Pathogenicity of Chrysoporthe deuterocubensis and Myrtoporthe bodenii gen. et sp. nov. on Eucalyptus in Sabah, Malaysia

Abstract

The Cryphonectriaceae (Diaporthales, Ascomycota) is an important family of fungi including endophytes and pathogens. These fungi cause cankers on trees and can shift hosts between genera and families in the Myrtales. They represent an understudied group in Southeast Asia, where species of Eucalyptus are grown for plantation forestry. Cankers on species of Eucalyptus were surveyed in Sabah, Malaysia, and their causal agents identified. Two species in the Cryphonectriaceae were isolated from Eucalyptus grandis in the Sipitang and Tawau provinces. These fungi were identified based on morphology and a phylogenetic species hypothesis using the internal transcribed spacer regions, the large subunit regions of ribosomal DNA, and the β–tubulin 1 and 2 gene regions. One species identified as Chrysoporthe deuterocubensis is a first report for Malaysia. The other species represented a new taxon, named here as Myrtoporthe bodenii gen. et sp. nov. Pathogenicity tests showed that both Chr. deuterocubensis and M. bodenii were pathogenic to E. grandis and E. deglupta and that M. bodenii is pathogenic to E. pellita. Myrtoporthe bodenii was equally as pathogenic as the well-known canker pathogen Chr. deuterocubensis and it should be regarded as a biosecurity concern.