The Biosystematics of the Genus Schizopora: (Aphyllophorales, Basidiomycetes) with Particular Reference to New Zealand Taxa

Abstract

The present study has examined the biosystematics of a cosmopolitan genus of wood-decay fungi, Schizopora (Aphyllophorales, Basidiomycetes), with particular emphasis on New Zealand taxa. Four known species were studied, viz. S. radula, S. paradoxa, S. flavipora, S. nothofagi, and a hitherto undescribed species which occurs in Taiwan and New Zealand. Morphological studies of basidiocarps and of cultural characters, intercompatibility tests and phylogenetic analysis of sequences derived from internal transcribed spacer regions of nuclear ribosomal DNA were undertaken. Compatibility tests showed complete reproductive separation between species, but intercompatibility between cultures from the same species, irrespective of their geographical origins (Chapter 3). S. radula was found to be the most common Schizopora species in New Zealand. Overall, the morphology of basidiocarps of S. radula from New Zealand differs only in minor respects from those of European and Argentinean origin, but shows a higher degree of variability than described for European specimens (Chapter 1). Further work is required to fully describe the variation and distribution of New Zealand specimens of a new species within the S. flavipora complex and of S. flavipora in New Zealand. In a phylogenetic analysis, all previously recognized Schizopora species are distinct although closely related to each other including S. nothofagi. The most diverged species was found to be S. paradoxa. Allopatric differentiation was apparent in S. radula, for which several geographically representative samples were available. Reconstruction of evolutionary events in this genus did, however, not clearly fit current mycogeographic hypotheses.