桑叶提取物1-DNJ对甜菜夜蛾幼虫生长和保护酶活性的影响

为研究桑树活性物质1-DNJ对甜菜夜蛾幼虫生长和体内保护酶活性的影响，本试验将被不同浓度1-DNJ浸泡30s后的甘蓝小叶饲喂4龄的甜菜夜蛾幼虫。结果表明：甜菜夜蛾4龄幼虫对1-DNJ在24、48 h的拒食率分别为77.20%、92.01%，拒食中浓度AFC50分别为0.48、0.21 g/L；生长抑制检测表明，1-DNJ对于甜菜夜蛾生长的抑制率最高达到92.34%，说明1-NDJ对甜菜夜蛾的生长具有明显抑制作用；1-DNJ对甜菜夜蛾体内保护酶活性具有明显的影响，其中SOD和CAT活性，在各时段的检测结果均呈现先被诱导后被抑制，CAT活性较对照下降幅度明显，与对照组差异达到显著水(P<0.05)，而1-DNJ对甜菜夜蛾体内POD活性影响不大。1-DNJ对甜菜夜蛾幼虫拒食和抑制生长的作用时间上滞后于对保护酶系统的破坏作用，表明：甜菜夜蛾幼虫体内保护酶系统对桑树活性物质1-DNJ反应敏感。本研究结果说明：桑树活性物质1-DNJ对甜菜夜蛾的生长和保护酶活性具有一定的影响，其结果可为将桑树作为开发植物源杀虫剂的原料提供基础资料和理论依据。

Effect of 1-DNJ from Mulberry Leaves on the Growth and Protective Enzymes of Spodoptera exigua

In order to study the influence of mulberry active substance (1-NDJ) on the growth and enzymatic activity of 4th S. exigua, which were feed cabbage leaves soaked by different concentrations for 30 second. The results showed that the highest anti-feeding rates were 77.20% and 92.01%, respectively at 24 h and 48 h, and the AFC50 were 0.48 and 0.21 g/L, respectively. The developmental inhibition rates decreased obviously with the increasing 1-DNJ concentration, which could up to 92.34%. While, activity of superoxide dismutase and carboxylesterase of the 4th S. exigua were induced and then inhibited in after treated with 1-DNJ, activity of carboxylesterase decreased significantly than CK (P<0.05), activity of peroxidase were few changed by 1-DNJ. The action time of anti-feeding and growth inhibitory were logged in effects of protective enzyme system, suggesting that protective enzyme system was sensitive to 1-DNJ. These results implied that mulberry was treasuries of bioactive substances useful as pesticides, which could provide basic data and theoretical basis for development of botanical pesticides using 1-DNJ of mulberry.