摘 要 ：以小白菜（Brassica campestris L. ssp. Chinensis (L.) Makino var. cammunis Tsen et Lee）为试材，研究了不同浓度毒死蜱对大棚栽培条件下小白菜抗氧化酶活性、MDA、脯氨酸、可溶性糖以及Vc含量的影响。结果表明，无论是喷施低浓度还是高浓度的毒死蜱对小白菜的抗氧化酶活性都产生较显著的影响，表现为先下降后上升的趋势。从喷药后第5天开始，毒死蜱胁迫使小白菜SOD、POD、CAT的活性均比对照有所提高，其中以SOD活性提高最大，直到第21天时，上述3种抗氧化酶的活性才基本恢复到对照水平。毒死蜱胁迫导致MDA含量增加，特别是喷施高浓度的毒死蜱加剧了MDA含量的增加，说明毒死蜱胁迫促进了小白菜的膜脂过氧化作用。毒死蜱胁迫可使脯氨酸含量在第3天和第5天比对照有所上升，到第7天时脯氨酸含量恢复到对照水平。毒死蜱胁迫对小白菜中可溶性糖和Vc含量产生了一定的影响，在胁迫初期降低了可溶性糖和Vc的含量，在胁迫后期其含量上升并恢复到对照水平。研究结果表明，植物体在受到农药胁迫后需要有一个较长的时间才能修复因农药对植物体本身造成的伤害。
Abstract:Effects of different concentration of chlorpyrifos on antioxidant enzyme(SOD, POD, CAT) activities, malondiadehyde(MDA), proline(Pro), soluble sugar, and deoxidization Vc contents in pakchoi（Brassica campestris L. ssp. Chinensis Makino var. communis Tsen et Lee）seedlings were investigated under greenhouse conditions. The results showed that the antioxidant enzyme activities were significantly influenced with both low and high concentration of chlorpyrifos spayed on the pakchoi seedlings. Most of these antioxidant enzyme activities showed to decline firstly and then to rise. Five days after treatment, the chlorpyrifos stress significantly increased the activities of SOD, POD, CAT in pakchoi, comparing with the control. Among of them SOD′s activity showed the highest level. Until 21d after the treatments, the activities of SOD, POD, CAT reinstated to the contol level. The MDA content was increased under chlorpyrifos stress, especially when spraying high concentration of chlorpyrifos, it was suggested that chlorpyrifos stress promote the lipid peroxidation. And the content of Pro was also increased in 3d,5d after the treatments. On the 7th d, Pro content reached to the control level, while. The contents of soluble sugar and deoxidization Vc were reduced in the early stage of the stress, and then rised to the control level. It was concluded that a long time was needed for the plants to recover from the pesticide stress.