油菜抗旱性及鉴定方法与指标 Ⅲ.油菜苗期抗旱性及鉴定指标筛选

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

运用隶属函数综合评判法将各生理指标结合在一起,对苗期油菜抗旱性进行综合评价。相关性分析表明,抗坏血酸过氧化物酶(APX)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性相对值及可溶性蛋白含量相对值与油菜苗期抗旱性呈显著正相关,可作为苗期油菜抗旱性鉴定指标。对以上指标进行回归分析,建立苗期抗旱性鉴定的数学模型:y=-1.059+0.281x1+0.776x2+0.112x3。该数学模型可对不同油菜品种苗期抗旱性进行辅助预测。采用远红外成像技术检测水分胁迫下油菜叶面温度变化,结果表明,根据生理指标筛选到的苗期抗旱性强的3号和10号品种的叶面温度高于抗旱性弱的15号和20号品种。干旱成活率试验结果表明,在严重干旱条件下,根据生理指标筛选到的苗期抗旱性强的品种3、4、10、16号具有较高的存活率,抗旱性弱的15、20号品种的存活率较低,从而证明前期油菜抗旱性鉴定方法是可行的。

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. 112xa （y-D value,xl-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-sen- sitive lines under drought condition, and the percentage of seedling survival were also higher than that of drought-sensitive lines under serious drought condition.