Novel Species and Records of Dictyosporiaceae from Freshwater Habitats in China and Thailand

Abstract

China and Thailand are rich in fungal diversity with abundant freshwater resources that are favorable for numerous fungal encounters. Resulting from this, the majority of the Dictyosporiaceae species reported were from these two countries. During the investigation on the diversity of lignicolous freshwater fungi in the Greater Mekong Subregion, eleven collections of cheirosporous species on submerged wood were collected from lentic and lotic habitats in China and Thailand. Phylogenetic analysis that combined nuclear small-subunit ribosomal RNA (SSU), internal transcribed spacer region (ITS), nuclear large subunit ribosomal RNA (LSU) and translation elongation factor 1α (tef 1-α) loci revealed six new species: Dictyocheirospora chiangmaiensis, D. multiappendiculata, D. suae, Digitodesmium aquaticum, Vikalpa grandispora and V. sphaerica. In addition, four known species were also identified and reported based on morphological and phylogenetic evidence. The detailed descriptions and illustrations of these taxa are provided with an updated phylogenetic tree of Dictyosporiaceae.

Three Novel Cheiroid Hyphomycetes in Dictyocheirospora and Dictyosporium (Dictyosporiaceae) from Freshwater Habitats in Guangdong and Guizhou Provinces, China

“…Within Dictyosporaceae, Dictyocheirospora and Dictyosporium are the two most prominent genera that accommodate the majority of freshwater species, with 11 and 9 reported freshwater species, respectively [24,25]. A geographical distribution review showed that numerous species within the family were reported from China and Thailand [2].…”

“…The phylogenetic relationships between genera in Dictyosporiaceae have been well investigated using DNA sequence data [1,2,7,12,24,25]. However, the interspecific phylogenetic relationships in some cases remain ambiguous due to the limitation of insufficient sequence data included in the phylogenetic tree.…”

“…thailandica also cannot be distinguished due to the absence of tef1-α sequence data for Dictyoc. thailandica [25]. The protein-coding genes are quite necessary in species identification within this fungal group.…”

“…The Blast analysis was performed on the NCBI platform (https://blast.ncbi.nlm.nih.gov (accessed on 10 February 2024)) to identify taxonomic matches. The taxa selected for constructing the phylogenetic tree were based on a recent published paper [25] and Blast results obtained from the NCBI. The dataset of each gene region was initially aligned independently using the 'auto' strategy (based on data size) by MAFFT v. 7 [34].…”

“…The new combinations were mainly based on the findings of their phylogenetic analyses. The majority of species have sequence data, and they also cluster in a well-supported monophyletic clade [2,22,24,25]. Four species, viz., Dictyoc.…”