Tremella guangxiensis F. Wu, L.F. Fan & Y. C. Dai, 2021

Fan, Long-Fei, Alvarenga, Renato Lucio Mendes, Gibertoni, Tatiana Baptista, Wu, Fang & Dai, Yu-Cheng, 2021, Four new species in the Tremella fibulifera complex (Tremellales, Basidiomycota), MycoKeys 82, pp. 33-56 : 33

Tremella guangxiensis F. Wu, L.F. Fan & Y. C. Dai sp. nov.

Figs 3C , 6

Holotype.

China. Guangxi, Jinxiu, Dayao Mountain, on angiosperm tree, 15 July 2017, F. Wu 3 (BJFC026009).

Etymology.

Refers to the distribution of the species in Guangxi, China.

Basidioma.

Sessile, when fresh soft gelatinous, milky to creamy-white, translucent, pustulate to irregularly cerebriform, with thick and undulate lobes, up to 4.0 cm long, 4.0 cm broad and 1.5 cm high from base, distinctly shrinking into a film and becoming lightly yellowish when dry, broadly attached to substratum.

Internal features.

Hyphae hyaline, smooth, thin- to slightly thick-walled, 2.0-6.0 µm in diameter, branched, interwoven, with abundant clamp connections, clamp complexes and anastomoses, slightly thick-walled hyphae usually present near to base of basidioma and sometimes swollen up to 9.0 μm; hyphidia hyaline, smooth, thin-walled, branched; swollen cells present, hyaline, smooth and various in the shape, sometimes slightly concave; vesicles and haustoria absent; mature basidia thin-walled, globose to subglobose, with a basal clamp connection, 14.0-17.0 × (13.6-)14.0-16.0(-17.0) μm, L = 15.9 µm, W = 14.8 µm, Q = 1.07 (n = 30/1), sometimes their width greater than length, usually longitudinally septate, rarely obliquely septate, 2-4-celled, with obvious oil drops; sterigmata up to 60 μm long, 1.5-2.0 in diameter, slightly protuberant at apex; probasidia thin-walled, clavate to ellipsoid, proliferating from terminal hyphae; basidiospores hyaline, thin-walled, broadly ellipsoid to slightly ovoid, apiculate, with oil drops, (7.5-)8.0-9.5 × 6.0-7.5(-8.0) μm, L = 8.7 µm, W = 6.8 µm, Q = 1.28 (n = 30/1), germinating by germ tubes or secondary spores; conidia massively present, originating from umbelliform conidiophores, hyaline, thin-walled, ovoid to broadly ellipsoid or fusiform to cylindrical, 2.0-3.2 × 1.8-3.0 μm.

Notes.

Tremella guangxiensis is closely related T. " Tremella neofibulifera " in our phylogenies (Figs 1 , 2 ). The most distinctive characteristic of the species is branched hyphidia and umbelliform conidiophores, but T. " Tremella neofibulifera " has parallel hyphidia and lacks of conidia. In addition, T. guangxiensis are different from T. australe and T. " Tremella neofibulifera " by 6.35% and 5.09% sequence differences in the ITS sequences and 3.39% and 1.97% in the partial nLSU sequences respectively.

Figures

Figure 1. The Maximum likelihood tree showing phylogenetic relationship of species in Tremella s. s. based on the ITS + partial nLSU dataset. Bootstrap support values for MP and ML greater than 50 % and BI greater than 0.95 are given at each node respectively. The samples used in this study are in bold.

Figure 2. The Maximum likelihood tree showing phylogenetic relationship of species in Tremella s. s. based on the combined ITS + partial nLSU + mtSSU + TEF 1 + RPB 1 + RPB 2 dataset. Bootstrap support values for MP and ML greater than 50 % and BI greater than 0.95 are given at each node respectively. The samples used in this study are in bold.

Figure 3. Basidioma A Tremella fibulifera (Alvarenga 471) B T. australe (Wu 154) C T. guangxiensis (Wu 3) D T. latispora (Dai 17568) E T. " Tremella neofibulifera " (Wu 244) F T. subfibulifera (Alvarenga 334). Scale bars: 1 cm (A-F).

Figure 6. Microscopic structures of Tremella guangxiensis (Wu 3) A basidiospores B germination tubes of basidiospores and secondary spores C conidia and conidiophores D basidia at different stages E, F probasidia G hyphae with clamp connections and clamp complexes H hyphidia I a section of hymenium. Scale bars: 10 μm (A-H); 20 μm (I).