抗虫转基因植物对非靶标节肢动物生态影响的研究进展

Progress in the assessment of ecological effects of insect-resistant plants on non-target arthropods

重组DNA技术的发展为培育高效的抗虫作物提供了前所未有的便利条件。通过转基因技术,全世界已培育出众多转基因抗虫植物品系。其中,表达苏云金芽孢杆菌(Bt)基因的作物品系如Bt棉花和Bt玉米已在很多国家大规模种植,在害虫控制方面发挥了重要的作用。转基因抗虫作物可能带来的生态风险问题,如对农田非靶标节肢动物的潜在影响,一直受到相关研究者及民众的广泛关注。至今,已有大量研究论文发表。本文在总结、归纳前人研究的基础上,阐述了从实验室到田间多层次评价转基因抗虫作物对非靶标生物影响的一般研究程序和方法,并简要综述了Bt玉米和Bt棉花2种已商业化种植的转基因抗虫作物对农田非靶标节肢动物生态影响的研究进展。现有研究表明:当前种植的Bt作物所表达的Cry蛋白杀虫专一性非常强,对农田非靶标节肢动物没有毒性;且Bt作物的利用降低了广谱化学杀虫剂的施用量,从而提高了非专一性害虫天敌的种群密度,加强了对害虫的控制,并有效地保护了生态环境和农民健康。因此,Bt作物可以作为害虫综合防治(IPM)的一个策略,结合其他防治措施可加强对害虫的有效控制。

Development of recombinant DNA technology has resulted in creating several lines of insect-resistant crop plants. Various crops expressing Cry toxins derived from Baccillus thuringiensis （Bt） have been grown on a wide scale in the world, and they are playing an important role in pest control. However, one ecological concern regarding the potential effects of insect-resistant GE plants on non-target organisms （NTOs） has been continued to be debated. An increasing body of laboratory and field studies is now available on this topic. By summarizing previous research, we here briefly elaborated the general procedure for assessing non-target effects of insect-resistant GE plants, and analyzed the potential effects of Bt maize and Bt cotton on non-target arthropods. The results indicated that the currently available Bt crops rarely had direct, acute toxicity on non-target arthropods. In addition, the use of Bt maize and Bt cotton often resulted in reductions of insecticide application, thus increasing the abundance of at least some beneficial insects and improving their potential to provide natural control of specific pests at a reduced damage to the environment. Consequently, Bt crops can be a useful component of IPM systems to protect these crops from some targeted pests.