Frequency, Distribution, and Characterization of Horseweed (Conyza canadensis) Biotypes with Resistance to Glyphosate and ALS-Inhibiting Herbicides

Weed Science ◽  
2009 ◽  
Vol 57 (6) ◽  
pp. 652-659 ◽  
Author(s):  
Greg R. Kruger ◽  
Vince M. Davis ◽  
Stephen C. Weller ◽  
J. M. Stachler ◽  
M. M. Loux ◽  
...  
Keyword(s):  
Plant Growth ◽  
Frequency Distribution ◽  
Acetolactate Synthase ◽  
Conyza Canadensis ◽  
Susceptible Population ◽  
Greenhouse Study ◽  
Northern Half ◽  
Southern Half ◽  
Als Inhibitors

Greenhouse studies were conducted to determine the prevalence of resistance to acetolactate synthase (ALS)-inhibiting herbicides in 266 Indiana horseweed populations, both glyphosate-susceptible and glyphosate-resistant, and to characterize the response of selected biotypes to combinations of glyphosate and cloransulam. Populations with individuals resistant to ALS inhibitors were more frequent in the northern half (38% of the populations in the NW and 50% of the populations in the NE) of Indiana than in the southern half (26% of the populations in the SW and 5% of the populations in the SE). Only 2% of the populations appeared to be resistant to both glyphosate and ALS inhibitors in an initial greenhouse study. Horseweed populations with resistance to ALS inhibitors exhibited herbicide doses required for 50% reduction in plant growth (GR50) values ranging from 14 to 255 g ai ha−1of cloransulam. The resistant : susceptible (R : S) ratio for four horseweed populations with suspected resistance to glyphosate and ALS inhibitors ranged from 0.3 to 50 and from 2.5 to 8.1 for cloransulam and glyphosate, respectively. The tank mixtures exhibited an antagonistic response to 3 of the 16 combinations of cloransulam and glyphosate on the susceptible population. The tank mixtures exhibited primarily an additive response to those same combinations in the multiple-resistant populations, but the response was occasionally synergistic for two of the four populations. The additive response between glyphosate and cloransulam indicates that, where the level of resistance is fairly low, combinations of these herbicides should be more effective for control of multiple-resistant populations compared with application of a single herbicide.

Growth and Seed Production of Horseweed (Conyza canadensis) Populations Resistant to Glyphosate, ALS-Inhibiting, and Multiple (Glyphosate + ALS-Inhibiting) Herbicides

Weed Science ◽  
2009 ◽  
Vol 57 (5) ◽  
pp. 494-504 ◽  
Author(s):  
Vince M. Davis ◽  
Greg R. Kruger ◽  
Jeff M. Stachler ◽  
Mark M. Loux ◽  
William G. Johnson
Keyword(s):  
Field Experiment ◽  
Seed Production ◽  
Acetolactate Synthase ◽  
Multiple Resistance ◽  
Conyza Canadensis ◽  
Greenhouse Experiments ◽  
Herbicide Treatments ◽  
Als Inhibitors ◽  
Shoot Mass ◽  
Southeastern Region

Horseweed populations with mixtures of biotypes resistant to glyphosate and acetolactate synthase (ALS)–inhibiting herbicides as well as biotypes with multiple resistance to glyphosate + ALS-inhibiting herbicides have been documented in Indiana and Ohio. These biotypes are particularly problematic because ALS-inhibiting herbicides are commonly tank mixed with glyphosate to improve postemergence horseweed control in soybean. The objective of this research was to characterize the growth and seed production of horseweed populations with resistance to glyphosate or ALS-inhibiting herbicides, and multiple resistance to glyphosate + ALS-inhibiting herbicides. A four-herbicide by four-horseweed population factorial field experiment was conducted in the southeastern region of Indiana in 2007 and repeated in 2008. Four horseweed populations were collected from Indiana or Ohio and confirmed resistant to glyphosate, ALS inhibitors, both, or neither in greenhouse experiments. The four herbicide treatments were untreated, 0.84 kg ae ha−1glyphosate, 35 g ai ha−1cloransulam, and 0.84 kg ae ha−1glyphosate + 35 g ai ha−1cloransulam. Untreated plants from horseweed populations that were resistant to glyphosate, ALS-inhibiting, or multiple glyphosate + ALS-inhibiting herbicides produced similar amounts of biomass and seed compared to populations that were susceptible to those herbicides or combination of herbicides. Furthermore, aboveground shoot mass and seed production did not differ between treated and untreated plants.

Resistance in Canadian biotypes of wild mustard (Sinapis arvensis) to acetolactate synthase inhibiting herbicides

Weed Science ◽  
2005 ◽  
Vol 53 (5) ◽  
pp. 631-639 ◽  
Author(s):  
Suzanne I. Warwick ◽  
Connie Sauder ◽  
Hugh J. Beckie
Keyword(s):  
Amino Acid ◽  
Single Gene ◽  
Acetolactate Synthase ◽  
Western Canada ◽  
Nucleotide Polymorphisms ◽  
Weed Species ◽  
Susceptible Population ◽  
Wild Mustard ◽  
Als Inhibitors ◽  
Als Inhibitor

Multiple cases of ALS inhibitor-resistant weed biotypes are reported for many species, including wild mustard. The physiological extent and molecular basis of resistance to ALS inhibitors was compared in four biotypes of wild mustard from western Canada: a sulfonylurea (SU)-resistant (R) biotype from Manitoba detected in 1992; an SU (ethametsulfuron)-R biotype from Alberta detected in 1993 (metabolism-based resistance); an SU-R biotype from Manitoba detected in 2002; and a SU- and imidazolinone (IMI)-R biotype from Saskatchewan detected in 2002. Herbicide dose-response experiments confirmed that the two Manitoba biotypes were resistant to the SU herbicides ethametsulfuron and tribenuron : thifensulfuron mixture, whereas the Saskatchewan biotype was resistant to both SU herbicides and to imazethapyr, an IMI herbicide. Sequence analysis of theALSgene detected target site mutations in three of the four R biotypes, with amino acid substitutions Pro197(CCT) to Ser (TCT) [Domain A of the gene] in the two SU-R Manitoba biotypes and Trp574(TGG) to Leu (TTG) [Domain B] in the Saskatchewan biotype. The Alberta SU-R biotype had the sameALSnucleotide and amino acid sequence as the susceptible population at these two positions. Two heterozygous individuals [Trp574(Tt/gG)] were detected in the Saskatchewan biotype, and genetic segregation for nucleotide bases and resistance phenotype was consistent with single gene control. Nucleotide variation in neutral regions of theALSgene varied with biotype, with no variation in the two Manitoba biotypes, two variants in the Saskatchewan biotype, and 16 neutral nucleotide polymorphisms (0.9%) in the Alberta biotype. The occurrence of at least three different ALS inhibitor-R biotypes in this important weed species is likely to impact negatively on the use of ALS inhibitors, such as the IMIs, and serves as a warning for strict implementation of herbicide rotations to prevent or delay the evolution and spread of such populations.

scholarly journals Characterization of Acetolactate Synthase (ALS)-Inhibitor Resistance in Pennsylvania smartweed (Persicaria pensylvanica)

Weed Science ◽  
2018 ◽  
Vol 66 (6) ◽  
pp. 710-714
Author(s):  
Vijay K. Varanasi ◽  
Jason K. Norsworthy ◽  
Chad Brabham ◽  
Robert C. Scott
Keyword(s):  
United States ◽  
Resistance Mechanism ◽  
Resistance Index ◽  
Acetolactate Synthase ◽  
Reduced Tillage ◽  
Tillage Systems ◽  
Als Inhibitors ◽  
Inhibitor Resistance ◽  
Als Inhibitor

AbstractPennsylvania smartweed [Persicaria pensylvanica(L.) M. Gómez] is a common weed of rice (Oryza sativaL.) in the midsouthern United States and has recently become a concern for farmers because of reduced tillage systems. Acetolactate synthase (ALS) inhibitors have been extensively used for controlling smartweeds in imidazolinone-resistant and conventional rice. In the present study, we confirmed resistance to commonly used ALS inhibitors in rice and characterized the underlying resistance mechanism in aP. pensylvanicabiotype from southeast Missouri. A dose–response experiment was conducted in the greenhouse using bensulfuron-methyl, imazethapyr, and bispyribac-sodium to determine the resistance index (resistance/susceptibility [R/S]) based on GR50estimates. The target-siteALSgene was amplified from R and S plants, and sequences were analyzed for mutations known to confer ALS-inhibitor resistance. TheP. pensylvanicabiotype in question was found to be resistant to bensulfuron-methyl (R/S=2,330), imazethapyr (R/S=12), and bispyribac-sodium (R/S=6). Sequencing of theALSgene from R plants revealed two previously known mutations (Pro-197-Ser, Ala-122-Ser) conferring resistance to sulfonylureas and imidazolinones. This is the first report of ALS-inhibitor resistance inP. pensylvanica.

scholarly journals The Basis of Tolerance Mechanism to Metsulfuron-Methyl in Roegneria kamoji (Triticeae: Poaceae)

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1823
Author(s):  
Wei Tang ◽  
Shengnan Liu ◽  
Xiaoyue Yu ◽  
Yongjie Yang ◽  
Xiaogang Zhou ◽  
...  
Keyword(s):  
Acetolactate Synthase ◽  
Cytochrome P450 Monooxygenases ◽  
Tolerance Mechanism ◽  
Glutathione S Transferase ◽  
Cross Tolerance ◽  
Susceptible Population ◽  
Metsulfuron Methyl ◽  
P450 Monooxygenases ◽  
Roegneria Kamoji ◽  
Als Inhibitors

Roegneria kamoji, a perennial monocot weed that belongs to the tribe Triticeae (family: Poaceae), is an emerging problematic weed in winter wheat (Triticum aestivum) fields in China. We have previously confirmed four R. kamoji populations tolerant to acetyl-CoA carboxylase (ACCase) inhibitors, and failed control of these populations by metsulfuron-methyl was observed. The objective of this study was to characterize the level of tolerance to metsulfuron-methyl, the basis of tolerance mechanism, and cross-tolerance to acetolactate synthase (ALS) inhibitors in R. kamoji. A whole-plant dose–response assay showed that plants of all R. kamoji populations (both from wheat fields and uncultivated areas) exhibited high tolerance to metsulfuron-methyl, based on their 100% survival at 6-fold recommended field dose (RFD) and ED50 values >6.84-fold RFD, no susceptible population was found. Gene sequencing indicated that no reported amino acid substitutions associated with resistance to ALS inhibitor were found in the ALS gene among the R. kamoji populations. Pretreatment with the known cytochrome P450 monooxygenases (CytP450) inhibitor malathion reduced the ED50 values of metsulfuron-methyl in two R. kamoji populations. These populations also exhibited cross-tolerance to RFD of mesosulfuron-methyl and bispyribac-sodium. The activities of glutathione-S-transferase (GST) and CytP450 could be induced by metsulfuron-methyl in R. kamoji, which is similar to the known tolerant crop wheat. This is the first report elucidating metsulfuron-methyl tolerance in R. kamoji. The reversal of tolerance by malathion and the GST and/or CytP450 enhanced herbicide metabolism suggests that non-target-site mechanisms confer tolerance to metsulfuron-methyl in R. kamoji.

ALS-Inhibitor Resistance in Populations of Eastern Black Nightshade (Solanum ptycanthum) from Ontario

2006 ◽  
Vol 20 (2) ◽  
pp. 308-314 ◽  
Author(s):  
Jamshid Ashigh ◽  
François J. Tardif
Keyword(s):  
Acetolactate Synthase ◽  
Susceptible Population ◽  
Eastern Black Nightshade ◽  
Solanum Ptycanthum ◽  
Black Nightshade ◽  
Adequate Control ◽  
Growth Room ◽  
Als Inhibitors ◽  
Inhibitor Resistance ◽  
Als Inhibitor

Populations of eastern black nightshade suspected of being resistant to acetolactate synthase (ALS) inhibitors have been reported since 1999 in different locations in Ontario, Canada. This event has threatened the use of ALS inhibitors for control of this species. The objectives of this study were to evaluate the spectrum of resistance to different ALS-inhibiting herbicides and to examine the effectiveness of alternative modes of action herbicides. Growth room experiments were conducted to determine the response to imazethapyr and atrazine in seven suspected ALS inhibitor– resistant populations. One resistant and one susceptible population were further characterized for their response to ALS inhibitors and chloroacetamides. Seven populations were able to survive imazethapyr at 100 g ai/ha, while there was no resistance to atrazine. Compared to a susceptible (S) population, resistant (R) population SOLPT 1 had 726-, 31-, 6-, and 4-fold resistance to postemergence (POST) applied imazethapyr, imazamox, primisulfuron, and flumetsulam, respectively. Preemergence (PRE) application of imazethapyr, flumetsulam, cloransulam, nicosulfuron, prosulfuron, and rimsulfuron did not provide control of the R population, whereas they totally controlled the S population. The chloroacetamide herbicides metolachlor, dimethenamid, and flufenacet all provided at least 90% control of both R and S populations when applied PRE at the recommended field rates. The ALS inhibitors will not provide adequate control of these resistant populations, but acceptable control could be achieved with chloroacetamides or with atrazine.

Cross-resistance to acetolactate synthase (ALS) inhibitors associated with different mutations in Japanese foxtail (Alopecurus japonicus)

Weed Science ◽  
2019 ◽  
Vol 67 (4) ◽  
pp. 389-396
Author(s):  
Ning Zhao ◽  
Yaling Bi ◽  
Cuixia Wu ◽  
Dandan Wang ◽  
Ludan You ◽  
...  
Keyword(s):  
Gene Sequencing ◽  
Acetolactate Synthase ◽  
Cross Resistance ◽  
Invasive Grass ◽  
Eastern Asia ◽  
Susceptible Population ◽  
Current State ◽  
Resistance Patterns ◽  
Als Inhibitors ◽  
Grass Weed

AbstractJapanese foxtail (Alopecurus japonicus Steud.) is an invasive grass weed that severely threatens the production of wheat (Triticum aestivum L.) and canola (Brassica napus L.) crops in eastern Asia. Mesosulfuron-methyl is a highly efficient acetolactate synthase (ALS)-inhibiting herbicide widely used for control of this species in China. However, in recent years, some A. japonicus populations have evolved resistance to mesosulfuron-methyl by different amino acid substitutions (AASs) within the ALS gene. In the current study, 11 populations of A. japonicus were collected from Anhui Province, China, where the wheat fields were severely infested with this weed. Based on single-dose screening, eight of these populations evolved resistance to mesosulfuron-methyl, and gene sequencing revealed three AASs located in codon 197 or 574 of the ALS gene in the different resistant populations. Subsequently, three typical populations, AH-1, AH-4, and AH-10 with Trp-574-Leu, Pro-197-Thr, and Pro-197-Ser mutations, respectively, in ALS genes were selected to characterize their cross-resistance patterns to ALS inhibitors. Compared with the susceptible population AH-S, AH-1 showed broad-spectrum cross-resistance to sulfonylureas (SUs), imidazolinones (IMIs), triazolopyrimidines (TPs), and sulfonyl-aminocarbonyl-triazolinones (SCTs); whereas AH-4 and AH-10 were resistant to SUs, TPs, and SCTs but sensitive to IMIs. Moreover, all three resistant populations were sensitive to both photosystem II inhibitor isoproturon and 4-hydroxyphenylpyruvate dioxygenase inhibitor QYM201 (1-(2-chloro-3-(3-cyclopropyl-5-hydroxy-1-methyl-1H-pyrazole-4-carbonyl)-6-(trifluoromethyl)phenyl)piperidin-2-one). Based on the current state of knowledge, this study is the first report of A. japonicus evolving cross-resistance to ALS-inhibiting herbicides due to a Pro-197-Ser mutation in the ALS gene.

scholarly journals Acetolactate synthase activity in Euphorbia heterophylla resistant to ALS- and protox- inhibiting herbicides

2013 ◽  
Vol 31 (4) ◽  
pp. 867-874 ◽  
Author(s):  
E. Xavier ◽  
M.C. Oliveira ◽  
M.M. Trezzi ◽  
R.A. Vidal ◽  
F. Diesel ◽  
...  
Keyword(s):  
Acetolactate Synthase ◽  
Inhibitory Effect ◽  
Cross Resistance ◽  
Multiple Resistance ◽  
Vitro Assay ◽  
Susceptible Population ◽  
Resistance Factors ◽  
Als Inhibitors ◽  
High Inhibitory Effect

The objective of this study was to determine the activity of the enzyme acetolactate synthase in biotypes of wild poinsettia (Euphorbia heterophylla) with multiple resistance to ALS- and Protox- inhibitors in the presence and absence of imazapyr, imazethapyr and nicosulfuron. We conducted in vitro assay of ALS enzyme extracted from plants of Vitorino, Bom Sucesso do Sul and Medianeira biotypes (with multiple resistance) and a susceptible population in the absence and presence of imazapyr, imazethapyr and nicosulfuron. In the absence of herbicides, biotypes with multiple resistance showed higher affinity for the substrate of the enzyme compared with the susceptible population. The herbicides imazapyr, imazethapyr and nicosulfuron had little effect on the enzyme activity of ALS-resistant biotypes and, conversely, high inhibitory effect on ALS of the susceptible population. Resistance factors were very high, greater than 438, 963 and 474 for Vitorino, Bom Sucesso do Sul and Medianeira biotypes, respectively. The resistance to ALS inhibitors is due to the insensitivity of ALS to herbicides of both imidazolinone and sulfonylurea groups, characterizing a cross-resistance.

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