Abstract:
Partial 28S rRNA gene sequence-data of the strains of the anamorphic genera Bahusutrabeeja, Diplococcium, Natarajania, Paliphora, Polyschema, Rattania and Spadicoides were analysed to predict their phylogenetic relationships and taxonomic placement within the Ascomycota. Results indicate that Diplococcium and morphologically similar genera, i.e. Spadicoides, Paliphora and Polyschema do not share a recent common ancestor. The type species of Diplococcium, D.spicatum is referred to Helotiales (Leotiomycetes). The placement of Spadicoides bina, the type of the genus, is unresolved but it is shown to be closely associated with Porosphaerella species, which are sister taxa to Coniochaetales (Sordariomycetes). Three Polyschema species analysed in this study represent a monophyletic lineage and are related to Lentithecium fluviatile and Leptosphaeria calvescens in Pleosporales (Dothideomycetes). DNA sequence analysis also suggests that Paliphora intermedia is a member of Chaetosphaeriaceae (Sordariomycetes). The type species of Bahusutrabeeja, B.dwaya, is phylogenetically related to Neodeightonia (=Botryosphaeria) subglobosa in Botryosphaeriales (Dothideomycetes). Monotypic genera Natarajania and Rattania are phylogenetically related to members of Diaporthales and Chaetosphaeriales, respectively. Future studies with extended gene datasets and type strains are required to resolve many novel but morphologically unexplainable phylogenetic scenarios revealed from this study. It is increasingly becoming evident that a fungal lineage may include a mosaic of anamorphs, teleomorphs and pleomorphs whose morphologies may not always be correlated. It is therefore suggested that where possible all new species descriptions, whether teleomorphic, anamorphic or pleomorphic, should include DNA sequence-data to facilitate amalgamation of anamorphic and pleomorphic genera in a single phylogenetic classification system.
