INTERNATIONAL HERBICIDE-RESISTANT WEED DATABASE
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GROUP B/2 resistance: (ALS INHIBITORS)
Inhibition of acetolactate synthase ALS (acetohydroxyacid synthase AHAS)
MUTATION: PROLINE 197 to GLUTAMINE
) is a dicot plant in the asteraceae family. A single amino acid substitution from Proline 197 to Glutamine has led to resistance to ALS inhibitors as indicated in the table below.
Intermediate Resistance < 10 fold
Resistant > 10 fold
Resistant > 10 fold
Different Pro197 substitutions were present within populations, and therefore specific cross resistance patterns conferred by specific substitutions are confounded.
Intanon, S. ; Perez-Jones, A. ; Hulting, A. G. ; Mallory-Smith, C. A.
ALS substitutions endow resistance to ALS inhibitors within and among mayweed chamomile populations
431 - 437
Mayweed chamomile seeds were collected from six different fields across the Pacific Northwest. All populations (each collection site was considered a population) were suspected to have some level of acetolactate synthase (ALS) resistance. Greenhouse and laboratory studies were conducted to determine if these populations were resistant to three different classes of ALS inhibitors: sulfonylureas (SU), imidazolinones (IMI), and triazolopyrimidines (TP). A whole-plant dose-response and
ALS activity studies confirmed cross-resistance to thifensulfuron+tribenuron/chlorsulfuron (SU), imazethapyr (IMI), and cloransulam (TP); however, resistance varied by herbicide class and population. Two
isoforms of the
) were identified in mayweed chamomile; however, only mutations in
were responsible for resistance. No mutations were found in
. Sequence analysis of the partial
gene identified four point mutations at position 197 (Pro
to Leu, Gln, Thr, or Ser) in the resistant populations. This study demonstrates genotypic variation associated with cross-resistance to ALS inhibitors within and between populations.
This case was entered by Patrick Tranel Email:
PERMISSION MUST BE OBTAINED FIRST if you intend to base a significant portion of a scientific paper on data derived from this site. Citation:
Heap, I. The International Herbicide-Resistant Weed Database. Online.
Thursday, January 21, 2021
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