Evaluation of seed yield stability of barley promising genotypes using principal coordinates analysis

Analysis of the structure of genotype by environment (GE) interaction is essential in crop stability programs. To study the effects of GE interaction on the seed yield and identify stable genotypes of barley for warm and humid regions, 16 barley genotypes with two check cultivars were assayed in a randomized complete block design with four replications in Gachsaran, Moghan, Khorramabad and Gonbad regions for three years (2017-2019). Combined analysis of variance for yield data of 12 environments (year/location combined) showed significant differences among environments and genotypes and significant GE interaction. The GE interaction was examined using principal coordinates analysis (PCoA). Based on the deviation from the grand mean, 12 environments were divided into two main groups: five environments with higher mean yield and seven environments with lower mean yield. The most stable genotypes based on the minimum spanning tree and distance from the center of plots were G13 (2.43 kg/ha), G2 (2.38 kg/ha), G14 (2.29 kg/ha), which could be recommended for environments with a yield lower than the average mean of all studied environments. The results of the PCoA showed that the genotype G18 (2.32 kg/ha) was also located five times in the vertex positions of high cycles and so it can be recommended for favorable or high yielding environments.