Drought Resistance and Identification Method and Evaluation Index in Brassica napus III.Selection of Drought Resistance Identification Index at Seedling Stage

The identification indexes of drought resistance were evaluated by subject function with correlation analysis at seedling stage.The results showed that the relative activity of APX,SOD and CAT and relative content of soluble protein were significantly positively correlated to drought-resistance,and these 4 indexes can be used to identify the drought-resistance of rapeseed at seedling stage.By line regression analysis,these 4 indexes were used to construct an equation y=-1.059+0.281x1+0.776x2+0.112x3(y-D value,x1-relative activities of APX,x2-relative activities of SOD,x3-relative content of soluble protein).Far IR thermography was employed to measure the variation of seedling leaf temperature of rapeseed under drought stress.The results showed that leaf temperature of drought-tolerant lines screened by physiological indexes were higher than that of drought-sensitive lines under drought condition,and the percentage of seedling survival were also higher than that of drought-sensitive lines under serious drought condition.