Inheritance of yield components of white endosperm maize [Zea mays L.]

This thesis examines the inheritance mode of grain yield, ear length, number of kernel rows per ear, number of kernels per row, 1000-kernel weight and plant height in a diallel cross of six white endosperm maize inbred lines. Comparative field trials with parent inbreds and hibrids were conducted in the locations of Pancevo, Becej, Indjija and Zemun Polje (Serbia, Yugoslavia) during 1997. Statistically very significant values of GCA (general combining ability) and SCA (special combining ability) were detected for all six examined traits. The analysis of variance for combining ability shows that dominant gene action is of crucial significance in inheritance of grain yield, ear length, number of kernels per row and plant height, while additive gene action is more important in the inheritance of the number of kernel rows per ear and 1000-kernel weight. Analysis of genetic components of variance shows that non-additive componet was the most important in all six examined traits. These results were not in accordance with the results of the combining ability analysis of traits 1000-kernel weight and number of kernel rows per ear. The presence of epistasis was detected only for plant height. The results of the Vr/Wr regression analysys demonstrate that superdomination is present in the mode of inheritance of all observed traits, except number of kernel rows per ear where partial domination was detected. The examined traits have a high-level of broad-sense heritability and a low level of narrow-sense heritability. Number of kernel rows is the only trait that has been found as an exception to this rule with a relatively high degree of heritability in the narrow sense. Pairwise rank correlation for grain yield per location shows that all four locations had an important role in the performance of monitored genotypes. Multiple rank correlation results indicate that there is a significant correlation among the ranks of hybrid yields achieved in Becej, Indjija and Zemun Polje (Serbia, Yugoslavia).