Aquapteridospora yadongensis R.J. Xu, Q. Zhao & Boonmee, 2024

Xu, Rong-Ju, Li, Jun-Fu, Zhou, De-Qun, Boonmee, Saranyaphat, Zhao, Qi & Chen, Ya-Ya, 2024, Three novel species of Aquapteridospora (Distoseptisporales, Aquapteridosporaceae) from freshwater habitats in Tibetan Plateau, China, MycoKeys 102, pp. 183-200 : 183

Aquapteridospora yadongensis R.J. Xu, Q. Zhao & Boonmee sp. nov.

Fig. 3

Etymology.

Referring to the location "Yadong County, China" where the holotype of this fungus was collected.

Holotype.

HKAS 128992.

Description.

Saprobic on decaying wood submerged in freshwater. Sexual morph: Undetermined. Asexual morph: Colonies on the natural substrate effuse, hairy, pale brown to brown, scattered or in small groups, usually retiform. Mycelium mostly superficial, consisting of branched, septate, smooth, pale brown to brown hyphae. Conidiophores 440-856 × 4-6 μm (x̄ = 581 × 5 μm, n = 20), macronematous, mononematous, solitary, erect, straight or slightly flexuous, unbranched, smooth, cylindrical, multi-septate, tapering towards apex, brown to pale brown, slightly constricted at some septa. Conidiogenous cells polyblastic, monoblastic, terminal, becoming intercalary, cylindrical, pale brown, integrated, denticles, bearing tiny, protuberant, circular scars. Conidia 14-20 × 4-7 μm (x̄ = 17 × 5 μm, n = 30), acropleurogenous, fusiform, smooth, 3-septate, rounded at apex, truncate at base, dark brown in central cells and light at end cells. Conidial secession schizolytic.

Culture characteristics.

Conidia were germinated on PDA within 48 hours. Germ tubes produced from each end. Colonies grown on PDA, regular concentric circles, flat, superficial, with dense mycelium at around, grey brown from above, dark brown from below.

Material examined.

China, Xizang, Shigatse City , Yadong County, on submerged decaying wood, 3061 msl, 27°21'11"N, 88°58'10"E, 01 July 2022, R.J. Xu, LTS-20 (HKAS 128992, holotype), ex-type living culture (KUNCC 10445) . Xizang, Shigatse City , Dingjie County, on submerged decaying wood, 3042 msl, 27°53'8.7"N, 87°27'36"E, 05 July 2022, L.T. Shun, LTS-20-1, (HKAS 128993), living culture (KUNCC 10448) .

Notes.

Aquapteridospora yadongensis possess its conidial characteristics that fit with Aquapteridospora ( Yang et al. 2015). In phylogenetic analyses, A. yadongensis formed a distinct lineage close to A. submersa with high bootstrap support (100% ML/1.00 PP, Fig. 1 ). A comparison of ITS nucleotide shows that A. yadongensis (KUNCC 10445) differs from A. submersa (KUNCC 10446) in 10/572 bp (1.8%, excluding gap), a comparison of TEF 1-α nucleotide shows that A. yadongensis (KUNCC 10445) differs from A. submersa (KUNCC 10446) in 8/821 bp (0.8%, excluding gap) ( Jeewon and Hyde 2016). In addition, A. yadongensis differs from A. submersa in having narrower conidiophores (4-6 vs. 5-12 μm), while conidia of A. submersa have slightly constricted septa; the culture of A. yadongensis have regular concentric circles differing from A. submersa having pale mycelium in the centre. Furthermore, A. yadongensis differs from A. lignicola in having long conidiophores (440-856 vs. 70-200 μm) and conidia without a conspicuous sheath ( Yang et al. 2015).

Figures

Figure 1. Maximum likelihood (ML) tree is based on combined LSU, TEF 1 - α and ITS sequence data. ML bootstrap support values equal to or greater than 70 % and Bayesian posterior probabilities (PP) equal to or greater than 0.95 given above the nodes, shown as " ML / PP ". The tree is rooted with Pseudostanjehughesia aquitropica (MFLUCC 16 - 0569) and P. lignicola (MFLUCC 15 - 0352). New species are indicated in red and type strains are in bold.

Figure 3. Aquapteridospora yadongensis (HKAS 128992, holotype) a colonies on the substratum b, c conidiophore and conidiogenous cell d-g conidiogenous cells with developmental conidia h-k conidia l germinating conidium m culture on PDA. Scale bars: 100 μm (b, c); 20 μm (d, g); 10 μm (h-l).