COMPARISON BETWEEN CONIDIAL DEVELOPMENT IN SPORENDOCLADIA-BACTROSPORAAND PHIALOCEPHALA-VIRENS

Conidium development was studied and compared in Sporendocladia bactro spora (thought to resemble Chalara spp.) and in Phialocephala virens. Techniques used in the study include bright field and fluorescence mic roscopy, as well as scanning and transmission electron microscopy. Spo rendocladia bactrospora had cylindrical conidia produced in true chain s from phialidic conidiogenous cells with long cylindrical collarettes . An area of wall building activity at the base of the conidiogenous c ell was characterized by secretory vesicles indicating ring wall build ing development. In Phialocephala virens, conidia were formed by apica l wall building and distinct periclinal thickening was evident. From t his study it was possible to confirm the fact that Phialocephala s.l. can clearly be divided into two distinct groups on the basis of conidi um development.