Comparison between conidial development in Sporendocladia bactrospora and Phialocephala virens

Abstract

Conidium development was studied and compared in Sporendocladia bactrospora (thought to resemble Chalara spp.) and in Phialocephala virens. Techniques used in the study include bright field and fluorescence microscopy, as well as scanning and transmission electron microscopy. Sporendocladia bactrospora had cylindrical conidia produced in true chains from phialidic conidiogenous cells with long cylindrical collarettes. An area of wall building activity at the base of the conidiogenous cell was characterized by secretory vesicles indicating ring wall building development. In Phialocephala virens, conidia were formed by apical wall building and distinct periclinal thickening was evident. From this study it was possible to confirm the fact that Phialocephala s.l. can clearly be divided into two distinct groups on the basis of conidium development. Key words: apical wall building, conidiogenesis, Phialocephala, ring wall building, Sporendocladia.