CONIDIUM DEVELOPMENT IN SPOROTHRIX ANAMORPHS OF OPHIOSTOMA

Hyalorhinocladiella and Sporothrix are two common mycelial anamorphs o f Ophiostoma that are difficult to distinguish from each other. Sporot hrix spp. differ visibly from Hyalorhinocladiella by the presence of d enticles on the conidiogenous cells. Graphium and Sporothrix are often synanamorphs of the same Ophiostoma species and the aim of this study was to determine whether a relationship exists between sympodial coni dium development in Sporothrix and annellidic development in Graphium. Conidium development was examined in Sporothrix schenckii, Ophiostoma nigrocarpum and Ophiostoma piceae. Using fluorescence microscopy, as well as scanning and transmission electron microscopy, distinct dentic les were observed on the conidiogenous cells in Sporothrix spp. In som e cases. these conidiogenous cells were reduced giving them a Hyalorhi nocladiella-like appearance. Results of this study suggest that a cont inuum in patterns of conidium development exists between Sporothrix, H yalorhinocladiella and Graphium. The linear extent, and the angle of t he proliferation stage with reference to the long axis of the conidiog enous cell, appear to determine the form of conidium development.