Susceptibility of Pericopsis elata (Assamela) to heartwood decay and identification of micro and macro fungi associated with the disease in Cameroon

Heartwood decay is one of the major pathological constraints affecting the quality and marketable volume of tropical timber. A study on its behavior was conducted on Pericopsis elata in order to contribute to its sustainable management in Cameroon. Tree susceptibility to heartwood decay was evaluated using three diameter classes, based on allometric equations between decayed and healthy trees. Wood samples and visible macromycetes were taken from living and felled trees with an auger. Isolation of microfungi was performed on potato dextrose agar medium and their identification was based on the morphological and microscopic characteristics of the mycelium and conidia with reference to identification keys of mycology. Identification of macromycetes was based on their morphological characteristics as described in reference books on macromycetes identification. Results show that diameter class ]110, 120[ presented highly significant (P<0.05) volume loss (3755.96 cm3), followed by diameter class ]100, 110[. Microfungi frequently associated with heartwood decay of P. elata were Cercospora sp (24.57%), Fusarium oxysporum (12.64%) and Penicillium sp (12.58%) in living decay trees and Aspergillus niger (25.19%), Cercospora sp (22.21%), Penicillium sp (17.69%) and Phoma sp (15.05%) in felled decay trees. Macrofungi associated with living trees were Inonotus sp and Ganoderma sp. This is the first time that these fungal species are reported on P. elata wood. This study provides baseline information for the study of heartwood decay and management of P. elata in Cameroon.