Abstract
Nine Monochoria vaginalis Pres1 accessions from Chonnam province, Korea were tested for resistance to the sulfonylurea herbicide, imazosulfuron, in whole-plant response bioassay. All accessions were confirmed resistant (R) to imazosulfuron. The GR50 (imazosulfuron concentration that reduced shoot dry weight by 50%) values of R accessions were 1112-3172 (accession #9) times higher than that of the standard susceptible (S) accession. Accession #9 exhibited cross-resistance to other sulfonylurea herbicides, bensulfuron-methyl, cyclosulfamuron and pyrazosulfuron-ethyl, but not to the imidazolinone herbicides, imazapyr and imazaquin. The R biotype could be controlled by other herbicides with different modes of action, such as mefenacet and pyrazolate, applied to soil at recommended rates. Foliar-applied herbicides, 2,4-D and bentazone, also controlled both the R and S biotypes. Sulfonylurea-based mixtures, except ethoxysulfuron plus fentrazamide, did not control resistant M. vaginalis. Rice yield was reduced 70% by resistant M. vaginalis that escaped pyrazosulfuron-ethyl plus molinate, compared with hand weeding in direct-seeded rice culture. In contrast, rice yield was reduced 44% by resistant M. vaginalis that survived the pyrazosulfuron-ethyl plus molinate treatment, compared with pyrazolate plus butachlor in transplanted rice culture. In vitro acetolactate synthase (ALS) activity of the R biotype was 183, 35, 130 and 31 times more resistant to imazosulfuron, bensulfuron-methyl, cyclosulfamuron and pyrazosulfuron-ethyl, respectively, than the S biotype. Imidazolinone herbicides, imazapyr and imazaquin had similar effect on in vitro ALS activity of the R and S biotypes. The in vivo ALS activity of the R biotype was also less affected than the S biotype by the sulfonylurea herbicides imazosulfuron and pyrazosulfuron-ethyl. Results of in vitro and in vivo ALS assays indicate that the resistance mechanism of M. vaginalis to sulfonylurea herbicides may be due, in part, to an alteration in the target enzyme, ALS. Since the level of resistance in the enzyme assay was much lower than that in the whole-plant assay, other mechanisms of resistance, such as herbicide metabolism, may be involved.
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Claims 18
Claim · model-written summary
Imazosulfuron-resistant Monochoria vaginalis accessions had GR50 values 1112-3172 times higher than the susceptible accession.
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“The GR50 (imazosulfuron concentration that reduced shoot dry weight by 50%) values of R accessions were 1112-3172 (accession #9) times higher than that of the standard susceptible (S) accession”
Claim · model-written summary
All Monochoria vaginalis accessions were confirmed resistant to imazosulfuron.
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“All accessions were confirmed resistant (R) to imazosulfuron”
Claim · model-written summary
Accession #9 showed cross-resistance to bensulfuron-methyl, cyclosulfamuron and pyrazosulfuron-ethyl.
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“Accession #9 exhibited cross-resistance to other sulfonylurea herbicides, bensulfuron-methyl, cyclosulfamuron and pyrazosulfuron-ethyl”
Claim · model-written summary
Accession #9 showed no cross-resistance to imazapyr and imazaquin.
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“Accession #9 exhibited cross-resistance to other sulfonylurea herbicides, bensulfuron-methyl, cyclosulfamuron and pyrazosulfuron-ethyl”
e3“but not to the imidazolinone herbicides, imazapyr and imazaquin”
Claim · model-written summary
The resistant biotype could be controlled by mefenacet and pyrazolate applied to soil at recommended rates.
- Taxon
- Monochoria vaginalise1
- Treatment
- mefenacet and pyrazolatee2
- Outcome
- R biotypee2
- Direction
- could be controllede2
Not reportedComparator
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“The R biotype could be controlled by other herbicides with different modes of action, such as mefenacet and pyrazolate, applied to soil at recommended rates”
Claim · model-written summary
Foliar-applied 2,4-D and bentazone controlled both the resistant and susceptible biotypes.
- Taxon
- Monochoria vaginalise1
- Treatment
- Foliar-applied herbicides, 2,4-D and bentazonee2
- Outcome
- both the R and S biotypese2
- Direction
- controllede2
Not reportedComparator
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“Foliar-applied herbicides, 2,4-D and bentazone, also controlled both the R and S biotypes”
Claim · model-written summary
Sulfonylurea-based mixtures did not control resistant Monochoria vaginalis, except ethoxysulfuron plus fentrazamide.
- Taxon
- Monochoria vaginalise1
- Treatment
- Sulfonylurea-based mixturese2
- Outcome
- resistant M. vaginalise2
- Direction
- did not controle2
- Qualifier
- except ethoxysulfuron plus fentrazamidee2
Not reportedComparator
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“Sulfonylurea-based mixtures, except ethoxysulfuron plus fentrazamide, did not control resistant M. vaginalis”
Claim · model-written summary
Resistant Monochoria vaginalis that escaped pyrazosulfuron-ethyl plus molinate reduced rice yield by 70% compared with hand weeding in direct-seeded rice.
- Taxon
- Rice
Oryza sativae2 - Treatment
- resistant M. vaginalis that escaped pyrazosulfuron-ethyl plus molinatee2
- Interactor
- M. vaginalise2weed
- Outcome
- Rice yielde2
- Direction
- reducede2
- Value
- 70%e2
- Comparator
- hand weedinge2
- Setting
- direct-seeded rice culturee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“Rice yield was reduced 70% by resistant M. vaginalis that escaped pyrazosulfuron-ethyl plus molinate, compared with hand weeding in direct-seeded rice culture”
Claim · model-written summary
Resistant Monochoria vaginalis that survived pyrazosulfuron-ethyl plus molinate reduced transplanted rice yield by 44% compared with pyrazolate plus butachlor.
- Taxon
- riceOryza sativae2
- Treatment
- resistant M. vaginalis that survived the pyrazosulfuron-ethyl plus molinate treatmente2
- Interactor
- M. vaginalise2weed
- Outcome
- rice yielde2
- Direction
- reducede2
- Value
- 44%e2
- Comparator
- pyrazolate plus butachlore2
- Setting
- transplanted rice culturee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“In contrast, rice yield was reduced 44% by resistant M. vaginalis that survived the pyrazosulfuron-ethyl plus molinate treatment, compared with pyrazolate plus butachlor in transplanted rice culture”
Claim · model-written summary
In vitro ALS activity of the resistant biotype was 183 times more resistant to imazosulfuron than the susceptible biotype.
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“In vitro acetolactate synthase (ALS) activity of the R biotype was 183, 35, 130 and 31 times more resistant to imazosulfuron, bensulfuron-methyl, cyclosulfamuron and pyrazosulfuron-ethyl, respectively, than the S biotype”
Claim · model-written summary
In vitro ALS activity of the resistant biotype was 35 times more resistant to bensulfuron-methyl than the susceptible biotype.
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“In vitro acetolactate synthase (ALS) activity of the R biotype was 183, 35, 130 and 31 times more resistant to imazosulfuron, bensulfuron-methyl, cyclosulfamuron and pyrazosulfuron-ethyl, respectively, than the S biotype”
Claim · model-written summary
In vitro ALS activity of the resistant biotype was 130 times more resistant to cyclosulfamuron than the susceptible biotype.
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“In vitro acetolactate synthase (ALS) activity of the R biotype was 183, 35, 130 and 31 times more resistant to imazosulfuron, bensulfuron-methyl, cyclosulfamuron and pyrazosulfuron-ethyl, respectively, than the S biotype”
Claim · model-written summary
In vitro ALS activity of the resistant biotype was 31 times more resistant to pyrazosulfuron-ethyl than the susceptible biotype.
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“In vitro acetolactate synthase (ALS) activity of the R biotype was 183, 35, 130 and 31 times more resistant to imazosulfuron, bensulfuron-methyl, cyclosulfamuron and pyrazosulfuron-ethyl, respectively, than the S biotype”
Claim · model-written summary
Imidazolinone herbicides had a similar effect on in vitro ALS activity of the resistant and susceptible biotypes.
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“Imidazolinone herbicides, imazapyr and imazaquin had similar effect on in vitro ALS activity of the R and S biotypes”
Claim · model-written summary
In vivo ALS activity of the resistant biotype was less affected than the susceptible biotype by imazosulfuron and pyrazosulfuron-ethyl.
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“The in vivo ALS activity of the R biotype was also less affected than the S biotype by the sulfonylurea herbicides imazosulfuron and pyrazosulfuron-ethyl”
Claim · model-written summary
Target-enzyme alteration in ALS may in part explain sulfonylurea resistance in Monochoria vaginalis.
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“Results of in vitro and in vivo ALS assays indicate that the resistance mechanism of M. vaginalis to sulfonylurea herbicides may be due, in part, to an alteration in the target enzyme, ALS”
Claim · model-written summary
The level of resistance in the enzyme assay was much lower than in the whole-plant assay.
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“Since the level of resistance in the enzyme assay was much lower than that in the whole-plant assay”
Claim · model-written summary
Other resistance mechanisms, such as herbicide metabolism, may be involved in Monochoria vaginalis resistance.
Verbatim
e1“Nine Monochoria vaginalis Pres1 accessions”
e2“other mechanisms of resistance, such as herbicide metabolism, may be involved”
The same questions in other papers
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See all 77 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.