二化螟越冬种群特点及其对三唑磷靶标抗性突变频率分析

摘要

调查分析了我国长江流域以及南方稻区20个地区的二化螟越冬代种群的龄期结构、个体体质量及其对三唑磷的靶标抗性突变频率.结果表明,在20个采集地中有18个以6龄幼虫所占比例最高,其中,广东广宁和安徽桐城均达到80％以上;在所有的采集地中,4龄、5龄和6龄个体的总数在整个采集样本中占的百分率均达90％以上,表明我国长江流域以及南方稻区二化螟种群均以高龄幼虫越冬.二化螟对三唑磷的靶标抗性突变频率检测结果显示,不同地区二化螟种群的靶标抗性基因突变频率存在很大差异,其中,处于我国二化螟主发生区的浙江(100％、31.3％)、福建(77.1％、66.7％)、江西(68.8％、43.8％)、湖南(35.4％、33.3％)以及接近二化螟主发生区的广西阳朔(72.9％)和广东广宁(33.3％)的突变频率较高;其他地区抗性突变频率较低(＜23％),其中,安徽阜南、湖北荆州、四川德阳和乐山、重庆江津的二化螟种群未检测到抗性突变.%Population structure and individual body weight of overwintering populations of Chilo suppressalis collected at 20 locations in China from September 2010 to February 2011 were compared. And the mutations associated with resistance to triazophos, an organophosphate insecticide, among these populations was also analysed by restriction fragment length polymorphism PCR (RFI.P PCR). Results showed that the 6th instar larva was the predominant in 18 of 20 populations, and the composition of the overwintering populations didn t vary with geographic locations, with the 4th, 5th or 6-1 instar larvae accounting for more than 90 percents of the overwintering individuals. Besides that, results also showed that the mutation frequencies associated with triazophos resistance differed among geographical populations, which closely related with the occurrence of the pest. In regions where C. suppressalis occurred frequently and severely, such as Zhejiang, Fujian Province and so on, high mutation frequencies were observed (ranged from 31.3% to 100%), while in other regions where C. suppressalis occurred infrequently, such as Funan, Anhui Province, Deyang,Sichuan Province, the mutation freqencies were relatively low (ranged from 0% to 23%).