Podridao do fruto de cacau (Theobroma cacao L.) causada por Phomopsis folliculicola em Pernambuco
In June 1997 fruits of cacao with brown rot were collected on the Campus of the Universidade Federal Rural de Pernambuco. Small pieces of decayed fruits were aseptically removed from the area of transition between healthy and diseased tissue, surface-sterilized and plated on potato-dextrose agar (PDA). The isolated fungus initially developed a white colony which became greyish with age and produced abundant pycnidia containing both a and a conidia. Pathogenicity of the isolate was tested by wound inoculating cacao fruits and leaves with 4-mm-diameter plugs of 14 days-old mycelium from PDA. The inoculated fruits were kept in moist chamber for 96 hr. Control fruits were inoculated with PDA disks only. Typical symptoms and signals of the pathogen on fruits were observed nine days after inoculation, represented by dark brown necrotic lesions. The pathogen was reisolated from necrotic tissues and subcultured in PDA, fulfilling Koch's postulates. Symptoms did not develop on the leaves until eight days after inoculation. The cultural and morphological characteristics of this pathogen of cacao match with the characteristics of Phomopsis folliculicola Punithalingam, producing solitary or agregated, mostly unilocular brown to black stromatic pycnidia 0,6-(0,8)-1 mm x 0,5-(0,7)-1 mm. The Ó conidia (phialospores) were hyaline, one-celled, fusiform to ellipsoid, 2-gutulate, 7,5-(9)-12,5 um. The Ó conidia (phialospores) were hyaline, uncellular, filliform, mostly curved at one side, 15-(19,4)-25 um x 1,25 um. This is the first report of Phomopsis folliculicola causing pod rot of cacao in Brazil.
| Main Authors: | , , , , , |
|---|---|
| Format: | biblioteca |
| Published: |
Ene-
|
| Subjects: | THEOBROMA CACAO, PHOMOPSIS FOLLICULICOLA, AISLAMIENTO, ENFERMEDADES FUNGOSAS, PODREDUMBRES, PERNAMBUCO, BRASIL, |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|