International Survey of Herbicide-Resistant Weeds

Countries Weeds Herbicides Mutations Graphs References Researchers
(Rapistrum rugosum)

Inhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)

Iran, Golestan
Turnipweed (Rapistrum rugosum) is a dicot weed in the Brassicaceae family.  In Iran this weed first evolved resistance to Group 2 (Legacy B) herbicides in 2010 and infests Winter wheat.   Group 2 (Legacy B) herbicides are known as Inhibition of Acetolactate Synthase (Inhibition of Acetolactate Synthase ).  Research has shown that these particular biotypes are resistant to bispyribac-sodium, florasulam, flucarbazone-Na, and tribenuron-methyl and they may be cross-resistant to other Group 2 (Legacy B) herbicides.

The 'Group' letters/numbers that you see throughout this web site refer to the classification of herbicides by their site of action. To see a full list of herbicides and HRAC herbicide classifications click here.

If we do not have a picture for this weed, or you can provide a better picture (scan, digital camera etc) please please e-mail it to us.

QUIK STATS (last updated Mar 11, 2016 )

Common NameTurnipweed
SpeciesRapistrum rugosum
GroupInhibition of Acetolactate Synthase HRAC Group 2 (Legacy B)
Herbicidesbispyribac-sodium, florasulam, flucarbazone-Na, and tribenuron-methyl
LocationIran, Golestan
Situation(s)Winter wheat
Contributors - (Alphabetically)Javid Gherekhloo 
Edit this Case  |  Add New Case of Resistance  |  Add Note



Javid Gherekhloo

Multiple Mechanisms Increase Levels of Resistance in Rapistrum rugosum to ALS Herbicides

Zahra M. Hatami1, Javid Gherekhloo1, Antonia M. Rojano-Delgado2, Maria D. Osuna3, Ricardo Alcántara2, Pablo Fernández2, Hamid R. Sadeghipour4 and Rafael De Prado2

*1 Department of Agronomy, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran, 2 Department ofAgricultural Chemistry and Soil Science, University of Córdoba, Córdoba, Spain, 3 Agrarian Research Center “Finca LaOrden” Valdesequera, Badajoz, Spain, 4 Department of Biology, Golestan University, Golestan, Iran

Rapistrum rugosum (turnip weed) is a common weed of wheat fields in Iran, which is most often controlled by tribenuron-methyl (TM), a sulfonylurea (SU) belonging to the acetolactate synthase (ALS) inhibiting herbicides group. Several cases of unexplained control failure of R. rugosum by TM have been seen, especially in Golestan provinceIran. Hence, there is lack of research in evaluation of the level of resistance of the R. rugosum populations to TM, using whole plant dose-response and enzyme assays, then investigating some potential resistance mechanisms Results revealed that the resistance factor (RF) for resistant (R) populations was 2.5–6.6 fold higher than susceptible (S) plant. Neither foliar retention, nor 14C-TM absorption and translocation were the mechanisms responsible for resistance in turnip weed. Metabolism of TM was the second resistant mechanism in two populations (Ag-R5 and G-1), in which three metabolites were found. The concentration of TM for 50% inhibition of ALS enzyme activity in vitro showed a high level of resistance to the herbicide (RFs were from 28 to 38) and cross-resistance to sulfonyl-aminocarbonyl-triazolinone (SCT), pyrimidinyl-thiobenzoate (PTB) and triazolopyrimidine (TP), with no cross-resistance to imidazolinone (IMI). Substitution Pro 197 to Ser 197 provided resistance to four of five ALS-inhibiting herbicides including SU, TP, PTB, and SCT with no resistance to IMI. These results documented the first case of R. rugosum resistant population worldwide and demonstrated that both RST and NRST mechanisms are involved to the resistance level to TM.

Edit this Note  |  Add New Note


Confirmation Tests

Field, and Greenhouse trials comparing a known susceptible Turnipweed biotype with this Turnipweed biotype have been used to confirm resistance. For further information on the tests conducted please contact the local weed scientists that provided this information.

Genetic studies on HRAC Group 2 resistant Turnipweed have not been reported to the site.  There may be a note below or an article discussing the genetics of this biotype in the Fact Sheets and Other Literature
Mechanism of Resistance

The mechanism of resistance for this biotype is either unknown or has not been entered in the database.  If you know anything about the mechanism of resistance for this biotype then please update the database.
Relative Fitness

There is no record of differences in fitness or competitiveness of these resistant biotypes when compared to that of normal susceptible biotypes.  If you have any information pertaining to the fitness of Group 2 (Legacy B) resistant Turnipweed from Iran please update the database.
Edit Case  |  Add Note  |  Add Article  |  Add New Case  |  Help


Associate Professor
Gorgan University of Agricultural Sciences and Natural Resources
Agronomy Department
Gorgan, 49189-43464, Golestan
Email Javid Gherekhloo


The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Iran have been instrumental in providing you this information. Particular thanks is given to Javid Gherekhloo for providing detailed information.
Herbicide Resistant Turnipweed Globally
(Rapistrum rugosum)
Herbicide Resistant Turnipweed Globally
(Rapistrum rugosum)
Drag a column header and drop it here to group by that column
Herbicide Resistant Turnipweed Globally
(Rapistrum rugosum)
#CountryFirstYearSituationActive IngredientsSite of Action
1 Australia (Queensland) AustraliaQueensland1996 Cereals, and Wheat chlorsulfuron 1 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
142Rapistrum rugosumTurnipweed528
2 Australia (New South Wales ) AustraliaNew South Wales 2021 Spring Barley imazamox, and imazapyr 1 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
142Rapistrum rugosumTurnipweed19215
3 IranIran 2010 Winter wheat bispyribac-sodium, florasulam, flucarbazone-Na, and tribenuron-methyl 79 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
142Rapistrum rugosumTurnipweed5550
4 SpainSpain 2018 Winter barley, and Winter wheat iodosulfuron-methyl-Na, and tribenuron-methyl 38 Inhibition of Acetolactate Synthase ( HRAC Group 2 (Legacy B)
142Rapistrum rugosumTurnipweed18171
Literature about Similar Cases

Page size:
Page: of 1
Items 1 to 4 of 4

Page size:
Page: of 1
Items 1 to 4 of 4
PERMISSION MUST BE OBTAINED FIRST if you intend to base a significant portion of a scientific paper on data derived from this site.
Cite this site as: Heap, I.  The International Survey of Herbicide Resistant Weeds.  Online.  Internet.  Saturday, July 20, 2024 .  Available
Copyright © 1993- 2024 All rights reserved. Fair use of this material is encouraged. Proper citation is requested.