Identifying superior barley (Hordeum vulgare L.) genotypes using GGE-biplot across warm and moderate environments under irrigated conditions in Iran

Multi-environmental trials (METs) are essential to study genotype by environment interaction (GEI) for effective line (s) selection and cultivar recommendations in breeding programs. Twenty promising barley genotypes were studied across 12 environments in a randomized complete block design with three replications in six different warm and moderate sites in Iran across two cropping seasons (2014-2015 and 2015-2016) using the GGE-biplot method. The combined analysis of variance revealed that environment accounted for 49.3% of the total variation while G and GE-interaction (GEI) explained 4.4% and 25.1%, respectively. Three genotypes, G6, G8, and G18, were superior in terms of high performance and stability. The 12 test environments were grouped into three different mega-environments (Mega-1, 2 and 3). Genotypes G16, G20 and G9 were identified as the best winning genotypes in Mega-1, 2 and 3, respectively. Based on the GGE-biplot, genotype G3 was found to be the ideal genotype and environments (E8 and E9) were found to be the ideal environments. GGE-biplot provided a reasonable visual examination of the relationships among the test environments, the genotypes, and the GEI. Overall, genotype G3 was better than the other genotypes and is recommended for the warm sites of Iran.