ENVIRONMENTAL SCANNING ELECTRON-MICROSCOPIC OBSERVATION OF THE HYPHALSHEATH AND MYCOFIBRILS IN POSTIA-PLACENTA

Environmental scanning electron microscopic observations of Postia pla centa grown on a defined medium and on red spruce wood allowed for the examination of the hydrated sheath of P. placenta. In the wood enviro nment, mature hyphae that were not adhering to the substrate were obse rved to have a mycofibrillar morphology whereas hyphal tips and branch points had a smooth sheath morphology. A mycofibrillar adhesive matri x was observed on the hyphae growing on glass slides in the defined me dium. These morphologies for hyphal sheaths in P. placenta are similar to those previously described by investigators from other laboratorie s who have used traditional electron microscopic preparative protocols that include dehydration steps. The potential future usefulness of en vironmental scanning electron microscopic technology in the study of t he fine details of extracellular matrices is briefly discussed.