新疆棉区转Bt基因棉对棉铃虫生物学的影响

Effects of transgenic Bt cotton on the biology of cotton bollworms in Xinjiang

棉铃虫Helicoverpaarmigera高龄幼虫取食转Bt基因棉花组织后 ,化蛹率、羽化率、蛹重、体长均有显著下降 ,在转Bt基因棉花上棉铃虫的取食行为也受到较大的影响 ,表现为取食次数明显减少、吐丝下垂次数明显增加 ;无论是转Bt基因棉花还是常规棉花 ,棉铃虫 3龄幼虫主要分布于繁殖器官上 ,在转Bt基因棉花各繁殖器官上的分布概率为 :花 >棉铃 >棉蕾 ,常规棉花上分布概率为 :棉蕾 >棉铃 >花 ;棉铃虫高龄幼虫取食转Bt基因棉花各组织 ,成虫羽化后产卵量、卵孵化率均有明显下降 ;在较低的棉铃虫虫口密度下 ,转Bt基因棉花对棉铃虫有一定的产卵排趋性。

The effects of transgenic Bt cotton in Xinjiang on cotton bollworms’ biology were studied. Key results are: (1) after eating Bt cotton larval pupation rate, eclosion rate, pupae weight and body length obviously decreased; (2) cotton bollworms’ feeding behavior on Bt cotton, such as feeding duration, was obviously reduced while spin drooping time was obviously increased relative to that on non-Bt cotton; (3) except for third instar larvae which were mainly distributed in plant breeding organs in both non-Bt and Bt cotton crops, preferred micro-habitats of cotton bollworms in transgenic Bt cotton were, in order of probability of bollworm occurrence: cotton blossom> cotton boll>cotton bud, compared to in non-Bt cotton: cotton bud>cotton boll> cotton blossom; (4) after older larvae ate the organs of transgenic Bt cotton,imago's ovipositing quantity and hatching rate obviously decreased. At low cotton bollworms density transgenic Bt cotton negatively influenced the oviposition rate.