Sensitivity of Colletotrichum acutatum Isolates from Citrus to Carbendazim, Difenoconazole, Tebuconazole, and Trifloxystrobin
Autor(a) principal: | |
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Data de Publicação: | 2020 |
Outros Autores: | , , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1094/PDIS-10-19-2195-RE http://hdl.handle.net/11449/196917 |
Resumo: | Postbloom fruit drop (PFD) of citrus is caused by the Colletotrichum acutatum and C. gloeosporioides species complexes. The disease is important when frequent rainfall occurs during the flowering period of citrus trees. In Brazil, until 2012, PFD was mainly controlled by preventive applications of the methyl-benzimidazole carbamate (MBC) carbendazim and demethylation-inhibitor (DMI) fungicides such as difenoconazole. Since then, mixtures containing the DMI tebuconazole and the quinone-outside inhibitor (QoI) trifloxystrobin have been commonly used. Fungicides are often applied preventively, sometimes even when conditions are not conducive for PFD development. Excessive fungicide applications may favor the selection of resistant populations of Colletotrichum spp. In this study, we assessed the fungicide sensitivity of C. acutatum isolates collected during the two distinct periods of PFD management in Brazil: before and after the trifloxystrobin and tebuconazole mixture became widely employed. The sensitivity of 254 C. acutatum isolates to carbendazim and difenoconazole and of 164 isolates to tebuconazole and trifloxystrobin was assessed. Mycelial growth inhibition of these isolates was evaluated for all the fungicides using either serial dilution of fungicide rates or the spiral gradient dilution method. In addition, inhibition of conidial germination was also assessed for trifloxystrobin. Analysis of partial beta-tub, cytb, and cyp51b gene sequences did not reveal any mutations related to resistance to MBCs, QoIs, and DMIs, respectively. In mycelia] growth assays, mean EC50 values were 0.14, 0.11, and 0.21 mu g/ml for difenoconazole, tebuconazole, and trifloxystrobin, respectively. The conidial germination inhibition by trifloxystrobin was similar among the tested isolates, and the mean EC50 value was 0.002 mu g/ml. All isolates had similar mean mycelial growth inhibition for carbendazim, regardless of the fungicide concentrations. Therefore, based on similar EC50 values and molecular analyses, no shift in the sensitivity of isolates has been observed to the fungicides commonly used in different citrus-producing areas in Brazil. |
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Sensitivity of Colletotrichum acutatum Isolates from Citrus to Carbendazim, Difenoconazole, Tebuconazole, and Trifloxystrobinpostbloom fruit dropfungicide resistancebaselinePostbloom fruit drop (PFD) of citrus is caused by the Colletotrichum acutatum and C. gloeosporioides species complexes. The disease is important when frequent rainfall occurs during the flowering period of citrus trees. In Brazil, until 2012, PFD was mainly controlled by preventive applications of the methyl-benzimidazole carbamate (MBC) carbendazim and demethylation-inhibitor (DMI) fungicides such as difenoconazole. Since then, mixtures containing the DMI tebuconazole and the quinone-outside inhibitor (QoI) trifloxystrobin have been commonly used. Fungicides are often applied preventively, sometimes even when conditions are not conducive for PFD development. Excessive fungicide applications may favor the selection of resistant populations of Colletotrichum spp. In this study, we assessed the fungicide sensitivity of C. acutatum isolates collected during the two distinct periods of PFD management in Brazil: before and after the trifloxystrobin and tebuconazole mixture became widely employed. The sensitivity of 254 C. acutatum isolates to carbendazim and difenoconazole and of 164 isolates to tebuconazole and trifloxystrobin was assessed. Mycelial growth inhibition of these isolates was evaluated for all the fungicides using either serial dilution of fungicide rates or the spiral gradient dilution method. In addition, inhibition of conidial germination was also assessed for trifloxystrobin. Analysis of partial beta-tub, cytb, and cyp51b gene sequences did not reveal any mutations related to resistance to MBCs, QoIs, and DMIs, respectively. In mycelia] growth assays, mean EC50 values were 0.14, 0.11, and 0.21 mu g/ml for difenoconazole, tebuconazole, and trifloxystrobin, respectively. The conidial germination inhibition by trifloxystrobin was similar among the tested isolates, and the mean EC50 value was 0.002 mu g/ml. All isolates had similar mean mycelial growth inhibition for carbendazim, regardless of the fungicide concentrations. Therefore, based on similar EC50 values and molecular analyses, no shift in the sensitivity of isolates has been observed to the fungicides commonly used in different citrus-producing areas in Brazil.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Sao Paulo, Escola Super Agr Luiz Queiroz, BR-13418900 Piracicaba, SP, BrazilUniv Florida, Gulf Coast Res & Educ Ctr, Wimauma, FL 33598 USASao Paulo State Univ, Campus Expt Registro, Registro, SP, BrazilFundo Defesa Citricultura Res & Dev, BR-14807040 Araraquara, SP, BrazilSao Paulo State Univ, Campus Expt Registro, Registro, SP, BrazilCNPq: 2015/06007-2Amer Phytopathological SocUniversidade de São Paulo (USP)Univ FloridaUniversidade Estadual Paulista (Unesp)Fundo Defesa Citricultura Res & DevGama, Andre B.Baggio, Juliana S.Rebello, Carolina S.Lourenco, Silvia de AfonsecaGasparoto, Maria Candida de G. [UNESP]Silva Junior, Geraldo Jose daPeres, Natalia A.Amoriml, Lilian2020-12-10T20:00:22Z2020-12-10T20:00:22Z2020-06-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article1621-1628http://dx.doi.org/10.1094/PDIS-10-19-2195-REPlant Disease. St Paul: Amer Phytopathological Soc, v. 104, n. 6, p. 1621-1628, 2020.0191-2917http://hdl.handle.net/11449/19691710.1094/PDIS-10-19-2195-REWOS:000535836200009Web of Sciencereponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengPlant Diseaseinfo:eu-repo/semantics/openAccess2024-05-03T13:19:55Zoai:repositorio.unesp.br:11449/196917Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T15:03:50.233665Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Sensitivity of Colletotrichum acutatum Isolates from Citrus to Carbendazim, Difenoconazole, Tebuconazole, and Trifloxystrobin |
title |
Sensitivity of Colletotrichum acutatum Isolates from Citrus to Carbendazim, Difenoconazole, Tebuconazole, and Trifloxystrobin |
spellingShingle |
Sensitivity of Colletotrichum acutatum Isolates from Citrus to Carbendazim, Difenoconazole, Tebuconazole, and Trifloxystrobin Gama, Andre B. postbloom fruit drop fungicide resistance baseline |
title_short |
Sensitivity of Colletotrichum acutatum Isolates from Citrus to Carbendazim, Difenoconazole, Tebuconazole, and Trifloxystrobin |
title_full |
Sensitivity of Colletotrichum acutatum Isolates from Citrus to Carbendazim, Difenoconazole, Tebuconazole, and Trifloxystrobin |
title_fullStr |
Sensitivity of Colletotrichum acutatum Isolates from Citrus to Carbendazim, Difenoconazole, Tebuconazole, and Trifloxystrobin |
title_full_unstemmed |
Sensitivity of Colletotrichum acutatum Isolates from Citrus to Carbendazim, Difenoconazole, Tebuconazole, and Trifloxystrobin |
title_sort |
Sensitivity of Colletotrichum acutatum Isolates from Citrus to Carbendazim, Difenoconazole, Tebuconazole, and Trifloxystrobin |
author |
Gama, Andre B. |
author_facet |
Gama, Andre B. Baggio, Juliana S. Rebello, Carolina S. Lourenco, Silvia de Afonseca Gasparoto, Maria Candida de G. [UNESP] Silva Junior, Geraldo Jose da Peres, Natalia A. Amoriml, Lilian |
author_role |
author |
author2 |
Baggio, Juliana S. Rebello, Carolina S. Lourenco, Silvia de Afonseca Gasparoto, Maria Candida de G. [UNESP] Silva Junior, Geraldo Jose da Peres, Natalia A. Amoriml, Lilian |
author2_role |
author author author author author author author |
dc.contributor.none.fl_str_mv |
Universidade de São Paulo (USP) Univ Florida Universidade Estadual Paulista (Unesp) Fundo Defesa Citricultura Res & Dev |
dc.contributor.author.fl_str_mv |
Gama, Andre B. Baggio, Juliana S. Rebello, Carolina S. Lourenco, Silvia de Afonseca Gasparoto, Maria Candida de G. [UNESP] Silva Junior, Geraldo Jose da Peres, Natalia A. Amoriml, Lilian |
dc.subject.por.fl_str_mv |
postbloom fruit drop fungicide resistance baseline |
topic |
postbloom fruit drop fungicide resistance baseline |
description |
Postbloom fruit drop (PFD) of citrus is caused by the Colletotrichum acutatum and C. gloeosporioides species complexes. The disease is important when frequent rainfall occurs during the flowering period of citrus trees. In Brazil, until 2012, PFD was mainly controlled by preventive applications of the methyl-benzimidazole carbamate (MBC) carbendazim and demethylation-inhibitor (DMI) fungicides such as difenoconazole. Since then, mixtures containing the DMI tebuconazole and the quinone-outside inhibitor (QoI) trifloxystrobin have been commonly used. Fungicides are often applied preventively, sometimes even when conditions are not conducive for PFD development. Excessive fungicide applications may favor the selection of resistant populations of Colletotrichum spp. In this study, we assessed the fungicide sensitivity of C. acutatum isolates collected during the two distinct periods of PFD management in Brazil: before and after the trifloxystrobin and tebuconazole mixture became widely employed. The sensitivity of 254 C. acutatum isolates to carbendazim and difenoconazole and of 164 isolates to tebuconazole and trifloxystrobin was assessed. Mycelial growth inhibition of these isolates was evaluated for all the fungicides using either serial dilution of fungicide rates or the spiral gradient dilution method. In addition, inhibition of conidial germination was also assessed for trifloxystrobin. Analysis of partial beta-tub, cytb, and cyp51b gene sequences did not reveal any mutations related to resistance to MBCs, QoIs, and DMIs, respectively. In mycelia] growth assays, mean EC50 values were 0.14, 0.11, and 0.21 mu g/ml for difenoconazole, tebuconazole, and trifloxystrobin, respectively. The conidial germination inhibition by trifloxystrobin was similar among the tested isolates, and the mean EC50 value was 0.002 mu g/ml. All isolates had similar mean mycelial growth inhibition for carbendazim, regardless of the fungicide concentrations. Therefore, based on similar EC50 values and molecular analyses, no shift in the sensitivity of isolates has been observed to the fungicides commonly used in different citrus-producing areas in Brazil. |
publishDate |
2020 |
dc.date.none.fl_str_mv |
2020-12-10T20:00:22Z 2020-12-10T20:00:22Z 2020-06-01 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1094/PDIS-10-19-2195-RE Plant Disease. St Paul: Amer Phytopathological Soc, v. 104, n. 6, p. 1621-1628, 2020. 0191-2917 http://hdl.handle.net/11449/196917 10.1094/PDIS-10-19-2195-RE WOS:000535836200009 |
url |
http://dx.doi.org/10.1094/PDIS-10-19-2195-RE http://hdl.handle.net/11449/196917 |
identifier_str_mv |
Plant Disease. St Paul: Amer Phytopathological Soc, v. 104, n. 6, p. 1621-1628, 2020. 0191-2917 10.1094/PDIS-10-19-2195-RE WOS:000535836200009 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Plant Disease |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
1621-1628 |
dc.publisher.none.fl_str_mv |
Amer Phytopathological Soc |
publisher.none.fl_str_mv |
Amer Phytopathological Soc |
dc.source.none.fl_str_mv |
Web of Science reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1808128453564694528 |