Genetic analysis of grain yield and its components of maize in lines and F2 progenies using diallel analysis by Hayman’s graphical approach

To estimate gene action and heritability of yield and yield components of maize, F2 progenies derived from half-diallel cross of five S7 maize lines along with parental lines were assessed in a randomized complete block design with three replications at the Research Farm of Graduate University of Advanced Technology, Kerman, Iran, in 2017-18. The studied traits were grain yield and its components including number of ear per plant, number of grain per ear, number of grain row, number of grain per row, ear length and 100-grain weight. Results of analysis of variance showed significant differences among genotypes for all studied traits at 1% probability level. The results of Hayman’s graphical analysis also indicated that the contribution of non-additive gene effects was more important than additive effects in controlling most traits. Number of ear, number of grain per row and grain yield per plant were controlled by the incomplete dominance effects of genes, while the other traits were controlled by over-dominance effects. Broad sence heritability of the traits varied from 0.03 for number of grain row to 0.50 for 100-grain weight. The results of this study showed that both hybrid production and selection methods can be used to breed the number of ear, number of grain per row and grain yield per plant, but to breed the other traits in the studied population, the use of heterosis phenomenon and hybrid production is suggested.