Herbicide Resistance: Diminished or failed response of PLANTS to HERBICIDES.Herbicides: Pesticides used to destroy unwanted vegetation, especially various types of weeds, grasses (POACEAE), and woody plants. Some plants develop HERBICIDE RESISTANCE.Plant Weeds: A plant growing in a location where it is not wanted, often competing with cultivated plants.Lolium: Common member of the Gramineae family used as cattle FODDER. It harbors several fungi and other parasites toxic to livestock and people and produces allergenic compounds, especially in its pollen. The most commonly seen varieties are L. perenne, L. multiflorum, and L. rigidum.Acetolactate Synthase: A flavoprotein enzyme that catalyzes the formation of acetolactate from 2 moles of PYRUVATE in the biosynthesis of VALINE and the formation of acetohydroxybutyrate from pyruvate and alpha-ketobutyrate in the biosynthesis of ISOLEUCINE. This enzyme was formerly listed as EC 4.1.3.18.Echinochloa: A plant genus of the family POACEAE that is grown mainly as a hay crop.Aminobutyrates: Derivatives of BUTYRIC ACID that contain one or more amino groups attached to the aliphatic structure. Included under this heading are a broad variety of acid forms, salts, esters, and amides that include the aminobutryrate structure.Drug Resistance: Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.Plants, Genetically Modified: PLANTS, or their progeny, whose GENOME has been altered by GENETIC ENGINEERING.Acetyl-CoA Carboxylase: A carboxylating enzyme that catalyzes the conversion of ATP, acetyl-CoA, and HCO3- to ADP, orthophosphate, and malonyl-CoA. It is a biotinyl-protein that also catalyzes transcarboxylation. The plant enzyme also carboxylates propanoyl-CoA and butanoyl-CoA (From Enzyme Nomenclature, 1992) EC 6.4.1.2.Poaceae: A large family of narrow-leaved herbaceous grasses of the order Cyperales, subclass Commelinidae, class Liliopsida (monocotyledons). Food grains (EDIBLE GRAIN) come from members of this family. RHINITIS, ALLERGIC, SEASONAL can be induced by POLLEN of many of the grasses.Glycine: A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter.Tobacco: A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.Atrazine: A selective triazine herbicide. Inhalation hazard is low and there are no apparent skin manifestations or other toxicity in humans. Acutely poisoned sheep and cattle may show muscular spasms, fasciculations, stiff gait, increased respiratory rates, adrenal degeneration, and congestion of the lungs, liver, and kidneys. (From The Merck Index, 11th ed)Genes, Dominant: Genes that influence the PHENOTYPE both in the homozygous and the heterozygous state.2,4-Dichlorophenoxyacetic Acid: An herbicide with irritant effects on the eye and the gastrointestinal system.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Drug Resistance, Microbial: The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).Drug Resistance, Bacterial: The ability of bacteria to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).2-Methyl-4-chlorophenoxyacetic Acid: A powerful herbicide used as a selective weed killer.Drug Resistance, Neoplasm: Resistance or diminished response of a neoplasm to an antineoplastic agent in humans, animals, or cell or tissue cultures.

*  List of Herbicide Resistant Weeds by Country

Multiple Resistance: 5 Sites of Action ACCase inhibitors (A/1). ALS inhibitors (B/2). Photosystem II inhibitors (C1/5). PSII ... Herbicide Resistant Weeds in Belgium. #. Species. Common Name. Country. State Name. First Year. CountryID. Site of Action. ... Cite this site as: Heap, I. The International Survey of Herbicide Resistant Weeds. Online. Internet. Wednesday, October 18, ...
weedscience.org/Summary/Country.aspx?CountryID=3

*  Fitness costs associated with evolved herbicide resistance alleles in plants - WRAP: Warwick Research Archive Portal

Resistance to the auxin analog herbicides. In: S. B. PowlesJ. A. M. Holtum eds. Herbicide Resistance in Plants. Biology and ... Resistance to acetyl coenzyme A carboxylase inhibiting herbicides. In: S. B. PowlesA. M. Holtum eds. Herbicide Resistance in ... Resistance to photosystem II inhibiting herbicides. In: S. B. PowlesJ. A. M. Holtum eds. Herbicide Resistance in Plants. ... Auxinic herbicide resistance may be modulated at the auxin-binding site in wild mustard (Sinapis arvensis L.): A light ...
wrap.warwick.ac.uk/2253/

*  List of Herbicide Resistant Weeds by Weed Species

Resistance by Site of Action *Graph Data for Resistance by SOA *Resistance by SOA listing species ... Herbicide Resistant Virginia Pepperweed Globally. (Lepidium virginicum). #. Country. Country. StateName. FirstYear. Situation. ... Cite this site as: Heap, I. The International Survey of Herbicide Resistant Weeds. Online. Internet. Tuesday, September 19, ...
weedscience.org/Summary/Species.aspx?WeedID=103

*  List of Herbicide Resistant Weeds by Weed Species

Multiple Resistance: 3 Sites of Action ALS inhibitors (B/2). PPO inhibitors (E/14). EPSP synthase inhibitors (G/9). 18. ... Herbicide Resistant Common Ragweed Globally. (Ambrosia artemisiifolia). #. Country. Country. StateName. FirstYear. Situation. ... Cite this site as: Heap, I. The International Survey of Herbicide Resistant Weeds. Online. Internet. Sunday, September 24, 2017 ... Multiple Resistance: 2 Sites of Action ALS inhibitors (B/2). PPO inhibitors (E/14). 18. Ambrosia artemisiifolia. Common Ragweed ...
weedscience.com/Summary/Species.aspx?WeedID=18

*  List of Herbicide Resistant Weeds by Country

Multiple Resistance: 2 Sites of Action ACCase inhibitors (A/1). ALS inhibitors (B/2). 10954. ... Herbicide Resistant Weeds in China. #. Species. Common Name. Country. State Name. First Year. CountryID. Site of Action. ... Cite this site as: Heap, I. The International Survey of Herbicide Resistant Weeds. Online. Internet. Wednesday, October 18, ... Multiple Resistance: 2 Sites of Action ACCase inhibitors (A/1). ALS inhibitors (B/2). 10955. ...
weedscience.org/Summary/Country.aspx?CountryID=9

*  List of Herbicide Resistant Weeds by Weed Species

Resistance by Site of Action *Graph Data for Resistance by SOA *Resistance by SOA listing species ... Herbicide Resistant Sweet Summer Grass Globally. (Brachiaria eruciformis). #. Country. Country. StateName. FirstYear. Situation ... Cite this site as: Heap, I. The International Survey of Herbicide Resistant Weeds. Online. Internet. Tuesday, September 19, ...
weedscience.org/Summary/Species.aspx?WeedID=318

*  List of Herbicide Resistant Weeds by Weed Species

Resistance by Site of Action *Graph Data for Resistance by SOA *Resistance by SOA listing species ... Herbicide Resistant Common False-pimpernel; Azena (Japanese) Globally. (Lindernia procumbens). #. Country. Country. StateName. ... Cite this site as: Heap, I. The International Survey of Herbicide Resistant Weeds. Online. Internet. Tuesday, September 19, ...
weedscience.org/Summary/Species.aspx?WeedID=109

*  List of Herbicide Resistant Weeds by Weed Species

Multiple Resistance: 2 Sites of Action PSI Electron Diverter (D/22). EPSP synthase inhibitors (G/9). 81. Eleusine indica. ... Herbicide Resistant Goosegrass Globally. (Eleusine indica). #. Country. Country. StateName. FirstYear. Situation. Active ... Multiple Resistance: 2 Sites of Action ACCase inhibitors (A/1). EPSP synthase inhibitors (G/9). 81. Eleusine indica. Goosegrass ... Multiple Resistance: 2 Sites of Action PSI Electron Diverter (D/22). Glutamine synthase inhibitors (H/10). 81. Eleusine indica ...
weedscience.org/Summary/Species.aspx?WeedID=81

*  List of Herbicide Resistant Weeds by Country

Multiple Resistance: 3 Sites of Action ACCase inhibitors (A/1). ALS inhibitors (B/2). Microtubule inhibitors (K1/3). 4. ... Herbicide Resistant Weeds in Australia. #. Species. Common Name. Country. State Name. First Year. CountryID. Site of Action. ... Multiple Resistance: 3 Sites of Action ACCase inhibitors (A/1). ALS inhibitors (B/2). Microtubule inhibitors (K1/3). 5042. ... Multiple Resistance: 3 Sites of Action ACCase inhibitors (A/1). ALS inhibitors (B/2). Microtubule inhibitors (K1/3). 15. ...
weedscience.org/Summary/Country.aspx?CountryID=1

*  Regional Listening Sessions Give Farmers a Voice in the Battle Against Herbicide Resistance | Weed Science Society of America

New Materials Available to Support Resistance Management. Concurrent with the listening sessions on herbicide resistance, new ... Both scientists and regulators have had a lot to say about the growing problem of herbicide resistance and how weed management ... Regional Listening Sessions Give Farmers a Voice in the Battle Against Herbicide Resistance. Posted on February 27, 2017 ... The themes that have emerged from the participants reflect the complexity of herbicide resistance management and the breadth of ...
wssa.net/2017/02/regional-listening-sessions-give-farmers-a-voice-in-the-battle-against-herbicide-resistance/

*  List of Herbicide Resistant Weeds by Weed Species

Multiple Resistance: 2 Sites of Action ALS inhibitors (B/2). Synthetic Auxins (O/4). 328. Hirschfeldia incana. Shortpod Mustard ... Herbicide Resistant Shortpod Mustard Globally. (Hirschfeldia incana). #. Country. Country. StateName. FirstYear. Situation. ... Cite this site as: Heap, I. The International Survey of Herbicide Resistant Weeds. Online. Internet. Tuesday, September 19, ...
weedscience.org/Summary/Species.aspx?WeedID=328

*  List of Herbicide Resistant Weeds by Country

Multiple Resistance: 3 Sites of Action ALS inhibitors (B/2). PSI Electron Diverter (D/22). EPSP synthase inhibitors (G/9). ... Herbicide Resistant Weeds in Brazil. #. Species. Common Name. Country. State Name. First Year. CountryID. Site of Action. ... Multiple Resistance: 3 Sites of Action ACCase inhibitors (A/1). ALS inhibitors (B/2). Cellulose inhibitors (L/26). 15069. ... Cite this site as: Heap, I. The International Survey of Herbicide Resistant Weeds. Online. Internet. Wednesday, October 18, ...
weedscience.org/Summary/Country.aspx?CountryID=5

*  Video: Herbicide Resistance Nothing New | CropWatch | University of Nebraska-Lincoln

UNL Weed Scientists on Weed Resistance. Although it has been getting more attention the last few years, the issue of herbicide ... Both note the importance of diverse weed management techniques to slow the spread of herbicide resistance and the significance ... Chris Proctor, a current UNL weed scientist, highlights some of the present-day issues with herbicide resistance management. ... In this video retired UNL weed scientist Alex Martin discusses some of the history of weed resistance and how we got to where ...
cropwatch.unl.edu/2017/video-herbicide-resistance-nothing-new

*  Social costs of herbicide resistance: the case of resistance to glyphosate

The economics of managing herbicide resistance in weeds has focused on cost-effective responses by growers to the development ... where social costs associated with glyphosate resistance need to be considered when assessing optimal use of this herbicide ... Social costs associated with the loss of glyphosate efficacy include potential failure of herbicide-resistant crop systems, ... In this paper we argue that the increasing possibility of widespread glyphosate resistance presents a case ...
https://ideas.repec.org/p/ags/aare06/139881.html

*  List of Herbicide Resistant Weeds by Country

Status of Herbicide Resistance in Canada - Hugh Beckie : January, 2014. Western Canada (prairie provinces of Alberta, ... Herbicide Resistant Weeds in Canada. #. Species. Common Name. Country. State Name. First Year. CountryID. Site of Action. ... Multiple Resistance: 3 Sites of Action ACCase inhibitors (A/1). ALS inhibitors (B/2). Lipid Inhibitors (N/8). 5076. ... Multiple Resistance: 2 Sites of Action Photosystem II inhibitors (C1/5). PSII inhibitor (Ureas and amides) (C2/7). 5048. ...
weedscience.org/Summary/Country.aspx?CountryID=7

*  List of Herbicide Resistant Weeds by Weed Species

Resistance by Site of Action *Graph Data for Resistance by SOA *Resistance by SOA listing species ... Herbicide Resistant Smooth Barley Globally. (Hordeum murinum ssp. glaucum). #. Country. Country. StateName. FirstYear. ... Cite this site as: Heap, I. The International Survey of Herbicide Resistant Weeds. Online. Internet. Tuesday, September 19, ...
weedscience.org/Summary/Species.aspx?WeedID=97

*  Herbicide Resistance

... As a service to producers around Australia, CSU conducts screening of weed ... Questions about the herbicide resistance screening program should be directed to John Broster. ... This information is essential to efforts to limit the development and spread of herbicide resistance. ... populations for resistance to commonly used herbicides. Identifying herbicide-resistant weeds enables producers to avoid using ...
csu.edu.au/weedresearchgroup/herbicide-resistance

*  Herbicide Resistance | Tags | Illinois Public Media

Content from Illinois Public Media on Herbicide Resistance ...
https://will.illinois.edu/index.php/tags/herbicide-resistance

*  State prepares for herbicide resistance | Delta Farm Press

If resistance is found, the cost of raising a cotton or soybean crop will jump tremendously. The cost of herbicide inputs would ... Smith says because of the mode of action of the chemicals, it isn't as easy to develop resistance to glyphosate as it is to a ... As long as resistance doesn't show, glyphosate will do the trick.. "But God help us if it does. ... If resistance to pigweed emerged there, it would likely "completely eliminate Roundup Ready crops. That's how serious it is. ...
deltafarmpress.com/state-prepares-herbicide-resistance

*  Herbicide resistance | Page 2 | LawnSite

Herbicide resistance. Discussion in 'Pesticide & Herbicide Application' started by phasthound, Dec 18, 2013. ... So here are two products that are used on many many acreas and no resistance. I don't think there will ever be resistance with ... Forums / Lawn Care Fertilizers and Pesticides / Pesticide & Herbicide Application / Certain XenForo add-ons by Waindigo™ ©2011- ... As far as I know...there is no resistance to 2-4,D and Dicamba. I don't know the exact history but these products have been ...
https://lawnsite.com/threads/herbicide-resistance.416763/page-2

*  Special Issue of Weed Science Explores Human Aspects of Herbicide Resistance

Weeds that evolve resistance to herbicides are a serious threat to global agricultural production. In this Special ... Weeds that evolve resistance to herbicides are a serious threat to global agricultural production. In this Special Issue of ... Full text of the article 'Human Dimensions of Herbicide Resistance' is now available in Weed Science Vol. 64 sp1, 2016. ... Several papers in this Special Issue are based on presentations at the 2014 Second Summit on Herbicide Resistance organized by ...
prweb.com/releases/wees_special_issue/2016/prweb13578473.htm

*  G4907 Herbicide Resistance in Weeds | University of Missouri Extension

Look carefully for resistance. How to identify herbicide resistance: As farmers learn about herbicide resistance, an ... Do not suspect herbicide resistance unless a herbicide failure fits the following traits:. *The same herbicide was used year ... ALS-herbicide resistance is a good example of the problem of cross resistance. ALS herbicides exist for many crops. The ... it is better to prevent resistance from becoming a problem. Herbicide cross resistance renders many herbicides useless at once ...
extension.missouri.edu/p/G4907

*  Research Fellow - Overcoming herbicide resistance - University of Birmingham - jobs.ac.uk

Research Fellow - Overcoming herbicide resistance. University of Birmingham - College of Engineering and Physical Sciences. ...
jobs.ac.uk/job/AJP025/research-fellow-overcoming-herbicide-resistance/

*  Beyond Pesticides Daily News Blog » Blog Archive New CA Law Protects Farmers from GE Contamination of Crops - Beyond...

There are many problems with GE crops as they are known to lead to insect resistance, create superweeds, contaminate other ... lead to antibiotic resistance, and unreasonable business contracts with farmers. ...
beyondpesticides.org/dailynewsblog/2008/10/new-ca-law-protects-farmers-from-ge-contamination-of-crops/

*  E-Newsletter Archives | Top Crop Manager

Herbicide Resistance Summit October 2015Crop hail payouts , Herbicide efficacy after frost October 2015Measure subsoil moisture ... History of herbicide resistance August 2015Organic seed coating for alfalfa , Conservation Hall of Fame inductee August 2015 ... Australia's fight against herbicide resistance February 2014New grain loading app , Demand for cheaper Ontario corn rises ... 2016Herbicide resistance predates GM crops , Defence mechanismsJuly 21, 2016Glyphosate-resistant weeds in Ontario , ...
https://topcropmanager.com/newsletter-archive

List of varieties of genetically modified maize: This is a partial list of varieties of maize that have been modified.Herbicide: Herbicide(s), also commonly known as weedkillers, are pesticides used to control unwanted plants. Selective herbicides control specific weed species, while leaving the desired crop relatively unharmed.Phenylacetylcarbinol: -PAC(R)-PACMallardPlant perception (physiology): Plant perception is the ability of plants to sense and respond to the environment to adjust their morphology, physiology and phenotype accordingly. Other disciplines such as plant physiology, ecology and molecular biology are used to assess this ability.ACACB: Acetyl-CoA carboxylase 2 also known as ACC-beta or ACC2 is an enzyme that in humans is encoded by the ACACB gene.Paddock: A paddock has two primary meanings in different parts of the English-speaking world. In Canada, the USA and UK, a paddock is a small enclosure used to keep horses.Glycine (plant): Glycine is a genus in the bean family Fabaceae. The best known species is the soybean (Glycine max).Nicotiana glauca: Nicotiana glauca is a species of wild tobacco known by the common name tree tobacco. Its leaves are attached to the stalk by petioles (many other Nicotiana species have sessile leaves), and its leaves and stems are neither [nor sticky like Nicotiana tabacum].Atrazine chlorohydrolase: Atrazine Chlorohydrolase (AtzA) is an enzyme (E.C.Iridogoniodysgenesis, dominant type: Iridogoniodysgenesis, dominant type (type 1, IRID1) refers to a spectrum of diseases characterized by malformations of the irido-corneal angle of the anterior chamber of the eye. Iridogoniodysgenesis is the result of abnormal migration or terminal induction of neural crest cells.Chromotropic acidSilent mutation: Silent mutations are mutations in DNA that do not significantly alter the phenotype of the organism in which they occur. Silent mutations can occur in non-coding regions (outside of genes or within introns), or they may occur within exons.Resistome: The resistome is a proposed expression by Gerard D. Wright for the collection of all the antibiotic resistance genes and their precursors in both pathogenic and non-pathogenic bacteria.MCPA

(1/64) Mutations in an auxin receptor homolog AFB5 and in SGT1b confer resistance to synthetic picolinate auxins and not to 2,4-dichlorophenoxyacetic acid or indole-3-acetic acid in Arabidopsis.

Although a wide range of structurally diverse small molecules can act as auxins, it is unclear whether all of these compounds act via the same mechanisms that have been characterized for 2,4-dichlorophenoxyacetic acid (2,4-D) and indole-3-acetic acid (IAA). To address this question, we used a novel member of the picolinate class of synthetic auxins that is structurally distinct from 2,4-D to screen for Arabidopsis (Arabidopsis thaliana) mutants that show chemically selective auxin resistance. We identified seven alleles at two distinct genetic loci that conferred significant resistance to picolinate auxins such as picloram, yet had minimal cross-resistance to 2,4-D or IAA. Double mutants had the same level and selectivity of resistance as single mutants. The sites of the mutations were identified by positional mapping as At4g11260 and At5g49980. At5g49980 is previously uncharacterized and encodes auxin signaling F-box protein 5, one of five homologs of TIR1 in the Arabidopsis genome. TIR1 is the recognition component of the Skp1-cullin-F-box complex associated with the ubiquitin-proteasome pathway involved in auxin signaling and has recently been shown to be a receptor for IAA and 2,4-D. At4g11260 encodes the tetratricopeptide protein SGT1b that has also been associated with Skp1-cullin-F-box-mediated ubiquitination in auxin signaling and other pathways. Complementation of mutant lines with their corresponding wild-type genes restored picolinate auxin sensitivity. These results show that chemical specificity in auxin signaling can be conferred by upstream components of the auxin response pathway. They also demonstrate the utility of genetic screens using structurally diverse chemistries to uncover novel pathway components.  (+info)

(2/64) Molecular analysis, cytogenetics and fertility of introgression lines from transgenic wheat to Aegilops cylindrica host.

Natural hybridization and backcrossing between Aegilops cylindrica and Triticum aestivum can lead to introgression of wheat DNA into the wild species. Hybrids between Ae. cylindrica and wheat lines bearing herbicide resistance (bar), reporter (gus), fungal disease resistance (kp4), and increased insect tolerance (gna) transgenes were produced by pollination of emasculated Ae. cylindrica plants. F1 hybrids were backcrossed to Ae. cylindrica under open-pollination conditions, and first backcrosses were selfed using pollen bags. Female fertility of F1 ranged from 0.03 to 0.6%. Eighteen percent of the sown BC1s germinated and flowered. Chromosome numbers ranged from 30 to 84 and several of the plants bore wheat-specific sequence-characterized amplified regions (SCARs) and the bar gene. Self fertility in two BC1 plants was 0.16 and 5.21%, and the others were completely self-sterile. Among 19 BC1S1 individuals one plant was transgenic, had 43 chromosomes, contained the bar gene, and survived glufosinate treatments. The other BC1S1 plants had between 28 and 31 chromosomes, and several of them carried SCARs specific to wheat A and D genomes. Fertility of these plants was higher under open-pollination conditions than by selfing and did not necessarily correlate with even or euploid chromosome number. Some individuals having supernumerary wheat chromosomes recovered full fertility.  (+info)

(3/64) Effects of genetically modified herbicide-tolerant cropping systems on weed seedbanks in two years of following crops.

The Farm Scale Evaluations (FSEs) showed that genetically modified herbicide-tolerant (GMHT) cropping systems could influence farmland biodiversity because of their effects on weed biomass and seed production. Recently published results for winter oilseed rape showed that a switch to GMHT crops significantly affected weed seedbanks for at least 2 years after the crops were sown, potentially causing longer-term effects on other taxa. Here, we seek evidence for similar medium-term effects on weed seedbanks following spring-sown GMHT crops, using newly available data from the FSEs. Weed seedbanks following GMHT maize were significantly higher than following conventional varieties for both the first and second years, while by contrast, seedbanks following GMHT spring oilseed rape were significantly lower over this period. Seedbanks following GMHT beet were smaller than following conventional crops in the first year after the crops had been sown, but this difference was much reduced by the second year for reasons that are not clear. These new data provide important empirical evidence for longer-term effects of GMHT cropping on farmland biodiversity.  (+info)

(4/64) Transgenic oilseed rape along transportation routes and port of Vancouver in western Canada.

The occurrence of transgenic herbicide-resistant oilseed rape (Brassica napus) in ruderal (non-crop disturbed) areas has not been investigated previously in Canada. The primary objective of this study was to document their occurrence in two main ruderal areas (along railways and roads) in the province of Saskatchewan, where half of all oilseed rape is grown, and at the port of Vancouver, British Columbia on the west coast of Canada, where most oilseed rape destined for export is transported by rail. During the 2005 growing season, leaf samples of oilseed rape plants were collected at randomly-selected sites along railways and roads across Saskatchewan ecoregions and at Vancouver; infestation area, density, and plant height of oilseed rape were measured at each site. The presence of the glyphosate and glufosinate resistance traits was determined using test strips. The infestation area of oilseed rape, averaged across 155 sampled sites in the Saskatchewan survey, was markedly smaller in populations along railways than roads; in contrast, infestation area averaged across 54 sites in the Vancouver survey was greater for populations along railways than roads. In both surveys, mean plant density was greater for populations found along railways than roads. Two-thirds of oilseed rape plants sampled across Saskatchewan ecoregions and at Vancouver were transgenic, although the relative proportion of plants with the glyphosate or glufosinate resistance trait varied between surveys. Frequency of occurrence of transgenic plants in ruderal areas was similar to the proportion of the oilseed rape area planted with transgenic cultivars in the recent preceding years. A single transgenic B. rapa x B. napus hybrid was found along a road in Vancouver, confirming the relatively high probability of hybridization between these two Brassica species. With current control measures, transgenic oilseed rape populations may persist and spread in these ruderal areas.  (+info)

(5/64) Detection of feral transgenic oilseed rape with multiple-herbicide resistance in Japan.

Repeated monitoring for escaped transgenic crop plants is sometimes necessary, especially in cases when the crop has not been approved for release into the environment. Transgenic oilseed rape (Brassica napus) was detected along roadsides in central Japan in a previous study. The goal of the current study was to monitor the distribution of transgenic oilseed rape and occurrence of hybridization of transgenic B. napus with feral populations of its closely related species (B. rapa and B. juncea) in the west of Japan in 2005. The progenies of 50 B. napus, 82 B. rapa and 283 B. juncea maternal plants from 95 sampling sites in seven port areas were screened for herbicide-resistance. Transgenic herbicide-resistant seeds were detected from 12 B. napus maternal plants growing at seven sampling sites in two port areas. A portion of the progeny from two transgenic B. napus plants had both glyphosate-resistance and glufosinate-resistance transgenes. Therefore, two types of transgenic B. napus plants are likely to have outcrossed with each other, since the double-herbicide-resistant transgenic strain of oilseed rape has not been developed intentionally for commercial purposes. As found in the previous study, no transgenic seeds were detected from B. rapa or B. juncea, and more extensive sampling is needed to determine whether introgression into these wild species has occurred.  (+info)

(6/64) Single-site mutations in the carboxyltransferase domain of plastid acetyl-CoA carboxylase confer resistance to grass-specific herbicides.

Grass weed populations resistant to aryloxyphenoxypropionate (APP) and cyclohexanedione herbicides that inhibit acetyl-CoA carboxylase (ACCase; EC 6.4.1.2) represent a major problem for sustainable agriculture. We investigated the molecular basis of resistance to ACCase-inhibiting herbicides for nine wild oat (Avena sterilis ssp. ludoviciana Durieu) populations from the northern grain-growing region of Australia. Five amino acid substitutions in plastid ACCase were correlated with herbicide resistance: Ile-1,781-Leu, Trp-1,999-Cys, Trp-2,027-Cys, Ile-2,041-Asn, and Asp-2,078-Gly (numbered according to the Alopecurus myosuroides plastid ACCase). An allele-specific PCR test was designed to determine the prevalence of these five mutations in wild oat populations suspected of harboring ACCase-related resistance with the result that, in most but not all cases, plant resistance was correlated with one (and only one) of the five mutations. We then showed, using a yeast gene-replacement system, that these single-site mutations also confer herbicide resistance to wheat plastid ACCase: Ile-1,781-Leu and Asp-2,078-Gly confer resistance to APPs and cyclohexanediones, Trp-2,027-Cys and Ile-2,041-Asn confer resistance to APPs, and Trp-1,999-Cys confers resistance only to fenoxaprop. These mutations are very likely to confer resistance to any grass weed species under selection imposed by the extensive agricultural use of the herbicides.  (+info)

(7/64) Gene flow from GM glyphosate-tolerant to conventional soybeans under field conditions in Japan.

Natural out-crossing rates were evaluated for conventional soybeans (Glycine max (L.) Merr.) cultivated adjacent to genetically modified (GM) glyphosate-tolerant soybeans under field conditions during a four-year period in Japan. A total of 107 846 progeny of 2772 plants harvested from conventional varieties were screened for glyphosate herbicide tolerance. The highest out-crossing rates, 0.19% in 2001 and 0.16% in 2002, were observed in adjacent rows 0.7 m from the pollen source. The highest rate in 2004 was 0.052%, which was observed at 2.1 m. No out-crossing was observed in the rows 10.5 m from the pollen source over the four-year period. The farthest distances between receptor and pollen source at which out-crossing was observed were 7 m in 2001, 2.8 m in 2002, and 3.5 m in 2004. The greatest airborne pollen density during the flowering period, determined by Durham pollen samplers located between the rows of each variety, was 0.368 grains.cm(-2).day(-1), with the average value at 0.18 grains.cm(-2).day(-1), indicating that the possibility of out-crossing by wind is minimal. Thrips species and predatory Hemiptera visited the soybean flowers more frequently during the four-year period than any other common pollinators, such as bees.  (+info)

(8/64) Mycorrhizal and rhizobial colonization of genetically modified and conventional soybeans.

We grew plants of nine soybean varieties, six of which were genetically modified to express transgenic cp4-epsps, in the presence of Bradyrhizobium japonicum and arbuscular mycorrhizal fungi. Mycorrhizal colonization and nodule abundance and mass differed among soybean varieties; however, in no case was variation significantly associated with the genetic modification.  (+info)



weeds


  • But there have been few organized opportunities for farmers to make their voices heard and to share their experiences in managing herbicide-resistant weeds. (wssa.net)
  • There remains an economic tradeoff between the decreased crop yields and increased long-term costs from resistant weeds versus the increased short-term costs of adopting resistance prevention practices. (wssa.net)
  • Zero tolerance policies for problematic, herbicide-resistant weeds should apply to everyone , including landowners, native seed producers and departments of transportation responsible for highway medians and rights of way. (wssa.net)
  • Although it has been getting more attention the last few years, the issue of herbicide resistant weeds is not new. (unl.edu)
  • The economics of managing herbicide resistance in weeds has focused on cost-effective responses by growers to the development of resistance at the individual farm and field level. (repec.org)

infests


  • In Venezuela this weed first evolved multiple resistance (to 2 herbicide sites of action) in 2008 and infests Rice. (weedscience.com)
  • In New Zealand this weed first evolved multiple resistance (to 3 herbicide sites of action) in 2015 and infests Grapefruit. (weedscience.com)
  • In New South Wales this weed first evolved multiple resistance (to 3 herbicide sites of action) in 1985 and infests Canola, Chickpea, Faba beans, Lentils, Lupins, Peas, Spring Barley, and Wheat. (weedscience.org)
  • In Chile this weed first evolved resistance to Group G/9 herbicides in 2001 and infests Fruit, and Orchards. (weedscience.org)

glyphosate resistance


  • These results confirm a new case of glyphosate resistance in a novel species, L. multiflorum , and correspond to the first case of glyphosate resistance reported from South America. (weedscience.org)
  • In this paper we argue that the increasing possibility of widespread glyphosate resistance presents a case where social costs associated with glyphosate resistance need to be considered when assessing optimal use of this herbicide resource at the farm level. (repec.org)

inhibitors


  • Group G/9 herbicides are known as EPSP synthase inhibitors (Inhibition of EPSP synthase). (weedscience.org)

resistant


  • These particular biotypes are known to have resistance to fluazifop-P-butyl, and glyphosate and they may be cross-resistant to other herbicides in the Groups A/1, and G/9. (weedscience.com)
  • The evaluated population was resistant to both herbicides, obtaining a RI= 2.25 for fluazifop-p-butil and RI=4,18 for glyphosate. (weedscience.com)
  • These particular biotypes are known to have resistance to amitrole, glufosinate-ammonium, and glyphosate and they may be cross-resistant to other herbicides in the Groups F3/11, G/9, and H/10. (weedscience.com)
  • Based on the herbicide rates giving 50% reduction in growth (GR50 values), populations A, J and O were 3.9, 4.5 and 3.8 times more resistant to glufosinate respectively, compared to the susceptible populations in a glufosinate doseeresponse experiment. (weedscience.com)
  • Studies on the mechanism of resistance of multiple resistant Rigid Ryegrass from New South Wales indicate that resistance is due to an altered target site, and enhanced metabolism. (weedscience.org)
  • Research has shown that these particular biotypes are resistant to glyphosate and they may be cross-resistant to other Group G/9 herbicides. (weedscience.org)
  • Social costs associated with the loss of glyphosate efficacy include potential failure of herbicide-resistant crop systems, reduced use of conservation tillage techniques, and a potential greater reliance on herbicides with greater health and environmental risks. (repec.org)

crops


  • There is a scarcity of herbicides available to help growers of vegetable and specialty crops diversify weed control and battle herbicide resistance. (wssa.net)

metabolism


  • Observed costs are evident from herbicide resistance-endowing amino acid substitutions in proteins involved in amino acid, fatty acid, auxin and cellulose biosynthesis, as well as enzymes involved in herbicide metabolism. (warwick.ac.uk)

populations


  • 1997. The persistence of trifluralin resistance in green foxtail (Setaria viridis) populations. (warwick.ac.uk)
  • The inefficient control of populations of this weed by glyphosate and fluazfop-p-butyl in rice fields in Cojedes state, made think the resistance occurrence, reason why it was carried out be this evaluation. (weedscience.com)

growers


  • As a result, it is hard for growers to commit to resistance management early, before they have the problem. (wssa.net)

dose


  • 1995). It was used a completely randomized design with 6 treatments (herbicide dose) and 22 repetitions for each population and herbicide evaluated. (weedscience.com)
  • The data was analyzed by analysis of variance and fit to log-logistic model of dose-response for the calculation of the resistance index (RI). (weedscience.com)

novel


  • There have been many studies quantifying the fitness costs associated with novel herbicide resistance alleles, reflecting the importance of fitness costs in determining the evolutionary dynamics of resistance. (warwick.ac.uk)
  • Fitness costs and benefits of novel herbicide tolerance in a noxious weed. (warwick.ac.uk)

mechanism of resistance


  • The mechanism of resistance for this biotype is either unknown or has not been entered in the database. (weedscience.com)
  • If you know anything about the mechanism of resistance for this biotype then please update the database. (weedscience.com)

Committee


  • The Herbicide Resistance Action Committee, The Weed Science Society of America, and weed scientists in Venezuela have been instrumental in providing you this information. (weedscience.com)
  • The idea for the listening sessions came about as a WSSA committee discussed plans for a third national summit on herbicide resistance. (wssa.net)

species


  • This is the first confirmed report of weed species that have developed multiple-resistance to glyphosate, glufosinate and amitrole. (weedscience.com)

control


  • Resistance to glyphosate and fluazifop-p-butyl herbicide of a Echinochloa colona L. population Echinochloa colona L. is one of the most important weed in rice crop under direct sowing in Venezuela and its control mainly is based on the use of herbicides. (weedscience.com)
  • These are the three main herbicides currently used for weed control in New Zealand vineyards. (weedscience.com)

literature


  • Second, to present a comprehensive analysis of the literature on fitness costs associated with herbicide resistance alleles. (warwick.ac.uk)

techniques


  • Both scientists and regulators have had a lot to say about the growing problem of herbicide resistance and how weed management techniques need to change in response. (wssa.net)
  • Both note the importance of diverse weed management techniques to slow the spread of herbicide resistance and the significance of thoughtful stewardship of our herbicide technologies to ensure their usefulness into the future. (unl.edu)

Multiple


  • Multiple resistance has evolved to herbicides in the Groups A/1, and G/9. (weedscience.com)

known


  • Greenhouse, and Laboratory trials comparing a known susceptible Junglerice biotype with this Junglerice biotype have been used to confirm resistance. (weedscience.com)

management


  • Chris Proctor, a current UNL weed scientist, highlights some of the present-day issues with herbicide resistance management. (unl.edu)
  • Optimal Agricultural Pest Management with Increasing Pest Resistance ," American Journal of Agricultural Economics , Agricultural and Applied Economics Association, vol. 56(3), pages 543-552. (repec.org)

case


  • This is the first confirmed case of amitrole resistance evolving within New Zealand and further work is currently underway to study this resistance. (weedscience.com)

costs


  • Predictions based on evolutionary theory suggest that the adaptive value of evolved herbicide resistance alleles may be compromised by the existence of fitness costs. (warwick.ac.uk)
  • This analysis reveals unquestionable evidence that some herbicide resistance alleles are associated with pleiotropic effects that result in plant fitness costs. (warwick.ac.uk)
  • However, these resistance fitness costs are not universal and their expression depends on particular plant alleles and mutations. (warwick.ac.uk)
  • Parasitism increases and decreases the costs of insecticide resistance in mosquitoes. (warwick.ac.uk)
  • Social costs and externalities associated with herbicide resistance have not generally been considered by economists. (repec.org)

plant material


  • However, many of these studies have incorrectly defined resistance or used inappropriate plant material and methods to measure fitness. (warwick.ac.uk)
  • The dry weight of plant material was measured 8 weeks after herbicide application. (weedscience.com)

field


  • also seeds of the same weed in a field in ecological production were collected where applications of herbicide have been made never (susceptible population). (weedscience.com)