野稷对烟嘧磺隆的抗性水平及抗性机制

Determination of resistance level and mechanism of Panicum miliaceum L.var. ruderale to nicosulfuron

[目的]明确辽宁省野稷对烟嘧磺隆的抗性水平及抗药性机制。[方法]采用整株生测法测定不同种群对烟嘧磺隆的抗药性水平及细胞色素P450s活性差异,并通过对野稷ALS序列片段进行扩增测序,研究ALS序列差异。[结果]采自辽宁省阜新市的种群R-3呈高等水平抗药性,GR50值为80.58 g a.i./hm^(2),抗性指数达22.2,种群R-1和R-2分别呈低和中水平的抗药性;供试种群中均未检测到突变;在施用马拉硫磷后,高、中、低抗性种群GR50值分别下降了89%、74%和75%。[结论]抗性种群对烟嘧磺隆抗药性并非由基因突变导致的靶标抗性机制,可能由细胞色素P450s活性增强介导的非靶标抗药性。

[Aims] This study aims to clarify the resistance level and resistance mechanism of Panicum miliaceum L.var.ruderale to nicosulfuron in Liaoning Province. [Methods] The whole plant bioassay method was used to determine the resistance level to nicosulfuron ande activity of cytochrome P450 s in different populations, and the ALS sequence differences were studied by amplifying and sequencing the ALS sequence fragments of P. miliaceum L.var. ruderale.[Results] The population R-3 collected from Fuxin City, Liaoning Province showed high resistance, the GR;value was80.58 g a.i./ha, the resistance index was 22.2, and the populations R-1 and R-2 showed low and medium resistance respectively;no mutation was detected in the tested population. After malathion application, the GR;values of high,medium and low resistant populations decreased by 89, 74 and 75% respectively. [Conclusions] The resistance of resistant populations to nicosulfuron is not a target resistance mechanism caused by gene mutation, but may be mediated by the enhancement of cytochrome P450 s activity.