Two new asexual genera and six new asexual species in the family Microthyriaceae (Dothideomycetes, Ascomycota) from China.

The family Microthyriaceae is represented by relatively few mycelial cultures and DNA sequences; as a result, the taxonomy and classification of this group of organisms remain poorly understood. During the investigation of the diversity of aquatic hyphomycetes from southern China, several isolates were collected. These isolates were cultured and sequenced and a BLAST search of its LSU sequences against data in GenBank revealed that the closest related taxa are in the genus Microthyrium. Phylogenetic analyses, based on the combined sequence data from the internal transcribed spacers (ITS) and the large subunit (LSU), revealed that these isolates represent eight new taxa in Microthyriaceae, including two new genera, Antidactylaria gen. nov. and Isthmomyces gen. nov. and six new species, Antidactylariaminifimbriata sp. nov., Isthmomycesoxysporus sp. nov., I.dissimilis sp. nov., I.macrosporus sp. nov., Triscelophorusanisopterioideus sp. nov. and T.sinensis sp. nov. These new taxa are described, illustrated for their morphologies and compared with similar taxa. In addition, two new combinations are proposed in this family.

Anacraspedodidymum submersum sp. nov. (Chaetosphaeriaceae, Chaetosphaeriales), a new species of freshwater hyphomycetes from southwest China.

During a mycological survey of freshwater hyphomycetes on submerged leaves in southwest China, a new species, Anacraspedodidymum submersum, was isolated. The new species A. submersum is characterized by having monophialidic conidiogenous cells with funnel shaped collarettes and globose or subglobose, aseptate and hyaline conidia. Morphologically, A. submersum is somewhat similar to A. aquaticum and A. hyalosporum in conidiophores and conidiogenous cells, but can be easily distinguished by its subglobose to globose and smaller conidia. Phylogenetic analysis of combined ITS and LSU sequences show that the new species of Anacraspedodidymum clustered together with the genus Thozetella in Chaetosphaeriaceae. A full description, illustrations and a phylogenetic tree showing the position of A. submersum are provided herein.

Phalangispora sinensis sp. nov. from Yunnan, China and two new members of Wiesneriomycetaceae.

Phalangispora sinensis, an aquatic hyphomycete collected from south-western PR China, is described as a new species. This new species is characterized by having multicellular branched conidia composed of a curved main axis and one or two laterals, with the laterals arising from the third or fourth cell of the base of the main axis. Combined analyses of the LSU, SSU, RPB2 and TEF1 gene sequence data revealed that Phalangispora and another aquatic hyphomycete genus, Setosynnema, belonged to Wiesneriomycetaceae, Tubeufiales, Dothideomycetes, Ascomycota.