title: Resistance of American sloughgrass (Bechmannia syzigachne) populations to ACCase-inhibiting herbicides involves three different target site mutations from China.
abstract: American sloughgrass [Beckmannia syzigachne (Steud.) Fernald] is a problematic annual grass weed in winter wheat fields of China, which causes great loss of wheat yield. Repeated use of acetyl-CoA carboxylase (ACCase)-inhibiting herbicides during the last two decades to control this weed has been selected for resistance in American sloughgrass in Jiangsu province. In this study, whole-plant dose-response assays were conducted to investigate the level of resistance in four resistant American sloughgrass populations (LY, JH, BYJ and BYP) to four ACCase-inhibiting herbicides belonging to aryloxyphenoxypropionates, cyclohexanediones, and phenylpyrazolines groups under greenhouse conditions. Based on resistance factor (RF), three populations, LY, BYJ and BYP, were highly resistant to fenoxaprop-P-ethyl, clodinafop propargyl, sethoxydim and pinoxaden. JH plants exhibited resistance to fenoxaprop-P-ethyl and clodinafop propargyl, but showed much lower RF values for sethoxydim and pinoxaden. Molecular analysis of resistance revealed that resistance in all the four populations was target site-based. Results confirmed that substitutions of Ile-1781-Leu, Ile-2041-Asn and Asp-2078-Gly, respectively, in LY, JH and BYJ/BYP, are responsible for diverse sensitivity to different ACCase-inhibiting herbicides in these populations. The substitution at position 1781 had been reported, while it is the first report of Ile-2041-Asn and Asp-2078-Gly mutations that corresponded to resistance in American sloughgrass.
authors.affiliation: Zhejiang Branch of National Pesticide R&D South Center, Zhejiang Chemical Industry Research Institute, Hangzhou 310023, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Tang
authors.affiliation: Institute of Plant Protection and Agro-Products Safety, Anhui Academy of Agricultural Sciences, Hefei 230031, China.
authors.forename: Fengyan
authors.initials: F
authors.lastname: Zhou
authors.affiliation: Institute of Plant Protection and Agro-Products Safety, Anhui Academy of Agricultural Sciences, Hefei 230031, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Zhejiang Branch of National Pesticide R&D South Center, Zhejiang Chemical Industry Research Institute, Hangzhou 310023, China. Electronic address: gina1965@163.com.
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
mesh_terms: D000103:Acetyl-CoA Carboxylase / Q000235:genetics*; D002681:China; D003512:Cyclohexanones / Q000633:toxicity; D053209:Herbicide Resistance / Q000235:genetics; D006540:Herbicides / Q000633:toxicity*; D006574:Heterocyclic Compounds, 2-Ring / Q000633:toxicity; D009154:Mutation / Q000235:genetics; D006109:Poaceae / Q000187:drug effects* / Q000235:genetics
chemical_list: D003512:Cyclohexanones; D006540:Herbicides; D006574:Heterocyclic Compounds, 2-Ring; C049437:sethoxydim; D000103:Acetyl-CoA Carboxylase; C542519:pinoxaden
keywords: ACCase gene; American sloughgrass; Clodinafop propargyl; Herbicide resistance; Target site mutation