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Fan F, Zhu YX, Wu MY, Yin WX, Li GQ, Hahn M, Hamada MS, Luo CX. Mitochondrial Inner Membrane ABC Transporter Bcmdl1 Is Involved in Conidial Germination, Virulence, and Resistance to Anilinopyrimidine Fungicides in Botrytis cinerea. Microbiol Spectr 2023; 11:e0010823. [PMID: 37318357 PMCID: PMC10434148 DOI: 10.1128/spectrum.00108-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 03/17/2023] [Indexed: 06/16/2023] Open
Abstract
Botrytis cinerea causes gray mold on thousands of plants, leading to huge losses in production. Anilinopyrimidine (AP) fungicides have been applied to control B. cinerea since the 1990s. Although resistance to AP fungicides was detected soon after their application, the mechanism of AP resistance remains to be elucidated. In this study, a sexual cross between resistant and sensitive isolates was performed, and the genomes of parental isolates and progenies were sequenced to identify resistance-related single nucleotide polymorphisms (SNPs). After screening and verification, mutation E407K in the Bcmdl1 gene was identified and confirmed to confer resistance to AP fungicides in B. cinerea. Bcmdl1 was predicted to encode a mitochondrial protein that belonged to a half-type ATP-binding cassette (ABC) transporter. Although Bcmdl1 was a transporter, it did not mediate resistance to multiple fungicides but mediated resistance specifically to AP fungicides. On the other hand, reductions in conidial germination and virulence were observed in Bcmdl1 knockout transformants compared to the parental isolate and complemented transformants, illustrating the biological functions of Bcmdl1. Subcellular localization analysis indicated that Bcmdl1 was localized in mitochondria. Interestingly, the production of ATP was reduced after cyprodinil treatment in Bcmdl1 knockout transformants, suggesting that Bcmdl1 was involved in ATP synthesis. Since Mdl1 could interact with ATP synthase in yeast, we hypothesize that Bcmdl1 forms a complex with ATP synthase, which AP fungicides might target, thereby interfering with the metabolism of energy. IMPORTANCE Gray mold, caused by B. cinerea, causes huge losses in the production of many fruits and vegetables. AP fungicides have been largely adopted to control this disease since the 1990s, and the development of resistance to AP fungicides initiates new problems for disease control. Due to the unknown mode of action, information on the mechanism of AP resistance is also limited. Recently, mutations in mitochondrial genes were reported to be related to AP resistance. However, the mitochondrial process of these genes remains to be elucidated. In this study, we identified several AP resistance-related mutations by quantitative trait locus sequencing (QTL-seq) and confirmed that mutation E407K in Bcmdl1 conferred AP resistance. We further characterized the expression patterns, biological functions, subcellular localization, and mitochondrial processes of the Bcmdl1 gene. This study deepens our understanding of the mechanism of resistance to and mode of action of AP fungicides.
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Affiliation(s)
- Fei Fan
- National Key Laboratory for Germplasm Innovation and Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yong-Xu Zhu
- National Key Laboratory for Germplasm Innovation and Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Min-Yi Wu
- National Key Laboratory for Germplasm Innovation and Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Wei-Xiao Yin
- Hubei Key Lab of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Guo-Qing Li
- Hubei Key Lab of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Matthias Hahn
- Department of Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Mohamed S. Hamada
- Pesticides Department, Faculty of Agriculture, Mansoura University, Mansoura, Egypt
| | - Chao-Xi Luo
- National Key Laboratory for Germplasm Innovation and Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Lab of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
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Fan F, Wu MY, Zhu YX, Li GQ, Luo CX. Site-directed transformants with E407K substitution in Bcmdl1 possesses different fitness from field anilinopyrimidine resistant isolates with E407K mutation in Botrytis cinerea. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 193:105427. [PMID: 37248005 DOI: 10.1016/j.pestbp.2023.105427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/13/2023] [Accepted: 04/15/2023] [Indexed: 05/31/2023]
Abstract
Botrytis cinerea is the causal agent of devastating disease gray mold on numerous crops worldwide. To control gray mold, anilinopyrimidine (AP) fungicides have been widely applied since the 1990s. However, the development of resistance in B. cinerea brought a new challenge to this disease control. Due to the unknown mode of action, the mechanism of AP resistance is still ambiguous. In our previous study, mutation E407K in Bcmdl1 was identified to be associated with AP resistance. Since this mutation is the major mechanism of AP resistance in our cases, it is essential to investigate the fitness of E407K strains before designing anti-resistance management strategies. Besides using field-resistant isolates with the E407K mutation, strains with E407K substitution obtained by site-directed mutagenesis were also used to estimate the specific effect of this mutation or substitution on fitness. The fitness of E407K strains were evaluated by determining mycelial growth, sporulation, conidial germination, virulence, acid production, osmotic and oxidative sensitivity, and sclerotial production and viability. Field resistant isolates with E407K mutation produced fewer sclerotia on intermediate medium (IM) but more conidia on PDA when compared with sensitive isolates, whereas site-directed transformants with E407K substitution did not show any fitness costs. The competitive ability of E407K strains was also evaluated on apple fruit using conidial mixtures at three initial ratios of resistant and sensitive isolates at 1:9, 1:1, and 9:1, respectively. Similar with fitness, impaired competitive ability was observed in field resistant isolates but not site-directed transformants at all initial ratios tested. These results indicated that field strains associated with AP resistance suffer a fitness penalty not linked directly to the E407K substitution in Bcmdl1.
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Affiliation(s)
- Fei Fan
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China
| | - Ming-Yi Wu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China
| | - Yong-Xu Zhu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China
| | - Guo-Qing Li
- Hubei Key Lab of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Chao-Xi Luo
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China; Hubei Key Lab of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
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Mosbach A, Edel D, Farmer AD, Widdison S, Barchietto T, Dietrich RA, Corran A, Scalliet G. Anilinopyrimidine Resistance in Botrytis cinerea Is Linked to Mitochondrial Function. Front Microbiol 2017; 8:2361. [PMID: 29250050 PMCID: PMC5714876 DOI: 10.3389/fmicb.2017.02361] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 11/15/2017] [Indexed: 12/11/2022] Open
Abstract
Crop protection anilinopyrimidine (AP) fungicides were introduced more than 20 years ago for the control of a range of diseases caused by ascomycete plant pathogens, and in particular for the control of gray mold caused by Botrytis cinerea. Although early mode of action studies suggested an inhibition of methionine biosynthesis, the molecular target of this class of fungicides was never fully clarified. Despite AP-specific resistance having been described in B. cinerea field isolates and in multiple other targeted species, the underlying resistance mechanisms were unknown. It was therefore expected that the genetic characterization of resistance mechanisms would permit the identification of the molecular target of these fungicides. In order to explore the widest range of possible resistance mechanisms, AP-resistant B. cinerea UV laboratory mutants were generated and the mutations conferring resistance were determined by combining whole-genome sequencing and reverse genetics. Genetic mapping from a cross between a resistant field isolate and a sensitive reference isolate was used in parallel and led to the identification of an additional molecular determinant not found from the characterized UV mutant collection. Together, these two approaches enabled the characterization of an unrivaled diversity of resistance mechanisms. In total, we report the elucidation of resistance-conferring mutations within nine individual genes, two of which are responsible for almost all instances of AP resistance in the field. All identified resistance-conferring genes encode proteins that are involved in mitochondrial processes, suggesting that APs primarily target the mitochondria. The functions of these genes and their possible interactions are discussed in the context of the potential mode of action for this important class of fungicides.
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Affiliation(s)
| | | | - Andrew D. Farmer
- National Center for Genome Resources, Santa Fe, NM, United States
- Syngenta Biotechnology Inc., Research Triangle Park, NC, United States
| | - Stephanie Widdison
- Syngenta Jealott's Hill International Research Centre, Bracknell, United Kingdom
| | | | | | - Andy Corran
- Syngenta Jealott's Hill International Research Centre, Bracknell, United Kingdom
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Fan F, Hamada MS, Li N, Li GQ, Luo CX. Multiple Fungicide Resistance in Botrytis cinerea from Greenhouse Strawberries in Hubei Province, China. PLANT DISEASE 2017; 101:601-606. [PMID: 30677353 DOI: 10.1094/pdis-09-16-1227-re] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Two hundred and forty isolates of Botrytis cinerea were collected during the early summer of 2012 and 2013 from strawberry greenhouses in 10 locations in Hubei Province and examined for sensitivity to five fungicides, most of which were commonly used to control this fungus. High frequency of resistance to carbendazim (Car, 63.63%) and cyprodinil (Cyp, 42.42%) was detected. Boscalid-resistant (BosR) isolates were detected for the first time in China, whereas no fludioxonil-resistant isolates were identified. Dual resistance to carbendazim and diethofencarb (Die) was also detected. There were six phenotypes of resistance profile (i.e., CarRDieSBosSCypS, CarRDieRBosSCypS, CarRDieSBosSCypR, CarRDieSBosRCypS, CarRDieRBosSCypR, and CarRDieSBosRCypR). CarRDieSBosSCypS and CarRDieSBosSCypR were the most common phenotypes, occurring at eight and seven locations, respectively. After 10 successive transfers on fungicide-free potato dextrose agar, tested resistant isolates retained levels of resistance similar to or comparative with the initial generation, indicating the stability of these resistances. Fitness evaluations based on investigation of mycelial growth, osmotic sensitivity, sporulation in vitro and in vivo, and virulence revealed the uncompromising fitness in resistant isolates, except that decreased virulence was observed in BosR isolates. The molecular basis of carbendazim, diethofencarb, and boscalid resistance was investigated. Results showed that all 13 sequenced carbendazim-resistant isolates harbored the mutation E198V or E198A in the β-tubulin gene and the five isolates with dual resistance to carbendazim and diethofencarb showed the mutation E198K in the same gene. BosR isolates possessed the H272R mutation in succinate dehydrogenase subunit B gene. The results achieved in this study challenge the current management strategies for B. cinerea, which largely depend on applications of these fungicides.
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Affiliation(s)
- F Fan
- Key Lab of Horticultural Plant Biology, Ministry of Education, and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - M S Hamada
- College of Plant Science and Technology, Huazhong Agricultural University, and Pesticides Department, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt
| | - N Li
- College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University
| | - G Q Li
- College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University
| | - C X Luo
- Key Lab of Horticultural Plant Biology, Ministry of Education, and College of Plant Science and Technology, Huazhong Agricultural University
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Kaan Selvi A, Delen N, Gencer R, Kinay Teksür P. Sensivity against some fungicides and molecular characterization of Botrytis cinerea isolates on grapes in Aegean region. ACTA ACUST UNITED AC 2016. [DOI: 10.17660/actahortic.2016.1144.41] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Fonseka DL, Gudmestad NC. Spatial and Temporal Sensitivity of Alternaria Species Associated With Potato Foliar Diseases to Demethylation Inhibiting and Anilino-Pyrimidine Fungicides. PLANT DISEASE 2016; 100:1848-1857. [PMID: 30682977 DOI: 10.1094/pdis-01-16-0116-re] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Early blight and brown spot, caused by Alternaria solani and Alternaria alternata, respectively, are important foliar diseases of potato, affecting both tuber yield and quality. Most of the commercial cultivars lack resistance; therefore, the application of foliar fungicides remains a primary disease management strategy. Baseline sensitivities of A. solani to difenoconazole and metconazole (demethylation inhibitors) using mycelial growth assay exhibited similar intrinsic activity against the pathogen with mean EC50 (the effective concentration at which the fungal growth is inhibited by 50%) values of 0.09 μg/ml. However, the sensitivity of individual baseline A. solani isolates to each fungicide varied substantially, resulting in very low and nonsignificant correlation coefficients among fungicides. Mean EC50 values for baseline A. alternata isolates in response to difenoconazole and metconazole were 0.14 and 0.26 μg/ml, respectively. The sensitivity of the majority of A. solani and A. alternata isolates collected from 2010 to 2014 from various potato production states was consistent with baseline isolates, therefore, these potato pathogens remain sensitive to the two demethylation inhibitor chemistries used to manage it. Baseline sensitivity assays of pyrimethanil (anilino-pyrimidine) also indicated great intrinsic activity against both foliar pathogens with mean EC50 values of 0.44 and 0.35 μg/ml for A. solani and A. alternata, respectively. Although A. alternata remains largely sensitive to pyrimethanil, 6 out of 245 A. solani isolates collected from 2010 to 2014 exhibited reduced-sensitivity to the fungicide in in vitro assays. Reduced-sensitive isolates were not controlled at most pyrimethanil doses except at 100 μg/ml in greenhouse in vivo efficacy tests. These chemistries remain valuable options for fungicide rotation programs in areas of high disease pressure.
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Affiliation(s)
- D L Fonseka
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108
| | - N C Gudmestad
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108
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Keinath AP. Baseline Sensitivity of Didymella bryoniae to Cyprodinil and Fludioxonil and Field Efficacy of these Fungicides Against Isolates Resistant to Pyraclostrobin and Boscalid. PLANT DISEASE 2015; 99:815-822. [PMID: 30699529 DOI: 10.1094/pdis-09-14-0993-re] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
To prevent yield reductions from gummy stem blight, fungicides often must be applied to watermelon (Citrullus lanatus) and muskmelon (Cucumis melo). Didymella bryoniae, the ascomycete fungus that causes gummy stem blight, is resistant to thiophanate-methyl, quinone-outside inhibitors (QoI), boscalid, and penthiopyrad. In place of these fungicides, premixtures of cyprodinil and fludioxonil (Switch 62.5WG) or cyprodinil and difenoconazole (Inspire Super 2.82SC) are used. The objectives of this study were to examine baseline isolates of D. bryoniae for sensitivity to cyprodinil and fludioxonil and to determine the efficacy of cyprodinil-fludioxonil and cyprodinil-difenoconazole against isolates resistant to QoI fungicides and boscalid. Colony diameters of 146 isolates of D. bryoniae collected in South Carolina and other U.S. states prior to 2008 were measured on glucose minimal medium amended with cyprodinil or fludioxonil. Mean effective concentration values that reduced relative colony diameter by 50% were 0.052 and 0.099 mg/liter cyprodinil and fludioxonil, respectively. In autumn 2008, 2009, and 2011, field-grown watermelon inoculated with isolates resistant to QoI fungicides and boscalid was treated with boscalid-pyraclostrobin alternated with chlorothalonil, cyprodinil-fludioxonil alternated with chlorothalonil, cyprodinil-difenoconazole alternated with chlorothalonil, tebuconazole alternated with chlorothalonil, chlorothalonil, or water. In 2008 and 2011, both cyprodinil treatments reduced disease severity compared with the water control treatment and chlorothalonil alone. In 2008 and 2009, cyprodinil-fludioxonil reduced severity compared with boscalid-pyraclostrobin and, in 2008, cyprodinil-difenoconazole and tebuconazole also did. Use of cyprodinil-fludioxonil should control gummy stem blight effectively and may delay development of resistance to cyprodinil and fludioxonil in D. bryoniae. However, because Botrytis cinerea became resistant to both cyprodinil and fludioxonil after multiple applications of cyprodinil-fludioxonil per season, prudent fungicide rotations should be followed when using cyprodinil-containing fungicides against D. bryoniae.
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Affiliation(s)
- Anthony P Keinath
- Coastal Research and Education Center, Clemson University, Charleston, SC 29414-5329
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Hahn M. The rising threat of fungicide resistance in plant pathogenic fungi: Botrytis as a case study. J Chem Biol 2014; 7:133-41. [PMID: 25320647 PMCID: PMC4182335 DOI: 10.1007/s12154-014-0113-1] [Citation(s) in RCA: 182] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 05/12/2014] [Indexed: 11/30/2022] Open
Abstract
The introduction of site-specific fungicides almost 50 years ago has revolutionized chemical plant protection, providing highly efficient, low toxicity compounds for control of fungal diseases. However, it was soon discovered that plant pathogenic fungi can adapt to fungicide treatments by mutations leading to resistance and loss of fungicide efficacy. The grey mould fungus Botrytis cinerea, a major cause of pre- and post-harvest losses in fruit and vegetable production, is notorious as a 'high risk' organism for rapid resistance development. In this review, the mechanisms and the history of fungicide resistance in Botrytis are outlined. The introduction of new fungicide classes for grey mould control was always followed by the appearance of resistance in field populations. In addition to target site resistance, B. cinerea has also developed a resistance mechanism based on drug efflux transport. Excessive spraying programmes have resulted in the selection of multiresistant strains in several countries, in particular in strawberry fields. The rapid erosion of fungicide activity against these strains represents a major challenge for the future of fungicides against Botrytis. To maintain adequate protection of intensive cultures against grey mould, strict implementation of resistance management measures are required as well as alternative strategies with non-chemical products.
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Affiliation(s)
- Matthias Hahn
- Department of Biology, University of Kaiserslautern, P.O. box 3049, Kaiserslautern, Germany
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Waly MA, Bader-Eldien ET, Aboudobarah ME, Aboumosalam EST. Synthesis and fungicidal evaluation of some new anilinopyrimidine derivatives. Med Chem Res 2013. [DOI: 10.1007/s00044-013-0535-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Fernández-Ortuño D, Chen F, Schnabel G. Resistance to Cyprodinil and Lack of Fludioxonil Resistance in Botrytis cinerea Isolates from Strawberry in North and South Carolina. PLANT DISEASE 2013; 97:81-85. [PMID: 30722260 DOI: 10.1094/pdis-06-12-0539-re] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Chemical control of gray mold of strawberry caused by Botrytis cinerea is essential to prevent pre- and postharvest fruit decay. For more than 10 years, the anilinopyrimidine (AP) cyprodinil and the phenylpyrrole fludioxonil (Switch 62.5WG) have been available to commercial strawberry producers in the United States for gray mold control. Both active ingredients are site-specific inhibitors and, thus, prone to resistance development. In this study, 217 single-spore isolates of B. cinerea from 11 commercial strawberry fields in North and South Carolina were examined for sensitivity to both fungicides. Isolates that were sensitive (53%), moderately resistant (30%), or resistant (17%) to cyprodinil were identified based on germ tube inhibition at discriminatory doses of cyprodinil at 1 and 25 mg/liter at 10 of the 11 locations. None of the isolates was fludioxonil resistant. Phenotypes that were moderately resistant or resistant to cyprodinil were not associated with fitness penalties for mycelial growth rate, spore production, or osmotic sensitivity. Detached fruit assays demonstrated cross resistance between the two AP fungicides cyprodinil and pyrimethanil, and that isolates that were characterized in vitro as moderately resistant or resistant were equivalent in pathogenicity on fruit sprayed with pyrimethanil (currently the only AP registered in strawberry as a solo formulation). This suggests that the in vitro distinction of moderately resistant and resistant isolates is of little if any field relevance. The absence of cross-resistance with fludioxonil, iprodione, cycloheximide, and tolnaftate indicated that multidrug resistance in the form of multidrug resistance phenotypes was unlikely to be involved in conferring resistance to APs in our isolates. Implications for resistance management and disease control are discussed.
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Affiliation(s)
| | - Fengping Chen
- School of Agricultural, Forestry & Life Sciences, Clemson University, Clemson, SC 29634
| | - Guido Schnabel
- School of Agricultural, Forestry & Life Sciences, Clemson University, Clemson, SC 29634
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Weber RWS. Resistance of Botrytis cinerea to Multiple Fungicides in Northern German Small-Fruit Production. PLANT DISEASE 2011; 95:1263-1269. [PMID: 30731691 DOI: 10.1094/pdis-03-11-0209] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
During the vegetation period 2010, 353 isolates of Botrytis cinerea from 23 Northern German strawberry, raspberry, highbush blueberry, and redcurrant fields were examined for sensitivity to the benzimidazole derivative thiophanate-methyl and the dicarboximide iprodione, as well as five fungicides currently used against gray mold in Germany. Of all isolates, 40.5% were highly resistant to thiophanate-methyl, 64.0% to iprodione, 45.0% to fenhexamid, 76.8% to trifloxystrobin, 21.5% to boscalid, and 14.7% to cyprodinil. No high resistance to fludioxonil was observed but medium resistance was recorded to fludioxonil as well as cyprodinil (41.1 and 27.2% of all isolates, respectively). In all, 63 isolates were sensitive to all five of the currently registered botryticides whereas 43, 81, 94, 49, and 23 isolates were medium or highly resistant to one, two, three, four, and five fungicides, respectively. Isolates resistant to five fungicides in vitro were capable of causing fruit rot on wounded apple pretreated with any one of the three commercially available products containing fenhexamid, pyraclostrobin plus boscalid, or cyprodinil plus fludioxonil. These results question the sustainability of the current gray mold control strategy relying exclusively on fungicides with specific, single-site modes of action.
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Affiliation(s)
- Roland W S Weber
- Esteburg Fruit Research and Advisory Center, Moorende 53, 21635 Jork, Germany
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Esterio M, Muñoz G, Ramos C, Cofré G, Estévez R, Salinas A, Auger J. Characterization of Botrytis cinerea Isolates Present in Thompson Seedless Table Grapes in the Central Valley of Chile. PLANT DISEASE 2011; 95:683-690. [PMID: 30731896 DOI: 10.1094/pdis-04-10-0298] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Botrytis cinerea isolates from flowers and berries of Vitis vinifera 'Thompson seedless' (grapevine) were characterized in terms of two transposable elements (TEs) Boty and Flipper, random amplified polymorphic DNA (RAPD), infection levels, and resistance to iprodione. The isolates were collected from grapevines under fungicide programs of variable numbers of iprodione applications, and replicated in three Chilean Central Valley locations. Recovery was repeated from clusters collected at four phenological stages. Highest infection levels were found at bloom. Fungicide programs including one iprodione application or a combination of other fungicides were most effective for reducing gray mold symptoms. A total of 457 isolates collected from fungicide programs including only one iprodione application, and the control program, were tested for the presence of TEs. In all locations and during all phenological stages, transposa isolates (containing both TEs) were most common, followed by Boty. Vacuma isolates (containing neither TE) were identified at very low levels in two locations and only in the control treatment, and isolates with only Flipper were not detected at any time or location. Vacuma and Boty isolates were all sensitive to iprodione, while transposa isolates showed a wide range of resistance. Based on response to iprodione, the presence of TEs, and presence of vegetative-incompatibility alleles (Bc-hch), the isolates studied belong to B. cinerea Group II, a phylogenetic species within B. cinerea. Hierarchical analysis of molecular variance and genetic diversity analyses of the RAPD genotypes showed a genetic differentiation linked to location, but it was not related to geographic distance. Moreover, a genetic differentiation related to the phenological stage of grapes was also detected.
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Affiliation(s)
- Marcela Esterio
- Departamento de Sanidad Vegetal, Facultad de Ciencias Agronómicas, Universidad de Chile, Código Postal 8820808, Santiago, Chile
| | - Gastón Muñoz
- Centro de Biotecnología del Gran Concepción. Facultad de Ciencias Biológicas, Universidad Andrés Bello, Sede Concepción, Autopista Concepción - Talcahuano 7100
| | - Cecilia Ramos
- Departamento de Sanidad Vegetal, Facultad de Ciencias Agronómicas, Universidad de Chile, Código Postal 8820808, Santiago, Chile
| | - Gonzalo Cofré
- Departamento de Sanidad Vegetal, Facultad de Ciencias Agronómicas, Universidad de Chile, Código Postal 8820808, Santiago, Chile
| | - Rodrigo Estévez
- Departamento de Sanidad Vegetal, Facultad de Ciencias Agronómicas, Universidad de Chile, Código Postal 8820808, Santiago, Chile
| | - Andrea Salinas
- Departamento de Sanidad Vegetal, Facultad de Ciencias Agronómicas, Universidad de Chile, Código Postal 8820808, Santiago, Chile
| | - Jaime Auger
- Departamento de Sanidad Vegetal, Facultad de Ciencias Agronómicas, Universidad de Chile, Código Postal 8820808, Santiago, Chile
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Sun HY, Wang HC, Chen Y, Li HX, Chen CJ, Zhou MG. Multiple Resistance of Botrytis cinerea from Vegetable Crops to Carbendazim, Diethofencarb, Procymidone, and Pyrimethanil in China. PLANT DISEASE 2010; 94:551-556. [PMID: 30754466 DOI: 10.1094/pdis-94-5-0551] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
One hundred and eight isolates of Botrytis cinerea from greenhouse cucumber and tomato in two locations in Jiangsu Province (Nanjing and Huaiyin) and one location in Shandong Province were tested for their sensitivities to the four fungicides commonly used in China. Isolates with resistance to all four fungicides-carbendazim, diethofencarb, procymidone, and pyrimethanil (CarRDieRPrcRPyrR)-were found in all three regions in this study. High frequencies (52 and 53%) of resistance to all four fungicides were observed among the 62 isolates collected in Nanjing and the 36 isolates collected in Huaiyin in Jiangsu Province. The 10 isolates from Shandong Province were all resistant to the four fungicides. Pathogenicity and sporulation in vivo, and mycelial growth, sporulation, spore germination, and osmotic sensitivity to NaCl in vitro, were similar for the group of quadruple-resistant and wild-type isolates (P > 0.05). In the present study, the complete two-component histidine kinase gene (Bos1) was sequenced for 10 procymidone-resistant and 3 procymidone-sensitive B. cinerea isolates. Isolates representing four different procymidone-resistant phenotypes (CarRDieSPrcRPyrS, CarRDieRPrcRPyrS, CarRDieRPrcRPyrR, and CarRDieRPrcRPyrR) all had nucleic acid point mutations resulting in amino acid changes at position 369 (change from glutamine to proline) as well as at amino acid position 373 (asparagine to serine) in the Bos1 gene.
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Affiliation(s)
- Hai-Yan Sun
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Han-Cheng Wang
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Yu Chen
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Hong-Xia Li
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Chang-Jun Chen
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Ming-Guo Zhou
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P. R. China
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Smilanick JL, Mansour MF, Mlikota Gabler F, Margosan DA, Hashim-Buckey J. Control of Postharvest Gray Mold of Table Grapes in the San Joaquin Valley of California by Fungicides Applied During the Growing Season. PLANT DISEASE 2010; 94:250-257. [PMID: 30754266 DOI: 10.1094/pdis-94-2-0250] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Fungicides applied before harvest were evaluated to control postharvest gray mold of table grapes, caused by Botrytis cinerea. The concentrations of thiophanate methyl (THM), iprodione (IPR), cyprodinil (CYP), pyraclostrobin + boscalid (PS+BO), pyrimethanil (PYR), or fenhexamid (FEN) that inhibited the growth of four isolates sensitive to these fungicides by 50% (EC50) were 12.4, 2.5, 0.61, 0.29/0.57, 0.26, or 0.17 mg liter-1, respectively. THM, IPR, CYP, PS+BO, PYR, or FEN were applied to detached 'Thompson Seedless' berries at the equivalent of the maximum approved rates of 600, 500, 270, 59/116, 370, or 290 mg liter-1, respectively, except PS+BO, which were used at 54.2% of their current registered maximum rates. The berries were inoculated with B. cinerea 48 or 24 h before treatment or 24 or 48 h after treatment. Gray mold 2 weeks after treatment and storage at 15°C was lowest after FEN application, followed by PYR, CYP, IPR, PS+BO, and THM. In commercial vineyards, one application of FEN, PYR, CYP, or PS+BO, all at their current maximum approved rates, 2 weeks before harvest reduced postharvest gray mold by approximately 50%. When fungicides were applied repeatedly after berry set either in mixtures or alternated with fungicides of different mode of action classes, postharvest gray mold was reduced by about 50% using a commercial air-blast sprayer and by 70 to 87% using a hand-held sprayer that was directed into the clusters. The fungicide sensitivity of isolates collected in numerous vineyards indicated those with reduced sensitivity to all of the tested fungicides, except FEN, were common. The efficacy of preharvest fungicide regimes was not sufficient to replace postharvest sulfur dioxide fumigation.
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Affiliation(s)
- J L Smilanick
- USDA ARS San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Avenue, Parlier, CA 93648
| | - M F Mansour
- USDA ARS San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Avenue, Parlier, CA 93648
| | | | - D A Margosan
- USDA ARS San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Avenue, Parlier, CA 93648
| | - J Hashim-Buckey
- University of California, Cooperative Extension Kern County, 1031 South Mount Vernon Avenue, Bakersfield 93307
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15
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Bardas GA, Myresiotis CK, Karaoglanidis GS. Stability and fitness of anilinopyrimidine-resistant strains of Botrytis cinerea. PHYTOPATHOLOGY 2008; 98:443-450. [PMID: 18944193 DOI: 10.1094/phyto-98-4-0443] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The fitness of anilinopyrimidine-resistant isolates of Botrytis cinerea compared with that of sensitive isolates, collected from vegetable crops in Greece during 2005, was investigated. Stability of resistance to anilinopyrimidine fungicides was determined after consecutive transfers of the fungal isolates on fungicide-free potato dextrose agar for 16 culture cycles or on fungicide-untreated cucumber seedlings for eight disease cycles. Results showed that after the consecutive transfers of the isolates either in vitro or in vivo sensitivity to cyprodinil was not changed significantly compared to the initial sensitivity in all the isolates tested, suggesting a stable genetically controlled trait. Fitness parameters measured were mycelial growth, spore production in vitro, osmotic sensitivity, virulence, spore production in vivo, percentage of spore germination, and competitive ability of the resistant isolates in four pairs with sensitive isolates both on artificial nutrient medium or on cucumber seedling plants. The measurements of the fitness components in individual isolates showed high variability within both sensitivity groups in all, except virulence, fitness components tested. As a group, resistant isolates showed significantly lower (P < 0.05) mycelial growth and virulence, while they were more osmotically sensitive than the sensitive isolates. In addition the resistant isolates showed higher (P < 0.05) spore production in vivo but there was no difference (P > 0.05) between the two sensitivity groups in spore production in vitro and in the percentage of spore germination. However, the correlation to test if there is any relationship between the values of each fitness component tested and the level of cyprodinil sensitivity of each isolate was for all, except the spore production in vivo, fitness components not significant (P > 0.05). This absence of significant correlation coefficient values suggests that the development of resistance to anilinopyrimidine fungicides did not affect the fitness of the resistant isolates. Competition of the resistant versus sensitive isolates was isolates-dependent, since in two of the isolate pairs the resistance frequency decreased significantly after five culture or disease cycles, while in the remaining two pairs resistance frequency increased significantly after five disease cycles or remained stable for one pair after five culture cycles on artificial nutrient media.
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Affiliation(s)
- G A Bardas
- Aristotelian University of Thessaloniki, Faculty of Agriculture, Plant Pathology Laboratory, Thessaloniki, Greece
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Li HX, Xiao CL. Characterization of fludioxonil-resistant and pyrimethanil-resistant phenotypes of Penicillium expansum from apple. PHYTOPATHOLOGY 2008; 98:427-435. [PMID: 18944191 DOI: 10.1094/phyto-98-4-0427] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Penicillium expansum is the primary cause of blue mold, a major postharvest disease of apple. Fludioxonil and pyrimethanil are two newly registered postharvest fungicides for pome fruit in the United States. To evaluate the potential risk of resistance development in P. expansum to the new postharvest fungicides, one isolate of each of thiabendazole-resistant (TBZ-R) and -sensitive (TBZ-S) P. expansum was exposed to UV radiation to generate fungicide-resistant mutants. Four fludioxonil highly-resistant mutants (EC(50) > 1,000 microg/ml) and four pyrimethanil-resistant mutants (EC(50) > 10 microg/ml) were tested for sensitivities to thiabendazole, fludioxonil, and pyrimethanil, and fitness parameters including mycelial growth, sporulation on potato dextrose agar (PDA), sensitivity to osmotic stress, and pathogenicity and sporulation on apple fruit. The stability of resistance of the mutants was tested on PDA and apple fruit. Efficacy of the three fungicides to control blue mold incited by the mutants was evaluated on apple fruit. Six fungicide-resistant phenotypes were identified among the parental wild-type isolates and their mutants based upon their resistance levels. All four fludioxonil highly-resistant mutants were sensitive to pyrimethanil and retained the same phenotypes of resistance to TBZ as the parental isolates. All four pyrimethanil-resistant mutants had a low level of resistance to fludioxonil with a resistance factor >15. The two pyrimethanil-resistant mutants derived from a TBZ-S isolate became resistant to TBZ at 5 microg/ml. After 20 successive generations on PDA and four generations on apple fruit, the mutants retained the same phenotypes as the original generations. All mutants were pathogenic on apple fruit at both 0 and 20 degrees C, but fludioxonil highly-resistant mutants were less virulent and produced fewer conidia on apple fruit than pyrimethanil-resistant mutants and their parental wild-type isolates. Compared with the parental isolates, all four fludioxonil highly-resistant mutants had an increased sensitivity to osmotic stress on PDA amended with NaCl, while the pyrimethanil-resistant mutants did not. Pyrimethanil was effective against blue mold caused by fludioxonil-resistant mutants at both 0 and 20 degrees C. Pyrimethanil and fludioxonil reduced blue mold incited by pyrimethanil-resistant mutants during 12-week storage at 0 degrees C but were not effective at 20 degrees C. TBZ was not effective against pyrimethanil-resistant mutants derived from TBZ-S wild-type isolates at room temperature but provided some control at 0 degrees C. The results indicate that: (i) a fitness cost was associated with fludioxonil highly resistant mutants of P. expansum in both saprophytic and pathogenic phases of the pathogen but not pyrimethanil-resistant mutants; (ii) pyrimethanil possessed a higher risk than fludioxonil in the development of resistance in P. expansum; and (iii) triple resistance to the three apple-postharvest fungicides could emerge and become a practical problem if resistance to pyrimethanil develops in P. expansum populations.
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Affiliation(s)
- H X Li
- Department of Plant Pathology, Washington State University, Tree Fruit Reseach and Extension Center, Wenatchee, WA 98801, USA
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17
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Kanetis L, Förster H, Jones CA, Borkovich KA, Adaskaveg JE. Characterization of genetic and biochemical mechanisms of fludioxonil and pyrimethanil resistance in field isolates of Penicillium digitatum. PHYTOPATHOLOGY 2008; 98:205-214. [PMID: 18943197 DOI: 10.1094/phyto-98-2-0205] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Genetic and biochemical mechanisms of fludioxonil and pyrimethanil resistance in isolates of Penicillium digitatum were evaluated and compared to those characterized in other fungi. Resistant isolates were naturally occurring in packinghouses and were not associated with crop losses. For the phenylpyrrole fludioxonil, EC50 values were 0.02 to 0.04 microg/ml for sensitive, 0.08 to 0.65 microg/ml for moderately resistant (MR), and > 40 microg/ml for highly resistant (HR) isolates. Two fludioxonil-sensitive isolates evaluated were also significantly more sensitive to the unrelated dicarboximide fungicide iprodione, that also disrupts osmotic regulation, than the MR and HR isolates. There was no consistent relationship, however, between the HR and MR isolates and their sensitivity to iprodione or osmotic stress. Although, two nucleotide substitutions were found in a sequence analysis of the N-terminal amino acid repeat region of the os-1-related histidine kinase gene among isolates of P. digitatum, these were not correlated with fludioxonil resistance. In mycelia not exposed to fludioxonil, the amount of phosphorylated OS-2-related protein (PdOS-2) was higher in fludioxonil-sensitive isolates and lowest in the HR isolate. An increase in PdOS-2 was observed for sensitive and resistant isolates after exposure to fludioxonil. In addition, glycerol content in untreated mycelia of the fludioxonil-sensitive isolate was significantly higher than in resistant isolates. After exposure to fludioxonil, glycerol concentrations significantly increased in the sensitive and MR isolates, but not in the HR isolate. Thus, our studies indicate that the mode of action of fludioxonil in P. digitatum is probably the mitogen-activated protein kinase pathway that stimulates glycerol synthesis in sensitive and MR isolates. The general suppression of this pathway in resistant isolates was supported by the fact that growth and sporulation of MR and HR isolates were significantly reduced from that of sensitive isolates. In studies on the mode of action of anilinopyrimidines (AP), EC50 values for mycelial growth of P. digitatum and the previously characterized Botrytis cinerea were determined for cyprodinil and pyrimethanil using a defined culture medium without and with the addition of selected amino acids and homocysteine. The addition of amino acids resulted in a reduced toxicity of the two AP fungicides in both fungi, but the effect of each additive was significantly lower for P. digitatum than for B. cinerea. This suggests that methionine biosynthesis is not the primary target site of APs in P. digitatum.
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Affiliation(s)
- L Kanetis
- Department of Plant Pathology, University of California, Riverside, CA 92521, USA
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18
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Myresiotis CK, Karaoglanidis GS, Tzavella-Klonari K. Resistance of Botrytis cinerea Isolates from Vegetable Crops to Anilinopyrimidine, Phenylpyrrole, Hydroxyanilide, Benzimidazole, and Dicarboximide Fungicides. PLANT DISEASE 2007; 91:407-413. [PMID: 30781182 DOI: 10.1094/pdis-91-4-0407] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
During February 2005, 55 single-spore isolates of Botrytis cinerea were collected at the end of the season from vegetable crops grown in 18 greenhouses on the island of Crete, Greece. They were tested for sensitivity to the anilinopyrimidine fungicides pyrimethanil and cyprodinil, the hydroxyanilide fungicide fenhexamid, the phenylpyrrole fungicide fludioxonil, the dicarboximide fungicide iprodione, and the benzimidazole fungicide carbendazim. Results of the study showed the existence of benzimidazole- and dicarboximide-resistant strains at frequencies of 61.8 and 18%, respectively. Moreover, for first time, the development of resistance to anilinopyrimidine fungicides by B. cinerea was detected in greenhouse vegetable crops on the island of Crete. High resistance frequencies of 49.1 and 57.4% were observed for pyrimethanil and cyprodinil, respectively. In addition, one isolate was found to be resistant to the hydroxyanilide fungicide fenhexamid, while no strains resistant to the phenylpyrrole fungicide were detected. Among the 55 isolates tested, 13 were resistant only to carbendazim, 6 were resistant only to anilinopyrimidines, 3 were resistant to both benzimidazoles and dicarboximides, 17 were resistant to both benzimidazoles and anilinopyrimidines, 6 were resistant to both dicarboximides and anilinopyrimidines, 1 was simultaneously resistant to benzimidazoles, dicarboximides, and anilinopyrimidines, 1 was resistant to both anilinopyrimidines and hydroxyanilides, and 8 were sensitive to all fungicides tested. A strong cross-resistance relationship was found between the two anilinopyrimidine fungicides tested when log transformed EC50 values of the isolates were subjected to a linear regression analysis (r = 0.71). Despite the detection of several phenotypes with simultaneous resistance to chemically unrelated active ingredients, in none of the remaining possible fungicide pairs was there observed any kind of cross-resistance relationship.
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Affiliation(s)
- C K Myresiotis
- Aristotelian University of Thessaloniki, Faculty of Agriculture, Plant Pathology Laboratory, POB 269, 54124, Thessaloniki, Greece
| | - G S Karaoglanidis
- Hellenic Sugar Industry S.A., Plant Protection Department, Sugar Factory of Platy, 59032, Platy Imathias, Greece
| | - K Tzavella-Klonari
- Aristotelian University of Thessaloniki, Faculty of Agriculture, Plant Pathology Laboratory, POB 269, 54124, Thessaloniki, Greece
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19
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Köller W, Wilcox WF, Parker DM. Sensitivity of Venturia inaequalis Populations to Anilinopyrimidine Fungicides and Their Contribution to Scab Management in New York. PLANT DISEASE 2005; 89:357-365. [PMID: 30795450 DOI: 10.1094/pd-89-0357] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Sensitivities of Venturia inaequalis isolates to the anilinopyrimidine fungicides (APs) pyrimethanil and cyprodinil were determined for nine populations by measuring the growth of colonies formed from germinating conidia derived from single scab lesions. At the discriminatory pyrimethanil dose of 0.2 μg ml-1, the mean relative growth range measured for eight V. inaequalis populations (n = 39 to 74) never treated with AP fungicides varied from 18.1 to 48.2, translating into an approximately sixfold difference in mean baseline sensitivities. For the composite of all 469 isolates tested, sensitivities to pyrimethanil and to the sterol demethylation inhibitor (DMI) myclobutanil were significantly correlated. When isolates were organized into subpopulations based on their sensitivities to an individual fungicide, sensitivities to both fungicides declined in parallel through the highly and moderately sensitive spectra of subpopulations, but they diverged for isolates in subpopulations least sensitive to either fungicide. The result suggested that at least one of the multiple genes conferring DMI resistance also lowered the sensitivity to AP fungicides. The relative contribution of AP fungicides to scab management was evaluated at an experimental orchard representative of the Great Lakes region of the United States. Frequencies of DMI-resistant isolates of V. inaequalis had progressed to the stage of practical resistance at the site, and the sensitivity to pyrimethanil was similar to several commercial orchard populations never treated with APs. For management programs at the experimental site involving the AP fungicides cyprodinil and pyrimethanil and conducted from 1996 to 2000, the level of fruit and terminal leaf scab control was inferior to that of nonspecific protectants such as mancozeb or captan. For the control of scab on cluster leaves, the efficacy of AP fungicides equaled the performance of nonspecific protectants. This modest contribution of AP fungicides to scab management might have been caused by a lack of the extended cool temperature conditions that were conducive to AP performance in northern Europe in previous studies, and/or by the reduced sensitivity to AP fungicides in this DMI-resistant V. inaequalis population.
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Affiliation(s)
- Wolfram Köller
- Department of Plant Pathology, Cornell University, New York State Agricultural Experiment Station, Geneva 14456
| | - W F Wilcox
- Department of Plant Pathology, Cornell University, New York State Agricultural Experiment Station, Geneva 14456
| | - D M Parker
- Department of Plant Pathology, Cornell University, New York State Agricultural Experiment Station, Geneva 14456
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Sholberg PL, Bedford KE, Stokes S. Effect of Preharvest Application of Cyprodinil on Postharvest Decay of Apples Caused by Botrytis cinerea. PLANT DISEASE 2003; 87:1067-1071. [PMID: 30812819 DOI: 10.1094/pdis.2003.87.9.1067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Dry-eye rot and gray mold of apple are important diseases caused by Botrytis cinerea. Fungicides available for their control are lacking, and this study was conducted to determine if cyprodinil (Vangard) could be used for this purpose. The mean EC50 value of cyprodinil for 32 Botrytis spp. isolates (27 from apple) was 0.02 μg ml-l, indicating that apple isolates are generally very sensitive. Some of the isolates (19%) were less sensitive and had EC50 values greater than 0.03 μg ml-l, and one isolate from 'Gala' apple was considerably less sensitive at 0.095 μg ml-l. Bloom sprays of cyprodinil alone in 1998 and 1999 or in combination with myclobutanil or metiram in 1998 reduced Botrytis spp. infection on developing fruit. Postharvest application of cyprodinil in 1998 indicated that cyprodinil protected apples from gray mold for 3 months. Cyprodinil applied 2 to 3 weeks before harvest in 1999 reduced lesion diameters 68 and 62% on 'Jonagold' and 'Gala' apples, respectively, that had been wounded and inoculated with B. cinerea after storage at 1°C for 6 months. In similar trials on 'Gala' apples in 2000 and 2001, preharvest applications of cyprodinil consistently reduced gray mold incidence and lesion diameter on inoculated apples stored for 6 months. New preharvest use patterns for cyprodinil are discussed for control of postharvest diseases caused by B. cinerea.
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Affiliation(s)
- Peter L Sholberg
- Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, Summerland, British Columbia, Canada V0H 1Z0
| | - Karen E Bedford
- Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, Summerland, British Columbia, Canada V0H 1Z0
| | - Sarah Stokes
- Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, Summerland, British Columbia, Canada V0H 1Z0
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Marín A, Oliva J, Garcia C, Navarro S, Barba A. Dissipation rates of cyprodinil and fludioxonil in lettuce and table grape in the field and under cold storage conditions. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2003; 51:4708-11. [PMID: 14705900 DOI: 10.1021/jf021222e] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Two fungicides (cyprodinil and fludioxonil) have recently been used in southeast Spain to control disease in lettuce and grape. Gas chromatography with a nitrogen-phosphorus detector (GC-NPD) was used to study the disappearance of these compounds from crops under field conditions and during refrigeration. Residual values 21 days after application were below the maximum residue limit (MRL = 0.05 mg kg(-1)) established by Spanish law in the field experiment for both compounds. However, with the exception of fludioxonil in lettuce, residues were above the MRL in the refrigerated farm produce for both fungicides. The half-lives were 3-6 times greater under refrigeration.
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Affiliation(s)
- Antonio Marín
- Centro de Edafología y Biología Aplicada del Segura (CEBAS), Campus de Espinardo, 30080 Murcia, Spain
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Baroffio CA, Siegfried W, Hilber UW. Long-Term Monitoring for Resistance of Botryotinia fuckeliana to Anilinopyrimidine, Phenylpyrrole, and Hydroxyanilide Fungicides in Switzerland. PLANT DISEASE 2003; 87:662-666. [PMID: 30812857 DOI: 10.1094/pdis.2003.87.6.662] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In Switzerland, the use of phenylpyrrole, anilinopyrimidine, and hydroxyanilide fungicides for control of Botryotinia fuckeliana, causal agent of gray mold in grapes, has been restricted to one treatment per fungicide class per year as part of an anti-resistance strategy. Resistance development in B. fuckeliana was monitored from 1995 to 2001 for the anilinopyrimidine cyprodinil and the phenylpyrrole fludioxonil and from 1997 to 2001 for the hydroxyanilide fenhexamid in experimental vineyards in Richterswil and Stäfa, Switzerland. In total, over 2,400 field isolates were tested. In 1996, the first case of field resistance to anilinopyrimidines was encountered in Richterswil. Efficacy of the anilinopyrimidine cyprodinil decreased significantly, and 54% of the isolates were resistant to anilinopyrimidines. During 7 years of monitoring, one field isolate was found that showed a slightly decreased sensitivity to the phenylpyrrole fludioxonil. Resistance to the hydroxyanilide fenhexamid was not found in 1997 and 1998. From 1999 to 2001, the level of fenhexamid-resistant isolates increased to 100% in Stäfa. The analysis of monitoring and efficacy data showed that subpopulations of B. fuckeliana resistant to cyprodinil and fenhexamid have increased significantly; however, the efficacy of a mixture of fludioxonil and cyprodinil and of fenhexamid alone was still effective. The objective of this study was to initiate long-term monitoring in order to establish an early resistance-detection system as a tool to assess the effectiveness of the anti-resistance strategy used in Switzerland.
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Affiliation(s)
- Catherine A Baroffio
- Department of Plant Pathology, Swiss Federal Research Station, CH-8820 Wädenswil, Switzerland
| | - Werner Siegfried
- Department of Plant Pathology, Swiss Federal Research Station, CH-8820 Wädenswil, Switzerland
| | - Urs W Hilber
- Department of Plant Pathology, Swiss Federal Research Station, CH-8820 Wädenswil, Switzerland
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23
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Leroux P, Fritz R, Debieu D, Albertini C, Lanen C, Bach J, Gredt M, Chapeland F. Mechanisms of resistance to fungicides in field strains of Botrytis cinerea. PEST MANAGEMENT SCIENCE 2002; 58:876-88. [PMID: 12233177 DOI: 10.1002/ps.566] [Citation(s) in RCA: 204] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Field strains of Botrytis cinerea Pers ex Fr, the causal agent of grey mould diseases, were collected from French vineyards between 1993 and 2000. Several phenotypes have been characterized according to the inhibitory effects of fungicides towards germ-tube elongation and mycelial growth. Two types of benzimidazole-resistant strains (Ben R1 and Ben R2) could be detected; negative cross-resistance to phenylcarbamates (e.g. diethofencarb) was only found in Ben R1. Benzimidazole resistance was related to point mutations at codon 198 (Ben R1) or 200 (Ben R2) of the beta-tubulin gene. Most dicarboximide-resistant strains were also weakly resistant to aromatic hydrocarbon fungicides (e.g. dicloran) but remained sensitive to phenylpyrroles (e.g. fludioxonil). These resistant field strains (Imi R1) contained a single base pair mutation at position 365 in a two-component histidine kinase gene, probably involved in the fungal osmoregulation. Three anilinopyrimidine-resistant phenotypes have been identified. In the most resistant one (Ani R1), resistance was restricted to anilinopyrimidines, but no differences were observed in the amino-acid sequences of cystathionine beta-lyase (the potential target site of these fungicides) from Ani R1 or wild-type strains. In the two other phenotypes (Ani R2 and Ani R3), resistance extended to various other groups of fungicide, including dicarboximides, phenylpyrroles and sterol biosynthesis inhibitors. This multi-drug resistance was probably determined by over-production of ATP-binding cassette transporters. The hydroxyanilide fenhexamid is a novel botryticide whose primary target site is the 3-keto reductase involved in sterol C-4 demethylations. Apart from the multi-drug-resistant strain Ani R3, three other fenhexamid-resistant phenotypes have been recognized. For two of them (Hyd R1 and Hyd R2) fenhexamid-resistance seemed to result from P450-mediated detoxification. Reduced sensitivity of the target site could be the putative resistance mechanism operating in the third resistant phenotype (Hyd R3). Increased sensitivity to inhibitors of sterol 14 alpha-demethylase recorded in Hyd R1 strains was related to two amino-acid changes at positions 15 and 105 of this enzyme.
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Affiliation(s)
- Pierre Leroux
- INRA, Unité de Phytopharmacie et Médiateurs Chimiques, 78026 Versailles, France.
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Köller W, Wilcox WF. Interactive Effects of Dodine and the DMI Fungicide Fenarimol in the Control of Apple Scab. PLANT DISEASE 2000; 84:863-870. [PMID: 30832140 DOI: 10.1094/pdis.2000.84.8.863] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Interactive effects of a mixture of fenarimol and dodine in the inhibition of Venturi inaequalis populations and the risk that resistance will develop when the mixture is used for control of apple scab were investigated. Interactive mixture effects were determined for a composite population (n = 1007) representative of the Great Lakes apple-growing region and for a population (n = 1,295) sampled over three years from a single experimental orchard subjected to various fungicide treatments. Several interactive effects were identified: (i) subpopulations of V. inaequalis isolates resistant to dodine contained a higher proportion of isolates also resistant to fenarimol, (ii) synergistic effects were apparent for a large proportion of dodine- or fenarimol-resistant isolates when tested in mixture, and (iii) the level of fenarimol resistance was higher in the subpopulation resisting the mixture than in the subpopulation resisting fenarimol alone. Interactive effects determined under in vivo test conditions were of low relevance in the control of apple scab. The partly pleiotropic resistance of dodine and fenarimol had no apparent impact on the fenarimol sensitivities of dodine-resistant populations, and expression of synergistic mixture effects were of low or no significance under orchard conditions of scab control. Treatments of apple trees with a half-rate mixture of fenarimol and dodine selected V. inaequalis isolates resistant to the mixture. Such isolates were poorly controlled by the mixture and by each component applied alone at twice their mixture rates; therefore, mixture-resistant isolates will be selected and must be controlled by other means. The level of fenarimol resistance was high for the mixture-resistant subpopulation; therefore, increasing the mixture rate of fenarimol is unlikely to significantly improve control of these isolates. The advantage of a half-rate mixture of fenarimol and dodine in scab management resides in a substantially lower frequency of selectable isolates compared to the frequencies encountered by fenarimol and dodine applied alone.
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Affiliation(s)
- W Köller
- Department of Plant Pathology, Cornell University, New York State Agricultural Experiment Station, Geneva 14456
| | - W F Wilcox
- Department of Plant Pathology, Cornell University, New York State Agricultural Experiment Station, Geneva 14456
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