转 Bt 基因玉米对粘虫的室内杀虫效果评价

Evaluation the control effects of the transgenic Bacillus thuringiensis corn expressing CrylAb protein on the larvae of Mythimna separata (Walker) in laboratory

在室内用生测法研究了表达 CrylAb 杀虫蛋白的 Bt 玉米 MON810和 Btll 小苗和心叶对粘虫 Mythimna separata (Walker)初孵幼虫以及玉米叶片对暴食期4龄和5龄幼虫的杀虫效果。结果表明,2种 Bt 玉米小苗及心叶对粘虫初孵幼虫都具有很好的控制效果,取食 MON810和 Btll 小苗的粘虫初孵幼虫第1天的存活率分别为69.44％和86.11％,到第3天时,取食 Btll 小苗的幼虫全部死亡,此时取食 MON810小苗的幼虫存活率仅为4.17％,到第7天全部死亡,而此时在各自相对应的对照玉米 DK647和 NX4906小苗上幼虫存活率分别为91.66％和88.89％。取食 MON810和Btll 心叶的粘虫初孵幼虫第2天时幼虫存活率急剧下降,分别为13.89％和19.45％,到第7天时,取食两种 Bt 玉米心叶的初孵幼虫全部死亡,而取食对照玉米心叶幼虫存活率分别为94.45％和97.22％,差异极显著。两种 Bt 玉米对粘虫4龄幼虫有很好的杀虫效果,取食的第11天4龄幼虫全部死亡,对照幼虫存活率均为100％;在 Btll 和 MON810叶片上取食的粘虫5龄幼虫也不能存活,分别在取食的第11天和12天全部死亡,对照存活率分别为96.00％和98.00％,差异极显著。表明 Bt 玉米对粘虫初孵幼虫和暴食期的4龄和5龄粘虫都具有显著的致死作用。

Control effects of the seedlings, whorl leaves and the leaves of transgenic Bacillus thuringiensis corn on the 1 st instar, 4th instar and 5th instar larvae of Mythimna separata （Walker） were evaluated in laboratory. Two Bt corn hybrids of events MON810 and Bt11 expressing Cry1Ab protein and their non-Bt controls were employed in the bioassays. Results showed the survival was 4.17% and 0 at the 3rd day when the 1st instar larvae feeding on the seedlings of MON810 and Bt11, compared with 91.66% and 88.99% in corresponding non-transgenic isogenic hybrid, respectively. The survival rate was 13.89% and 19.45% for the 1st instar larvae when feeding on whorl leaves of MON810 and Btl 1 at the 2nd day, respectively, and none survived at the 7th day. The mortality was 100% for 4th instar larvae of M. separate when feeding on the leaves of MON810 and Bt11 at the 11th day, compared with 0 mortality in non-transgenic isogenic hybrid. The 4th and 5th instar larvae exhibited weight loss when fed on MON810 and Bt11 leaves, and showed weight gain when fed on two non-Bt controls.It was shown that the Bt corn expressing Cry1 Ab toxin had good control effects on M. separate, not only the 1 st instar larvae, but also the 4th and 5th instar larvae.