Stability and genotype × environment analysis of oil yield of sunflower single cross hybrids in diverse environments of Iran

Multi-environment trials have a fundamental role in the selection of the best genotypes across different environments before its commercial release. This study was carried out to identify high-yielding stable sunflower hybrids using the graphical method of the GGE biplot. For this purpose, 11 new hybrids along with four hybrid cultivars were evaluated in a randomized complete block design with four replications across 8 environments (combination of years and locations) during the 2018–2020 growing seasons. The mean oil yield of the environments varied from 833 kg ha⁻¹ in E4 to 1565 kg ha⁻¹ in E5 and the oil yield of hybrids ranged from 1085 kg ha⁻¹ in hybrid H9 to 1565 kg ha⁻¹ in hybrid H8. The results indicated that genotype (G), environment (E) and genotype × environment (G × E) effects were significant for oil yield. The G, E, and G × E interaction effects accounted for 64.83, 11.86, and 23.31% of the total variation, respectively. Results of biplot analysis showed that the first and second principal components accounted for 45.9% and 20.4%, respectively, and in total 66.3% of oil yield variance. GGE biplot analysis indicated two major mega-environments of sunflower testing locations in Iran. Based on the hypothetical ideal genotype biplot, the hybrids H3 and H5 were better than the other hybrids in terms of oil yield and stability, which had the highest general adaptation to all of the environments. Based on the ideal genotype from the most desirable to the most undesirable the hybrids were ranked as follows: H5 > H3 > H8 > H14 > H6 > H2 > H13 > H12 > H10 > H11 > H1 > H7 > H4 > H15 > H9. Furthermore, ranking of the environments based on the ideal environment introduced Sari as the best environment. Therefore, Sari can be used as a suitable test location for selecting superior sunflower hybrids in Iran.