ABSTRACT
Species within Tetraplosphaeriaceae have been frequently documented in recent years with the extensive investigations of microfungi along a latitudinal gradient from north to south in the Asian/Australian region. Both bamboo substrates and freshwater habitats serve as extensive reservoirs, hosting a rich diversity of fungi that exhibit broad geographical distributions. The most common fungi in these two environments are generally distributed in distinct families. However, our statistics have revealed an intriguingly distinct preference of Tetraplosphaeriaceae species for inhabiting both bamboo substrates and freshwater habitats. The genera Pseudotetraploa (100%) and Triplosphaeria (100%) exhibit a strong preference, followed by Shrungabeeja (71%) and Quadricrura (67%). Our taxonomic and phylogenetic study of microfungi in southern China have identified four additional novel species, viz., Aquatisphaeria bambusae sp. nov., Pseudotetraploa phyllostachydis sp. nov., Pseudotetraploa yangjiangensis sp. nov., and Tetraploa submersa sp. nov. from bamboo substrates and freshwater habitats. In addition, Aquatisphaeria thailandica has previously been documented from freshwater habitats in Thailand; however, we have once again isolated this species from decaying bamboo substrates in Guangdong, China. The new findings substantiate our hypothesis that the preference of Tetraplosphaeriaceae species for colonizing bamboo substrates and freshwater habitats will be more evident through more extensive investigations conducted in such environments.
ABSTRACT
Twelve new specimens of sporidesmium-like taxa were collected from freshwater habitats in China and Thailand. Phylogenetic analysis of nuc 28S rDNA (LSU), internal transcribed spacer (ITS), translation elongation factor 1-alpha (TEF1-α) and second-largest subunit of RNA polymerase II (RPB2) sequence data, combined with morphological data, revealed that they are Distoseptispora species. Among them, six new species, including D. aqualignicola, D. aquamyces, D. crassispora, D. curvularia, D. nonrostrata and D. pachyconidia, are introduced. Two new combinations, D. adscendens and D. leonensis, are transferred from Ellisembia. A new habitat and geographical record are reported for D. clematidis, collected from a freshwater habitat in China. New RPB2 sequence data for D. dehongensis are provided.
ABSTRACT
Pleurotheciales is the largest order in Savoryellomycetidae with a large proportion of species known from freshwater habitats. In order to investigate the phylogenetic relationships of taxa within Pleurotheciales and contribute to their diversity, submerged wood was collected from freshwater habitats in China (Yunnan Province) and Thailand. Two dematiaceous, sporodochial hyphomycetes and one annulatascales-like ascomycete with unusual morphology as compared to extant ones were discovered. They were subjected to DNA-based phylogenetic analyses and the results revealed three distinct lineages in Savoryellomycetidae. This morpho-phylo taxonomic study supports the establishment of five novel taxa including two novel genera, Obliquifusoideum and Saprodesmium, and three novel species, Coleodictyospora muriformis, Obliquifusoideum guttulatum and Saprodesmium dematiosporum. Coleodictyospora muriformis and S. dematiosporum are placed in Pleurotheciales, while O. guttulatum is referred to Savoryellomycetidae genera incertae sedis. The phylogenetic relationships are also presented for Coleodictyospora and Pseudocoleodictyospora, which raises an intriguing taxonomic issue. These two genera are positioned in two different classes, viz Sordariomycetes and Dothideomycetes, although they are quite similar except for the presence of a conidial sheath. This study expands our knowledge of the fungal diversity of freshwater fungi, and also indicates that Pleurotheciales species are mostly found in freshwater habitats.
ABSTRACT
During our ongoing surveys of fungi on submerged wood in the Greater Mekong Subregion, we collected two new species similar to Bactrodesmium longisporum. Pseudobactrodesmium gen. nov. is introduced to accommodate the new species, P. aquaticum, P. chiangmaiensis and B. longisporum is transferred to this genus. Fasciculate conidiophores, enteroblastic conidiogenous cells and subulate to fusiform, phragmoseptate conidia with a tapering apical cell and sheath characterize the genus. Pseudobactrodesmium aquaticum has longer conidia than P. chiangmaiensis. The placement of Pseudobactrodesmium in Dactylosporaceae (Eurotiomycetes) is a novel finding based on analyses of combined LSU, SSU, ITS and RPB2 sequence data. Our study reveals that Pseudobactrodesmium is likely to be a speciose genus with different species in streams around the world.
