黏虫对Cry1Ab蛋白的抗性遗传规律及与其他蛋白的交互抗性

Inheritance of Cry1Ab resistance in oriental armyworm Mythimna separata and its cross-resistance to other Bt toxins

为转Bt作物抗性治理策略的有效实施提供依据,采用遗传杂交和毒力生测方法评价黏虫Mythimna separata Cry1Ab蛋白抗性品系对Cry1Ab蛋白的抗性显性度,明确调控抗性基因的位置和数目以及对Cry1F和Vip3Aa19蛋白的敏感性。结果显示,Cry1Ab蛋白对黏虫正交F1代和反交F1代的LC50分别为15.30μg/g和12.91μg/g,抗性为常染色体调控;在浓度2.5~50.0μg/g范围内黏虫对Cry1Ab蛋白的抗性显性水平随着浓度的变化而变化,即在2.5μg/g时黏虫对Cry1Ab蛋白的抗性为不完全显性遗传,在50.0μg/g时黏虫对Cry1Ab蛋白的抗性为不完全隐性遗传。黏虫对Cry1Ab蛋白的抗性受多基因调控。另外,黏虫Cry1Ab抗性品系对Cry1F和Vip3Aa19蛋白未产生交互抗性,抗性倍数分别为0.9和1.1。

In order to provide useful information for developing resistance management strategies of Bt crops,genetic crosses and diet bioassays were conducted to evaluate the degree of dominance in oriental armyworm Mythimna separata to Cry1Ab,the position and number of resistance genes and the susceptibility to Cry1F and Vip3Aa19 proteins.The results showed that the LC50 values were not significantly different between R♀S♂and R♂S♀,with a LC50 value of 15.30μg/g and 12.91μg/g,respectively,indicating that the resistance was autosomal.The degree of dominance to Cry1Ab changed with the change of concentration ranging from 2.5μg/g to 50.0μg/g,suggesting the resistance was functionally incompletely dominant at 2.5μg/g and incompletely recessive at 50.0μg/g.The analysis of observed and expected mortalities of the progeny from the backcross(F1×RR)suggested that more than one locus was responsible for conferring Cry1Ab resistance.Besides,the Cry1Ab-resistant strain showed no crossresistance to Cry1F and Vip3Aa19 proteins with a resistance ratio of 0.9 and 1.1,respectively.