Genotype×environment interaction analysis using GGE biplot in grain maize (Zea mays L.) hybrids under different irrigation conditions

Evaluating of the maize genotypes under different stresses would be useful to identify genotypes with stable and high yield potential. The objective of this study was to estimate yield stability of the grain maize hybrids and identifying high yielding stable hybrids under different water stress conditions in Moghan, Ardabil, Iran. So, seven maize hybrids were assessed by randomized complete block design with three replications under four irrigation conditions including normal irrigation (E1), water deficit at vegetative (E2), water deficit at flowering and (E3) water deficit at grain filling (E4) stages during three years (totally 12 environments). Combined analysis of variance showed that the effects of environments, genotypes and genotype-by-environment (GE) interaction were significant, suggesting that the hybrids responded differently in the studied environment conditions. Therefore,  there was the possibility of stability analysis. Results of stability analysis by GGE biplot method revealed that two first and second principal components of the GGE biplot explained 94.7% of the total yield variation. In stability ranking graph of the GGE biplot, SC700, TWC600 and SC724 hybrids were the most stable hybrids, respectively, and the higher grain yield hybrids than the average grain yield were SC704, SC724, SC703, SC720 and SC647 hybrids, respectively. Based on a hypothetical ideal genotype biplot, the hybrid SC704 was better than the other hybrids across environments for grain yield and stability and had the high general adaptation to all environments. Furthermore, the hybrid SC704 at E1, E2 and E4 environments and hybrid SC647 in E3 environment were superior hybrids with the high specific adaptation. Also, comparison of the studied environments showed that the E1 and E4 environments were quite similar in ranking, grouping and assessing stability of the hybrids, whereas the E2 and E3 environments were different from the other environments.