Nicosulfuron-resistant Amaranthus retroflexus L. in Northeast China. (August 2019)

• Record Type: Journal Article
• Authors: Huang, Zhaofeng; Huang, Hongjuan; Chen, Jinyi; Chen, Jingchao; Wei, Shouhui; Zhang, Chaoxian
• Is Part Of: Crop protection. Volume 122(2019)
• Page Start: 79
• Page End: 83
• Publication Date: 2019-08
• Subjects: Amaranthus retroflexus L. -- Nicosulfuron -- ALS -- Mutation -- Herbicide resistance; Plants, Protection of -- Periodicals; 632.05
• DOI: 10.1016/j.cropro.2019.04.024
• Languages: English
• ISSNs: 0261-2194

Abstract

Abstract: Amaranthus retroflexus L. is a troublesome broadleaf weed in autumn crop fields in China. Farmers complain that A. retroflexus cannot be controlled by nicosulfuron at the recommended field rate in maize fields in Heilongjiang Province. The aim of this study was to determine the molecular basis of nicosulfuron resistance in A. retroflexus . Whole-plant response assays revealed that two resistant populations (R1 and R2) exhibited resistance (14.50- and 44.24-fold) to nicosulfuron. In vitro acetolactate synthase (ALS) activity assays indicated that the nicosulfuron I50 values for R1 and R2 populations were 8.12 and 22.32 times higher than that for the susceptible population (S), respectively. Sequence analysis of ALS showed amino acid mutations Ser-653-Asn in R1 and Trp-574-Leu in R2. These two target-site mutations seem to play a primary role in A. retroflexus resistance to nicosulfuron, and this is the first time that the Ser-653-Asn mutation has been reported in this species. Highlights: Two Amaranth retroflexus populations (R1 and R2) exhibited resistance to nicosulfuron. The ALS activities of R1 or R2 populations were much higher than that of S population. Sequence analysis revealed Ser-653-Asn in R1 and Trp-574-Leu in R2. The Ser-653-Asn mutation in A. retroflexus is reported first time.