Drought Tolerance Study in Canola (Brassica napus L.) Using DroughtTolerance Indices

In order to investigation of drought stress effect on yield and yield components in canola cultivars and identification of drought tolerant cultivars, an experiment was conducted in research field of agriculture faculty in Islamic Azad University- Karaj branch in 2009-2010. Ten canola varieties in a Randomized Complete Block Design with three replications investigated under normal and stress conditions. Analysis of variance indicated significant differences between genotypes for all traits except lateral branch and weight of hundred kernels. The highest kernel yield in normal experiment was for Likord and Hyola308 cultivars 875.7 and 820.1 grams per square meter respectively. The highest kernel yield in stress experiment was for Likord and Sarigol cultivars 287.88 and 242.65 grams per square meter respectively. Stress Tolerance including Mean Productivity, Geometric Mean Profitability, Tolerance index and Harmonic average were capability to revealed cultivars with high yield potential and drought tolerant and known as best tolerance indices. Base these indices the best cultivar was Likord. Base biplot graph Likord and Zarfam cultivars were the best tolerant and Modena, Okapi, Hyola401 and Hyola308 were the high susceptible cultivars to drought stress.