*Bambusicola aquatica 2020

*Bambusicola aquatica W. Dong, H. Zhang & K.D. Hyde, sp. nov.2020 

Index Fungorum number: IF557906; Facesofungi number: FoF0924

Holotype : CHINA, Yunnan Province, Dehong, on submerged wood in a stream, 25 November 2017, G.N. Wang, H29A-1 (MFLU 18-1164, holotype), ex-type living culture MFLUCC 18-1031; ibid., H29A-2 (HKAS 101730, isotype), ex-type living culture KUMCC 18-0080.

Morphological description 

Saprobic on decaying bamboo submerged in freshwater. Sexual morph: Ascomata 180–210 μm high, 250–370 μm diam., black, gregarious, densely clustered in a large group, semi-immersed to superfcial, conical or dome-shaped in section. Peridium comprising host and fungal tissues, laterally 85–95 μm thick, composed of dark brown to black, thick-walled cells of textura angularis intermingled with host cells, with thinner basal part 10–35 μm thick, composed of subhyaline, rim-like cells. Pseudoparaphyses 1.4–1.8 μm diam., numerous, trabeculate, fliform, hyaline, indistinctly septate. Asci 80–126.5(–202) × 7–9.5(–10.5) μm (x̄ = 99.5 × 9 μm, n = 15), 8-spored, bitunicate, cylindrical, apically rounded, with a shallow chamber and a short, twisted or straight pedicel, easily and rapidly elongate when mounted in water, up to 202 μm long. Ascospores 18–22.5 × 4–5 μm (x̄ = 20.5 × 4.5 μm, n = 40), overlapping biseriate or partially uniseriate, narrowly fusiform, the upper cell slightly broader than the lower one, sharply narrowed towards to ends which are narrowly rounded, mostly slightly curved, rarely straight, hyaline, 1-septate, deeply constricted at the septum, slightly constricted at a quarter, guttulate, the guttula in upper cell larger than the lower cell, thin-walled, smooth, with a thin, hyaline, inconspicuous, mucilaginous sheath which is 2 μm thick when mounted in water, but 5–10 μm thick when mounted in Indian Ink. Asexual morph: Undetermined. Culture characteristics: On PDA, colony irregular, reaching 30 mm diam. in 30 days at 25 °C, brown with pale green margin from above, dark brown from below, surface rough, with dense mycelium, dry, mucoid after old, edge undulate

Habitat: on submerged wood in a stream 

Distribution CHINA

GenBank Accession: 

Notes: :Bambusicola aquatica is most similar to B. loculata D.Q. Dai & K.D. Hyde in having narrowly fusiform, 1-septate, hyaline ascospores with narrowly rounded ends and an inconspicuous mucilaginous sheath (Dai et al. 2015). However, they can be distinguished by their ascus characteristics (cylindric-clavate, bi- to tri-seriate, 80–105 × 8–13 μm in B. loculata vs. cylindrical, overlapping biseriate or partially uniseriate, 80–126.5(–202) × 7–9.5(–10.5) μm in B. aquatica). Additionally, the ascomata of B. loculata are solitary or clustered in a small group, while those of B. aquatica are gregarious and densely clustered in a large group.

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

Bambusicola aquatica (MFLU 18-1164, holotype). a, b Appearance of black ascomata on host. c, d Vertical sections of ascomata. e Structure of peridium. f Pseudoparaphyses. g–i Bitunicate asci. j–l Ascospores. m Germinated ascospore. n Colony on PDA (from front). Scale bars: c, d = 100 μm, e = 50 μm, f, j–m = 10 μm, g–i = 20 μm