嗜线虫致病杆菌CB6菌株对小菜蛾幼虫生物活性的研究

Bioactivity of Xenorhabdus nematophila CB6 strain against larvae of Plutella xylostella L

用叶碟法测定了嗜线虫致病杆菌CB6菌株发酵液对小菜蛾幼虫的致死率、拒食活性以及对生长发育的影响。结果表明 ,其发酵液对幼虫有较高的生物活性 ,取食 3d后 ,1～ 3龄幼虫的校正死亡率分别为 84 75 %、6 8 33%和 5 9 32 %。 4龄幼虫取食量显著减少 ,选择性拒食率为 76 5 9% ,非选择性拒食率为 6 9 72 %。 3龄幼虫取食发酵液处理的叶片后 ,生长极其缓慢 ,在 4 8h时体重抑制率达 10 0 % ,化蛹率和羽化率均明显下降 ,其中化蛹率仅为 15 5 6 % ,10 0 %蛹不能羽化。

The effects of Xenorhabdus nematophila CB6 culture both on the survival, feeding disfunction and development of Plutella xylostella L. were reported. The results indicated that the fermentation liquid of the bacteria had high bioactivity against the pest. The insect larvae feeding leaves treated with fermentation liquid for 3 days, the mortality of 1st, 2nd and 3rd instar larvae was 84.75%, 68.33% and 59.32%, respectively. The anti-feeding rate of 4th instar larvae was 76.59% in selective test and 69.72% in non-selective test. The 3rd instar larvae feeding treated leaves for 48 h, the rate of growth inhibition was 100%, and pupation rate was 15.56% and the adult could not emerge completely.