Freshwater Dothideomycetes

Abstract

Freshwater Dothideomycetes are a highly diverse group of fungi, which are mostly saprobic in freshwater habitats worldwide. They are important decomposers of submerged woody debris and leaves in water. In this paper, we outline the genera of freshwater Dothideomycetes with notes and keys to species. Based on multigene analyses and morphology, we introduce nine new genera, viz. Aquimassariosphaeria, Aquatospora, Aquihelicascus, Fusiformiseptata, Neohelicascus, Neojahnula, Pseudojahnula, Purpureofaciens, Submersispora; 33 new species, viz. Acrocalymma bipolare, Aquimassariosphaeria kunmingensis, Aquatospora cylindrica, Aquihelicascus songkhlaensis, A. yunnanensis, Ascagilis submersa, A. thailandensis, Bambusicola aquatica, Caryospora submersa, Dictyocheirospora thailandica, Fusiformiseptata crocea, Helicosporium thailandense, Hongkongmyces aquaticus, Lentistoma aquaticum, Lentithecium kunmingense, Lindgomyces aquaticus, Longipedicellata aquatica, Neohelicascus submersus, Neohelicomyces dehongensis, N. thailandicus, Neohelicosporium submersum, Nigrograna aquatica, Occultibambusa kunmingensis, Parabambusicola aquatica, Pseudoasteromassaria aquatica, Pseudoastrosphaeriella aquatica, Pseudoxylomyces aquaticus, Purpureofaciens aquatica, Roussoella aquatica, Shrungabeeja aquatica, Submersispora variabilis, Tetraploa puzheheiensis, T. yunnanensis; 16 new combinations, viz. Aquimassariosphaeria typhicola, Aquihelicascus thalassioideus, Ascagilis guttulaspora, A. queenslandica, A. seychellensis, A. sunyatsenii, Ernakulamia xishuangbannaensis, Neohelicascus aquaticus, N. chiangraiensis, N. egyptiacus, N. elaterascus, N. gallicus, N. unilocularis, N. uniseptatus, Neojahnula australiensis, Pseudojahnula potamophila; 17 new geographical and habitat records, viz. Aliquandostipite khaoyaiensis, Aquastroma magniostiolata, Caryospora aquatica, C. quercus, Dendryphiella vinosa, Ernakulamia cochinensis, Fissuroma neoaggregatum, Helicotruncatum palmigenum, Jahnula rostrata, Neoroussoella bambusae, N. leucaenae, Occultibambusa pustula, Paramonodictys solitarius, Pleopunctum pseudoellipsoideum, Pseudocapulatispora longiappendiculata, Seriascoma didymosporum, Shrungabeeja vadirajensis and ten new collections from China and Thailand, viz. Amniculicola guttulata, Aquaphila albicans, Berkleasmium latisporum, Clohesyomyces aquaticus, Dictyocheirospora rotunda, Flabellascoma fusiforme, Pseudoastrosphaeriella bambusae, Pseudoxylomyces elegans, Tubeufia aquatica and T. cylindrothecia. Dendryphiella phitsanulokensis and Tubeufia roseohelicospora are synonymized with D. vinosa and T. tectonae, respectively. Six orders, 43 families and 145 genera which belong to freshwater Dothideomycetes are reviewed. Of these, 46 genera occur exclusively in freshwater habitats. A world map illustrates the distribution of freshwater Dothideomycetes.

Five Novel Freshwater Ascomycetes Indicate High Undiscovered Diversity in Lotic Habitats in Thailand

“…Freshwater ascomycetes have been extensively studied over the past two decades [8,10,14], but it was only in early 2000 that molecular data was used to resolve species [7,9,[89][90][91][92]. Monographs and outlines of freshwater Dothideomycetes and Sordariomycetes have been provided by Dong et al [14] and Luo et al [10]. One hundred and forty-five genera of freshwater Dothideomycetes (six orders, 43 families) were included, with 32% (46 genera) being unique to freshwater habitats [8,14].…”

“…Phyllachoraceous taxa are biotrophic, obligate plant parasitic fungi, and saprobic on palms (Arecaceae) and submerged decaying wood [16]. Notes: Neoxylomyces is similar to Xylomyces in having brown, thick-walled, multiseptate chlamydospores [14,48]. The latter, typified by X. chlamydosporus, is placed in Aliquandostipitaceae while Neoxylomyces clustered with other taxa of Phyllachorales with 100% ML, 1.00 BYPP support (Figure 7).…”

“…In this paper, six novel taxa of freshwater ascomycetes in Thailand are introduced by combining multiloci phylogeny and morphology approaches. It appears that there are numerous new taxa awaiting to be discovered and described as new freshwater habitats are explored, or a particular genus is studied with molecular data, wherein its diversity is much higher than previously anticipated [10,14,25,27].…”

“…Several new taxa have been introduced and existing taxa lacking molecular data have been recollected and sequenced resolving their taxonomic placements [8][9][10][11][12][13]. Several monographs and taxonomic revisions of freshwater fungi have also been published [10,[14][15][16]. In Thailand, Zhang et al [17] listed 173 species belonging to 112 genera recorded from freshwater habitats in 2010.…”

“…Hu et al [18] reported 782 species of freshwater fungi in China. Since then, many additional novel taxa have been described in these countries, bringing the number even higher (see [9][10][11]14,[19][20][21][22][23][24][25][26]. In this paper, six novel taxa of freshwater ascomycetes in Thailand are introduced by combining multiloci phylogeny and morphology approaches.…”