Thysanorea yunnanensis Hern.-Restr. & Crous, Fungal Syst Evol 6, 21 (2020)
Index Fungorum number: IF833928; MycoBank number: MB833928; Facesoffungi number: FoF16124
Saprobic on submerged decaying wood. Asexual morph: Colonies superficial, effuse, hairy, scattered, dark drown. Conidiophores (90–) 120–250 × (2.6–) 4.3–8 µm (x̅ = 159.3 × 5.6 µm, n = 20), mononematous, macronematous, erect, unbranched, cylindrical, straight or flexuous, septate, smooth, thick-walled, dark brown at the base, and gradually paler towards the apex, swollen into a subglobose at the base. Conidiogenous cells integrated, terminal, sympodially proliferating, subhyaline to pale brown. Conidia 22–38 × 3.4–7.2 µm (x̅ = 32.3 × 5.5 µm, n = 40), acrogenous, clavate to fusiform, solitary, straight or slightly curved, 5–9-septate when mature, septum darker, smooth, subhyaline to pale brown, with a hilum at the base. Sexual morph: Undetermined.
Culture characteristics – Conidia germinating on PDA within 12 h, and germ tubes produced from the both ends and middle. Colonies on PDA reaching 50 mm diameter after 4 weeks of incubation at room temperature. Mycelium dry, dense, colonies on the surface of PDA, circular, with regular edge, with a small bulbous protrusion in the center, dark brown, the outermost part has a loose layer of hyphae, velvety. Reverse dark green to black, smooth.
Material examined – China, Yunnan Province, Wenshan Zhuang and Miao Autonomous Prefecture, Bamei Town, on submerged decaying wood, 28 February 2023, W.P. Wang, S-4355 (HKAS 131402), living culture KUNCC 23–13737.
Notes – Minimelanolocus aquaticus was introduced by Liu et al. (2015a) from a freshwater habitat in Yunnan Province, China. Hernández-Restrepo et al. (2020) transferred M. aquaticus to Thysanorea as T. yunnanensis. Phylogenetic analysis showed that our new collection (KUNCC23– 13737) clustered with the type strain of T. yunnanensis (MFLUCC 15–0414) with 76% ML/1.00 PP support (Fig. 2). Our new collection is similar to T. yunnanensis (MFLUCC 15–0414) in having unbranched, straight or flexuous conidiophores that are gradually paler towards the apex, and clavate to fusiform and similar-sized conidia, but our new collection has more septa when mature (5–9 vs. 3–7) (Liu et al. (2015a). Comparison of the ITS sequence of our new collection and the ex-type strain of T. yunnanensis showed that 99.11% (557/562 bp, two gaps) similarity.
Figure 1 – Thysanorea yunnanensis (HKAS 131402). a Colonies on the substratum. b−f Conidiophores. g–i Conidia. j Germinating conidium. k, l Colonies on PDA from surface and reverse. Scale bars: b–d = 30 µm, e, f = 40 µm, g–j = 10 µm.
Figure 2 – RAxML tree based on analysis of Herpotrichiellaceae that combined LSU, ITS, and SSU dataset. The combined analyses include 48 strains with 2355 characters, including gaps (LSU: 6584 857 bp, ITS: 556 bp, and SSU: 942 bp). Bootstrap support values for maximum likelihood (ML) greater than 75% and Bayesian posterior probabilities greater than 0.95 are indicated above branches as ML/PP. The tree is rooted with Cyphellophora oxyspora (CBS 698.73) and C. sessilis (CBS 243.85). The new collections are indicated in red. Ex-type strains are indicated with “T” after the strain number.