内蒙古草原亚洲小车蝗抗药性的生化和分子特征研究

In recent years, the outbreaks of the locusts occur frequently in Inner Mongolia steppe due to some suitable conditions such as aridity, degeneration and land desertification. However, the chemical controls so far are still the major measures taken in locust abatement programs. The abuse of insecticides leads to the resistence development, which in turn reduces the effect of insecticides and lays hidden perils in animal husbandry production. To detect the resistance level of locusts and study the mechanism of insecticide resistance is the prerequisite of locusts control. Unfortunately, the research on the pesticide resistance in locusts of grassland is still nearly blank at home or abroad.Our study object is Oedaleus asiaticus, the dominant species of the locusts in Inner Mongolia steppe. 1.The field populations of Oedaleus asiaticus from Ulanqab、Erdos、Alxa、Khorchin、Xilin Gol and Hulun Buir are to be bioassayed with several traditional insecticides. 2.Study and compare the biochemical characters of enzymes associated to pesticide resistance in Oedaleus asiaticus from different fields. 3.Clone the cDNA of the relevant enzymes associated to pesticide resistance in Oedaleus asiaticus. Check the mechanism of resistance at the molecular level preliminarily. This research will make clear the resistance level and the mechanism of insecticide resistance of locusts from different fields in Inner Mongolia steppe. Moreover, Our work will provide theoretical basis for the resistance-management.

近年来，由于草原的退化、沙化、特殊气候等的影响，导致内蒙古地区草原蝗虫灾害频繁爆发。化学防治是防治草原蝗虫的主要措施，杀虫药剂的过度使用导致蝗虫产生抗药性，不仅使防治效果下降，还给畜牧业生产带来安全隐患。明确草原蝗虫的抗性水平及其抗性机制是合理使用杀虫药剂控制蝗虫的基础，但是国内外对草原蝗虫的抗药性机制研究还是一个空白。本项目以内蒙古主要草原区蝗虫优势种群-亚洲小车蝗为研究对象，从乌兰察布、鄂尔多斯、阿拉善、科尔沁、锡林郭勒、呼伦贝尔等草原区亚洲小车蝗对常用药剂的抗性水平检测、亚洲小车蝗不同种群抗性相关解毒酶性质比较、主要杀虫药剂分子靶标和相关解毒酶基因克隆、比较分析等方面进行研究，明确内蒙古不同草原区蝗虫对常用杀虫剂的抗性水平和抗性机制，为其抗药性的有效治理提供依据。

近年来，内蒙古地区草原蝗虫灾害频繁爆发，杀虫药剂的过度使用导致蝗虫产生抗药性，本研究内蒙古主要草原区蝗虫优势种群-亚洲小车蝗为研究对象，检测了乌兰察布、巴彦淖尔、科尔沁、锡林郭勒、呼伦贝尔草原区亚洲小车蝗对生产中七种常用杀虫剂的抗性水平，探明了不同草原区亚洲小车蝗对常用杀虫剂的抗性水平；并比较了亚洲小车蝗不同田间种群抗性相关解毒酶的生化性质；克隆得到亚洲小车蝗主要杀虫药剂分子靶标和相关解毒酶基因序列，并比较分析了不同田间种群解毒酶基因的表达量差异。. 研究发现，不同草原亚洲小车蝗自然种群对几种常用杀虫剂已经产生了不同程度的抗药性，阿维菌素的LD50在67.1-2300.54 ng/g，氟虫脲的LD50在34.61-617.87 ng/g，氟虫腈的LD50在3.12-42.15 ng/g，高效氯氰菊酯的LD50在20.75-65.5 ng/g，溴氰菊酯的LD50在3.74-23.66ng/g，甲氰菊酯的LD50在31.86-214.16 ng/g，马拉硫磷的LD50在1466.87-5886.52 ng/g； 其中，正蓝旗和科尔沁左翼中旗种群对阿维菌素的抗性倍数为22.5倍和34.3倍，科尔沁左翼中旗种群对氟虫脲的抗性倍数为17.8倍，已达到中抗水平，这表明，内蒙古草原上亚洲小车蝗自然种群已经对这几种杀虫剂产生了一定的抗药性。. 通过比较了亚洲小车蝗不同田间种群解毒酶的生化性质，我们发现不同田间种群对拟除虫菊酯类农药的抗药性可能与其解毒酶活性升高有关，我们克隆获得了3个亚洲小车蝗羧酸酯酶基因片段以及到3个谷胱甘肽S-转移酶基因片段，进一步分析比较了亚洲小车蝗不同种群羧酸酯酶基因和谷胱甘肽S-转移酶基因的mRNA表达量差异，结果表明，解毒酶基因的上调可能导致了亚洲小车蝗抗药性的增加，其中，OaCSCA5基因起重要的作用。