Evaluation of Grain Yield Stability and Genotype- Environment Interaction of Barley Promising Lines in Warm and Humid Regions of the Country

In order to investigation of genotype - environment interaction is essential for selecting compatible and stable genotypes in plant breeding. For this order analysis of genotype × environment interaction and identify barley stable genotypes for warm and humid regions, this study conducted in a randomized complete block design with 4 replications and 16 genotypes with two check cultivars in Gachsaran, Moghan, Khorramabad and Gonbad regions for three years (2018-2020). Results of combined analysis of variance for grain yield showed that the effects of genotype and genotype × environment interaction were significant. In order to evaluate yield stability, parametric methods including variance and regression-based methods were used. Results showed that the genotypes 1, 3, 6 and 8 using variance-based methods and the genotypes 1, 6, 12, 13 and 15 using regression-based methods were stable genotypes. Because of different result that obtained from stability analysis methods, the SIIG index was used for grouping of genotypes based on all stability parameters. The check variety of Khorram and Mahoor and genotype 13 and 6 had the highest value of SIIG index and were the most stable genotypes. Genotypes 3, 4, 5 and 9 were the most unstable genotypes. The check varieties and genotype 13 with the high yield had the high agronomic stability and are suitable for high yield areas. Despite of high stability, genotype 6 had the lowest yield and its stability is biological type and thus is suitable for low yield areas.