NOVEL APPROACHES TO VISUALIZE THE SEPTAL PORE CAP

This paper describes some non-conventional techniques for electron mic roscopy applied to the study of septal pore caps occurring in Basidiom ycetes. The septal pore caps of Schizophyllum commune and Trichosporon sporotrichoides have been studied by the use of freeze-substitution, preferential staining of the endoplasmic reticulum with zinc iodide-os mium tetroxide and intracellular scanning electron microscopy, and for S. commune freeze fracturing and replication as well. The septal pore cap of S. commune differs from the endoplasmic reticulum in reactivit y with zinc iodide-osmium tetroxide, whereas in T. sporotrichoides bot h showed the same reactivity. The septal pore cap of T. sporotrichoide s was found to be made up of little differentiated tubular and vesicul ar endoplasmic reticulum.