title: EPSPS Gene Copy Number and Whole-Plant Glyphosate Resistance Level in Kochia scoparia.
abstract: Glyphosate-resistant (GR) Kochia scoparia has evolved in dryland chemical fallow systems throughout North America and the mechanism of resistance involves 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene duplication. Agricultural fields in four states were surveyed for K. scoparia in 2013 and tested for glyphosate-resistance level and EPSPS gene copy number. Glyphosate resistance was confirmed in K. scoparia populations collected from sugarbeet fields in Colorado, Wyoming, and Nebraska, and Montana. Glyphosate resistance was also confirmed in K. scoparia accessions collected from wheat-fallow fields in Montana. All GR samples had increased EPSPS gene copy number, with median population values up to 11 from sugarbeet fields and up to 13 in Montana wheat-fallow fields. The results indicate that glyphosate susceptibility can be accurately diagnosed using EPSPS gene copy number.
authors.affiliation: Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, United States of America.
authors.forename: Todd A
authors.initials: TA
authors.lastname: Gaines
authors.affiliation: Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, United States of America.
authors.forename: Abigail L
authors.initials: AL
authors.lastname: Barker
authors.affiliation: Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, United States of America.
authors.forename: Eric L
authors.initials: EL
authors.lastname: Patterson
authors.affiliation: Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, United States of America.
authors.forename: Philip
authors.initials: P
authors.lastname: Westra
authors.affiliation: Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado, United States of America.
authors.forename: Eric P
authors.initials: EP
authors.lastname: Westra
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska, Scottsbluff, Nebraska, United States of America.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Wilson
authors.affiliation: Southern Agricultural Research Center, Montana State University, Huntley, Montana, United States of America.
authors.forename: Prashant
authors.initials: P
authors.lastname: Jha
authors.affiliation: Southern Agricultural Research Center, Montana State University, Huntley, Montana, United States of America.
authors.forename: Vipan
authors.initials: V
authors.lastname: Kumar
authors.affiliation: Department of Plant Sciences, University of Wyoming, Laramie, Wyoming, United States of America.
authors.forename: Andrew R
authors.identifier: http://orcid.org/0000-0003-2551-4959
authors.initials: AR
authors.lastname: Kniss
mesh_terms: D051229:3-Phosphoshikimate 1-Carboxyvinyltransferase / Q000235:genetics*; D027467:Bassia scoparia / Q000187:drug effects / Q000235:genetics; D005784:Gene Amplification; D018628:Gene Dosage; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology; D053209:Herbicide Resistance / Q000235:genetics*; D006540:Herbicides / Q000494:pharmacology; D000097797:Glyphosate
chemical_list: D051229:3-Phosphoshikimate 1-Carboxyvinyltransferase; D005998:Glycine; D006540:Herbicides; D000097797:Glyphosate