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Abstract(s)
Após a colheita da castanha (Castanea sativa Mill.), a maior preocupação das unidades de processamento é o controlo de agentes de deterioração, incluindo os fungos causadores de podridões. Atualmente, o fungo Gnomoniopsis smithogilvyi, agente causal da podridão castanha, tornou-se o principal causador de perdas de castanha em toda a Europa. Os objetivos deste trabalho foram: i) Analisar in vitro a atividade de um biofungicida comercial e de bactérias isoladas em laboratório no controlo dos agentes causais das podridões da castanha, em particular G. smithogilvyi; ii) Identificar a(s) bactéria(s) com potencial de controlo; iii) Estudar o modo de ação dos agentes selecionados contra G. smithogilvyi. Para tal, foram testados como potenciais agentes de controlo os produtos comerciais Serenade® ASO (Bacillus amyloliquefaciens) e Codasil® (solução de silício), e três isolados bacterianos. Como controlo positivo foi usado o fungicida Horizon® (Tebuconazol). Verificou-se que Serenade® ASO, Horizon® e a bactéria BCA1 tiveram efeito de controlo contra G. smithogilvyi, Trichoderma viridescens, Penicillium brevicompactum, Penicillium expansum, Mucor racemous e Ciboria batschiana. Codasil® estimulou o crescimento dos fungos. A bactéria BCA1 foi selecionada como potencial agente de biocontrolo, e foi identificada por métodos moleculares como B. amyloloquefaciens. Foram observados nos resultados do halo de inibição, que o agente químico Horizon® apresentou maior inibição do fungo que os tratamentos com agentes de controlo biológico (Serenade® ASO e BCA1). Porém os agentes biológicos causaram um desenvolvimento celular do fungo diferente quando comparado aos outros tratamentos. Na análise metabolómica, foi detectada a presença de Diplodiatoxina, uma toxina que em grandes quantidades causa problemas para saúde do consumidor. Este estudo é o primeiro, a associar o fungo G. smithogilvyi à produção desta importante toxina, o que permite concluir que o patógeno, não é só responsável por elevadas perdas na produção de castanha, como também põe em risco a saúde e a segurança do consumo de castanhas contaminadas. Sendo assim, o estudo do uso e identificação de agentes biológicos que controlem a podridão da castanha causada por G. smithogilvyi, bem como avaliação e aplicação do uso em armazenamento de pós colheita devem ser avaliados, a fim de proporcionar alternativas biológicas eficazes de controle deste fungo.
After the chestnut (Castanea sativa Mill.) is harvested, the main concern of the processing units is the control of spoilage agents, including rot-causing fungi. Currently, the fungus Gnomoniopsis smithogilvyi, the causal agent of chestnut brown rot, has become the main cause of chestnut losses throughout Europe. The objectives of this work were: i) To analyze in vitro the activity of a commercial biofungicide and bacteria isolated in the laboratory in the control of the causal agents of chestnut rot, in particular, G. smithogilvyi; ii) Identify the bacterium(a) with potential control; iii) Study the mode of action of selected agents against G. smithogilvyi. For this, the commercial products Serenade® ASO (Bacillus amyloliquefaciens) and Codasil® (silicon solution) and three bacterial isolates were tested as potential control agents. As a positive control, the fungicide Horizon® (Tebuconazole) was used. Serenade® ASO, Horizon®, and the bacterium BCA1 were found to have a controlling effect against G. smithogilvyi, Trichoderma viridescens, Penicillium brevicompactum, Penicillium expansum, Mucor racemous and Ciboria batschiana. Codasil® stimulated fungal growth. The BCA1 bacterium was selected as a potential biocontrol agent and was identified by molecular methods as B. amyloloquefaciens. It was observed in the inhibition halo results that the chemical agent Horizon® showed greater inhibition of the fungus than treatments with biological control agents (Serenade® ASO and BCA1). However, the biological agents caused a different cellular development of the fungus when compared to the other treatments. The metabolomic analysis, was detected, a presence of Diplodiatoxin, a toxin that in large quantities causes problems for consumer health. This study is the first to associate the fungus G. smithogilvyi with the production of this important toxin, which allows us to conclude that the pathogen is not only responsible for high losses in chestnut production, but also puts health and safety at risk to the consumption of contaminated nuts. Therefore, the study of the use and identification of biological agents that control the brown rot caused by G. smithogilvyi, as well as the evaluation and application of the use in post-harvest storage should be evaluated, in order to provide effective biological alternatives to control this disease. fungus.
After the chestnut (Castanea sativa Mill.) is harvested, the main concern of the processing units is the control of spoilage agents, including rot-causing fungi. Currently, the fungus Gnomoniopsis smithogilvyi, the causal agent of chestnut brown rot, has become the main cause of chestnut losses throughout Europe. The objectives of this work were: i) To analyze in vitro the activity of a commercial biofungicide and bacteria isolated in the laboratory in the control of the causal agents of chestnut rot, in particular, G. smithogilvyi; ii) Identify the bacterium(a) with potential control; iii) Study the mode of action of selected agents against G. smithogilvyi. For this, the commercial products Serenade® ASO (Bacillus amyloliquefaciens) and Codasil® (silicon solution) and three bacterial isolates were tested as potential control agents. As a positive control, the fungicide Horizon® (Tebuconazole) was used. Serenade® ASO, Horizon®, and the bacterium BCA1 were found to have a controlling effect against G. smithogilvyi, Trichoderma viridescens, Penicillium brevicompactum, Penicillium expansum, Mucor racemous and Ciboria batschiana. Codasil® stimulated fungal growth. The BCA1 bacterium was selected as a potential biocontrol agent and was identified by molecular methods as B. amyloloquefaciens. It was observed in the inhibition halo results that the chemical agent Horizon® showed greater inhibition of the fungus than treatments with biological control agents (Serenade® ASO and BCA1). However, the biological agents caused a different cellular development of the fungus when compared to the other treatments. The metabolomic analysis, was detected, a presence of Diplodiatoxin, a toxin that in large quantities causes problems for consumer health. This study is the first to associate the fungus G. smithogilvyi with the production of this important toxin, which allows us to conclude that the pathogen is not only responsible for high losses in chestnut production, but also puts health and safety at risk to the consumption of contaminated nuts. Therefore, the study of the use and identification of biological agents that control the brown rot caused by G. smithogilvyi, as well as the evaluation and application of the use in post-harvest storage should be evaluated, in order to provide effective biological alternatives to control this disease. fungus.
Description
Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do Paraná
Keywords
Podridões pós colheita Podridão castanha Gnomoniopsis smithogilvyi Biocontrolo