Periconia thysanolaenae E.F. Yang, H.B. Jiang and Phookamsak, J. Fungi 8, 243, 24 (2022)

Index Fungorum number: IF559499; MycoBank number: MB559499; Facesoffungi number: FoF16122

Saprobic on submerged decaying wood. Asexual morph: Colonies superficial, scattered, effuse, hairy, brown, with loose conidia clump in the apex of conidiophores. Mycelium partly superficial, partly immersed, composed of branched, septate, smooth, brown hyphae. Conidiophores 130–240 × 3.5–6.4 µm (x̅ = 179.7 × 4.8 µm, n = 10), macronematous, mononematous, solitary, straight or slightly flexuous, septate, brown to dark brown, smooth to minutely verrucose, thick-walled, occasionally branched at the apex. Conidiogenous cells 4.2–5.9 × 3.4–5.4 µm (x̅ = 5 × 4.1 µm, n = 10), polyblastic, integrated, terminal, ovoid to subglobose, brown, proliferating. Conidia 4–6 × 3.9– 5.7 µm (x̅ = 4.9 × 4.6 µm, n = 40), catenate or solitary, globose, pale brown to dark brown, aseptate, slightly verrucose, thin-walled. Sexual morph: Undetermined.

Culture characteristics – Conidia germinating on PDA within 12 h, and germ tubes produced from the surface. Colonies on PDA reaching 25 mm diameter after 2 weeks of incubation at room temperature. Mycelium dry, dense, colonies on the surface of PDA, with regular edges, fluffy, white, velvet. Reverse brown, 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-3277 (HKAS 131352), living culture KUNCC 23–13708.

Notes – Phylogenetic analysis showed that our new collection (KUNCC 23–13708) clustered with the type strain of Periconia thysanolaenae (KUMCC 20–0262) with 97% ML/1.00 PP support. Our new collection fits well with the description of P. thysanolaenae in having conidiophores that are branched at the apex, polyblastic, terminal, ovoidal to subglobose conidiogenous cells, and small (4–6 × 3.9–5.7 vs. 4.5–6 × 4–6 µm), catenate or solitary, globose, aseptate, rough-walled conidia. Comparison of the LSU, ITS, SSU, and tef1-α sequences of our new collection and the holotype of P. thysanolaenae showed 99.49% (785/789 bp, two gaps), 99.81% (512/513 bp, one gaps), 100% (1002/1002 bp) and 99.89% (896/897 bp) similarity, respectively. Periconia thysanolaenae was introduced by Yang et al. (2022) on dead culms of Thysanolaena latifolia (Poaceae) in Yunnan Province, China. This is the first report of this species from a freshwater habitat.

Figure 1 – Periconia thysanolaenae (HKAS 131352). a Colony on the substratum. b Conidiophore. c-e Conidiophores with conidia. f-h Conidiogenous cells and conidia. i Conidia. j Germinated conidium. k, l Colonies on PDA from the surface and reverse. Scale bars: b-d = 50 µm, e = 30 µm, f, g, j = 10 µm, h = 15 µm, i = 5 µm.

Figure 2 – RAxML tree based on analysis of Periconia that combined LSU, ITS, tef1-α, and SSU dataset. The combined analyses include 86 strains with 3216 characters, including gaps (LSU: 830 bp, ITS: 502 bp, tef1-α: 874 bp, and SSU: 1010 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 Massarina cisti (CBS 266.62) and M. eburnea (CBS 473.64). The new collections are indicated in red. Ex-type strains are indicated with “T” after the strain number.