抗精噁唑禾草灵的日本看麦娘ACCase基因突变

为明确日本看麦娘抗性种群对精噁唑禾草灵的抗性水平及抗性产生的分子机制,采用整株水平测定法测定了日本看麦娘对精噁唑禾草灵的抗性水平,扩增和比对了日本看麦娘抗性和敏感种群间乙酰辅酶A羧化酶(acetyl-Co A carboxylase,ACCase)基因的差异。结果显示,与敏感种群AH-7相比,抗性种群AH-25对精噁唑禾草灵的抗性倍数为33.82;AH-25种群ACCase基因CT区域2 078位氨基酸发生了突变,由天冬氨酸GAT突变为甘氨酸GGT;AH-25种群对炔草酯、烯草酮和烯禾啶产生了高水平的抗性,抗性倍数分别为35.66、38.64和29.14,对高效氟吡甲禾灵产生了低水平的抗性,抗性倍数为3.04,对精喹禾灵和唑啉草酯较敏感。表明ACCase基因2 078位氨基酸的突变可能是导致精噁唑禾草灵产生高水平抗性的重要原因。

Mutation in the acetyl-CoA carboxylase confers resistance to fenoxaprop-P-ethyl in Alopecurus japonicus populations

Whole-plant dose-response experiments were conducted to evaluate the resistance levels to fenoxaprop-P-ethyl in resistant and susceptible Alopecurus japonicus populations. The results showed that the resistant population AH-25, compared with the susceptible population AH-7, had evolved high-level resistance to fenoxaprop-P-ethyl, and the resistance index was 33.82. An acetyl-CoA carboxylase(ACCase) gene fragment was amplified and sequenced. The nucleotide sequence analysis showed that a substitution of aspartic acid (Asp) 2 078 by glycine (Gly) existed in the CT domain of ACCase gene in AH-25 population. The AH-25 population showed a high-level resistance to clodinafop-propargyl, clethodim and sethoxydim, with a resistance index of 35.66, 38.64 and 29.14, respectively, and a low-level resistance to haloxyfop-R-methyl with a resistance index of 3.04, and was susceptible to quizalofop-P-ethyl and pinoxaden. This study indicated that the aspartate to glycine mutation at position 2 078 in the ACCase gene was the important reason for resistance to fenoxaprop-P-ethyl in A. japonicus populations.