A new genus of Magnaporthaceae (Ascomycota) causing take-all disease on Paspalum guenoarum in Brazil

• Ano de defesa: 2020
• Autor(a) principal: Custódio, Fábio Alex
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa; Fitopatologia
• Palavras-chave em Português: Raízes (Botânica) - Doenças e pragas; Fungos de solo; Gaeumannomyces; Fitopatologia
• Link de acesso: https://locus.ufv.br//handle/123456789/30051

In Brazil, Paspalum species are commonly utilized in sports lawns, landscape projects and specially as forage for livestock. Paspalum guenoarum plants showing symptoms of take-all disease were observed in the state of Rio Grande do Sul, Brazil. The fungus Gaeumanomyces graminis is the only species reported associated with this disease on Paspalum. In recent years, new species of Gaeumannomyces have been proposed based on molecular studies, demonstrating the existence of a species complex. In Brazil, take-all is reported on rice and wheat plants, however, the etiology of this disease on P. guenoarum plants is still unknown. Due to the lack of suitable diagnostic studies up to now, this work aimed to elucidate the etiology of the take-all on P. guenoarum in Brazil, and evaluate possible alternative hosts of agricultural importance. Based on combined phylogenetic analyses of ITS, LSU, TEF-1α, and RPB1 a new genus belonging to the family Magnaporthaceae was identified and it will be proposed in accordance with the International Code of Nomenclature for algae, fungi and plantae. A representative isolate was inoculated on healthy P. guenoarum plants and reproduced the same symptoms of take-all observed in the field. Furthermore, this fungus also is able to cause take-all on wheat plants and temperature directly affects the development of the disease in this crop. Take-all on Paspalum guenoarum in Brazil is caused by a new genus belonging the family Magnaporthaceae. Keywords: Gaeumannomyces. Root disease. Root rot. Soil fungi.