Department of Crop, Soil, and Environmental Sciences, University of Arkansas, Fayetteville, AR, USA.
Pest Manag Sci. 2022 Jan;78(1):287-295. doi: 10.1002/ps.6633. Epub 2021 Sep 28.
Florpyrauxifen-benzyl (FPB) is an arylpicolinate herbicide (Group IV) for barnyardgrass control in rice. One susceptible (Sus) and three putative FPB-resistant (R1, R2, and R3) barnyardgrass biotypes were selected based on resistant/susceptible (R/S) ratios obtained from dose-response tests and used to investigate the potential resistance mechanisms.
Based on visual control results, the R/S ratios of barnyardgrass biotypes R1, R2, and R3 were 60-, 33-, and 16-fold greater than the Sus standard, respectively. Sequencing results of TIR1 and AFB genes in the tested barnyardgrass revealed no difference between Sus and R barnyardgrass biotypes. Absorption of [ C]-FPB in Sus barnyardgrass increased over time and reached 90%, which was >10 percentage points greater than that in R biotypes. The [ C]-FPB absorption in all R barnyardgrass equilibrated after 48 h. For both Sus and R barnyardgrass, most [ C]-FPB absorbed was present in the treated leaf (79.8-88.8%), followed by untreated aboveground (9.5-18.6%) and belowground tissues (1.3-2.2%). No differences in translocation were observed. Differences between Sus and R barnyardgrass biotypes were found for FPB metabolism. Production of the active metabolite, florpyrauxifen-acid, was greater in Sus barnyardgrass (21.5-52.1%) than in R barnyardgrass (5.5-34.9%).
In conclusion, reductions in FPB absorption and florpyrauxifen-acid production may contribute to the inability to control barnyardgrass with FPB. © 2021 Society of Chemical Industry.
Florpyrauxifen-benzyl (FPB) 是一种用于稻田稗草防治的芳基吡啶羧酸类除草剂（IV 组）。根据剂量反应试验获得的抗性/敏感（R/S）比值，选择了一个敏感（Sus）和三个假定的 FPB 抗性稗草生物型（R1、R2 和 R3），用于研究潜在的抗性机制。
根据目测控制结果，稗草生物型 R1、R2 和 R3 的 R/S 比值分别比 Sus 标准高 60、33 和 16 倍。测试稗草的 TIR1 和 AFB 基因测序结果表明，Sus 和 R 稗草生物型之间没有差异。Sus 稗草对 [C]-FPB 的吸收随时间增加，达到 90%，比 R 稗草生物型高 10 个百分点以上。所有 R 稗草的 [C]-FPB 吸收在 48 小时后达到平衡。对于 Sus 和 R 稗草，吸收的 [C]-FPB 大部分存在于处理叶中（79.8-88.8%），其次是未处理的地上部分（9.5-18.6%）和地下部分（1.3-2.2%）。没有观察到转运差异。Sus 和 R 稗草生物型之间在 FPB 代谢方面存在差异。活性代谢产物 florpyrauxifen-acid 的产生在 Sus 稗草中（21.5-52.1%）大于 R 稗草（5.5-34.9%）。
总之，FPB 吸收减少和 florpyrauxifen-acid 产生减少可能导致 FPB 无法控制稗草。© 2021 化学工业协会。
