直播稻田牛筋草对乙酰辅酶A羧化酶类除草剂抗性水平及其分子机制

为明确直播稻田牛筋草对乙酰辅酶A羧化酶 (ACCase) 类除草剂的抗药性水平及其抗性产生的分子机制，采用整株生物测定法测定了牛筋草对6种ACCase类除草剂的抗性水平，并分别对抗性种群和敏感种群的ACCase基因部分片段进行了扩增和测序。结果表明:疑似抗性种群SJ-1对唑酰草胺、氰氟草酯、精唑禾草灵、高效氟吡甲禾灵和烯禾啶产生了高水平抗性，其抗性倍数分别为56.6、62.5、128、52.0和16.3；对烯草酮产生了低水平抗性，相对抗性倍数为4.86。将抗性种群和敏感种群的ACCase基因片段序列进行比对分析发现，SJ-1种群ACCase基因2078位氨基酸由天冬氨酸 (GAT) 突变为甘氨酸 (GGT)，该位点氨基酸突变可能是其对ACCase类除草剂产生抗药性的主要原因之一。

Resistance of Eleusine indica to acetyl-CoA carboxylase-inhibiting herbicides in direct-seeded rice and its molecular mechanism

The objectives of this study were to illuminate the sensitivity of Eleusine indica population in rice field of direct seeding to acetyl-CoA carboxylase (ACCase)-inhibiting herbicides and reveal its molecular resistance mechanism. Whole-plant bioassay showed that the population SJ-1 was highly resistant to metamifop, cyhalofop-butyl, fenoxaprop-p-ethyl, haloxyfop-R-methyl and sethoxydim, with resistance indexes of 56.6, 62.5, 128, 52.0 and 16.3, respectively. And it was slightly resistant to clethodim, with a resistance index of 4.86. By comparing the partial ACCase sequences derived from the resistant and susceptible populations, the SJ-1 population was found to contain one amino acid substitution of aspartate (GAT) for glycine (GGT) at the codon position 2078. This mutation in the ACCase gene might be responsible for the resistance to ACCase-inhibiting herbicides in the resistant population of E. indica.