Translator Disclaimer
1 January 2011 Wide Distribution of the Waterhemp (Amaranthus tuberculatus) ΔG210 PPX2 Mutation, which Confers Resistance to PPO-Inhibiting Herbicides
Author Affiliations +
Abstract

Resistance in waterhemp to herbicides that inhibit protoporphyrinogen oxidase (PPO) previously was shown to result from the deletion of a glycine codon at position 210 (ΔG210) in the PPO-encoding gene, PPX2. Research was conducted to determine if this same mechanism accounted for resistance in geographically separated populations—from Illinois, Kansas, and Missouri—and, if so, to determine if the mutation conferring resistance was independently selected. A dose–response study with lactofen indicated that the resistant populations had different levels of resistance. These differences, however, could be accounted for by different frequencies of resistant individuals within populations and, therefore, the dose–response data were consistent with the hypothesis that the populations contained the same resistance mechanism. Direct evidence in support of this hypothesis was provided by DNA sequencing, which showed that nearly all resistant plants evaluated contained the ΔG210 mutation. A variable region of the PPX2 gene was sequenced and resulting sequences were aligned and organized into a phylogenetic tree. The phylogenetic tree did not reveal clear clustering by either geography or phenotype (resistant vs. sensitive). Possibly recombination within the PPX2 gene has masked its evolutionary history.

Nomenclature: Common waterhemp, Amaranthus tuberculatus (Moq.) Sauer var. rudis (Sauer) Costea and Tardif AMATU.

Weed Science Society of America
Kate A Thinglum, Chance W Riggins, Adam S Davis, Kevin W Bradley, KASSIM AL-KHATIB, and Patrick J Tranel "Wide Distribution of the Waterhemp (Amaranthus tuberculatus) ΔG210 PPX2 Mutation, which Confers Resistance to PPO-Inhibiting Herbicides," Weed Science 59(1), 22-27, (1 January 2011). https://doi.org/10.1614/WS-D-10-00085.1
Received: 3 June 2010; Accepted: 1 September 2010; Published: 1 January 2011
JOURNAL ARTICLE
6 PAGES


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