Distoseptispora euseptata W.L. Li, H.Y. Su & Jian K. Liu, 2021

Li, Wen-Li, Liu, Zuo-Peng, Zhang, Tian, Dissanayake, Asha J., Luo, Zong-Long, Su, Hong- Yan & Liu, Jian-Kui, 2021, Additions to Distoseptispora (Distoseptisporaceae) associated with submerged decaying wood in China, Phytotaxa 520 (1), pp. 75-86 : 80

Distoseptispora euseptata W.L. Li, H.Y. Su & Jian K. Liu , sp. nov. FIGURE 2

Index Fungorum number: IF557967; Facesoffungi number: FoF 09450

Etymology: —referring to the ‘euseptate’ conidia.

Holotype: — HKAS 111958

Saprobic on decaying submerged wood in freshwater. Sexual morph: undetermined. Asexual morph: Colonies gregarious or scattered, effuse, hairy, olivaceous. Mycelium mostly immersed, comprised of branched, septate, smooth, paler brown to brown hyphae. Conidiophores 19–28 μm long (x = 23 μm, SD = 4, n = 30), 4–5 μm wide (x = 4.5 μm, SD = 0.3, n = 30), macronematous, mononematous, branched or unbranched, straight or slightly flexuous, cylindrical, smooth-walled, brown to pale olivaceous, septate, thin-walled. Conidiogenous cells, monoblastic, holoblastic, terminal, determinate, cylindrical, brown to pale olivaceous. Conidia 37–54 μm long (x = 45 μm, SD = 8, n = 30), 8–9 μm wide (x = 8.5 μm, SD = 0.7, n = 30), acrogenous, solitary, obpyriform to obclavate, straight or curved, 4–7-euseptate, often constricted at septa, guttulate, olivaceous, becoming paler towards the apex, thick-walled, smooth, rounded at apex, truncate at base.

Material examined:— CHINA, Yunnan Province, Lancang River , on submerged wood, October 2018, Z.L. Luo, LC H 5–17–1 ( HKAS 111958 , holotype), ex-type living culture MFLUCC 20–0154 ; Ibid., on submerged wood, October 2018, Z.L. Luo, LC H 1–28–2 ( MFLU 20–0568 , paratype), living culture DLUCC S2024 .

Culture characteristics:— Conidia germinate on PDA within 24 h producing the germ tubes from the apex. Colonies on PDA reach 10 mm diam. within two weeks at room temperature (25 °C) in natural light. Colonies on PDA circular, fimbriate margin, with umbonate surface, paler brown in the bump, medium gray in the middle circle, dark gray in the periphery; in reverse dark green to black.

Notes:— Phylogenetic analyses ( FIG. 1 ) indicated that two isolates of Distoseptispora euseptata clustered together and it is sister to D. bambusae and D. suoluoensis with high statistical support (100% ML, 100% MP and 1.00 PP). Distoseptispora euseptata resembles D. bambusae in having obclavate, olivaceous or brown conidia and cylindrical, unbranched, septate conidiophores, but differs from D. bambusae by its smaller conidia (37–54 μm vs. 45–74 μm) and conidiophores (19–28 μm vs. 40–96 μm) ( Sun et al. 2020). Distoseptispora suoluoensis differs from D. euseptata in having percurrent proliferations of conidia, which are not observed in D. euseptata . Distoseptispora euseptata resembles D. guttulate , D. lignicola and D. rayongensis in having euseptate conidia, but D. guttulate and D. rayongensis have rostrate conidia with the base of thicken and darken and more conidial septate than D. euseptata (11–14 vs. 9–13 vs. 4–7). Distoseptispora lignicola differs from D. euseptata by its larger conidiophores (84–124 μm vs. 19–28 μm) and conidia (60–128 μm vs. 37–54 μm).

Figures

FIGURE 1. Phylogram generated from maximum likelihood analysis (ML) based on combined LSU, ITS, tef1-α and rpb2 sequence dataset. Bootstrap support values for ML, MP greater than 75% and Bayesian posterior probabilities greater than 0.95 PP are given above the nodes as MLBS/MPBS/PP. Branches with 100% ML BS, 100% MP BS and 1.00 PP are thickened. The tree is rooted to Pseudoplagiostoma variabile (CBS 113067) and Valsella salicis (BPI 748461). Ex-type isolates are given in bold and newly generated isolates in this study are in red.

FIGURE 2. Distoseptispora euseptata (HKAS 111958, holotype) a Colonies on natural substrate. b–d Conidiophores with conidia. e–g Conidia. h Germinating conidium. i, j Culture on PDA from above and reverse (14d). Scale bars: b = 30 µm; c–d = 40 µm; e–h = 20 µm.