PROBLEMS WITH FIXATION AND EMBEDDING OF ARBUSCULAR MYCORRHIZAL FUNGI (GLOMALES)

In order to conduct ultrastructural studies to clarify the nature of t he spores formed in Glomales, an order of arbuscular mycorrhizal fungi , techniques for fixation and embedding of these spores were tested. O f nine methods, none was effective for fixation of Acaulospora, Gigasp ora, and Scutellospora spores, but one was efficient for fixation of G lomus. This method included fixation with glutaraldehyde in a microwav e oven, and breaking the spores under liquid nitrogen before postfixat ion with osmium tetroxide. For spore walls, however, most of the techn iques were satisfactory for all of the genera tested.