Identifying drought Tolerant Canola Genotypes using Selection Index of Ideal Genotype

Drought stress is one of the most important abiotic factors which adversely affects growth, metabolism and yield of crops worldwide. The goal of the research was identify drought tolerate canola genotypes using the different drought tolerance indices. The experiment was conducted as split plot based on randomized complete block design with three replications at the experimental farm of agricultural and natural resources research center, Yazd, Iran .Two irrigation levels consisting of irrigation after 80mm evaporation from class “A” pan as control, no irrigation from flowering stage were applied in main plots and subplots were 21 winter canola cultivars/double haploid. Six drought tolerance indices, including stress tolerance index (STI), geometric mean productivity (GMP), stress susceptibility index (SSI), mean productivity (MP), stress tolerance (TOL), harmonic mean (HM) were used and calculated for all treatments. Then selection index of ideal genotype (SIIG) based on both tolerance indices (STI, GMP, SSI, MP, TOL, and HM) and morphological traits were defined and calculated. Selection index of ideal genotype (SIIG) is a decision making method that is very simple to implement. The results showed water stress negatively affected yield and yield components, plant height, and number of branches of rapeseed genotypes. Based on the results "SLM046" and "Adriana" with maximum SIIG (0.791 and 0.756) were identified as the most ideal genotypes among assessed genotypes. As "SLM046" and "Adriana" genotypes were superior to the other genotypes under drought condition, they can be considered as promising genotypes for drought regions. These results were also approved by three dimensional scatter graphs. It is concluded that selection index of ideal genotype (SIIG) could be serve as an appropriate index to identify drought tolerance genotypes based on a set of drought stress tolerance indices and morphological traits in crops.