Pest Management Science (2022) 78, 1206-1212

Jinyi Chen, Qin Yu, Mechelle Owen, Heping Han, Eric Patterson, Chad Sayer and Stephen Powles (2022)
Target-site resistance to trifluralin is more prevalent in annual ryegrass populations from Western Australia
Pest Management Science 78 (3), 1206-1212
Abstract:
BACKGROUND
Trifluralin is widely used in Australia as one of the important pre-emergence herbicides to control annual ryegrass (Lolium rigidum Gaud.) populations. Trifluralin resistance evolution and mechanisms have been identified in some ryegrass populations.
RESULTS
In this study, 21 putative resistant field survey populations from Western Australian were screened with trifluralin, and 90% (19 of 21) contained individuals surviving 480 g ha^-1 trifluralin treatment. Twelve populations contained individuals possessing the known α-tubulin resistance mutations at Val-202, Thr-239 and Arg-243 in TUA4 (alpha-tubulin 4 n), plus multiple potential resistance mutations in TUA4 pending genetic confirmation. Three populations had only individuals carrying newly identified (but uncharacterized) mutations in TUA3/TUA4. Radioactive work found that six populations evolved metabolic resistance to trifluralin, and at least four of them also possessed the known and/or putative target-site mutations.
CONCLUSION
These results confirm that a high incidence of resistance to the dinitroaniline herbicide (trifluralin) is present, and target-site tubulin mutations make a major contribution to resistance in these annual ryegrass populations. Co-evolution of both target-site and non-target-site resistance to per-emergence herbicides warrants diverse management tactics.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Qin Yu, Stephen B. Powles

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Lolium rigidum (weed)		Australia (Western)