Publicação
Canker and Dieback diseases or Eucalyptus in Portugal
| Resumo: | Native of Australia, eucalypts are one of the most planted forest trees in the world due to their fast growth rate and adaptability to different environments. They were introduced into Portugal over 100 years ago, and presently represent 26% of the forest area. Their use is mainly for pulp and paper production, representing a very important economic activity. Until a few decades ago, they were relatively free of pests and diseases. Since the 1990s, a leaf disease caused by species of Mycosphaerella and Teratosphaeria have caused severe defoliation in young plantations in several areas in the country. Since then, other diseases, such as canker and dieback, became more frequent. This situation also occurred in other areas of the world where eucalypts are planted as exotic species. Although difficult to determine, several factors can contribute to these emerging diseases such as climate change, introduction of new pathogens or hosts shifts of pathogen from native species. To identify the fungi associated with these diseases, a national survey was conducted and samples from diseases trees collected. The fungi associated with the symptoms were identified using classical morphological methods and biomolecular techniques and their pathogenicity tested in controlled conditions. As a result of this survey, two new pathogen of eucalypts, Quambalaria eucalypti and Phytophthora alticola, were reported for the first time in Portugal and in the Northern Hemisphere. An account of the diversity and pathogenicity of Botryosphaeriaceae species associated with eucalypts and its possible host shift with cork oak, another important species of Portuguese forests, was also investigated. During this study, a new nursery disease associated with Neopestalotiopsis species was characterized and five species of this genus described as new. The results reported in this thesis are of paramount importance to take measures to avoid the spread and damage caused by these diseases. Among others, the most efficient measure to control fungal disease in forests is breeding for resistance. Since these are emergent diseases, they were not previously included in the breeding programs of eucalypts. Another possible tool is biological control. Although very successful in the control of forest pests, it is a new area to be developed for fungi causing diseases in forest. |
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| Autores principais: | Diogo, Eugénio Luís Fraga |
| Assunto: | Emergent forest diseases Neopestalotiopsis species Pathogenicity Phytophthora alticola Quambalaria eucalypti |
| Ano: | 2022 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade Nova de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório Institucional da UNL |
| Resumo: | Native of Australia, eucalypts are one of the most planted forest trees in the world due to their fast growth rate and adaptability to different environments. They were introduced into Portugal over 100 years ago, and presently represent 26% of the forest area. Their use is mainly for pulp and paper production, representing a very important economic activity. Until a few decades ago, they were relatively free of pests and diseases. Since the 1990s, a leaf disease caused by species of Mycosphaerella and Teratosphaeria have caused severe defoliation in young plantations in several areas in the country. Since then, other diseases, such as canker and dieback, became more frequent. This situation also occurred in other areas of the world where eucalypts are planted as exotic species. Although difficult to determine, several factors can contribute to these emerging diseases such as climate change, introduction of new pathogens or hosts shifts of pathogen from native species. To identify the fungi associated with these diseases, a national survey was conducted and samples from diseases trees collected. The fungi associated with the symptoms were identified using classical morphological methods and biomolecular techniques and their pathogenicity tested in controlled conditions. As a result of this survey, two new pathogen of eucalypts, Quambalaria eucalypti and Phytophthora alticola, were reported for the first time in Portugal and in the Northern Hemisphere. An account of the diversity and pathogenicity of Botryosphaeriaceae species associated with eucalypts and its possible host shift with cork oak, another important species of Portuguese forests, was also investigated. During this study, a new nursery disease associated with Neopestalotiopsis species was characterized and five species of this genus described as new. The results reported in this thesis are of paramount importance to take measures to avoid the spread and damage caused by these diseases. Among others, the most efficient measure to control fungal disease in forests is breeding for resistance. Since these are emergent diseases, they were not previously included in the breeding programs of eucalypts. Another possible tool is biological control. Although very successful in the control of forest pests, it is a new area to be developed for fungi causing diseases in forest. |
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