Translator Disclaimer
30 May 2019 Target Site–Based Penoxsulam Resistance in Barnyardgrass (Echinochloa crus-galli) from China
Author Affiliations +

Barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] is acknowledged to be the most troublesome weed in rice fields in Anhui and Jiangsu provinces of China. It cannot be effectively controlled using certain acetolactate synthase (ALS)-inhibiting herbicides, including penoxsulam. Echinochloa crus-galli samples with suspected resistance to penoxsulam were collected to identify the target site–based mechanism underlying this resistance. Populations AXXZ-2 and JNRG-2 showed 33- and 7.3-fold resistance to penoxsulam, respectively, compared with the susceptible JLGY-3 population. Cross-resistance to other ALS inhibitors was reported in AXXZ-2 but not in JNRG-2, and occasionally showed higher sensitivity than JLGY-3. In vitro ALS activity assays revealed that penoxsulam concentrations required to inhibit 50% of ALS activity were 11 and 5.2 times greater in AXXZ-2 and JNRG-2, respectively, than in JLGY-3. DNA and predicted amino acid sequence analyses of ALS revealed Ala-205-Val and Ala-122-Gly substitutions in AXXZ-2 and JNRG-2, respectively. Our results indicate that these substitutions in ALS are at least partially responsible for resistance to penoxsulam.

© Weed Science Society of America, 2019.
Jiapeng Fang, Tingting Liu, Yuhua Zhang, Jun Li, and Liyao Dong "Target Site–Based Penoxsulam Resistance in Barnyardgrass (Echinochloa crus-galli) from China," Weed Science 67(3), 281-287, (30 May 2019).
Received: 22 October 2018; Accepted: 18 January 2019; Published: 30 May 2019

Get copyright permission
Back to Top