Genotype x Environment Interactions and Simultaneous Selection for High Seed Yield and Stability in Winter Rapeseed (Brassica napus) Multi-Environment Trials

摘要

Multi-environment trials have a fundamental role in selecting the better performing genotypes stable across different environments before its commercial release. Thus, the study was carried out to identify high-yielding stable rapeseed genotypes using different parametric and nonparametric statistics involving 11 new advanced genotypes and 2 cultivars. The genotypes were evaluated in a randomized complete block design with three replications across 12 environments (combination of years and locations) during 2015-2017 growing seasons. The results indicated that genotype, environment and genotype x environment (G x E) effects were significant for seed yield, indicating differential responses of the genotypes to the environments, enabling the stability analysis. According to correlation coefficient and principal components analysis (PCA), the nonparametric measures of S-i((2)), S-i((3)), S-i((6)), NPi(2), NPi(3), NPi(4) and KR were positively and significantly correlated with mean seed yield and thus these measures can be used for selection of the stable genotypes. In general, based on our results four genotypes, G13, G2, G1 and G5 had higher seed yield and stability than control genotypes (G10 and G11). The genotype G13 with the highest yielding and stability performance is the most recommended as promising genotype for commercial release to farmers for cultivation in cold and moderately cold regions of Iran and other similar environments for adoption. Oil content of the genotype G13 was 44.36. Oleic acid, a prominent component (65.78) followed by linoleic acid (16.72) was recognized as the main components in oil content of the genotype G13.