Fusoidispora aquatica: A new freshwater ascomycete from Hong Kong based on morphology and phylogeny inferred from rDNA gene sequences

During a survey of freshwater ascomycetes in Hong Kong, an interesting ascomycete with fusoid ascospores that had mucilaginous pads at both apices was identified. The affinities of this taxon extend between a wide range of unitunicate ascomycetes (viz. Annulatascaceae, Magaporthaceae, Pleurotremaceae, Trichosphaeriaceae). In order to evaluate its familial placement and generic relatedness with other known ascomycetes, partial DNA sequences derived from the large subunit ribosomal DNA (28S rDNA) were analyzed. Results from the phylogenetic analyses indicate that the family Annulatascaceae is polyphyletic. The unidentified taxon has close affinities with the Annulatascaceae and Ophiostomataceae but does not belong in any existing genera. Thus a new genus and species, Fusoidispora aquatica, is established to accommodate it.