Performance and Heterosis for the Yield Traits and Components of Maize (Zea mays L.) Using the Full Diallel Cross Method

Abstract

For the purpose of evaluating five pure lines of maize through the diallel and reciprocal crosses that resulting from it, by estimating Heterosis on basis of deviation of the average of the first generation from the higher and mean parents in the traits of growth and yield. A field experiment was conducted in spring season to perform the full diallel crosses and the autumn season of the year 2020 to compare genotypes in a comparison experiment using RCBD. The results showed significant differences in the traits of days to 50% silking, plant height, number of ears per plant, number of grains per row, 300-grain weight, and grains yield per plant, indicating the variation of the pure lines involved in hybridization. Pure line (5) showed superiority in the number of ears per plant, number of grains per row, 300-grain weight, and grains yield per plant, pure line (3) was distinguished of days to 50% silking trait and pure line (2) in plant height trait. The cross (1×5) was the best diallel crosses at all the studied traits. Regarding the reciprocal crosses, the crosses were superiority as the following : (4×2) in traits of days to 50% silking, and cross (4×3) in the plant height and the two crosses (4×1) and (5×4) in the number of ears per plant trait and (2×1) number of grains per row trait and cross (5x2) in 300-grain weight trait, and cross (4×1) in the grains yield per plant trait. While the results of Heterosis, on basis of deviation of the average of the first generation from average parents, showed that cross in days to 50% silking, 13 crosses in plant height, 20 crosses for the number of ears per plant, and the number of grains per row, 14 crosses in 300-grain weight and 20 crosses in grains yield per plant gave Heterosis in the desired direction in diallel and reciprocal crosses, the values highest of Heterosis in grains yield per plant trait were 26.66% for the diallel cross (1×5). As for the Heterosis based on basis of deviation of the average of the first generation from higher parents was (3) crosses in days to 50% silking, 16 crosses in plant height, 19 crosses for the number of ears per plant and number of grains per row, 8 crosses in 300-grain weight and 20 crosses in grains yield per plant gave the hybrid strength in the desired direction in reciprocal and reverse hybrids, the highest values of Heterosis in grains yield per plant were 47.48% for the cross (1×5). It can be concluded that Heterosis depends on the diversity between the pure lines, which was clear in the pure lines (1) and (5).