Graphic analysis of genotype, environment and genotype × environment interaction on the seed yield of sunflower

Studying the reaction of the different genotypes under different environmental conditions helps breeders to detect stable and high-yielding genotypes. In this regard, 11 new sunflower hybrids along with four cultivars (Golsa, Ghasem, Shams, and Farrokh) were evaluated in a randomized complete block design with four replications in four experimental field stations (Karaj, Sari, Kermanshah, and Dezful) during two cropping seasons. GGE biplot statistical method (genotype effect + genotype × environment interaction) was used to study the adaptation of genotypes in the studied environments. Results of combined analysis of variance indicated that the effects of environments, genotypes, and genotype × environment interaction were significant, suggesting that the genotypes responded differently in the studied environment conditions. Results of the GGE biplot method showed that the two first and second principal components of the GGE biplot explained 66.4% of the total seed yield variation. Based on the biplot polygon view, the hybrid RGK15×AGK1221 in Sari and Karaj locations and the hybrid RGK25×AGK330 and Shams cultivar in Dezful location were superior genotypes with the high specific adaptation. Besides, all environments had high discriminating ability so that could able to show differences between genotypes. Sari environment was the nearest environment to the ideal environment that had the highest discriminating ability and representativeness.