The Study On Genetic Variation Of Partial Quality Indices In Maize

Genetic variability~ genetic effect and genetic correlation of 12 quality indices and heritability genetic advance of 10 of them in a improved maize population NEAU-2 were studied by the means of Triple Test Cross design. The objective of this study was to determine the extent of variability, genetic model and correlativity of these quality indices and to inform the genetic potentiality of this population in order that the quality traits of this population would be utilized and improved more effectively and the result would supply theoretic basis and gist for improving quality traits and breeding high quality maize hybrid.The analysis of Triple Test Cross design suggested that both additive and dominance effect played a magisterial role in all of indices, and epistasis effect was not significant at all of these indices, which could draw a conclusion that all indices?heredity conformed to additive & dominance genetic model. The estimates of genetic constitutions showed that additive effect was relatively big among volume weight, the weight ratio of embryo and endosperm and albumin, based mainly on general compatible ability when selecting them. Dominance effect was relatively big among globulin and gross starch, based mainly on special compatible ability when selecting them. Additive effect and dominance effect played almost the same important role among the other indices, based on general compatible ability and special compatible ability at one time when selecting them.By estimating results of the degree of dominance, it was learned that the degree of dominance of all indices were bigger than 1, which informed that the expression of heterosis of these indices were belong to super-dominance gene action, therefore some breeding materials with indices higher than those of original population might be selected out from this population.The analysis of genetic variance showed that the measure of dispersion and heritability of these indices were relatively big and implied that there were extensively enough measure of dispersion and rather high heritability about these indices in this population and it would result in relatively high genetic advancement. At the same time it also accounted that improvement of these quality indices in this population was feasible.The results of correlation analysis showed that there were pervasive genetic correlated to different degrees among these indices. Furthermore, there were significant or extremely significant correlations to moderate or high degrees among some indices. So indirect selection might be exercised by terms of their genetic correlation and improvement effect would also be enhanced apparently.