Multiple Mechanisms and Multiple Herbicide Resistance inLolium rigidum

Repeated use of the preemergence herbicide triallate has selected for wild oat populations that are resistant (R) to field use rates. Field collections and an inbred R line were shown in greenhouse and petri dish dose response experiments to be 6- to 20-fold more tolerant to triallate than susceptible (S) lines. R populations and the inbred line were also resistant (8-fold) to the related thiocarbamate herbicide diallate, as well as to the chemically unrelated postemergence herbicide difenzoquat (60-fold).14C-triallate uptake and translocation patterns were similar between R and S lines for the first 24 h after application. However, translocation of radioactivity was more rapid in S lines than R lines from 24 through 60 h after application.14C-difenzoquat uptake was the same in R and S lines 12 h after application, but was 10 to 20% higher in R lines than S lines by 24 through 96 h after application. Similarly, translocation of radioactivity after14C-difenzoquat application was 7 to 14% greater in R than S lines after 12 h, although translocated radioactivity amounts were not significantly different between R and S lines. The relatively minor differences in triallate and difenzoquat uptake and translocation patterns between R and S lines are most likely not of sufficient magnitude to explain the observed resistance levels.

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Glyphosate, paraquat and ACCase multiple herbicide resistance evolved in a Lolium rigidum biotype

Planta ◽

10.1007/s00425-006-0364-3 ◽

2006 ◽

Vol 225 (2) ◽

pp. 499-513 ◽

Cited By ~ 125

Author(s):

Qin Yu ◽

Andrew Cairns ◽

Stephen Powles

Keyword(s):

Herbicide Resistance ◽

Lolium Rigidum ◽

Multiple Herbicide Resistance

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Multiple-herbicide resistance across four modes of action in wild radish (Raphanus raphanistrum)

Weed Science ◽

10.1614/ws-03-016r ◽

2004 ◽

Vol 52 (1) ◽

pp. 8-13 ◽

Cited By ~ 74

Author(s):

Michael J. Walsh ◽

Stephen B. Powles ◽

Brett R. Beard ◽

Ben T. Parkin ◽

Sally A. Porter

Keyword(s):

Herbicide Resistance ◽

Crop Production ◽

Acetolactate Synthase ◽

Wild Radish ◽

Raphanus Raphanistrum ◽

Production Program ◽

Use Patterns ◽

Modes Of Action ◽

Herbicide Use ◽

Multiple Herbicide Resistance

Populations of wild radish were collected from two fields in the northern Western Australian wheatbelt, where typical herbicide-use patterns had been practiced for the previous 17 seasons within an intensive crop production program. The herbicide resistance status of these populations clearly established that there was multiple-herbicide resistance across many herbicides from at least four modes of action. One population exhibited multiple-herbicide resistance to the phytoene desaturase (PDS)–inhibiting herbicide diflufenican (3.0-fold), the auxin analog herbicide 2,4-D (2.2-fold), and the photosystem II–inhibiting herbicides metribuzin and atrazine. Another population was found to be multiply resistant to the acetolactate synthase–inhibiting herbicides, the PDS-inhibiting herbicide diflufenican (2.5-fold), and the auxin analog herbicide 2,4-D amine (2.4-fold). Therefore, each population has developed multiple-herbicide resistance across several modes of action. The multiple resistance status of these wild radish populations developed from conventional herbicide usage in intensive cropping rotations, indicating a dramatic challenge for the future control of wild radish.

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