Evaluation of seed yield stability of oilseed rape genotypes in cold and temperate-cold environments

Genotype ´ environment interaction is one of the most important concepts in plant breeding which can be estimated using diffrerent statistical procedures. In this study, seed yield stability of 22 oilseed rape genotypes under normal and late sowing dates was evaluated during three cropping seasons (2011-14) in West-Islammabad filed station, Kermanshah, Iran. Results of combined analysis of variance showed significant differences between environments, among genotype, as well as genotype ´ environment interaction. Results also indicated that genotypes such as Hyola308, Zarfam, Shiralee, MHA01/18, Elite, Parade and Opera produced higher seed yield with 4487, 4475, 4442, 4408, 4350, 4333 and 4257 kg.ha-1, respectively. Results of AMMI analysis showed that four principal components of genotype ´ environment were significant at the 1% probability level. Proportional of sum of squares for the four principal components genotype ´ environment were 40.7, 28.5, 17.1 and 12.1 percent, respectively. Based on the first two principal components of genotype ´ environment, Parade, Kimberly, Elect, Goliath, Elite and Shiralee were positioned next to the center of biplot which implies high wide-adaptation. Simultaneous selection for stability and seed yield identified Shiralee, Hyola308, Zarfam, Parade, MHA01/18 and Kristina as high yielding and stable genotypes.