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

Fig. 2

Etymology.

Referring to the location "Linzhi City, China" where the holotype of this fungus was collected.

Holotype.

HKAS 128991.

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. Mycelium mostly superficial, consisting of branched, septate, smooth, pale brown to brown hyphae. Conidiophores 113-210 × 4-6 μm (x̄ = 162 × 4 μm, n = 15), macronematous, mononematous, solitary or 2-3 group, erect, straight or slightly flexuous, simple, unbranched, smooth, cylindrical, 6-12-septate, brown at the base, pale brown towards apex. Conidiogenous cells polyblastic, monoblastic, terminal, becoming intercalary, cylindrical, pale brown, integrated, with several sympodial proliferations, conspicuous denticles, bearing tiny, protuberant, circular scars. Conidia 10-14 × 5-6 μm (x̄ = 12 × 6 μm, n = 25), solitary or acropleurogenous, fusiform or elliptical, smooth, 2-septate, truncate at base, dark brown in central cells and subhyaline at end cells, guttulate. Conidial secession schizolytic.

Culture characteristics.

Conidia were germinated on PDA within 48 hours. Germ tubes produced from each end. Colonies grown on PDA, circular, flat, superficial, dark brown from above, reverse-side brown in the centre, with greyish white near the edge.

Material examined.

China, Xizang, Linzhi City , Motuo County, on submerged decaying wood, 1675 msl, 29°10'56"N, 95°8'53"E, 11 July 2022, R.J. Xu, XK-33-3 (HKAS 128991, holotype), ex-type living culture (KUNCC 10420) . Xizang, Linzhi City, Motuo County, Gelin Village , on submerged decaying wood, 1143 msl, 29°1'43"N, 94°48'5.7"E, 12 July 2022, R.J. Xu, XK-32, (HKAS 128990), living culture (KUNCC 10444) .

Notes.

Phylogenetic analyses show that Aquapteridospora linzhiensis (KUNCC 10420 and KUNCC 10444) clustered into a distinct subclade and sister to A. fusiformis (MFLUCC 18-1606) with bootstrap support (93% ML/1.00 PP, Fig. 1 ). However, A. linzhiensis differs from A. fusiformis in having obvious, guttulate conidia and less septate on maturity (2-septate vs. 3-4-septate) ( Luo et al. 2019). Additionally, comparisons of ITS sequences demonstrate a 6.7% (39/586 bp, excluding gaps) difference between A. linzhiensis and A. fusiformis Jeewon and Hyde (2016). Therefore, A. linzhiensis was identified as a new species supported with both morphological and phylogenetic evidences.

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 2. Aquapteridospora linzhiensis (HKAS 128991, holotype) a colonies on the substratum b-e conidiophores, conidiogenous cells with conidia f, g conidiogenous cells with developmental conidia h-k conidia l, m culture on PDA. Scale bars: 50 μm (b-e); 20 μm (f, g); 10 μm (h-k).