Type.

Taxon classification

Fungi

Tremellales

Tremellaceae

Zhao

Ying

Liu

Xin-zhan

Bai

Feng-yan

Four new species of

Tremella

(

Tremellales

Basidiomycota

) based on morphology and DNA sequence data

MycoKeys27220192019477595

10.3897/mycokeys.47.29180

Tremella

salmonea

MycoBank: MB827188

X.Z. Liu & F.Y. Bai

sp. nov.

Figures 3, 6

Type.

CHINA. Guangxi Province, Hechi city, Luocheng county, Jiuwan Mountain National Nature Reserve, 108°48'E, 25°19'N, G.J. Li, H.S. Ma, Z.L. Lin & M.Z. Zhang, 7 August 2017, GX20172637 (HMAS 279588).

Etymology.

Salmonea refers to the colour of the basidioma.

Description.

Basidiomata small, gyrose to cerebriform, 0.6–1.0 cm in diameter, firm gelatinous and thick, pale orange when fresh, yellow orange when dry, flat on the substrate. Hyphae smooth, thin-walled, slender, 2.0–3.5 μm in diameter, often with clamp connections. Haustoria rare, small, globose or subglobose, 2.0–4.0 μm in diameter, with single hyphae. Hyphidia rare, smooth, thin-walled, 2.0–4.0 μm, branched. Probasidial initials mostly subglobose to globose, sometimes broadly ellipsoid. Basidia, when mature, subglobose to globose, four-celled, occasionally two-celled, thin-walled, 31.0–38.0 μm × 29.0–37.0 μm, with longitudinally cruciate-septate, without stalk-like base; sterigmata up to 110.0 μm long, not swollen at apex. Basidiospores globose to subglobose, 16.0–22.0 μm × 15–20.0 μm, L = 18.3 ± 1.3 μm, W = 17.8 ± 1.4 μm, Q = 0.9–1.3 (n = 25), with a distinct apiculus. Conidia present, ellipsoid, fusiform to cylindrical, 8.0–17.0 μm × 2.0–5.0 μm, L = 10.7 ± 2.2 μm, W = 3.5 ± 0.5 μm, Q = 2–5.8 (n = 40), hyaline, clamped, arranged in cluster. Terminally and laterally swollen cells appearing abundant in the subhymenium, citriniform, pyriform or broadly ellipsoid, 9.0–20.0 μm × 5.6–13.0 μm, L = 14.2 ± 2.8 μm, W = 8.8 ± 1.8 μm, Q = 1.1–2.8 (n = 40).

Figure 6.

Microscopic structure of Tremellasalmonea (HMAS 279588). A Section through hymenium B Hyphae from context C Swollen cells D Conidia in cluster E–G Mature basidia H–M Basidiospres. Scale bars: 10 μm (A–M).

Habitat.

On wood of deciduous tree, in forest dominated by Rosaceae, Moraceae, Lauraceae, and Theaceae.

Notes.

Only one specimen representing T.salmonea formed a distinct clade closely related to T.taiwanensis with 96.8%–98.3% sequence identities in D1/D2 domain and 95.4%–96.6% in ITS region, respectively. The affinity of T.salmonea to T.taiwanensislacked high support by the coalescent-based method (Fig. 1). Tremellasalmonea differs from T.taiwanensis in its larger basidia (31.0–38.0 μm × 29.0–37.0 μm in T.salmonea vs 23.0–29.0 μm × 22.0–27.0 μm in T.taiwanensis) and basidiospores (16.0–22.0 μm × 15.0–20.0 μm in T.salmonea vs 14.0–18.0 μm ×14.0–20.0 μm in T.taiwanensis). In addition, hyphae-like conidiogenous cells and dikaryotic conidia were observed in T.salmonea compared to monokaryotic conidia produced from apex of sterigmata (Chen 1998). Swollen cells were located in the hymenium in T.salmonea whereas they were absent in T.taiwanensis (Chen 1998).

Figure 3.

Macromorphology of Tremella basidiomata. AT.cheejeniiBT.erythrina C T.salmonea. Scale bars: 1 cm.

Figure 1.

The maximum likelihood tree of the novel species and related taxa in Tremella sensu stricto based on the combined sequences of the nuc rDNA ITS region and nuc 28S rDNA D1/D2 domain. Bootstrap supports (BP) (> 50%) of maximum likelihood method and Bayesian posterior probability (BPP) values (> 0.9) are shown at each node. Note: ns, not supported (BP < 50% or PP < 0.9); nm, not monophyletic.

Chen

(1998) Morphological and molecular studies in the genus

Tremella

.Bibliotheca Mycologica174: 1–225.