Key Laboratory of Weed Biology and Management, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuan West Road, Beijing 100193, People's Republic of China.
Key Laboratory of Weed Biology and Management, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuan West Road, Beijing 100193, People's Republic of China.
Pestic Biochem Physiol. 2020 Jun;166:104571. doi: 10.1016/j.pestbp.2020.104571. Epub 2020 Apr 4.
Cyperus difformis has evolved resistance to pyrazosulfuron-ethyl and other acetohydroxyacid synthase (AHAS) inhibitors in paddy fields in China. To understand the distribution of resistance and the mutations involved, 38 populations collected were from 7 provinces and compared. Application of pyrazosulfuron-ethyl at 30 g a.i. ha identified 16 populations that survived, demonstrating resistance to this herbicide. Two exons of 498 and 1428 bp in length and a 1228-1233-bp intron of AHAS were cloned by genome walking, and three pairs of primers were designed to amplify eight conserved regions in this gene. In the 16 resistant (R) populations, five different types of mutations in the conserved region of the AHAS gene were identified: Pro-197-Ser, Pro-197-Arg, Pro-197-Leu, Asp-376-Glu, and Trp-574-Leu. Three R populations, YX15-22, YX12-10 and YX15-38, were chosen for in vitro AHAS activity assays, and the results showed that AHAS from YX15-22 carrying the Pro-197 mutation was insensitive to pyrazosulfuron-ethyl (resistance index (RI) = 310.0) and penoxsulam (RI = 10.0), whereas the enzyme from YX12--10 and YX15-38 was insensitive to pyrazosulfuron-ethyl, penoxsulam, imazapic and bispyribac‑sodium (RI values ranging from 4.3 to 4462.0). AHAS inhibitor cross-resistance bioassays showed that YX12-10 and YX15-38 had cross-resistance to all of the tested herbicides (RI values ranging from 5.8 to 3321.9), while the YX15-22 population only had resistance to pyrazosulfuron-ethyl (RI = 827.4) and penoxsulam (RI = 6.6). This study clarified the distribution of resistant C. difformis in China and the different cross-resistance patterns given by various mutation types of AHAS.
香附子对吡嘧磺隆和其他乙酰乳酸合成酶（AHAS）抑制剂在稻田中产生了抗药性。为了了解抗性的分布和涉及的突变，从 7 个省采集了 38 个种群进行比较。应用 30 克有效成分/公顷的吡嘧磺隆鉴定出 16 个存活的种群，表明它们对该除草剂具有抗性。通过基因组步移克隆了长度为 498 和 1428bp 的两个外显子和长度为 1228-1233bp 的 AHAS 内含子，并设计了三对引物来扩增该基因的 8 个保守区。在 16 个抗性（R）种群中，在 AHAS 基因的保守区鉴定出了五种不同类型的突变：Pro-197-Ser、Pro-197-Arg、Pro-197-Leu、Asp-376-Glu 和 Trp-574-Leu。选择了三个 R 种群，YX15-22、YX12-10 和 YX15-38，进行体外 AHAS 活性测定，结果表明，携带 Pro-197 突变的 YX15-22 的 AHAS 对吡嘧磺隆（抗性指数（RI）=310.0）和肟嘧磺隆（RI=10.0）不敏感，而 YX12-10 和 YX15-38 的酶对吡嘧磺隆、肟嘧磺隆、咪唑烟酸和双吡氟草胺不敏感（RI 值范围为 4.3 至 4462.0）。AHAS 抑制剂的交互抗性生物测定表明，YX12-10 和 YX15-38 对所有测试的除草剂均具有交互抗性（RI 值范围为 5.8 至 3321.9），而 YX15-22 种群仅对吡嘧磺隆（RI=827.4）和肟嘧磺隆（RI=6.6）具有抗性。本研究阐明了中国香附子抗性种群的分布以及不同 AHAS 突变类型所产生的不同的交互抗性模式。
