盐城棉区棉铃虫田间种群对Bt蛋白的抗性基因频率

【背景】转Bt基因抗虫棉已经在我国进行了近20年的大规模商业化种植,产生了显著的经济和环境效益。但是,靶标害虫棉铃虫的抗性是转Bt基因抗虫棉产业健康发展所面临的最大问题,而抗性监测是解决这一问题的必要管理措施。盐城市是江苏省转基因抗虫棉的主产区,但有关该地区棉铃虫对转Bt基因抗虫棉的抗性基因频率未见报道。【方法】于2012年在盐城三龙镇和东台镇棉区采集田间棉铃虫种群,检测了初孵幼虫对花铃期转Bt基因抗虫棉中30幼嫩叶片的敏感性,用区分剂量法检测了2龄幼虫对Bt蛋白的抗性基因频率。【结果】取食转Bt基因抗虫棉叶片后,棉铃虫初孵幼虫在9 d内全部死亡;三龙镇和东台镇棉铃虫2龄幼虫对Bt蛋白的抗性基因频率分别为7.6×10-3和6.9×10-3。【结论与意义】目前,盐城棉区的棉铃虫对转Bt基因抗虫棉仍保持很高的敏感性,棉铃虫种群对Bt蛋白的抗性基因频率没有发生显著变化,但仍需持续监测。

Frequency of resistance alleles to Bt toxin in the populations of Helicoverpa armigera（ Hübner） from cotton fields in Yancheng,Jiangsu Province

【Background】Transgenic Bt cotton has been grown commercially in a large scale in China for nearly 20 years. The evolution of resistance by the target pest,the cotton bollworm（ Helicoverpa armigera Hübner） is the most important threat to the sustainable development of the cotton industry. Resistance monitoring is a necessary management measure to extend the usefulness of transgenic Bt cotton. The Yancheng area is the principal planting area of transgenic Bt cotton in Jiangsu Province,but the resistant gene frequency of H. armigera in this area has not been reported. 【Method】Populations of H. armigera were collected in the cotton fields near Yancheng City in 2012 and the sensitivity of newly hatched larvae to the young leaves of Bt cotton（ Zhong-30） was tested. The resistance allele frequency of second instar larvae was studied using the distinguishing dosage method. 【Result】All the individuals of newly hatched larvae of H. armigera from Yancheng died within 9 d after feeding on transgenic Bt cotton leaves. The resistance allele frequency to Bt protein of second instar larvae from Sanlong and Dongtai Towns were 7. 6 × 10-3and 6. 9 × 10-3respectively.【Conclusion and significance】The current populations of H. armigera from the Yancheng cotton fields remained highly sensitive to transgenic Bt cotton,and their frequency of resistance alleles did not change significantly. However,continuous monitoring of the resistance allele frequency in field populations is still necessary.