Notes on Ceratocystis paradoxa causing internal post-harvest rot disease on immature coconut in Brazil

Abstract

Currently there is a large and increasing demand for immature coconuts for fresh consumption of their liquid endosperm (coconut water). The occurrence of post-harvest diseases prevent its sale and change the taste, making it inappropriate for consumption. In 2011, coconut fruits showing internal post-harvest rot symptoms were found in a market in Belo Horizonte and after incubation for 5 days in a humid chamber at room temperature, fungal structures were observed. Fruiting structures show morphology typical of Ceratocystis paradoxa. For molecular identification, DNA sequences were generated for the Internal Transcribed Spacer regions 1 and 2 including the 5.8S rRNA gene, part of the β-tubulin and the Transcription Elongation Factor 1-α gene regions. These data were compared with those of other C. paradoxa using phylogenetic analysis. Koch's postulates was confirmed by inoculation of 6-mm-diameter PDA plugs with the isolate on fruits of coconut. Morphology of the isolates in culture as well as phylogenetic inference showed that the causal agent of internal post-harvest rot disease on coconut is C. paradoxa. © Brazilian Phytopathological Society.