Abstract Flixweed (Descurainia sophia L.) is widely distributed in winter wheat (Triticum aestivum L.) fields in the North China Plain and has evolved resistance to herbicides, including the acetolactate synthase (ALS) inhibitor florasulam. However, the florasulam resistance status of flixweed in the North China Plain is poorly understood, which hinders the integrated management of this weed in winter wheat production systems. Thus, 45 flixweed populations were collected in wheat fields in these areas, and their sensitivity to florasulam and ALS-inhibitor-resistant mutation diversity were assessed. Meanwhile, alternative herbicides/herbicide mixtures for the control of florasulam-resistant flixweed were screened and evaluated under greenhouse and field conditions. Of the populations, 30 showed florasulam resistance (RRR and RR), 9 had a high risk of evolving florasulam resistance (R?) and 6 were susceptible. These populations had 5.3 to 345.1-fold resistance to florasulam, and 4 ALS resistance mutations (P197H, P197S, P197T and W574L) were observed. The subsequent herbicide sensitivity assay showed that the SD-06 population (with ALS1 P197T and ALS2 W574L mutations) exhibited cross-resistance to all ALS inhibitors tested, but was sensitive to MCPA-Na, fluroxypyr, carfentrazone-ethyl and bipyrazone. Meanwhile, the other HN-07 population with non-target-site resistance (NTSR) also showed resistance to all tested ALS inhibitors, and it was “R?” to MCPA-Na while sensitive to fluroxypyr, carfentrazone-ethyl and bipyrazone. The field experiments were conducted at the research farm where the SD-06 population was collected, and the results suggested that florasulam at 3.75–4.5 g ai ha−1 had little efficacy (0.6–12.1%), whereas MCPA-Na + carfentrazone-ethyl (87.1–91.2%) and bipyrazone+fluroxypyr (90.1–97.8%) controlled the resistant flixweed.

中文翻译：

---

华北平原禾草 (Descurainia sophia L.) 及其化学防治替代除草剂的氟磺草胺抗性现状

摘要 Flixweed (Descurainia sophia L.) 广泛分布于华北平原的冬小麦 (Triticum aestivum L.) 田中，已进化出对乙酰乳酸合酶 (ALS) 抑制剂氟草胺等除草剂的抗性。然而，目前对华北平原禾本科杂草抗性花青素抗性状况了解甚少，这阻碍了冬小麦生产系统对该杂草的综合治理。因此，在这些地区的麦田中收集了 45 种黄花菜种群，并评估了它们对氟磺草胺和 ALS 抑制剂抗性突变多样性的敏感性。同时，在温室和田间条件下筛选和评估了用于控制耐氟磺草胺的除草剂/除草剂混合物的替代性除草剂/除草剂混合物。在人群中，30 个显示出氟磺草胺耐药性（RRR 和 RR），9 人具有发展氟磺草胺耐药性 (R?) 的高风险，6 人易感。这些人群对氟磺草胺具有 5.3 至 345.1 倍的耐药性，并观察到 ​​4 个 ALS 耐药突变（P197H、P197S、P197T 和 W574L）。随后的除草剂敏感性测定表明 SD-06 种群（具有 ALS1 P197T 和 ALS2 W574L 突变）对所有测试的 ALS 抑制剂表现出交叉抗性，但对 MCPA-Na、氟草烟、氟草酮-乙基和双吡酮敏感。同时，另一个具有非靶位点耐药（NTSR）的 HN-07 群体也对所有测试的 ALS 抑制剂表现出耐药性，并且是“R？” MCPA-Na，而对氟草烟、氟草酮-乙基和双吡酮敏感。田间试验在收集 SD-06 种群的研究农场进行，结果表明氟磺草胺为 3.75-4。