ULTRASTRUCTURE OF ZYGOSPORE IN ENDOGONE FLAMMICORONA TRAPPE AND GERDEMANN

The ultrastructural organization of the spores of the sporocarp of E. flammicorona was studied. Two types of organization are described. Initially the spore possessed a vacuolate protoplasm and was bound by 2 cell wall layers. The spore was surrounded by a hyphal mantle formed of a sheet of vacuolized hyphae with uniformly thin walls. Later, although the ultrastructural features of the spore appeared the same, it was surrounded by a hyphal mantle with unevenly thickened walls (i.e., the so-called flaming crown) due to the gradual and irregular deposition of granules and lamellae. This crown gave the spore its most commonly observed morphological feature and is the preminent character employed taxonomically to speciate E. flammicorona Trappe and Gerdemann.