Frequency of Bt Resistance Alleles in Helicoverpa armigera in the Xinjiang Cotton-Planting Region of China
Frequency of Bt Resistance Alleles in Helicoverpa armigera in the Xinjiang Cotton-Planting Region of China
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DOI：
10.1603/en10077
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发表时间：
2010-10-01
影响因子：
1.7
通讯作者：
Wu, Kongming
中科院分区：
文献类型：
--
作者：
Li, Guoping;Feng, Hongqiang;Wu, Kongming
棉铃虫Helicoverpa armigera Hubner(鳞翅目：夜蛾科)是中国西北部新疆棉区的一种重要棉花害虫。在这一地区，棉花平均每年种植165万公顷(1.53公顷，相当于180万公顷)，主要是单一种植的农业景观，类似于美国或澳大利亚的种植制度。在这种种植制度下，自然产生的避难所(与非Bt作物)可能不足以防止棉铃虫对Bt毒素的抗性发展。因此，我们评估了2005-2009年来自该地区两个不同地点的棉铃虫等雌棉铃虫F-1和F-2后代对Cry1Ac毒素的抗性等位基因频率。更具体地说，从库尔勒县收集了224个等雌品系(大约70%的Bt棉被采用)，从莎车县收集了402个品系(大约5%的Bt棉种植)。随后的后代用Cry1Ac人工饲料进行筛选。2005年至2009年，库尔勒地区的抗性基因频率在0.0000~0.0040之间波动，莎车县的抗性基因频率在0.0000~0.0008之间，2005年至2009年两县的抗性基因频率均无显著增加。幼虫的相对平均发育率(RADR)在库尔勒显著高于莎车，但在莎车没有显著提高。F-1代幼虫的RADR与F-2代后代的RADR显著相关，表明田间棉铃虫种群对毒素的反应存在遗传变异。虽然新疆中国棉区抗棉铃虫等位基因的出现率较低，但库尔勒县棉铃虫抗性的发展仍需特别关注。
Helicoverpa armigera Hubner (Lepidoptera: Noctuidae) is a key insect pest of cotton in Xinjiang cotton-planting region of northwest China. In this region, cotton is grown on average similar to 1.65 million ha (1.53 similar to 1.80 million ha) annually in largely monoculture agricultural landscapes, similarly to cropping systems in the United States or Australia. Under such cropping regimes, naturally occurring refuges (with non-Bt crops) may be insufficient to prevent H. armigera resistance development to Bt toxins. Therefore, we assessed frequency of alleles conferring resistance to Cry1Ac toxin of F-1 and F-2 offspring of H. armigera isofemale lines from two distinct localities in the region during 2005-2009. More specifically, a total of 224 isofemale lines was collected from Korla County (approximate to 70% Bt cotton adoption) and 402 lines from Shache County (approximate to 5% Bt cotton planting). Subsequent offspring was screened on Cry1Ac artificial diet. From 2005 to 2009, resistance gene frequency in Korla fluctuated between 0.0000 and 0.0040, while being 0.0000-0.0008 in individuals collected from Shache, and there were no significant increases in both counties from 2005 to 2009. Relative average development rates (RADRs) of larvae in F, tests showed significant increases from Korla, but not in Shache. RADR of F-1 larvae is significantly correlated with RADR of F-2 offspring, indicating genetic variation in response to toxin in field H. armigera population. Although the occurrence of Cry1Ac resistance alleles was low in Xinjiang cotton-planting region of China, particular attention should be given to H. armigera resistance development in Korla County.