Heterosis, Genetic Parameters ofMaize (Zea Mays L.) Usingthe Half Diallel Cross Method

Abstract

ABSTRACT: A field experiment was conducted in the spring season to conduct single crosses with half diallel cross, and autumn from the year 2020 For comparing eight genotypes (Zm-1, Zm-2, Zm-3, Zm-4, Zm-5, S2, S5 and S6) in a comparison experiment using a randomized complete block design (RCBD). The results showed significant differences in the traits: days to 50% silking (DTS), plant height (PLH), number of ears per plant s per plant (NEPP), number of grains per row (NGPR), 300 grain weight (300 GW) and grains yield per plant (GY), indicating the variance pure lines involved in hybridization. pure line (2) was distinguished by its superiority in the trait of plant height, number of ears per plant s per plant and grains yield per plant. It was also found that the pure line (1) in the traits of days to 50% silking, the pure line (5) in 300 grain weight, and pure line (8) in the trait of number of grains per row. the cross (5×7) was the best hybrid in traits, with 300 grain weight and plant grain yield. The results of the study of Heterosis Relative to Mean Parents showed that (28) crosses in days to 50% silking, (27) crosses in plant height, (20) crosses for number of ears per plant s per plant, (28) in number of grains per row and grains yield per plant, (26) crosses 300 grain weight gave Heterosis Relative to Mean Parents in the desired significant direction in single crosses, As for the Heterosis Relative to Higher Parents, it was (28) crosses in traits of days to 50% silking, (26) crosses in plant height, (18) crosses for number of ears per plant s per plant, (24) in number of grains per row, (20) crosses At a 300 grain weight and (22) in grains yield per plant. The highest values of Heterosis Relative to Mean and best parents in traits of grains yield per plant, were 24.08% and 23.18 for the cross (5×7), respectively. It can be concluded that the heterosis depends on the diversity between the lines, which was evident in the lines (5) and (7). The ratio of σ2sca\σ2gca was less than one for all the studied traits in crosses. This was reflected in the value of degree of dominance, which was greater than one in all the studied traits of crosses. The ratio of broad sense heritability was high and in the narrow sense low in all traits .studied in the crosses