Genetic analysis of flowering times and physiological maturity traits by analyzing the generation mean analysis of four maize hybrids and calculating the hybrid vigor and the of hetrosis percentage (field traits)

Abstract

With the aim of determining the optimal way to develop yield characteristics by adopting statistical and genetic design as an electoral indicator to improve yield characteristics in new generations. A field experiment was carried out at the Field Crops Research Station, College of Agricultural Engineering Sciences - University of Baghdad - Al-Jadriyah to estimate the averages of the six generations, the hybrid vigor, and the hetrosis percentage that control the inheritance of the field traits of the selected inbred lines and their resulting hybrids using Generation Mean Analysis. Five were selected Pure inbred lines of maize (ZA17WR), Zi17WZ, ZM74, ZM19, ZM49W3E), from fifteen different strains with flowering and maturity times. In the spring season of 2019, it was multiplied according to the objective (early In the spring season (2020) to produce the six generations: P1, P2, F1, F2, BC1, and... The six generations (BC2), P1, P2, F1, F2, BC1, and (BC) of the four hybrids were evaluated in comparative experiments using a randomized complete block design (RCBD) with three replications. In the fall season of 2020, statistical analysis was carried out on the hybrid vigor, and the hetrosis percentage of hybrids was calculated for the characteristics of tasselling and Silking, plant height, comb height, number of leaves, and leaf area index. The results of the analysis showed that the fourth hybrid gave the first generation the lowest number of days of tasselling, amounting to 47.33 days, and the second backcrossed parent was 53.33 days later than the two parents. The same applies to the silking characteristic, as the average number of days for the first generation was 50.66 days, and for the second regressive father, 57.66 days. Negative hybrid vigor and a negative hybrid ratio indicate the presence of superior or partial dominance of the genes of the earlier father. The third hybrid excelled by giving it the highest plant height of 181.15 cm and a positive hybrid and hybrid strength of 10.71. While the second hybrid excelled in the upper plant height, reaching 108.34 cm, the second regressive parent 97.99 cm, with negative and positive hybrid vigor, and a hetrosis rate of 13%.. The second hybrid also excelled in the number of leaves and leaf area index over the rest of the hybrids by 15.45 leaves (3.025 leaves, respectively. We conclude from the above that the superior or molecular dominance of the genetic action is the result of the superiority of the individuals of the first generation over the parents and their average in field traits. Therefore, we recommend using the method of reciprocal recurrent selection (RRS).