Investigation of genotype × environment interaction using path analysis and mixed models in barley superior lines

This study was conducted to investigate the yield stability and determine the portion of some Morpho-phonological traits in the GEI effect in barley. For this purpose, a total of 20 barley genotypes were investigated at five tropical research stations of Iran during the 2018-2020 cropping seasons. In all trials, a RCBD with three replications was used. Stability analysis was performed using two set of stability models including parametric statistics and REML/BLUP-based statistics. The results of parametric were pooled in genotype SIIG as a unique stability index. Morpho-phonological data were analyzed using the path analysis. The days-to heading (X1) and days-to maturity (X2), plant height (X3), and 1000-kernels weight (X4) were considered to be sequential traits for the development of grain yield productivity (Y). Based on results, genotypes G6, G2, G3, G5, G13, G17, G11, G12 and G14 with greater grain yield than average grain yields and high values of stability statistics were identified as desirable genotypes in terms of yield performance and stability. Furthermore, three BLUP-based statistics, HMGV, RPGV and HMRPGV, were recognized genotypes G20, G6, G2, G3, G11, G12 and G17 as the high-yielding and stable genotypes. In total, lines G6, G3 and G11, which were superior in both methods, were selected. The results of path analysis revealed that DHE has a positive relationship with grain yield; hence more emphasis should be placed on selection based on spike emergence later to improve the yield potential of barley in warm regions of Iran.