Species of Cryphonectriaceae occupy an endophytic niche in the Melastomataceae and are putative latent pathogens of Eucalyptus

Species of Cryphonectriaceae can occur as asymptomatic fungal endophytes in Melastomataceae trees and shrubs. One hypothesis suggests Chrysoporthe cubensis (Cryphonectriaceae) is an endophyte of the Melastomataceae that has undergone a host switch to infect species of Eucalyptus in South America. The potential for similar host switches by other species of the Cryphonectriaceae is exacerbated by native stands of Melastomataceae that grow alongside commercial plantations of Eucalyptus. We sought to determine the diversity of Cryphonectriaceae endophytic in Melastomataceae trees that occur naturally adjacent to Eucalyptus plantations in Colombia. Branch segments were taken from six different species in three genera of the Melastomataceae. A technique that simulated natural conditions was used to promote fruiting of endophytic Cryphonectriaceae. Taxa were identified using a phylogenetic species concept based on sequence data from the internal transcribed spacer and β-tubulin gene regions. Three species of Cryphonectriaceae, Aurapex penicillata, C. cubensis and C. inopina, were identified. We tested whether these endophytes were potential pathogens of Eucalyptus, and each species was mildly pathogenic. The results showed that at least six species of Melastomataceae are hosts of the Cryphonectriaceae in Colombia. They also emphasize the biosecurity risk of moving superficially healthy stem tissue of the Melastomataceae to new environments.