文摘
Fungal sporocarps and cultures associated with signs and symptoms of root-rot disease were collected from Acacia mangium and other tropical hardwood species. The collections were identified by either morphological characters and/or by phylogenetic analysis based on DNA sequences as Ganoderma philippii, G. mastoporum, G. aff. steyaertanum, G. australe and Amauroderma rugosum. Phylogenetic analysis unequivocally placed in the G. philippii clade four sequences amplified from A. mangium root and butt tissue showing clear signs of red root-rot disease (roots are covered by a red rhizomorphic skin). Whereas G. philippii was the most frequently encountered fungal species in A. mangium with red root-rot disease, this study indicates that other fungal species related to G. mastoporum may cause root-rot disease with very similar symptoms. An isolate (FRIM 138) that had caused red root-rot disease in artificial inoculations carried out before this study and was presumed to be G. philippii, is here determined to be closely related to G. mastoporum, G. cupreum and G. sinense. A Ganoderma species associated with a yellow-brown root-rot disease killing trees in an A. mangium plantation in Central Java, previously identified as G. lucidum, is shown by phylogenetic analysis to be closely related to G. steyaertanum, though some morphological characters vary from the original description of that species.