsas, which showed the highest means for most of studied traits through the three cuts compared by other two crosses as well as their parents. This finding reflected the presence of heterotic effect and the higher frequency of dominance genes controlling these traits in this cross. ??Positive heterotic values relative to higher parent were observed in the cross Guatemala <U+00D7> Balsas in the three cuts in all studied fodder traits except for leaves weight/stems weight ratio (L/S ratio) in the 1st and 2nd cuts, while negative values were observed in most of occasion for other two crosses, indicating the superiority of this cross Guatemala <U+00D7> Balsas and the presence of high frequency of dominance genes in its parents. ??The results showed that the estimates of mean effect (m) which reflects the contribution due to the over all mean plus the locus effects and the interaction of the fixed loci was found to be highly significant for all studied fodder traits with respect to the three crosses in the three cuts. This finding reflects the contribution of additive, dominance and epistatic gene effects in the genetic expression of these traits. ??The heritability in broad sense estimates were larger in magnitude than the corresponding values in narrow sense and the dominance degree ratio exceeded unity for most of fodder yield components with respect to the three studied crosses. These results insure the role of over dominance in the genetic expression of these traits. Therefore, the production of F1 hybrids could be the best method for improving teosinte forage yield components. ??A significant positive genotypic and phenotypic correlations were observed between green fodder yield/plant and each of number of tillers/plant, plant height, number of leaves/plant and dry fodder yield/plant. ??the high similarity was observed between the F1 hybrids (Guatemala <U+00D7> Balsas) and one of its parental races (Guatemala). This finding may explain the presence of heterosis over better parent in this cross wit respect to fodder yield components.