Wood Decay By Inonotus Rickii and Bjerkandera Adusta: A Micro- And Ultra-Structural Approach

Abstract

Bjerkandera adusta (Willd.) P. Karst. and Inonotus rickii (Pat.) D.A. Reid. are important xylophagous fungi affecting street trees in Buenos Aires City, Argentina. The objective of this paper is to describe the decay patterns produced by these species in London plane wood (Platanus acerifolia (Ait.) Willd.), which is one of the most abundant tree species in the city, through light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). A better knowledge of the decay patterns of these fungi at early stages would provide useful information for optimizing tree management programs. Microscopic observations showed that B. adusta, having caused an important loss of dry weight, showed more extensive degradation of wood after three months than I. rickii, affecting mainly fiber walls with potential consequences in tree strength and stiffness. Inonotus rickii, on the other hand, selectively affected vessel walls and middle lamellae between fibers. Rays remained virtually unaltered in all decayed wood.