Mechanism and pattern of resistance to some ACCase inhibitors in winter wild oat (Avena sterilis subsp. ludoviciana (Durieu) Gillet & Magne) biotypes collected within canola fields

Wild oat (Avena fatuaL. ♯3AVEFA) andAvena sterilisL. ♯ AVEST accessions from the United States were screened for tolerance to diallate [S-(2,3-dichloroallyl) diisopropylthiocarbamate], triallate [S-(2,3,3-trichloroallyl) diisopropylthiocarbamate], barban (4-chloro-2-butynylm-chlorocarbanilate), diclofop {2-[4-(2,4-dichlorophenoxy) phenoxy] propanoic acid}, difenzoquat (1,2-dimethyl-3,5-diphenyl-1H-pyrazolium), flamprop [N-benzoyl-N-(3-chloro-4-fluorophenyl)-DL-alanine], and MSMA (monosodium methanearsonate). Some accessions were tolerant to more than one herbicide but none were tolerant to all herbicides. Tolerance to a herbicide was not restricted to certain areas of origin of the accessions, and tolerant accessions occurred even in locations that had not been treated previously with the herbicide. In general, accessions from Southern California and Arizona were shorter, produced more tillers, and required the least number of days to panicle emergence. However, accessions from within individual areas were nearly as variable in these characteristics as the entire 1200 accessions. Tolerance of accessions to flamprop, difenzoquat, MSMA, and diclofop was not due to low leaf surface area, since the tolerant accessions usually had the most leaf surface area. All the accessions tolerant to difenzoquat, MSMA, and flamprop, and three of the four accessions tolerant to diclofop, tillered less than the susceptible accessions.

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Resistance to Aryloxyphenoxypropionate Herbicides in Two Wild Oat Species (Avena fatuaandAvena sterilisssp.ludoviciana)

Weed Science ◽

10.1017/s0043174500058185 ◽

1992 ◽

Vol 40 (4) ◽

pp. 599-605 ◽

Cited By ~ 43

Author(s):

Ali M. Mansooji ◽

Joseph A. Holtum ◽

Peter Boutsalis ◽

John M. Matthews ◽

Stephen B. Powles

Keyword(s):

Methyl Ester ◽

Western Australia ◽

South Australia ◽

Avena Fatua ◽

Wild Oat ◽

Avena Sterilis ◽

Susceptible Control ◽

Low Levels ◽

Marked Resistance

Resistance to the methyl ester of diclofop, an aryloxyphenoxypropionate graminicide, was shown for a wild oat (Avena fatua) population from Western Australia, and marked resistance to a range of aryloxyphenoxypropionate and cyclohexanedione graminicides was detected in a winter wild oat (Avena sterilisssp.ludoviciana) population from South Australia. TheA. sterilisbiotype exhibited high levels of resistance to the aryloxyphenoxypropionate herbicides diclofop, fluazifop, haloxyfop, fenoxaprop, quizalofop, propaquizafop, and quinfurop and low levels of resistance to the cyclohexanedione herbicides sethoxydim, tralkoxydim, and cycloxydim. Ratios of LD50values for responses of resistant and susceptibleA. sterilisto the aryloxyphenoxypropionate herbicides were between 20 for propaquizafop and > 1,000 for fluazifop, and were between 2.5 and 3 for the cyclohexanedione herbicides. The LD50value for diclofop for theA. fatuabiotype was 442 g ai ha-1which was 2.7-fold that of a susceptible control. Thirty-three percent of the plants survived at the registered rate of application.

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Competition between ACCase-Inhibitor Resistant and Susceptible Sterile Wild Oat (Avena sterilis) Biotypes

Weed Science ◽

10.1614/ws-d-12-00065.1 ◽

2013 ◽

Vol 61 (1) ◽

pp. 26-31 ◽

Cited By ~ 14

Author(s):

Ilias S. Travlos

Keyword(s):

Seed Germination ◽

Plant Height ◽

Competitive Ability ◽

Plant Biomass ◽

Wild Oat ◽

Seedling Vigor ◽

Acetyl Coa Carboxylase ◽

Replacement Series ◽

Avena Sterilis ◽

Canopy Area

Studies were conducted to determine the growth, fecundity, and competitive ability of an acetyl-CoA carboxylase (ACCase)–inhibitor resistant (R) sterile wild oat biotype compared with a susceptible (S) biotype. Seed germination studies indicated that there were no differences in seed germination and seedling vigor between R and S biotypes at any temperature regime. R and S biotypes were grown under noncompetitive and competitive arrangement in the greenhouse. Under noncompetitive greenhouse conditions, growth of the R biotype was similar to that of the S biotype on the basis of plant height, canopy area, and plant biomass. Seed production and weight of R and S plants were also at the same levels. Furthermore, relative competitiveness among the R and S sterile wild oat biotypes was investigated by means of replacement series experiments. The R and S biotypes were compared under seven mixture proportions (6 : 0, 5 : 1, 4 : 2, 3 : 3, 2 : 4, 1 : 5, and 0 : 6). No significant differences in competitive ability were observed between R and S biotypes on the basis of plant height, canopy area, or plant biomass. In most cases, relative crowding coefficient (RCC) values at 20, 60, and 100 d after transplanting (DAT) were close to one, indicating equal competitiveness between the R and S biotypes of wild oat used in this competitive study. However, in some cases, the RCC value was 1.31 for plant height, evident of a slight competitive advantage for the R biotype at 100 DAT. In general, ACCase-inhibitor R and S sterile wild oat biotypes were equally competitive, clearly without any growth penalty for R plants in either noncompetitive or competitive conditions.

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Differences in Germination of ACCase-Resistant Biotypes Containing Isoleucine-1781-Leucine Mutation and Susceptible Biotypes of Wild Oat (Avena sterilis ssp. ludoviciana)

Plants ◽

10.3390/plants10112350 ◽

2021 ◽

Vol 10 (11) ◽

pp. 2350

Author(s):

Fatemeh Benakashani ◽

Jose L. Gonzalez-Andujar ◽

Elias Soltani

Keyword(s):

Seed Germination ◽

Soil Water ◽

Management Practices ◽

Integrated Management ◽

Wild Oat ◽

Avena Sterilis ◽

Germination Characteristics ◽

Cereal Fields ◽

The Right ◽

Clodinafop Propargyl

Herbicide resistance can affect seed germination and the optimal conditions required for seed germination, which in turn may impose a fitness cost in resistant populations. Winter wild oat [Avena sterilis L. ssp. ludoviciana (Durieu) Gillet and Magne] is a serious weed in cereal fields. In this study, the molecular basis of resistance to an ACCase herbicide, clodinafop-propargyl, in four A. ludoviciana biotypes was assessed. Germination differences between susceptible (S) and ACCase-resistant biotypes (WR1, WR2, WR3, WR4) and the effect of Isoleucine-1781-Leucine mutation on germination were also investigated through germination models. The results indicated that WR1 and WR4 were very highly resistant (RI > 214.22) to clodinafop-propargyl-contained Isoleucine to Leucine amino acid substitution. However, Isoleucine-1781-Leucine mutation was not detected in other very highly resistant biotypes. Germination studies indicated that resistant biotypes (in particular WR1 and WR4) had higher base water potentials than the susceptible one. This shows that resistant biotypes need more soil water to initiate their germination. However, the hydrotime constant for germination was higher in resistant biotypes than in the susceptible one in most cases, showing faster germination in susceptible biotypes. ACCase-resistant biotypes containing the Isoleucine-1781-Leucine mutation had lower seed weight but used more seed reserve to produce seedlings. Hence, integrated management practices such as stale seedbed and implementing it at the right time could be used to take advantage of the differential soil water requirement and relatively late germination characteristics of ACCase-resistant biotypes.

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