树种保护酶活性与PV曲线水分参数变化的关系

The relationship between the activities of protecting enzymes and water parameters from pressure-volume curves in six tree species

在水分胁迫条件下,树种间SOD(超氧化物歧化酶)活性与其DI(抗旱性指数)值的排序结果基本一致,表明SOD活性变化所反映的树木抗氧化伤害力大小与PV曲线水分参数所指示的树木耐旱性强弱具有密切的正相关性。但是树种间POD(过氧化物酶)活性变化与DI值之间的关系则不密切。其原因:1清除H2O2的抗氧化酶类较多(POD只是其中之一);2某些树种中且存在歧化H2O2的抗氧化剂。在水分胁迫阶段,海红的DI值最大,其SOD活性亦最高,这可能是其对生态环境适应的重要生态生理反应之一。

In the water stress period of annual growing season,the activities of SOD(superoxide dismutase)were positively correlated with the DI (drought resistance index)values,among the six species: Malus micromalus,Populus beijingensis,P.hopeiensis,P.simonii,Caragana korshinskii and Robinia pseudoacacia. However the activity of peroxide(POD) was not correlated significantly because other anti oxidant enzymes and/or antioxidants,which play a same role as POD,may exist in some of the tested species.In the stress period M.micromalus had greater DI value and higher level of SOD activity than other tested species,and this may be one of its important physioecological responses to ecological environment.