*Aquimassariosphaeria kunmingensis 2020

*Aquimassariosphaeria kunmingensis W. Dong, Doilom & K.D. Hyde, sp. nov 2020 

Index Fungorum number: IF557912; Facesofungi number: FoF08734; 

Holotype: CHINA, Yunnan Province, Kunming University of Science & Technology, on submerged wood in a stream, 10 May 2017, C.X. Liu, L47 (HKAS 102148), 

living culture KUMCC 18-1019.

Morphological description

Saprobic on decaying wood submerged in freshwater. Sexual morph: Ascomata 300–350 × 370–400 μm, scattered or solitary, erumpent, mostly superfcial, subglobose to ellipsoidal, black, coriaceous, with ostiolate papilla. Peridium 30–40 μm thick, two-layered, outer layer comprising 4–6 layers of dark brown or black, thin-walled, compressed cells of textura angularis or irregular cells, inner layer comprising 3–5 layers of pale brown to hyaline, thin-walled, large cells of textura angularis. Pseudoparaphyses 2 μm diam., numerous, cellular, hyaline, unbranched, septate, embedded in a matrix. Asci 160–200 × 15–18 μm (x̄ = 180 × 17 μm, n = 5), 8-spored, bitunicate, narrowly clavate, short pedicellate, apically rounded. Ascospores 35–46(–55) × 6.5–9.5 μm (x̄ = 40 × 7.8 μm, n = 25), bi- to tri-seriate in the upper part, uniseriate in the lower part, narrowly fusiform or vermiform occasionally narrowly clavate with elongate basal cells, with rounded ends, brown, 6–7-septate, occasionally 5- or 8-septate, constricted at the septa, asymmetric, obviously enlarged at the third or fourth cell from the apex, straight or curved, smooth, thin-walled, without a sheath. Asexual morph: Undetermined. Culture characteristics: On PDA, colony circular, reaching 10 mm in 15 days at 25 °C, black from above, dark brown from below, surface rough, with sparse mycelium, mostly immersed in culture, dry, raised, edge entire

Habitat: on submerged wood in a stream 

Distribution: CHINA 

GenBank Accession: HKAS 102148 

Notes: Aquimassariosphaeria kunmingensis clusters with A. typhicola with moderate bootstrap support (Figs. 2, 61). Aquimassariosphaeria kunmingensis has superfcial ascomata and thin-walled, smooth ascospores without a sheath, while the latter has completely immersed ascomata that staining substrate purple and thick-walled, heavily grained sculpted ascospores with a well-defined, mucilaginous sheath (Leuchtmann 1984). Comparison of single genes between A. kunmingensis (KUMCC 18-1019) and A. typhicola (CBS 609.86) shows that there are 4, 1 and 16 nucleotide diferences in LSU, SSU and RPB2 sequence data, respectively, which supports them to be diferent species.

Reference: 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, Tubeufa aquatica and T. cylindrothecia. Dendryphiella phitsanulokensis and Tubeufa 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

Aquimassariosphaeria kunmingensis (HKAS 102148). a, b Appearance of ascomata on host substrate. c Vertical section of ascoma. d Structure of peridium. e, f Bitunicate asci. g Pseudoparaphyses. h–m Ascospores. n Germinated ascospore. o, p Colony on PDA (left-front, right-reverse). Scale bars: c = 50 μm, d–n = 20 μm