Distoseptispora yunnanensis 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 : 80-83

Distoseptispora yunnanensis W.L. Li, H.Y. Su & Jian K. Liu , sp. nov. FIGURE 3

Index Fungorum number: 557968; Facesoffungi number: FoF 09451.

Etymology:— The specific epithet ‘yunnanensis’ refers to the locality where the fungus was collected, Yunnan Province, China.

Holotype:— MFLU 20–0625

Saprobic on decaying submerged wood in freshwater habitats. Sexual morph: undetermined. Asexual morph: Colonies effuse, olivaceous or dark brown, hairy or velvety. Mycelium mostly immersed, consisting of unbranched, septate, smooth, hyaline to pale brown hyphae. Conidiophores 131–175 μm long (x = 153 μm, SD = 22, n = 30), 6–7 μm wide (x = 6.5 μm, SD = 0.6, n = 30), macronematous, mononematous, solitary or in groups of a few, erect, straight or flexuous, 6–10-septate, unbranched, cylindrical, smooth, brown to dark brown, round at the apex, Conidiogenous cells monoblastic, holoblastic, integrated, terminal, determinate or indeterminate, brown to olivaceous, cylindrical. Conidia 58–108 μm long (x = 83 μm, SD = 25, n = 30), 8–10 μm wide (x = 9 μm, SD = 0.9, n = 30), acrogenous, solitary, obclavate, rostrate, straight or slightly curved, 6–10-euseptate, slightly constricted at septa, mid olivaceous to brown, becoming paler towards the apex, truncate with a darkened scar at base, smooth-walled.

Material examined:— CHINA, Yunnan Province, Lancang River , saprobic on submerged decaying wood, June 2018, W.L. Li, 2L H 1–5–1 ( MFLU 20–0625 , holotype), ex-type living culture MFLUCC 20–0153 .

Cultural characteristics:— Conidia germinating on PDA within 24 h and germ tubes produced from the apex. Colonies on PDA reaching 5–10 mm diam. at 14 days at 25 °C, in natural light, circular, with fluffy, dense, dark olivaceous mycelium on surface with entire margin; in reverse dark green to black.

Notes:— The phylogenetic result ( FIG. 1 ) showed that our isolate ( MFLUCC 20–0153) clustered together with Distoseptispora bambusae , D. euseptata and D. suoluoensis , forming a distinct clade with high supported bootstrap (100% ML, 100% MP, 1.00 PP). Distoseptispora yunnanensis is phylogenetically close to D. euseptata . However, Distoseptispora yunnanensis differs from D. euseptata in having much larger conidiophores (131–175 μm vs. 19– 28 μm) and conidia (58–108 μm vs. 37–54 μm), as well as more conidial septate (6–10 vs. 4–7). Distoseptispora yunnanensis can be easily distinguished from D. bambusae by its rostrate conidia and sometimes percurrently elongating conidiogenous cells. In addition, Distoseptispora yunnanensis has larger conidiospores (131–175 μm vs. 40–96 μm) and conidia (58–108 μm vs. 45–74 μm) ( Sun et al. 2020). The conidiogenous cells of D. suoluoensis are lageniform or cylindrical with truncate apex, while they are cylindrical with rounded apex in D. yunnanensis ( Yang et al. 2017) .

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 3. Distoseptispora yunnanensis (MFLU 20-0625, holotype) a Colonies on natural substrate. b–e Conidiophores with conidia. f–i Conidiogenous cells. j–l Conidia. m Germinating conidia. n, o Culture on PDA from above and reverse (14d). Scale bars: b = 80 µm; c–e = 60 µm; f, g = 30 µm; h–k, m = 40 µm; l = 50 µm.