新疆南部转基因棉区棉铃虫种群长期动态研究

Long-term Dynamic Change of Helicoverpa armigera(Hübner) Population in Bt Cotton-growing Areas in South Xinjiang

转Bt(Bacillus thuringiensis)基因抗虫棉在新疆南部推广已超过10 a,为探索Bt棉大面积种植对棉铃虫(Helicoverpa armigera)种群动态的影响,于1999—2010年使用诱虫灯监测了Bt棉大面积种植区域(麦盖提)和非Bt棉大面积种植区域(阿瓦提)棉铃虫的种群动态。结果表明:新疆南部地区20世纪90年代末发生棉铃虫害较重,2000—2004年种群数量保持较高水平;自2005年Bt棉大面积推广以后,Bt棉区棉铃虫的种群数量显著下降,棉铃虫种群数量随Bt棉种植比例的上升而下降(P<0.05);随着Bt棉大面积推广年数的增加,Bt棉区棉铃虫各代种群数量均逐渐下降,第二代种群数量和高峰期蛾量下降速率均较越冬代和第一代快,且第二代棉铃虫种群相对丰富度也逐渐下降。因此,新疆地区Bt棉的大面积种植能较好地控制棉铃虫的种群数量,而且对第二代棉铃虫种群的控制效果最好。

Transgenic cotton has been engineered to produce insecticidal toxins from Bacillus thuringiensis （Bt） to resist cotton bollworms, Helicoverpa armigera （Htibner） has been commercially cultivated in China since 1997, and it has been intensively planted in Xinjiang fore more than 10 years, where cotton was cultivated in large area, and the crop systems were quite different from other areas. Therefore, it was suspected that the current results about the impact of Bt cotton planting on the seasonal population patterns of cotton bollworms may not reflect the actual situation in Xinjiang. The monitoring of cotton bollworms with light trapping was carried out in a high Bt density re- gion in Markit County and in a low Bt density region in Awat County, Xinjiang during the period from 1999 to 2010. The analyzed results indicated that the population size of cotton bollworms was decreased only in the high Bt density region, but the change in the low Bt density region was not significant. There was a significant negative cor- relation between the percentage of Bt cotton planting and the light-trapped H. armigera moths. The population size of H. armigera moths of all three generations was decreased with the time of planting Bt cotton, the population size and light-trapped moths of the second generation were dramatically decreased compared with th and first generations, and the relative abundance of the second generation was also decreased ose of the overwinter gradually. These re- suhs demonstrated that cotton bollworm population was suppressed by high Bt density cultivation at present, espe- cially for the second generation.