Translator Disclaimer
1 October 2016 Mechanisms of Resistance to Pyroxsulam and ACCase Inhibitors in Japanese Foxtail (Alopecurus japonicus)
Author Affiliations +
Abstract

Japanese foxtail is a predominant tetraploid grass weed in wheat and oilseed rape fields in eastern China. In China, pyroxsulam is mainly used to manage annual grass weeds, especially those resistant to acetyl coenzyme A carboxylase (ACCase)-inhibiting herbicides. Using dose–response studies, a pyroxsulam-resistant population, ACTC-1, was identified with a resistance index value of 58. Additionally, ACTC-1 was cross-resistant to sulfonylureas, imidazolinones, triazolopyrimidines, pyrimidinyl-benzoates, and sulfonylaminocarbonyl-triazolinones and multiresistant to ACCase and photosystem II inhibitors. Sequence analysis revealed four gene fragments encoding acetolactate synthase (ALS) from ACTC-1, and three from JNXW-1, a pyroxsulam-sensitive population. An Asp-376-Glu substitution was found in ALS1;2 and an Ile-2041-Asn in Acc1;1, which may be responsible for its resistance to pyroxsulam and ACCase inhibitors, respectively. In vitro assays of ALS activity revealed that in ACTC-1, the sensitivity of ALS to pyroxsulam was lower, and the basal ALS activity was twofold higher than that of sensitive population JNXW-1. Additionally, the combined application of pyroxsulam with malathion or piperonyl butoxide increased the sensitivity of ACTC-1 to pyroxsulam, although it could not completely overcome the resistance. It was inferred that both target-site-based resistance and nontarget-site-based resistance may be involved in the resistance to pyroxsulam.

Nomenclature: Malathion; piperonyl butoxide (PBO); pyroxsulam; Japanese foxtail, Alopecurus japonicas Steud; birdsrape mustard, Brassica campestris L.; wheat, Triticum aestivum L.

Yujuan Feng, Yuan Gao, Yong Zhang, Liyao Dong, and Jun Li "Mechanisms of Resistance to Pyroxsulam and ACCase Inhibitors in Japanese Foxtail (Alopecurus japonicus)," Weed Science 64(4), 695-704, (1 October 2016). https://doi.org/10.1614/WS-D-16-00042.1
Received: 12 March 2016; Accepted: 1 May 2015; Published: 1 October 2016
JOURNAL ARTICLE
10 PAGES


SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top