Dendryphion verrucosum S. Luan, H.W. Shen & Z.L. Luo, 2024

Wang, Wen-Peng, Luan, Sha, Shen, Hong-Wei, Liu, Ning-Guo, Li, Yun-Xia & Luo, Zong- Long, 2024, Two new freshwater dematiaceous hyphomycetes of Pleosporales from Yunnan Province, China, Phytotaxa 676 (1), pp. 63-74 : 69

Dendryphion verrucosum S. Luan, H.W. Shen & Z.L. Luo , sp. nov. FIGURE 3 .

Index Fungorum number: IF902832

Etymology:—Referring to the verrucose conidia of this fungus.

Holotype:—KUN-HKAS 130436

Saprobic on submerged decaying wood in a freshwater habitat. Asexual morph: Hyphomycetous. Colonies on the substratum superficial, scattered, effuse, hairy, brown to dark brown. Mycelium is mostly immersed, composed of branched, septate, pale brown to brown hyphae. Conidiophores 97–171 × 3.4–6.4 µm (x = 130 × 5 µm, n = 10), macronematous, mononematous, erect, straight to flexuous, cylindrical, brown, thick-walled, septate, simply branched in the upper part. Conidiogenous cells polytretic, integrated, terminal to intercalary, pale brown to brown. Conidia 10–26(–41) × 5.4–8.2 µm (x = 18 × 6.7 µm, n = 50), mostly solitary, sometimes catenate to branched, monilioid, composed of subglobose to globose cells, dry, straight or slightly curved, rounded at both ends, pale brown to brown, (1–)2–8-septate, constricted at septum, verrucose. Sexual morph: Undetermined.

Culture characteristics:—Conidia germinating on PDA within 12 hours and germ tubes produced from both sides. Colonies on PDA reach 3 cm in 3 weeks at room temperature. Mycelium dry, dense, colony circular, surface flat, with entire edges, white to greyish brown from above, white in center, becoming blue to black from below.

Material examined:— China, Yunnan Province, Erhai Lake (25°42′38.76″N, 100°14′03.32″E, 1963m), on submerged decaying wood, 20 March 2021, Si-Ping Huang, L-227 (KUN-HKAS 130436, holotype), ex-type culture CGMCC 3.27013 = KUNCC 23–16367.

Notes:—In the phylogenetic analysis, Dendryphion verrucosum is sister to D. aquaticum , D. comosum , and D. europaeum with 0.97 PP support ( FIGURE 4 ). However, Dendryphion verrucosum has significantly smaller conidiophores size than D. aquaticum , D. comosum , and D. europaeum ( TABLE 2). Additionally, Dendryphion aquaticum , D. comosum , and D. europaeum have penicillate branches at the tip, but D. verrucosum only has simple branches ( TABLE 2). We, therefore, identify Dendryphion verrucosum as a new species in Dendryphion .

Figures

FIGURE 3.Dendryphion verrucosum (KUN-HKAS130436,holotype).aColonies onthe substratum.bConidiophores.c, d Conidiophores and conidia. e–k Conidia. l Germinated conidium. m, n Colony on PDA from front and reverse. Scale bars: b–d = 30 µm, e–l = 10 µm.

FIGURE 4. RAxML tree generated from combined ITS, LSU, tef1-α, rpb2, and SSU dataset. The combined analyses include 33 strains with 4196 characters (ITS: 1–493 bp, LSU: 494–1317 bp, tef1-α: 1318–2159 bp, rpb2: 2160–3209 bp, and SSU: 3210–4196 bp). The tree is rooted with Ohleria modesta (CBS 141480 and Wu 36870). Tree topology of the maximum likelihood analysis and Bayesian analysis are similar. The best RAxML tree with a final likelihood value of –14602.166902 is presented. The matrix had 1000 distinct alignment patterns, with 38.71% undetermined characters or gaps. Estimated base frequencies were as follows: A = 0.244739, C = 0.259730, G = 0.270612, T = 0.224919; substitution rates AC = 1.809641, AG = 3.424483, AT = 1.833075, CG = 0.961050, CT = 8.952848, GT = 1.000000, gamma distribution shape parameter α = 0.132609 and tree-length = 0.776520. Bootstrap values for ML ≥ 75% and Bayesian posterior probabilities (PP) ≥ 0.95 are labelled on the nodes. The newly obtained sequence is indicated in red, and ex-type strains are in bold.