Thysanorea lotorum (Morgan-Jones) Hern.-Restr. & Crous, Fungal Syst Evol 6, 18 (2020)
Index Fungorum number: IF833922; MycoBank number: MB833922; Facesoffungi number: FoF16105
Saprobic on submerged decaying wood. Asexual morph: Colonies superficial, effuse, hairy, scattered, dark brown, with subhyaline, fusiform conidia on the apex of conidiophores. Mycelium mostly immersed, composed of septate, pale brown, smooth hyphae. Conidiophores (70–) 130–230× 3.2–8.4 µm (x̅ = 153.4 × 4.9 µm, n = 15), mononematous, macronematous, erect, unbranched, cylindrical, straight or slightly flexuous, septate, smooth, thick-walled, dark brown at the base, and gradually paler towards the apex. Conidiogenous cells polyblastic, integrated, terminal, sympodially proliferating, subhyaline to pale brown. Conidia (10–) 25–50 × 3–8.5 µm (x̅ = 38.5 × 5.6 µm, n = 40), acrogenous, mostly fusiform, sometimes clavate, solitary, straight or slightly curved, 7–8-septate when mature, septum darker, sometimes slightly constricted at the septum, 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 20 mm diameter after 2 weeks of incubation at room temperature. Mycelium dry, dense, colonies on the surface of PDA, with regular edge, has a bulbous protrusion in the center, celadon. Reverse dark green, smooth.
Material examined – China, Yunnan Province, Wenshan Zhuang and Miao Autonomous Prefecture, Bamei Town, on submerged decaying wood, 7 February 2022, W.P. Wang, S-3487 (HKAS 131400), living culture KUNCC 23–13725.
Notes – Pseudospiropes lotorum (Leotiomycetes) was introduced by Morgan-Jones (1977), but there is no corresponding molecular data for this fungus. Castañeda et al. (2001) transferred P. lotorum to Nigrolentilocus (Dothideomycetes). However, phylogenetic analysis showed that P. lotorum (CBS 235.78) nested within Thysanorea and clustered with Minimelanolocus submersus (KUMCC 15–0206). Therefore, Hernández-Restrepo et al. (2020) synonymized P. lotorum and M. submersus under Thysanorea lotorum. In the phylogenetic analysis, our collection clustered with T. lotorum clade (Fig. 2), and our collection resembles T. lotorum in having unbranched, straight or slightly flexuous conidiophores that are gradually paler towards the apex, integrated, sympodially proliferating, terminal conidiogenous cells, and clavate or fusiform, subhyaline to pale brown conidia (Hyde et al. 2016b). We, therefore, identified our new collection as T. lotorum.
Figure 1 – Thysanorea lotorum (HKAS 131400). a, b Colonies on the substratum. c, d Conidiophores with conidia. e Conidiophore. f Conidiogenous cell. g Conidiogenous cell with conidium. h–n Conidia. o Germinating conidium. p, q Colonies on PDA from surface and reverse. Scale bars: c–e = 50 µm, f, g = 20 µm, h = 25 µm, i–o = 15 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.