氰戊菊酯对小白菜抗氧化酶活性及丙二醛（MDA）含量的影响

为探讨菊酯类农药胁迫对蔬菜生理生化过程的影响,以小白菜为研究对象,采用大田试验研究了不同浓度氰戊菊酯(20%乳油,推荐用量:稀释1500倍;加倍用量:稀释750倍)对小白菜抗氧化酶活性及丙二醛(MDA)含量的影响.结果表明:喷施推荐用量及喷施加倍用量氰戊菊酯对小白菜抗氧化酶活性均有不同程度的影响.超氧化物歧化酶(SOD)活性在喷施氰戊菊酯后3d内明显受到抑制,之后明显增加,第21d又受到抑制;过氧化氢酶(CAT)活性在喷药后小幅增加,第21d与对照基本一致;过氧化物酶(POD)活性在喷药后明显受到抑制.喷施推荐用量及喷施加倍用量氰戊菊酯均可引起小白菜MDA含量显著增加,且喷药浓度越高MDA含量越大,存在一定的剂量效应关系,表明氰戊菊酯胁迫促进了小白菜的膜脂过氧化作用.氰戊菊酯可对小白菜产生一定的氧化损伤,导致SOD、CAT、POD活性发生不同程度的变化.氰戊菊酯胁迫对SOD和POD活性以及MDA含量的影响相对较大,其中对MDA的影响最大,MDA含量可作为植物受到氰戊菊酯胁迫时的标记物.

Effects of Fenvalerate on the Activities of Antioxidant Enzymes, and Contents of Malondiadehyde (MDA) in Pakchoi

In order to study the pyrethroids pesticides stress on the physiological and biochemical process of vegetables, effects of different concentrions of fenvalerate stress(20% emulsifiable concentrate, recommended dose: 1500 times dilution; double dose: 750 times dilution)on the activities of antioxidant enzymes, and contents of malondiadehyde(MDA)in pakchoi were investigated under the open-field condition. Results showed that effects of fenvalerate stress on the activities of antioxidant enzymes were different, whether the recommended dose or double dose. After spaying pesticide, superoxide dismutase(SOD)activity in pakchoi was inhibited in 3d, and then increased, on the 21st day it was inhibited again. Catalase(CAT)activity was slightly increased, and reached to the control level on the 21st day, but the activity of peroxidase(POD)was evidently inhibited in pakchoi. Fenvalerate with different concentrations could increase content of MDA in pakchoi. The content of MDA increased with the increase of concentrations of fenvalerate, and there was a certain dose-response relationship between them. So fenvalerate stress could promote the lipid peroxidation of pakchoi. Fenvalerate could cause certain oxidative damage on pakchoi, and cause SOD, CAT, POD activities change in different degrees. Fenvalerate stress had larger impact on the activities of SOD and POD, and the content of MDA. Among them the impact on MDA content was the greatest. So the content of MDA could be used as the marker under the stress of fenvalerate on the plants.