Evaluation of three Manitoba redroot pigweed (Amaranthus retroflexus L.) populations resistant to acetolactate synthase-inhibitors

Simple item page
dc.contributor.authorSarker, Sampa
dc.contributor.examiningcommitteeDuncan, Robert (Plant Science)
dc.contributor.examiningcommitteeLaforest, Martin (Agriculture and Agri-Food Canada)
dc.contributor.supervisorGulden, Rob
dc.date.accessioned2023-07-21T17:13:01Z
dc.date.available2023-07-21T17:13:01Z
dc.date.issued2023-06-20
dc.date.submitted2023-06-20T12:59:44Zen_US
dc.degree.disciplinePlant Scienceen_US
dc.degree.levelMaster of Science (M.Sc.)
dc.description.abstractRedroot pigweed (Amaranthus retroflexus L.) is a common broadleaf weed species in Manitoba, Canada. Producers in this region have been reporting reduced response of this weed to commonly used Acetolactate synthase (ALS) inhibiting herbicides. Three suspected resistant populations of redroot pigweed were compared with known susceptible populations in a greenhouse study to determine the level of resistance to the ALS-inhibiting herbicides imazethapyr and thifensulfuron-methyl. A laboratory experiment was conducted to identify the mechanism of herbicide resistance of these three populations. Dose response curves to these herbicides indicated that all three pigweed populations were resistant to imazethapyr (~30 to >170-times), but only one of these populations showed a low level (7-fold) of cross resistance to thifensulfuron-methyl. Acetolactate synthase (ALS) gene sequence analysis detected a Ser653Asn amino acid substitution that was consistent in the two populations ArMB1 & ArMB2 which were highly resistant to imazethapyr. A Ser653Asn/Ile substitution was found in population ArMB3. That population showed high resistance to imazethapyr and low levels of resistance to thifensulfuron-methyl. A malathion treatment study was conducted to determine the presence of non-target site resistance through enhanced metabolism among the three resistant populations. Cytochrome P450 induced metabolism based non-target site resistance (NTSR) did not contribute to resistance to imazethapyr or thifensulfuron-methyl among the three resistant populations. Target site resistance alone was the mechanism conferring resistance to these two ALS inhibitors among the three resistant redroot pigweed populations and that facilitates the development of rapid detection markers to identify the resistant redroot pigweed with these mutations.
dc.description.noteOctober 2023
dc.description.sponsorshipPlant Surveillance Initiative, Canadian Agricultural Partnership, Western Grains Research Foundation, University of Manitoba Graduate Fellowship.
dc.identifier.urihttp://hdl.handle.net/1993/37424
dc.language.isoeng
dc.rightsopen accessen_US
dc.subjectRedroot pigweed (Amaranthus retroflexus L.)
dc.subjectImazethapyr
dc.subjectThifensulfuron-methyl
dc.subjectMalathion
dc.subjectTarget-site resistance
dc.subjectNon-target-site resistance
dc.titleEvaluation of three Manitoba redroot pigweed (Amaranthus retroflexus L.) populations resistant to acetolactate synthase-inhibitors
dc.typemaster thesisen_US
local.subject.manitobayes
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Sarker_Sampa.pdf.pdf
Size:
826.06 KB
Format:
Adobe Portable Document Format
Description:
Download
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
770 B
Format:
Item-specific license agreed to upon submission
Description:
Download
Collections
FGS - Electronic Theses and Practica
Manitoba Heritage Theses