种植Bt棉花可有效控制棉铃虫在我国多作物生态系统中的发生与危害

为防治棉铃虫，我国1997年开始种植Bt棉花，到2000年已在华北地区大面积商业化种植。由于人类对于大规模种植Bt植物对生态环境可能产生的潜在影响尚缺乏足够的经验和认识，Bt棉花对害虫地位演化的影响受到高度重视并引起广泛争议。本研究组在1997-2007年间在河北省系统研究了棉铃虫在Bt棉花田和常规棉花田的种群动态，结合华北地区1992—2006年100个试验点棉铃虫种群监测数据的模型分析表明：Bt棉花的大规模商业化种植破坏了棉铃虫在华北地区季节性多寄主转换的食物链，压缩了棉铃虫的生态位，不仅有效控制了棉铃虫对棉花的危害，而且高度抑制了棉铃虫在玉米、大豆、花生和蔬菜等其它作物田的发生与危害。这一研究成果明确了我国商业化种植Bt棉花对靶标害虫的生态效应，为阐明转基因抗虫作物对昆虫种群演化的调控机理提供了重要基础，对发展利用Bt植物可持续控制重大害虫区域性灾变的新技术有重要指导意义。

Suppression of Cotton Bollworm in Multiple Crops in China in Areas with Bt Toxin-containing Cotton

Transgenic cotton that has been engineered to produce insecticidal toxins from Bacillus thuringiensis （Bt） and so resist the pest cotton bollworm has been widely planted in China. In order to understand the ecological consequence and the insect status evolution in the agricultural system connected with Bt cotton planting, we monitored population dynamics of cotton bollworm in cotton, corn, soybean, peanut and vegetables in northern China from 1992 to 2007. The study area included six provinces in northern China with an annual total of 3 million ha of cotton and 22 million ha of other crops grown by more than 10 million resource-poor farmers. Our results indicated that a marked decrease in regional outbreaks of cotton bollworm in multiple crops was associated with the planting of Bt cotton, which suggested that Bt cotton not only controls cotton bollworm on transgenic cotton designed to resist this pest but also may reduce its presence on other host crops and reduce the need for insecticide sprays in general.