The effects of drought stress on MDA content and 3 antioxidant enzymes activities in leaves of one-year-old Carya illinoensis seedlings were studied by using PEG-6000 artificial simulation of drought stress. The results showed that mild drought did not cause the membrane lipid peroxidation in leaves of C. illinoensis. With the intensification of drought stress and the extension of time, the MDA content in C. illinoensis leaves increased,the membrane lipid peroxidation reaction in leaves was enhanced,and the damage to membrane system increased. Under mild drought stress, the antioxidant enzymes activities in C. illinoensis increased, there was a certain self-regulation and adaptation mechanism. However, under severe drought stress, the stress injury was irreversible,the defense and self-repair ability of protective enzymes had a certain threshold.%以1年生薄壳山核桃实生苗为材料,采用 PEG-6000 人工模拟干旱胁迫的方法, 研究了干旱胁迫对其叶片丙二醛(MDA) 含量和 3 种抗氧化酶活性的影响.结果表明: 轻度干旱不会引起薄壳山核桃叶片膜脂过氧化,随着干旱胁迫程度的加强和时间的延长,薄壳山核桃叶片中的 MDA 含量呈上升趋势, 叶片的膜脂过氧化反应增强,对膜系统的伤害增加;在轻度干旱胁迫条件下, 薄壳山核桃植株的抗氧化酶活性增加, 具有一定的自身调节与适应机制,而在重度干旱胁迫条件下,其遭受的胁迫伤害不可逆,保护酶的防御及自我修复能力存在一定阀值.
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