Analysis of grain yield stability and assessment of genotype × environment interaction for grain sorghum (Sorghum bicolor L. Moench) genotypes

The interaction of genotype × environment creates complications in yield prediction and is a challenge for agronomy and plant breeding programs. To evaluate grain yield stability and genotype × environment interaction for 18 local and exotic grain sorghum cultivars, lines, and hybrids, a field experiment was conducted using randomized complete block design with three replications in four regions of Karaj, Gorgan, Birjand, and Isfahan, Iran in two cropping seasons (2016 and 2017). Combined analysis of variance showed that locations, genotypes and their interaction effect were signifinat on grain yield. Mean comparisons showed that genotype No. 15 (High yield700) had the highest grain yield (7986 kg.ha-1) followed bygenotypes No. 17, 6, 16, and 8 with grain yield of 6894, 6172, 5960, and 5906 kg.ha-1, respectively. Genotypes No. 15 and 17 had the lowest year within location variance, and in addition to high grain yield stability had optimal grain yield. Analysis of variance by AMMI model and fitting of principal components to the interactions of genotype × environment showed that five main components were significant (P ≤0.01). These five components explained 94.1% of the observed variance of genotype × environment interaction. Cluster analysis identified four genotypic groups based on the first main component of genotype × environment interaction. In this study, high yielding genotypes also had good grain yield stability. AMMI model and AMMI stability value (ASV) parameter showed that genotypes No. 17 (Drought tolerant), 4 (Fast green400), 6 (FGCSI04), 15 (High yield700) and 16 (Human900) had high grain yield and yield stability. Genotypes No. 15 and 17 identiifed as superior genotypes well adapted to different test environments, in this study.