whole_ChangYuShyun1992_thesis.pdf (28.53 MB)
Taxonomic studies of Strophariaceae (Agaricales) in south-east Tasmania
thesisposted on 2023-05-27, 07:36 authored by Yu, Shyun Chang
This project is a study of the family Strophariaceae utilizing comparative morphology, electrophoresis of extracellular enzymes and mating compatibility approaches. The study has found macromorphology to be effective in the delineation of taxa in the majority of cases. Isozyme profiles of extracellular laccase, pectinesterase and polygalacturonase are found to be species distinctive in most species across the genera of this family. The one exception found is Hypholoma whose species show a certain degree of conservativeness in the enzymes examined in the study. This approach is found to be useful in establishing putative species groups which can then be further investigated through mating studies. The multifaceted approach employed in the study has successfully resolved the relationships between Psi locybe subaeruginosa and P. australiana, P. eucalypta and P. tasmaniana, identified sibling species in both Stropharia and Pholiota, and established Pholiota. squarrosipes Clel. and P. multicingulata Horak as species showing a wide range of morphological variations. It is suggested from this study that P. multicingulata sensu lato may encompass P. multicingulata Horak and P. austrospumosa Hongo forming the southern hemisphere equivalent of Pholiota spumosa complex. In addition, a multifaceted approach such as that adopted in the study also lends support to the applicability of the common species concept proposed for Hymenomycetes in the family Strophariaceae. Results gained have enabled a confident approach to the separation and enumeration of species within the family. Results from electrophoresis show that delineation of taxa can be achieved through distinctions in zymogram patterns. For example, the recently described species Psilocybe australiana Guzman & Wading, P. eucalypta Guzman & Watling and P. tasrnaniana Guzman & Wading are shown to be synonymous with P. subaeruginosa Clel. In this particular case, the considerable degree of similarity in zymogram patterns is highly indicative of a single species and this conclusion is supported by mating studies. Diagnostic morphological characters used in previous studies to differentiate these taxa are shown to be invalid. The phenomenon of sibling species is not uncommon in fungi. Electrophoretic analyses showed that within the genera of Stropharia and Pholiota sibling species were concealed within common morphological entities. This is exemplified in the semiglobata-like forms in Stropharia. Within this single morphological entity, two distinct species were identified by comparison of isozyrne profiles and UPGMA cluster analysis using band frequencies, later the segregation was confirmed by mating compatibility studies. The study has confirmed the use of enzyme electrophoresis as a useful technique when applied to a wide range of species across a family from the Agaricales. When this technique is used in conjunction with mating compatibility study, findings from electrophoresis have been complimented and confirmed by those from mating. Thus, the study has avoided some of the problems associated with a purely morphological approach, and as illustrated by the case of Psilocybe subaeruginosa the multifaceted approach employed here allows much more confidence to be placed on the described boundaries of the species studied. 31 taxa are delineated from the study, and of these, eight are previously undescribed species and one being a new variety.
Rights statementCopyright the Author - The University is continuing to endeavour to trace the copyright owner(s) and in the meantime this item has been reproduced here in good faith. We would be pleased to hear from the copyright owner(s). Includes bibliographical references (leaves 167-180). Thesis (Ph.D.)--University of Tasmania, 1993