干旱胁迫对坡柳等抗旱树种幼苗膜脂过氧化及保护酶活性的影响

以金沙江干热河谷主要树种坡柳、银合欢、山毛豆实生幼苗为材料，通过盆栽苗自然干旱胁迫，同时以浇水处理为对照，研究了干旱胁迫对坡柳、银合欢、山毛豆3个树种丙二醛含量、膜相对透性及保护酶活性的影响。结果表明，干旱胁迫下3个树种幼苗的细胞膜透性、MDA及SOD, POD酶活性都发生了变化，只是变化的幅度和进程不同。干旱胁迫对银合欢膜系统损伤生成的主要降解产物不是MDA；山毛豆清除活性氧毒害作用主要不是通过SOD和POD的作用；通过叶片相对保水力测定及膜透性、MDA相对含量、酶活性变化情况的分析，3个树种中坡柳耐旱性最强，其次为银合欢，山毛豆居后。

Effects of drought stress on lipid peroxidation and activity of defense enzymes of Dodonaea viscosa, Leucaena leucocephala and Tephrosia candida seedlings

Taking seedlings of Dodonaea viscosa,Leucaena leucocephala and Tephrosia candida from Jin Sha River as materials,the effects of drought stress on their lipid peroxidation and activity of defense enzymes under natural drought stress were studied in contrast to effects under watering. The results show that the cytomembrane permeability,MDA content,SOD and POD activity are all more or less changed under drought stress although the extent and process of variation is different.As for Leucaena leucocephala seedlings, MDA is not the main product of lipid peroxidation and Tephrosia candida seedlings do not only rely on SOD and POD action to reduce active oxygen content.Through comprehensive analysis on water holding capacity of leaf,cytomembrane permeability,MDA content and SOD,POD activity,Dodonaea viscosa seedlings show the highest drought resistance,then Leucaena leucocephala,Tephrosia candida the last.