Pest Management Science (2018) 74, 1094-1100

The D. Ngo, Mahima Krishnan, Peter Boutsalis, Gurjeet Gill and Christopher Preston (2018)
Target-site mutations conferring resistance to glyphosate in feathertop Rhodes grass (Chloris virgata) populations in Australia
Pest Management Science 74 (5), 1094-1100
Abstract:
Background
Chloris virgata is a warm-season, C₄, annual grass weed affecting field crops in northern Australia that has become an emerging weed in southern Australia. Four populations with suspected resistance to glyphosate were collected in South Australia, Queensland and New South Wales, Australia, and compared with one susceptible (S) population to confirm glyphosate resistance and elucidate possible mechanisms of resistance.
Results
Based on the rate of glyphosate required to kill 50% of treated plants (LD₅₀), glyphosate resistance (GR) was confirmed in four populations of C. virgata (V12, V14.2, V14.16 and V15). GR plants were 2–9.7-fold more resistant and accumulated less shikimate after glyphosate treatment than S plants. GR and S plants did not differ in glyphosate absorption and translocation. Target-site EPSPS mutations corresponding to Pro-106-Leu (V14.2) and Pro-106-Ser (V15, V14.16 and V12) substitutions were found in GR populations. The population with Pro-106-Leu substitution was 2.9–4.9-fold more resistant than the three other populations with Pro-106-Ser substitution.
Conclusion
This report confirms glyphosate resistance in C. virgata and shows that target-site EPSPS mutations confer resistance to glyphosate in this species. The evolution of glyphosate resistance in C. virgata highlights the need to identify alternative control 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): Peter Boutsalis

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

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Chloris virgata (weed)		Australia (South+SE)
	Chloris virgata (weed)		Australia (NT+QLD)