Morphological,molecular phylogenetic and pathogenic analyses of Erysiphe spp. causing powdery mildew on cashew plants in Brazil |
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| Authors: | W L Fonseca J E Cardoso M A Ootani S O S Brasil F S Assunção C S Lima F M P Viana C R Muniz I L Andrade M V V Martins |
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| Institution: | 1. Departamento de Fitotecnia, Universidade Federal do Ceará, CEP 60356-001 Fortaleza, CE, Brazil;2. Laboratório de Fitopatologia, Embrapa Agroindústria Tropical, Caixa Postal 3761, CEP 6060511-110 Fortaleza, CE, Brazil;3. Laboratório de Bioprocessos, Centro de Tecnologias Estratégicas do Nordeste, CEP 50740-540 Recife, PE, Brazil |
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| Abstract: | Cashew powdery mildew is presently the most important disease of cashew trees in all Brazilian growing regions. Although it was described over a century ago, it had never threatened the Brazilian cashew industry until the first decade of the 21st century. Morphological and pathogenic evidence indicated the possibility of different pathogen species being involved in early and late types of cashew powdery mildew. This study was designed to elucidate this issue by comparing two different powdery mildew fungi occurring on cashew plants in Brazil according to the morphological characteristics, phylogenetic relationships with closely related powdery mildew fungi and pathogenic relationships. Based on morphology, molecular phylogenetics and pathogenicity on cashew, it was shown that two species of powdery mildew specimens are without question associated with cashew trees. One species, which infects young immature tissues such as shiny leaves, flowers and young fruits, is Erysiphe quercicola, while Erysiphe necator is associated exclusively with mature leaves. This is the first report of both E. quercicola and E. necator causing cashew powdery mildew, and the first detection of E. necator on cashew. |
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| Keywords: | 28S rDNA Anacardium occidentale Erysiphe necator Erysiphe quercicola internal transcribed spacer sequences |
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