Phaeotremella yunnanensis L.F. Fan, F. Wu & Y.C. Dai, sp. nov.
Index Fungorum number: IF 556263; MycoBank number: MB 556263; Facesoffungi number: FoF 05842; Figs. 1, 2
Etymology – Referring to the distribution of the species in Yunnan, China.
Holotype – BJFC 019764.
Basidiocarps gelatinous and no odor when fresh, foliaceous, 0.4–1.8 cm high, 1.6–4.0 cm diam, greyish brown to fuscous, sessile, lobes with single-layer structure and undulate caespitose lobes arising directly from the central point of attachment, becoming firmly gelatinous and deep brown when dry. Hyphae clamped, thin- to slightly thick-walled, 2–9 μm diam, hyaline to brownish, inflated, anastomosing, branched and slightly interwoven. Haustoria, hyphidia and vesicles absent. Swollen cells rarely present. Basidia globose to subglobose or widely ellipsoid, colorless, thin-walled, longitudinally septate, rarely obliquely septate, with a basal clamp connection, obvious oil drops and 1–4 long sterigmata, (11.0–)12.0–15.0(–22.0)×(11.0–)12.0–16.0(–18.0) μm, L=13.7 µm, W=13.8 µm, Q =1.07(n=30/1), occasionally wider than long. Basidiospores globose or broadly ellipsoid, hyaline, thin-walled, smooth, apiculate, with oil drops, (6.0–)7.0–8.0(–8.9)×6.0–7.3(–9.0) μm, L=7.4 µm, W=6.9 µm, Q =1.07 (n=30/1), sometimes broader than long, germinating and producing secondary spores by germ tubes. Conidia usually plentiful, spherical or ovoid to ellipsoid, hyaline, thick-wall, smooth, usually originating from inflated conidiophores interspersed among basidia in the hymenium, (3.0–)3.8–5.0(–6.0)×(2.0–)2.5–3.8(–4.0) µm, L=4.5 µm, W=3.0 µm, Q=1.50 (n=30/1).
Material examined: CHINA, Yunnan Province, Yongde County, Daxueshan Nature Reserve, on dead angiosperm branch, 27 August 2015, Dai 15660 (BJFC 019764, holotype); Jingdong County, Ailaoshan Nature Reserve, on fallen angiosperm branch, 24 August 2015, Dai 15621 (BJFC 019725).
GenBank numbers – ITS: MK559397, MK559396; LSU: MK559399, MK559398; TEF1-α: MK559401, MK559400.
Notes – In the phylogeny (Fig. 3), the new species is closely related to Phaeotremella roseotincta (Lloyd) V. Malysheva and P. fuscosuccinea (Chee J. Chen) Spirin & Yurkov, but the former differs from P. yunnanensis by its pinkish basidiocarps when fresh, slightly larger basidia (16–20×11–18 µm) and basidiospores (7–10×7–9 µm); the latter differs by its habits on fallen spruce associated with S. sanguinolentum (Malysheva et al. 2018) and smaller basidia (11–15×8–10.5 µm) (Chen 1998). Macro-morphologically, P. yunnanensis resembles P. foliacea (Pers.) Wedin et al. in the brownish tint, but differs from the new species by its slightly narrower basidiospores (5.3–9.1×4.7–8.5 µm) and the presence of swollen cells producing ellipsoid or subglobose conidial cells. In addition, P. foliacea has slightly thick-walled basidia and grows on conifers associated with Stereum sanguinolentum (Malysheva et al. 2018).
Figure 1 – A basidiocarp of Phaeotremella yunnanensis (BJFC 019764, holotype)
Figure 2 – Microscopic structures of Phaeotremella yunnanensis (BJFC 019764, holotype). a Basidiospores. b Conidia. c Basidia. d Conidiophores with conidia. e Hyphae from context
Figure 3 – Phylogenetic position of Phaeotremella yunnanensis inferred from the ITS, LSU and TEF1-α sequences. Bootstrap support values (ML and MP)≥50% and Bayesian posterior probabilities≥0.90 are given near nodes respectively. The tree is rooted with Gelidatremea spencermartinsiae (CBS10760T). The new isolates are in bold