Stability analysis of bread wheat genotypes (Triticum aestivum L.) by GGE biplot

Biplot related to the effects of genotype and genotype × environment is called GGE biplot. This method is used to assess the stability of genotypes. In this methodology, selection of sustainable varieties is based on genotype and genotype by environment interaction effects. In this research, the stability of 18 bread wheat genotypes was investigated in six environments (three years and two environmental conditions, irrigated and rainfed). The experiment was carried out in randomized complete block design with three replications under both conditions in experimental field of Faculty of Agriculture, Razi University, Kermanshah, Iran, during three years (2010-2012 and 2014-2015). The results of combined analysis of variance showed that the environment, genotype and genotype by environment interaction effects were 75%, 5.9% and 14.9% of total variance, respectively. Pishtaz and WC-4530 genotypes were the nearest genotypes to ideal genotype. Due to the high correlation between E1 (rainfed condition, 2010-2011) and E2 (irrigated condition, 2010-2011) and among E5 (rainfed condition, 2014-2015), E3 (rainfed condition, 2011-2012) and E4 (irrigated condition, 2011-2012), these environments were identified as similar environments. Simultaneous evalution of stability and yield of the studied genotypes showed that WC-4530 is stable and high yielding genotype. View of polygon graph revealed five superior genotypes and three mega-environments, and the compatible genotypes were determined for each mega-environment. All experimental environments had good differentiation ability.