Podredumbre basal de plantas adultas de tomate causada por pythium aphanidermatum (Oomycota)

• Autores: Grijalba, Pablo Enrique; Zapata, Raúl Lorenzo; Palmucci, Hemilse Elena; Barón, Claudio Gabriel
• Año de publicación: 2015
• Idioma: español castellano
• Tipo de recurso: artículo
• Fuente: Boletín de la Sociedad Argentina de Botánica; Vol.50, no.1; 11-15; http://www.botanicargentina.com.ar/
• Materia: TOMATO; PYTHIUM APHANIDERMATUM; PYTHIUM; OOMYCETES; OOMYCETE; MYCELIUM (GENUS); LYCOPERSICON ESCULENTUM
• Institución: Universidad de Buenos Aires. Facultad de Agronomía

Fil: Grijalba, Pablo Enrique. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Fitopatología. Buenos Aires, Argentina.
Fil: Zapata, Raúl Lorenzo. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Fitopatología. Buenos Aires, Argentina.
Fil: Palmucci, Hemilse Elena. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Fitopatología. Buenos Aires, Argentina.
Fil: Barón, Claudio Gabriel. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Fitopatología. Buenos Aires, Argentina.
In roots of adult tomato plants a wet and brown lesion, extending 2-4 cm above the soil was observed. Diseased plants withered and died. The objective of this paper was to isolate and to identify the causal organism of these symptoms. General and selective culture media were used. After 24 hours colonies with white cottony mycelium were developed. The morphology of the colony and the production, morphology and size of reproductive structures were evaluated. The rDNA extraction was made from mycelium of pure cultures 7-10 days old grown in agarized media. The ITS region was amplified using ITS4 and ITS5 primers, sequenced and compared in gene bank - NCBI BLAST server to verify their sequence similarity to the type or holotype available. Coenocytic mycelium, spherical-globular sporangium and aplerotic oospores, characteristic of the genus Pythium were observed in microscopic slides. Pathogenicity tests were conducted with positive results; a microorganism identical to the original was re-isolated. The characterization achieved by traditional techniques, molecular studies and the results of the pathogenicity tests support the conclusion that Pythium aphanidermatum is the causal agent of basal rot on mature plants of tomato.