【摘要】 以崖柏和侧柏幼苗为对象,研究其叶片在秋冬季节性自然降温过程中抗氧化酶、渗透调节物质和丙二醛(MDA)的变化特征,并比较两树种对低温胁迫的适应能力。结果表明:在秋冬季节性自然降温过程中,日最低气温由12.50℃降至-13.96℃,崖柏幼苗叶片的超氧化物歧化酶(SOD)活性均显著增强,但过氧化物酶(POD)活性基本没有变化,而侧柏的SOD和POD活性同时增强;两树种叶片脯氨酸(Pro)含量、可溶性糖含量均显著增加,但崖柏的增加幅度低于侧柏;两树种叶片MDA含量均极显著增加,但崖柏增加幅度较大。日最低气温与侧柏的SOD、POD和可溶性糖含量均极显著相关,但仅与崖柏的SOD极显著相关,表明在季节性自然降温过程中,侧柏比崖柏更能够建立较完善的防御系统进行自身调节以适应低温环境。研究结果可为崖柏迁地保存和栽培管理工作提供参考。更多还原

【Abstract】 The paper focused on two species seedlings,Thuja sutchuenensis and Platycladus orientalis.Their adaptability to low temperature stress was compared by detecting and analyzing the leaves variable characteristics of antioxidant enzymes,osmotic adaptive substances and malondialdehyde(MDA) in the process of seasonal cooling in autumn and winter.The results showed that: during the process of seasonal cooling,the daily minimum air temperature decreased from 12.5 ℃ to-13.96 ℃,the superoxide dismutase(SOD) activity of T.sutchuenensis was strengthened significantly,however,the change of Peroxidase(POD) activity was not obvious,and both SOD and POD activities of P.orientalis were strengthened.The content of proline(Pro) and soluble sugars in leaves increased significantly in two species,T.sutchuenensis was lower than P.orientalis.The MDA content in leaves of the two species increased significantly,while T.sutchuenensis increased more than P.orientalis.The daily minimum air temperature was significantly correlated with the SOD,POD activity and soluble sugar content in P.orientalis,but it just correlated with the SOD activity in T.sutchuenensis.All these suggest that,during seasonal cooling,P.orientalis is more adaptive to low temperature stress than T.sutchuenensis through establishing better defensive system and conducting self-adjustment.The results of the research can provide reference for the T.sutchuenensis ex-situ conservation and cultivation management.更多还原