甘蓝型油菜苗期抗旱性鉴定及抗旱生理指标的评价

Identification of drought resistance and physiological evaluation of drought resistance of Brassica napus L.at seedling stage

以120份西北地区甘蓝型油菜种质为试验材料,人工气候室盆栽,油菜五叶期时采用PEG-6000模拟干旱处理,通过抗旱指数和生理指标测定,对120份材料进行抗旱鉴定,探讨甘蓝型油菜抗旱指数与8个抗旱生理指标之间的相关关系及甘蓝型油菜抗旱性鉴定指标的选择。结果表明:120份种质中高抗旱材料6份、中抗10份、低抗23份、低感42份和高感39份;不同油菜种质干旱处理后可溶性糖、脯氨酸、可溶性蛋白等生理指标发生明显变化,增加率分别为94.7%、432.8%和95.7%;抗旱指数与可溶性蛋白含量(0.521**)、可溶性糖含量(0.506**)、脯氨酸含量(0.495**)和叶片保水力(0.426**)呈极显著正相关,与丙二醛含量(-0.372**)呈极显著负相关;对抗旱指数直接影响最大的是可溶性蛋白,直接通径系数为0.384,间接影响最大的是SPAD值,间接综合效应为0.196。通过主成分分析,可将相关指标综合为3大类:渗透调节因子、水分保持因子和膜脂损伤因子。

One hundred and twenty species of Brassica napus L.germplasms in northwestern China were used as experimental materials in a pot experiment in artificial climate chamber with PEG-6000 simulated drought treatment at five-leaf stage of rapeseed,phenotypic identification,and physiological index determination.The data was analyzed by correlation analysis and principal component analysis and the drought resistance of 120 materials was evaluated.The correlation between drought resistance index of Brassica napus L.and 8 drought resistance physiological indexes were discussed,and the main influencing factors of drought resistance of Brassica napus L.were determined.The results showed that there were 6 high drought-resistant materials among 120 germplasms,10 in medium resistance,23 in low resistance,42 in low-sensitivity,and 39 in high-sensitivity.Soluble sugar,proline and soluble protein in different rapeseed germplasms after drought treatment showed significant changes with the increase rates of 94.7%,432.8%,and 95.7%,respectively;There were significant correlations between the drought resistance index and soluble protein content(0.521**),soluble sugar content(0.506**),and proline content(0.495**).There was a significant positive correlation with leaf water retention(0.426**)and a significant negative correlation with malondialdehyde content(-0.372**).The most direct impact of drought resistance index was on soluble protein with a direct diameter coefficient of 0.384.The most influential was the SPAD value,and the indirect combined effect was 0.196.Through principal component analysis,the relevant indicators was integrated into three categories:osmotic adjustment factor,water retention factor,and membrane lipid damage factor.