INTERNATIONAL HERBICIDE-RESISTANT WEED DATABASE

COMMON COCKLEBUR (Xanthium strumarium) with GROUP B/2 resistance: (INHIBITION OF ACETOLACTATE SYNTHASE ) Inhibition of Acetolactate Synthase

MUTATION: ALANINE 205 to VALINE

Common cocklebur (Xanthium strumarium) is a dicot plant in the asteraceae family. A single amino acid substitution from Alanine 205 to Valine has led to resistance to Inhibition of Acetolactate Synthase as indicated in the table below.		Common cocklebur

Chemical Family	Example Herbicide	Resistance Level
Imidazolinones	Imazethapyr	Intermediate Resistance < 10 fold
Pyrimidinyl benzoates	Bispyribac-Na	Intermediate Resistance < 10 fold
Sulfonylureas	Chlorsulfuron	Intermediate Resistance < 10 fold
Triazolopyrimidine - Type 1	Chloransulam-methyl	Intermediate Resistance < 10 fold
Triazolinones	Flucarbazone-Na	Not Determined

REFERENCES

Woodworth, A. P., P. Bernasconi, M. Subramanian, And B. Rosen.. 1996. A second naturally occurring point mutation confers broad-based tolerance to acetolactate synthase inhibitors. Plant Physiology 111 : S105.

This case was entered by Patrick Tranel Email: tranel@illinois.edu

Heap, I. The International Herbicide-Resistant Weed Database. Online. Monday, September 28, 2026. Available at www.weedscience.org

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