An ultrastructural study of the asci and banded ascospores of Fasciatispora petrakii

Abstract

Ascospores of Fasciatispora petrakii are brown and unicellular and are provided with pallid central bands with unknown function. Ascospores were examined at the electron microscopic level in order to establish their fine structure. The bands are narrow regions of the ascospore wall with less pigmentation. They may act as areas of weakness through which spores can germinate. Ascospores are surrounded by a mucilaginous sheath, which is also illustrated at ultrastructural level. The asci are similar to those found in species of Xylaria (Xylariaceae) and placement of Fasciatispora in the Xylariaceae is considered most appropriate.