Evaluation of F1S ’ , F2S ’ Hybrids , Heterosis , and Inbreeding Depression of Maize (Zea mays L.)

Abstract

Six hybrids maize (Zea mays L.) line:(1) ZM4L,(2) ZM51L,(3) ZP-301,(4) ZM19L, (5) OH, and(6) Un440 were used in crossing program for obtaining first-generation hybrids during the spring 2016 season. Selfing F1s’ of the previous hybrids on autumn season of the same year led to obtained the second-generation hybrids. The inbred lines Two generations hybrids were planted on 2017 spring season. The experiment was carried out by using Randomized Complete Block Design (RCBD), with three replicates. The goal of the experiment was to find out the performance of genotypes and estimation of heterosis based on the best parent, of the commercial hybrid (CADZ). of first-generation hybrids and inbreeding depression of the second-generation on the days to female flowering. Other characteristics including; plant height, leaf area, number of rows per ear , number of kernel in each row, weight of 300 grains, and yield of individual plant . The results of the statistical analysis revealed significant differences of all the studied characteristics of each parents, the first-generation, and second-generation except for the number of days of male flowering. Hybrid; Un440 x ZM4L showed a significant and desirable heterosis for the plant height, leaf area, and number of kernel in the rows compared to the best parents and commercial variety. The hybrids; ZM19L x ZM51L and Un440 x ZM51L, showed it did not happen to them inbreeding depression because of the negative and significant correlation with the desired the number of kernels in the row. While, the hybrid; OH x ZM4L , for the number of rows per ear and the hybrid; OH x ZM19L , for the weight of 300 grains.