ABSTRACT
The occurrence of a leaf spot disease of carnation caused by Burkholderia andropogonis is recorded for the first time in Portugal. Symptoms consisted of ‘eyespot’ lesions on all aerial plant parts, often bordered by water-soaked halos on the leaves. As the disease progressed lesions became dark brown and affected areas dried out. Phenotypic studies and Polymerase Chain Reaction using specific primers Pf/Pr targeted to 16S rDNA of B. andropogonis were used to identify the pathogen. Pathogenicity tests on china pink plants, re-isolation of the pathogen from inoculated plants and further PCR testing confirmed the identification of the bacterium. Infected plants came from an open air nursery and the whole production was destroyed to avoid dissemination of the pathogen.
Key-words: Leaf spot of carnation; Dianthus caryophyllus; first record.
]]> RESUMO
A ocorrência da mancha bacteriana do craveiro causada por Burkholderia andropogonis é pela primeira vez assinalada em Portugal. Os sintomas observados consistiam em manchas em forma de olho-de-perdiz em todos os órgãos aéreos das plantas afectadas, frequentemente circundadas por halos hidrópicos nas folhas. À medida que a doença progredia, as lesões adquiriam uma coloração castanha escura, acabando os órgãos afectados por secar. A identificação do agente causal da doença baseou-se no estudo dos seus caracteres fenotípicos e na Reacção em Cadeia da Polimerase (PCR), utilizando os iniciadores específicos Pf/Pr dirigidos à região 16S rDNA de B. andropogonis. A identificação foi confirmada por ensaios de patogenicidade em cravinas, reisolamento do agente causal da doença a partir das plantas inoculadas e novos ensaios PCR. As plantas infectadas provinham de um viveiro ao ar livre e toda a produção foi destruída a fim de evitar a disseminação do patogéneo.
Palavras-chave: Mancha bacteriana do craveiro; Dianthus caryophyllus; primeira detecção.
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1Instituto Nacional de Recursos Biológicos. Tapada da Ajuda, Edifício 1, 1349-018 Lisboa, Portugal. Corresponding author: madalenaeloy@dgpc.min-agricultura.pt, Comunicação apresentada no 5º Congresso da Sociedade Portuguesa de Fitopatologia, Coimbra, 2007
Recepção/Reception: 2008.02.19 aceitação/acception: 2008.07.22
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