1. Multiple resistance to ACCase- and ALS-inhibiting herbicides in black-grass (Alopecurus myosuroides Huds.) in China.
- Author
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Lan, Yuning, Li, Wenyu, Wei, Shouhui, Huang, Hongjuan, Liu, Zhen, and Huang, Zhaofeng
- Subjects
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HERBICIDE resistance , *HERBICIDES , *WINTER wheat , *MALATHION , *SEQUENCE analysis , *AMINO acids - Abstract
Two black-grass (Alopecurus myosuroides Huds.) populations (R2105 and R1027) that were suspected to be resistant to clodinafop-propargyl, an acetyl-CoAcarboxylase (ACCase) inhibitor, were found in winter wheat fields in China. Research was carried out to investigate whether resistance to clodinafop-propargyl was present and the molecular mechanism of herbicide resistance in these two populations. Dose–response assays confirmed high level resistance to clodinafop-propargyl in both R2105 and R1027 populations, with resistance indexes 25.1 and 22.1. ACCase gene sequence comparison revealed three amino acid mutations (Trp-1999-Leu, Ile-2041-Asn, or Asp-2078-Gly) in R2105 population and Ile-2041-Asn mutation in R1027 population. Sensitivity to other herbicides assays indicated that R2105 and R1027 populations were cross resistant to fenoxaprop-P-ethyl and multiple resistant to pyroxsulam and mesosulfuron-methyl. The ALS gene sequence analysis revealed that all resistant individuals in R2105 and R1027 populations had the Trp-574-Leu mutation. Applying malathion, significantly decreased the rate of metabolism of clodinafop-propargyl in both R2105 and R1027 populations. This is the first report of multiple resistance to ACCase- and ALS-inhibiting herbicides conferred by target-site mutations and enhanced metabolism in black-grass in China. [Display omitted] • Two Alopecurus myosuroides populations were resistant to ACCase and ALS herbicides. • ACCase and ALS sequencing revealed target site mutations. • P450s inhibitor malathion could reduce clodinafop-propargyl resistance. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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