Infektion und Abbau des Wurzelholzes von Fichte durch Fomes annosus.

The paper describes the mode of infection and subsequent deterioration of spruce root wood by Forties annosus using light and electronmicroscopic observations. In the secondary xylem the overall penetration of cell walls is effected by means of microhyphae which produce boreholes. The degradation of cell walls is initiated in the S2 layer by diffusion of enzymes along the cellulose fibrils with subsequent hydrolysis of the amorphic incrusting substances.