东北地区稻稗对五氟磺草胺的抗药性机制

Resistance Mechanism of Echinochloa oryzicola(Vasing.)Vasing to Penoxsulam in Northeast China

[目的]明确东北地区稻稗对五氟磺草胺的抗药性机制。[方法]采用整株生测法测定不同种群对五氟磺草胺的抗药性水平及P450s活性差异,并采用基因测序法,研究ALS序列差异。[结果]种群R-2呈高等水平抗药性,抗性指数达25.67,种群R-1和R-3分别呈低和中等水平抗药性;3个抗性种群均未检测到突变;在施用马拉硫磷后,抗性指数比分别为1.99、5.42和1.60。[结论]抗性种群对五氟磺草胺抗药性并非靶标基因突变导致的,可能是P450s活性增强导致的非靶标抗药性。

[Aims]The study aims to clarify the mechanism of resistance of Echinochloa oryzicola(Vasing.)Vasing to penoxsulam in Northeast China.[Methods]Whole-plant dose-response was used to determine resistance levels and P450s activity differences,target enzymes sequencing was used to determine ALS sequence differences.[Results]R-2 population showed high level of resistance to penoxsulam,with resistant index of 25.67,while R-1 and R-3 expressed low and medium resistance level to penoxsulam respectively.There were no resistance endowing amino acid substitutions in the three resistant populations compared with the sensitive population.The resistance index to penoxsulam of three resistant populations decreased 1.99,5.42 and 1.60 times respectively after exposure to the cytochrome P450-inhibition malathion.[Conclusions]The decrease of sensitivity of three resistant populations to penoxsulam was not caused by mutation of target enzyme gene,it may be due to the non-target resistance caused by the increased activity of P450s.