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Stephen B. Powles - One of the best experts on this subject based on the ideXlab platform.
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cytochrome p450 cyp81a10v7 in lolium rigidum confers metabolic resistance to Herbicides across at least five modes of action
Plant Journal, 2021Co-Authors: Heping Han, Roland Beffa, Susana Gonzalez, Frank Maiwald, Jing Wang, Stephen B. PowlesAbstract:Rapid and widespread evolution of multiple Herbicide resistance in global weed species endowed by increased capacity to metabolize (degrade) Herbicides (metabolic resistance) is a great threat to Herbicide sustainability and global food production. Metabolic resistance in the economically damaging crop weed species Lolium rigidum is well known but a molecular understanding has been lacking. We purified a metabolic resistant (R) subset from a field evolved R L. rigidum population. The R, the Herbicide susceptible (S) and derived F2 populations were used for candidate Herbicide resistance gene discovery by RNA sequencing. A P450 gene CYP81A10v7 was identified with higher expression in R vs. S plants. Transgenic rice overexpressing this Lolium CYP81A10v7 gene became highly resistant to acetyl-coenzyme A carboxylase- and acetolactate synthase-inhibiting Herbicides (diclofop-methyl, tralkoxydim, chlorsulfuron) and moderately resistant to hydroxyphenylpyruvate dioxygenase-inhibiting Herbicide (mesotrione), photosystem II-inhibiting Herbicides (atrazine and chlorotoluron) and the tubulin-inhibiting Herbicide trifluralin. This wide cross-resistance profile to many dissimilar Herbicides in CYP81A10v7 transgenic rice generally reflects what is evident in the R L. rigidum. This report clearly showed that a single P450 gene in a cross-pollinated weed species L. rigidum confers resistance to Herbicides of at least five modes of action across seven Herbicide chemistries.
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distribution and frequency of Herbicide resistant wild oat avena spp across the western australian grain belt
Crop & Pasture Science, 2009Co-Authors: Mechelle J Owen, Stephen B. PowlesAbstract:In 2005, a random survey was conducted across 14 million hectares of the Western Australian grain belt to establish the frequency and distribution of Herbicide-resistant wild oat (Avena spp.) in cropping fields. In total, 677 cropping fields were visited, with wild oat populations collected from 150 fields. These wild oat populations were screened with several Herbicides commonly used to control this weed. Most of the wild oat populations (71%) were found to contain individuals resistant to the ACCase-inhibiting Herbicide diclofop-methyl. Resistance to other ACCase-inhibiting Herbicides was markedly lower. Herbicides of alternative modes of action were effective on all wild oat populations. Overall, wild oat resistance to diclofop-methyl was found to be widespread across the Western Australian grain belt, but resistance to other Herbicides was relatively low. Therefore, through diversity in Herbicide use and with cultural management, it is possible to maintain wild oat populations at a low level and/or minimise Herbicide resistance evolution.
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multiple Herbicide resistance across four modes of action in wild radish raphanus raphanistrum
Weed Science, 2004Co-Authors: Michael J Walsh, Stephen B. Powles, Brett R Beard, Ben T Parkin, Sally A PorterAbstract:Abstract 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 ...
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evolution of Herbicide resistance in weeds initial frequency of target site based resistance to acetolactate synthase inhibiting Herbicides in lolium rigidum
Heredity, 2002Co-Authors: C. Preston, Stephen B. PowlesAbstract:The frequency of individuals resistant to two acetolactate synthase (ALS)-inhibiting Herbicides in three previously untreated populations of Lolium rigidum was determined. The frequency of individuals resistant to the sulfonylurea Herbicide sulfometuron-methyl varied from 2.2 × 10−5 to 1.2 × 10−4 and the frequency of individuals resistant to the imidazolinone Herbicide imazapyr varied from 1 × 10−5 to 5.8 × 10−5 depending on the population. Application of sulfometuron-methyl selected individuals with a Herbicide-insensitive ALS, which was also cross-resistant to imazapyr. The high initial frequency of individuals resistant to ALS-inhibiting Herbicides in L. rigidumpopulations never previously exposed to these Herbicides helps explain the rapid evolution of Herbicide resistance in this species once ALS-inhibiting Herbicides were used.
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multiple Herbicide resistance in annual ryegrass lolium rigidum a driving force for the adoption of integrated weed management
1992Co-Authors: Stephen B. Powles, John M MatthewsAbstract:Ryegrass (Lolium rigidum) is an abundant, polymorphic, wind-pollinated, self-incompatible annual grass that is ubiquitous in cropping regions of southern Australia. Over the past decade hundreds of Herbicide resistant rye grass populations have appeared in response to selection pressure from Herbicides. A striking feature of resistance in ryegrass is the development of multiple Herbicide resistance. Currently there are biotypes of ryegrass that are resistant to Herbicides within ten different chemical classes. There are varying patterns of resistance between different biotypes. Ryegrass populations that have developed resistance to one Herbicide can rapidly develop resistance to new Herbicides that are effective initially. Genetic diversity in ryegrass and the frequent exposure of huge numbers of plants to Herbicide results in the selection of one to many different resistance genes.
John Broster - One of the best experts on this subject based on the ideXlab platform.
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Herbicide resistance levels in annual ryegrass lolium rigidum gaud and wild oat avena spp in southwestern new south wales
Plant protection quarterly, 2013Co-Authors: John Broster, Eric KoetzAbstract:In 2010, a random survey was conducted across the cereal cropping zone of southwestern New South Wales to determine the level of Herbicide resistance in annual ryegrass (Lolium rigidum Gaud.) and wild oat (Avena spp.) populations. In total, 192 paddocks were visited resulting in 124 annual ryegrass and 104 wild oat seed samples collected for testing. These samples were then screened to the Herbicide groups commonly used for annual ryegrass (ACCase, ALS, triazine, dinitroaniline and glycine) and wild oat (ACCase, ALS, thiocarbamate and glycine) control in Australia. The majority of ryegrass samples were resistant to aryloxyphenoxypropionate (56%) and sulfonylurea (53%) Herbicides. High levels of resistance were also found for cyclohexanedione (32%) and imidazolinone (38%) Herbicides. This represents an increase compared to the 10-14% detected in a 1991 survey. Resistance was found only within ACCase Herbicides in the wild oat; 37% were resistant to a aryloxyphenoxypropionate Herbicide and 14% were resistant to a cyclohexanedione Herbicide. Thirty four percent of the 110 ryegrass samples tested to five Herbicide groups (aryloxyphenoxypropionate, cyclohexanedione, ALS, triazine and dinitroaniline) were resistant to two or more Herbicide groups, while multiple resistance was only detected in 8% of wild oat samples tested to four Herbicide groups (aryloxyphenoxypropionate, cyclohexanedione, ALS and thiocarbamate). Thirty percent of ryegrass and 62% of wild oat samples were susceptible to all Herbicides. Resistance levels for both ryegrass and wild oat in this survey were lower than reported for a 2007 survey to the immediate east of this survey. The levels of resistance found for many Herbicides, while lower than the adjoining survey, are still significant and highlight the importance of adopting an integrated approach to weed management. This integrated approach is necessary for minimising resistance to commonly used Herbicides, and extending their commercial life.
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a decade of monitoring Herbicide resistance in lolium rigidum in australia
Animal Production Science, 2006Co-Authors: John Broster, James PratleyAbstract:Charles Sturt University commenced Herbicide resistance monitoring in 1991. A random survey in 1991 to determine the level of resistance in annual ryegrass (Lolium rigidum) to selective Herbicides across the south-west slopes region of New South Wales found that 30% of samples were resistant to at least 1 Herbicide. A subsequent survey of commercially available ryegrass seed found that 58% of these samples were resistant to at least 1 Herbicide. As a result of these findings, a commercial testing service was established and has since received samples from a large proportion of the southern Australian cropping belt. Seventy-seven percent of samples tested were resistant to Group AI, 40% to Group B and 22% to Group AII Herbicides. Lower levels of resistance were found to Group D (8%), Group C (1%) and Group M (0.4%) Herbicides. The correlation between resistance in Group AI and AII Herbicides was lower than expected given that these Herbicides are considered to have the same mode of action. Within the Group AI Herbicides the observed response of the samples was consistent across Herbicide formulations. Resistance to clethodim varied from observed responses to other Group AII Herbicides. The variation in resistance levels (and degree of multiple resistance) in each Australian state is discussed in relation to environmental conditions and cultural practices. The size of this dataset allows for the analysis of the relationships present among Herbicide resistant annual ryegrass.
Michael M. Primiani - One of the best experts on this subject based on the ideXlab platform.
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Sulfonylurea Herbicide resistance in common chickweed, perennial ryegrass, and Russian thistle
Pesticide Biochemistry and Physiology, 1992Co-Authors: Leonard L. Saari, Josephine C. Cotterman, W. F. Smith, Michael M. PrimianiAbstract:Abstract Sulfonylurea Herbicide resistance was demonstrated in two broadleaf species, common chickweed (Stellaria media [L]. Vill.) and Russian thistle (Salsola iberica Sennen & Pau), and in one grass species, perennial ryegrass (Lolium perenne L.), in greenhouse tests by determining the sulfonylurea and imidazolinone Herbicide rates required to reduce the dry weight accumulation of resistant and susceptible weed biotypes. The Herbicide resistance in each of the three weed biotypes was due to an acetolactate synthase (ALS) enzyme that was less sensitive to inhibition by ALS-inhibiting Herbicides, including five sulfonylurea, one imidazolinone, and one dichlorosulfonanilide Herbicides. The Km (pyruvate) and specific activity values associated with ALS isolated susceptible biotypes. Both susceptible and resistant biotypes of each weed species metabolized radiolabeled sulfonylurea Herbicides at similar rates, indicating that Herbicide metabolism was not contributing to the differential plant response of the biotypes to ALS-inhibiting Herbicides.
James Pratley - One of the best experts on this subject based on the ideXlab platform.
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a decade of monitoring Herbicide resistance in lolium rigidum in australia
Animal Production Science, 2006Co-Authors: John Broster, James PratleyAbstract:Charles Sturt University commenced Herbicide resistance monitoring in 1991. A random survey in 1991 to determine the level of resistance in annual ryegrass (Lolium rigidum) to selective Herbicides across the south-west slopes region of New South Wales found that 30% of samples were resistant to at least 1 Herbicide. A subsequent survey of commercially available ryegrass seed found that 58% of these samples were resistant to at least 1 Herbicide. As a result of these findings, a commercial testing service was established and has since received samples from a large proportion of the southern Australian cropping belt. Seventy-seven percent of samples tested were resistant to Group AI, 40% to Group B and 22% to Group AII Herbicides. Lower levels of resistance were found to Group D (8%), Group C (1%) and Group M (0.4%) Herbicides. The correlation between resistance in Group AI and AII Herbicides was lower than expected given that these Herbicides are considered to have the same mode of action. Within the Group AI Herbicides the observed response of the samples was consistent across Herbicide formulations. Resistance to clethodim varied from observed responses to other Group AII Herbicides. The variation in resistance levels (and degree of multiple resistance) in each Australian state is discussed in relation to environmental conditions and cultural practices. The size of this dataset allows for the analysis of the relationships present among Herbicide resistant annual ryegrass.
Philip Westra - One of the best experts on this subject based on the ideXlab platform.
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Potential for weeds to develop resistance to sugarbeet Herbicides in North America
Journal of Sugarbeet Research, 1991Co-Authors: Edward E. Schweizer, Philip WestraAbstract:Current knowledge on Herbicide resistant weeds, mechanisms of Herbicide resistance, fitness and adaptability, gene flow, and management of Herbicide resistance was reviewed. Sixty eight percent of the 37 important problem weeds in sugarbeets have developed biotypes that are resistant to one or more Herbicide classes in Africa, Australia, Europe, or North America. Eighteen of these weeds have biotypes that are resistant to Herbicides in North America, but only two of these weeds have biotypes that are resistant to sugarbeet Herbicides. Common lambsquarters is resistant to pyrazon in Switzerland and green foxtail is resistant to trifluralin in Canada. Diclofop methyl, fluazifop, paraquat, pyrazon, and trifluralin are considered high risk sugarbeet Herbicides. Presently, it seems unlikely that problem weeds in sugarbeets in North America will develop resistance to sugarbeet Herbicides or to other Herbicides currently registered for use in sugarbeet rotations because sugarbeet growers integrate weed management programs, including crop and Herbicide rotations and tillage. Preventive action against the evolution of Herbicide- resistant weeds is advocated. Resistant weed biotypes in sugarbeets may increase as a result of the occurrence of cross and multiple-resistance to many Herbicides within the same biotype and the development of sugarbeet lines resistant to nonselective Herbicides.
