GGE Biplot analysis of genotype × environment interaction in barley genotypes

The interaction between the genotype and the environment creates complexity in yield prediction and is a challenge for breeding programs. The aim of this study was to investigate the genotype × environment interaction and study the grain yield stability of 21 barley genotypes using the GGE biplot model. The experiment was carried out in randomized complete block designs with two replications during 2014-2015, 2015-2016, 2016-2017 growing seasons under rain-fed and irrigation conditions (a total of six environments). The combined analysis of variance for grain yield showed a significant difference for year, genotype, genotype × year, year × location and year × location × genotype. The results of stability analysis by GGE biplot showed that the two first components of GGE biplot explained 72.6% of total grain yield variation. The polygon view of GGE biplot showed three superior genotypes and suitable genotypes in each mega-environment. Based on the biplot patterns, the genotypes 19 was the most unstable accession, whereas genotypes 9 and 1 were identified as stable genotypes, which suggests the superiority of these genotypes compared to the other genotypes. The irrigation environment in 2014 was identified as the most distinctive and representative environment due to its proximity to the average environment.