Resistance to acetohydroxyacid synthase inhibitors in foxtail species in Ontario

dc.contributor.advisorTardif, François J.
dc.contributor.authorLaplante, Julie of Horticultural Scienceen_US of Guelphen_US of Scienceen_US
dc.description.abstractFive green foxtail populations and one giant foxtail population were suspected of resistance to acetohydroxyacid synthase (AHAS) inhibitors. This study aimed at confirming resistance and determining its physiological and molecular basis. The response to four AHAS inhibitors was determined at the whole plant and enzyme levels. 'AHAS' genes were sequenced and Southern hybridization analysis was used to document 'AHAS' gene copy number. Resistance was confirmed at the whole plant and enzyme levels in all suspected populations. All green foxtail populations had resistance to imazethapyr with cross-resistance to nicosulfuron and flucarbazone but only three populations had cross-resistance to pyrithiobac. Giant foxtail was resistant to all inhibitors. Resistance in green foxtail was caused by single base-pair mutations in the 'AHAS' gene coding for four amino acid substitutions (Ser653Thr, Ser653Asn, Ser 653Ile and Gly654Asp). Two 'AHAS' genes were confirmed in giant foxtail; a single base-pair mutation coding for Ser 653Asn was found in gene II.en_US
dc.publisherUniversity of Guelphen_US
dc.rights.licenseAll items in the Atrium are protected by copyright with all rights reserved unless otherwise indicated.
dc.subjectgreen foxtailen_US
dc.subjectgiant foxtailen_US
dc.subjectacetohydroxyacid synthase inhibitorsen_US
dc.titleResistance to acetohydroxyacid synthase inhibitors in foxtail species in Ontarioen_US


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