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Abstract(s)
A oliveira é uma cultura muito importante para a região do Mediterrâneo e Península Ibérica. Todavia, na última década, tem-se observado um aumento de incidência de potenciais novas doenças e de doenças comuns desta cultura, tais como a Tuberculose, que causam elevadas perdas ao nível da produção. O presente estudo pretende ser um primeiro contributo para: i) o conhecimento de potenciais novas doenças da oliveira e dos seus agentes causais; ii) a identificação de um novo meio de luta biológico contra a tuberculose da oliveira. Assim, de forma a atingir o primeiro objetivo, começou-se por descrever novas lesões que ocorrem com elevada incidência em ramos, folhas e frutos de oliveiras na região de Mirandela, e por caracterizar a comunidade fúngica que lhe está associada com o intuito de identificar potenciais agentes causais destas lesões. Para atingir o segundo objetivo, avaliou-se o efeito da aplicação de um consórcio de microrganismos endófitos, obtido de oliveiras centenárias com tolerância à tuberculose, na incidência e severidade da tuberculose em plântulas de oliveira. Os resultados obtidos permitiram identificar um total de sete lesões diferentes, a maioria das quais em folhas, podendo cada uma delas corresponder a uma potencial nova doença. Em três destas lesões foi identificada a presença exclusiva de espécies fúngicas (Neofabraea vagabunda, Botrytis sp., Phoma macrostoma e Cytospora pruinosa), sugerindo tratarem-se de potenciais agentes causais destas lesões. Este resultado necessita, contudo, de confirmação. A aplicação do consórcio de microrganismos endófitos em plântulas de oliveira permitiu reduzir significativamente a incidência e a severidade da tuberculose face às plantas inoculadas exclusivamente com o agente causal desta doença, Pseudomonas savastanoi pv. savastanoi. Este efeito benéfico da microbiota na oliveira revelou ser superior quando a inoculação com a microbiota ocorria previamente à inoculação com o patogénico. A utilização desta microbiota endófita poderá constituir uma estratégia inovadora na luta biológica contra a tuberculose, e cujo mecanismo de ação deverá ser estudado no futuro.
The olive tree is an important crop for the Mediterranean countries, including the Iberian Peninsula. However, in the last decade, there has been an increase in the incidence of potential new diseases and common diseases of this crop, such as olive knot, which cause high yield losses. This study intends to be a first contribution to: i) the knowledge of potential new diseases of the olive tree and its causal agents; (ii) the identification of a new biological control method against olive knot disease. Thus, in order to reach the first objective, we began to describe new lesions that occur with high incidence in branches, leaves and fruits of olive trees in the region of Mirandela, and to characterized the fungal community associated with it in order to identify potential causal agents of these lesions. In order to reach the second objective, the effect of the application of a consortium of endophytic microorganisms, obtained from centennial olive trees with tolerance to olive knot, on the incidence and severity of olive knot in olive tree seedlings was evaluated. Overall, a total of seven different lesions, most of them in leaves, were identified. Each of these lesions could correspond to a potential new disease. Some fungal species (Neofabraea vagabunda, Botrytis sp., Phoma macrostoma and Cytospora pruinosa) were found to be unique to a specific lesion, suggesting that they are potential causal agents of these lesions. This result requires, however, confirmation. The application of the consortium of endophytic microorganisms in olive tree seedlings reduced significantly both the incidence and severity of olive knot, when compared to plants inoculated exclusively with the causal agent of this disease, Pseudomonas savastanoi pv. savastanoi. This beneficial effect of the microbiota on the olive tree was shown to be highest when inoculation with the microbiota occurred prior to inoculation with the pathogen. The use of this endophyte microbiota could be an innovative strategy in the biological fight against tuberculosis, and its mechanism of action should be studied in the future.
The olive tree is an important crop for the Mediterranean countries, including the Iberian Peninsula. However, in the last decade, there has been an increase in the incidence of potential new diseases and common diseases of this crop, such as olive knot, which cause high yield losses. This study intends to be a first contribution to: i) the knowledge of potential new diseases of the olive tree and its causal agents; (ii) the identification of a new biological control method against olive knot disease. Thus, in order to reach the first objective, we began to describe new lesions that occur with high incidence in branches, leaves and fruits of olive trees in the region of Mirandela, and to characterized the fungal community associated with it in order to identify potential causal agents of these lesions. In order to reach the second objective, the effect of the application of a consortium of endophytic microorganisms, obtained from centennial olive trees with tolerance to olive knot, on the incidence and severity of olive knot in olive tree seedlings was evaluated. Overall, a total of seven different lesions, most of them in leaves, were identified. Each of these lesions could correspond to a potential new disease. Some fungal species (Neofabraea vagabunda, Botrytis sp., Phoma macrostoma and Cytospora pruinosa) were found to be unique to a specific lesion, suggesting that they are potential causal agents of these lesions. This result requires, however, confirmation. The application of the consortium of endophytic microorganisms in olive tree seedlings reduced significantly both the incidence and severity of olive knot, when compared to plants inoculated exclusively with the causal agent of this disease, Pseudomonas savastanoi pv. savastanoi. This beneficial effect of the microbiota on the olive tree was shown to be highest when inoculation with the microbiota occurred prior to inoculation with the pathogen. The use of this endophyte microbiota could be an innovative strategy in the biological fight against tuberculosis, and its mechanism of action should be studied in the future.
Description
Mestrado de dupla diplomação com a Universidade Federal do Recôncavo da Bahia
Keywords
Luta biológica Comunidade microbiana Oliveira Novas doenças