تجزیه پایداری عملکرد روغن در ژنوتیپ های مختلف کلزا (Brassica napul L.) در دو تاریخ کاشت نرمال و تاخیری در استان کرمانشاه

In order to evaluate oil yield stability in oilseed rape genotypes and genotype´environment interaction, 22 oilseed rape genotypes were evaluated using RCBD design with 4 replications in Agricultural Research Station of Islam Abad-e-Gharb during 3 cropping seasons in normal and delayed sowing date conditions. Combined variance analysis showed that genotype, environment and genotype´environment interaction were statistically significant. Proportion of environment effect followed by genotype´environment interaction was so greater than genotype effect. Based on biplot of two first genotype´environment interaction components, that explains proportion of oilseed rape genotypes in genotype´environment, genotypes Parade, Kristinia, Goliath, Shiralee, Kimberly and Elect were located next to center of biplot so that had the least proportion for the Genotype´Environment effect and were stable from the viewpoint of oil production. AMMI stability values (ASV) of genotypes confirmed the above mentioned results. Hyola401 and Zarfam were located away from the center of biplot so that were unstable genotypes for oil production. Biplot display indicated that environments E1, E3 and E4 had the most scores for genotype´environment interaction whereas E2 had the least proportion in genotype´environment interaction effect. Dissimilarity in ranking of selected genotypes from the viewpoint of oil yield based on other stability parameters suggests that it would be better using of numerous stability parameters to reliable and accurate selection of stable genotypes.