吡虫啉对褐飞虱DNA多态性的影响

Effects of Imidacloprid on DNA Polymorphism in the Brown Planthopper

吡虫啉在对抗水稻褐飞虱虫害中大量使用。本研究结合ISSR和AFLP分子标记技术检测吡虫啉对褐飞虱的遗传多样性影响。利用20个ISSR引物对连续施用吡虫啉的褐飞虱9个世代的19份材料扩增,共获得49个位点,其中只有1个位点出现特异性条带。利用25对AFLP引物对供试材料扩增,结果共有111个扩增位点,呈现多态性条带的位点11个。共获得59个多态性条带。其中多态性条带比例最高的是G8(10.2%),比例最低的是G1(1.69%)。多态性条带比例变化趋势表明,在筛选的早期G1、G2和G3世代,褐飞虱对吡虫啉的应答较快;在筛选的中期G4、G5和G6世代,褐飞虱对吡虫啉的应答呈现较大幅度的波动,变化范围在1.69%～8.47%之间;在筛选的晚期G7,G8和G9世代,褐飞虱对吡虫啉的应答波动幅度较小,趋于一个相对稳定的水平,变化范围在6.78%～10.2%之间。本研究结果表明,吡虫啉的连续使用,可能会造成褐飞虱DNA的突变,从而使害虫产生抗药性。本研究结果为揭示褐飞虱抗药性产生的分子机理提供了重要信息。

In recent years, the insecticide imidacloprid is wildly used in rice fields. In this study, ISSR and AFLP techniques were used to test the DNA variation in the brown planthopper during the continuous application of imidacloprid. By using 20 ISSR primers, 49 loci were identified, of which only one site display polymorphism within samples. With 25 pairs of AFLP primers, 111 loci were obtained, of which 11 site displayed polymorphisms within samples. The highest and lowest rate of polymorphisms was 10.2% and 1.69% , which were occurred at the eighth and first generation, respectively. The polymorphism change trend indicated that, in the early screening stage （the earliest three generations） , the brown planthopper responded genetically to imidacloprid quickly. In the middle screening stage （ from 4th to 6th generations） , its responses fluctuated substantially with AFLP polymorphism rate of 1.69% - 8.47%. In the late screening stage （from 7th to 9th generations） , its responses vared very little reaching AFLP polymorphism rate of 6.78% -10.2%. These results showed that the imidacloprid could induce DNA mutation in brown planthopper, therefore develop the resistance to insecticides. Our results provide important information on molecular mechanism of brown planthopper resistance to imidaeloprid.