UBC Theses and Dissertations
Taxonomic and ecologic aspects of zoosporic fungi in coastal and steppe soils Booth, Thomas
Certain criteria used to distinguish chytrid taxa are highly variable and unstable. This variability is evident from a study of ten single-spore isolates of an Entophlyctis species collected in Western Canada, Oregon, California and Nevada. The observed variations place these Entophlyctis isolates in different species, genera, subfamilies, families, and series, thus demonstrating that various current taxonomic dispositions and concepts are of questionable value. Zoosporic fungi, mainly Chytridiales, are widely distributed in coastal and steppe soils. Based on distributional records and determination of physical and chemical parameters for each soil collection, eleven chytrid and chytridiaceous species are divisible into four groups: a) obligately marine, b) marine, c) facultatively marine and d) marine occasionals. Certain aspects of this study are problematic which emphasizes the necessity of a more sophisticated line of approach. Temperature-salinity growth responses of fifty-seven axenic single-spore cultures of zoosporic fungi, maintained under similar controlled conditions for a minimum of six months, correlate with habitat types and certain environmental parameters. These responses, similar over several isolates of a species from the same soil collection, are temporally constant and, thus, are ecotypic.