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Cryphonectriaceae endophytes in Melastomataceae: latent pathogens in hiding

Michael J. Wingfield: Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria

<div>Species of Cryphonectriaceae can occur as asymptomatic fungal endophytes in Melastomataceae trees and shrubs. These fungi pose threats to biosecurity because they cannot easily be detected by conventional routine quarantine inspections. Host switches in the Cryphonectriaceae have been shown to occur between species of Myrtales including the Myrtaceae and Melastomataceae. The aim of this study was to identify the species of Cryphonectriaceae that occur in the asymptomatic tissues of four native and two introduced species of Melastomataceae that naturally occur alongside <em>Eucalyptus </em>(Myrtaceae) plantations in Colombia. Healthy branch segments were collected in five provinces of Colombia and incubated for two to four weeks to promote sporulation of endophytes. Fruiting bodies of Cryphonectriaceae that emerged were isolated and identified based on DNA sequence data for two gene regions. Three species were identified including <em>Aurapex penicillata</em>, <em>Chrysoporthe cubensis </em>and <em>C. inopina</em>. The results showed that a relatively large number of species of Melastomataceae are hosts of the Cryphonectriaceae in Colombia. Some of these such as <em>C. cubensis</em> are already emerging as important pathogens of <em>Eucalyptus</em> in that country. Importantly, the risks involved in moving plant tissue with endophytes of the Melastomataceae is high, as they act as reservoirs of aggressive pathogens of Myrtaceae in plantations and natural woody ecosystems.</div>