Bt转基因抗虫棉田昆虫群落结构研究

选用3个转Bt基因抗虫棉品种DP99B、20B、1560BG和2个非抗虫棉对照品种鄂杂棉1号、湘杂棉2号,比较研究了不同棉花群体中昆虫群落结构特征。结果表明,在未采取任何防治措施的情况下,3个转Bt基因抗虫棉对棉铃虫种群,尤其是在棉花生育前期有很好的抑制作用;同时对其他鳞翅目害虫种群也有一定控制效果,这使得棉蚜、棉叶蝉、烟粉虱等刺吸式害虫上升为主要害虫。但抗虫棉棉田昆虫群落、害虫亚群落以及天敌亚群落的多样性、均匀性均较对照棉田小,而优势集中性比对照棉田高,反映出抗虫棉棉田昆虫群落结构稳定性较差。相对来说,DP99B和20B抗虫性能较好,其棉田昆虫群落结构也比较稳定。因此,转Bt基因抗虫棉的大面积应用中,除了要关注抗毒性棉铃虫的产生和危害以外,还应特别注意其他可能上升为主要害虫(如棉蚜、棉叶蝉、烟粉虱等)的防治工作。

Study on the Pest Community Structure in Bt Transgenic Cotton Fields

The insect community feature in two types of cotton fields with boll-worm resistant varieties(Bt transgenic cotton) of DP99B, 20B and 1560BG, and the conventional varieties(non-Bt cotton) of E-za-mian NO. 1 and Xiang-za-mian NO.2 were investigated. The result showed that Bt cotton limited the population of boll-worm and other pests, especially at its early growing stage, with no any measures taken to control the pest, which made it possible for the pests with injecting and sucking juice such as Aphis gossypii, cotton leaf hopper, Trialeurodes vaporariorum to be the main pest. However, the diversity and evenness of insect community, pest sub-community and natural enemy sub-community in Bt cotton fields were smaller than that of non-Bt cotton field, but dominance was more obvious, that meant there was the weakness of insect community structure in Bt cotton fields. Nevertheless, the structure of insect community in DP99B and 20B fields were more stable. Therefore, special attention should be paid to the controlling of the possible main pest such as Aphis gossypii, cotton leaf hopper and Trialeurodes vaporariorum in large scale Bt transgenic cotton.