Molecular phylogeny and morphology reveal three new plant pathogenic fungi species (Septobasidiales, Basidiomycota) from China

Three new fungal species, <i>Septobasidiummacrobasidium</i>, <i>S.puerense</i> and <i>S.wuliangshanense</i>, are proposed based on a combination of the morphological features and molecular evidence. The taxon <i>S.macrobasidium</i> is characterized by the coriaceous basidiomata with a cream surface, cylindrical basidia, straight, 4-celled, subglobose or ovoid probasidia and thin-walled, narrowly cylindrical basidiospores with septa, measuring as 7-9 × 3.5-4.5 µm, the haustoria consisting of irregularly coiled hyphae; in addition, this fungus was found associated with the insect of Diaspididae. The species <i>S.puerense</i> is characterised by resupinate coriaceous basidiomata with a cinnamon brown to chestnut brown surface, cylindrical or slightly irregular basidia, 2-3-celled, slightly curved, subglobose to pyriform probasidia, probasidia cell persistent after the formation of the basidia and the haustoria with two types consisting of irregularly coiled hyphae and spindle-shape. The fungus was found associated with the insect species <i>Pseudaulacaspispentagona</i>. The species <i>S.wuliangshanense</i> is characterised by the coriaceous basidiomata with a slightly brown surface, cylindrical or slightly irregular basidia, 2-3-celled, straight or slightly curved, pyriform, subglobose or ovoid and probasidia, haustoria consisting of irregularly coiled hyphae, associated with the insect genus <i>Aulacaspis</i>. Sequences of internal transcribed spacer region (ITS) were analysed maximum likelihood, maximum parsimony and Bayesian inference methods. The new species <i>S.macrobasidium</i> was clustered with <i>S.maesae</i>. Furthermore, <i>S.puerense</i> was retrieved as a sister to <i>S.carestianum</i>. The phylogenetic tree, inferred from the ITS sequences, highlighted that <i>S.wuliangshanense</i> was the sister to <i>S.aquilariae</i> with strong supports. Application of PHI test to the ITS tree-locus sequences revealed no recombination level within phylogenetically related species.