In vitro wood decay of teak (Tectona grandis) by Rigidoporus cf. microporus (Meripiliaceae, Polyporales, Basidiomycota)

Abstract

The use of exotic species like teak for industry demands has increased over the last decades in Central America, however its vulnerability to decay by saprophytic fungi has not been well studied. Among these fungi, Rigidoporus spp. have been described as white rotters of dead hardwoods and conifers worldwide. In Costa Rica, R. microporus has been found growing on teak stumps. The aim of this study was to determine the effects of this white rot fungus on the chemical, mechanical and physical properties of teak wood from trees of different ages. Six and ten year old sapwood and heartwood samples were used in the assays. Severe anatomical damage and the highest weight and resistance losses were observed on 6 yr. old sapwood samples. There was an increase in the quantity of soluble materials in 1% NaOH (relative values) and lignin content in all the samples analyzed, after 3 months exposure and up to the end of the experiment. Mass loss reduction and increased resistance of wood to compressive strength parallel to the grain were related to both the type of wood and the age of the tree. Knowledge of the potential damage that this fungus can cause to teak wood might help in a better selection of wood and developing more effective protection measures against decay in the field or in construction wood.