水分胁迫下新红星苹果超氧物自由基累积和膜脂过氧化作用

以新红星苹果盆栽幼树为试材，研究了水分胁迫下新红星苹果超氧物自由基累积和膜脂过氧化作用，结果表明：（1）不同程度水分胁迫均使叶片内O2ˉ·产生速率增加，膜脂过氧化产物MDA含量增多，细胞质膜相对透性增大。（2）不同程度水分胁迫使叶片内SOD、CAT活性、ASA含量在水分胁迫前期比对照均有不同程度的提高，随着胁迫时间的延长，SOD、CAT活性、ASA含量大幅度下降，且下降幅度：重度胁迫＞中度胁迫＞轻度胁迫。轻度胁迫SOD、CAT活性、ASA含量高于对照水平；中度胁迫SOD、CAT活性虽下降，但仍高于对照水平，ASA于第21天低于对照水平；重度胁迫SOD、CAT活性、ASA含量均于第18天低于对照水平。

Effects of Water Stress on Accumulation of Superoxide Free Radical and Membrane Lipid Peroxidation of Starkrimson Apple Young Leaves

Effects of water stress on accumulation of superoxide radical and membrane lipid peroxidation of Starkrimson apple young leaves were studied under pot cultivation in 1996～1998．The results showed that under different water stress， generation rate of the superoxide free radical，the malondialdehyde content，the membrane permeability were increased． The superoxide dismutase activity， the catalase activity and ASA content were increased during the early period， the range was mild，moderate，severe water stress along with the duration of water stress， the activity of SOD，CAT and ASA content were decreased， the excessive accumulation of O2ˉ· was resulted by the reduced SOD，CAT activity and ASA content．