Study on stability parameters for determining the adaptation of sugar beet commercial varieties in different areas of Iran

To perform stability analysis and study G*E interaction, eight commercial sugar beet varieties were evaluated in eight major sugar beet producing areas of Karaj, Mashad, Miandoab, Esfahan, Shiraz, Kermanshah, Moghan and Hamadan in three years using a Randomized Complete Block Design with four replications. The evaluated varieties were BR1, 7233, PP.8, IC, 7233-P29, PP22, H5505 and 41RT. Having done the simple and combined analysis, the stability parameters such as environmental variation, environmental coefficient of variation, Wrick’s ecovalence, stability variance (Shukla), coefficient of linear regression, mean square of deviation from regression, linear coefficient of determination and intralocation variation for six traits including RY, SY, WSY, Yield, K/S and KNa/S were calculated and compared with each other. Results of the combined analysis showed a significant difference in genetic variation among varieties for all traits and between years and locations, too. G * E interaction for RY, SY, Yield, K/S and Kna/s and G *L interactions for WSY were significant. Results derived from stability analysis showed the utmost utility of the variety, IC, in comparison with other varieties, because of its absolute stability based on three important traits: RY, SY and WSY. Two parameters, Wrick’s equivalence and stability Variance of Shukla, were shown to be exactly the same to determine the stable variety. Environmental variation and environmental coefficient of variation, in spite of having similarities in most traits, was not completely the same. There was a high correlation between the mean square of determination from regression and linear coefficient of determination in all traits and it was expectable because they both show the fitness of regression line.