Helminthosporium submersum Z.L. Luo, N. Zhao, K.D. Hyde & H.Y. Su, 2018

Zhao, Na, Luo, Zong-Long, Bhat, Darbhe J., Liu, Jian-Kui, Bao, Dan-Feng, Hao, Yu-E, Su, Hong-Yan & Hyde, Kevin D., 2018, Helminthosporium submersum sp. nov. (Massarinaceae) from submerged wood in north-western Yunnan Province, China, Phytotaxa 348 (4), pp. 269-278 : 274-275

Helminthosporium submersum Z.L. Luo, N. Zhao, K.D. Hyde & H.Y. Su , sp. nov. Figure 2

Index Fungorum number: IF553931; Facesoffungi number: FoF 03770.

Etymology: Referring to the submerged habitat of this fungus.

Holotype: MFLU 17-1429

Saprobic on decaying, submerged wood in freshwater. Sexual morph: undetermined. Asexual morph: Colonies effuse, velvety, dark brown or black. Mycelium immersed, composed of septate, branched, smooth, thick-walled hyphae. Conidiophores 239–423 μm long (x = 331 μm, SD = 92, n = 15), 8.5–15.5 μm wide (x = 12 μm, SD = 3.5,

n = 15), mononematous, macronematous, solitary or in group of 2–4, straight or curved, 9–14-septate, unbranched,

dark brown, smooth, paler towards to the apex, bulbous at base. Conidiogenous cells mono- to polytretic, cylindrical, integrated, terminal and intercalary, with noncicatrized, distinct pores. Conidia 41–55 μm long (x = 48 μm, SD = 7, n = 30), 14.5–18.5 μm wide (x = 16.5 μm, SD = 2, n = 30). 6–10-distosepate, smooth, pale brown to mid-brown, guttulate.

straight or curved, wider below than apex, truncate and dark at base, apically rostrate and pale. Conidial secession schizolytic.

Material examined:— CHINA, Yunnan Province, saprobic on decaying wood submerged in Lancang River, April

2015, H.Y. Su, HL 8-13-1 (MFLU 17-1429 holotype, HKAS 92961 isotype), ex-type living culture, MFLUCC 16-

1360; saprobic on decaying wood submerged in Jinsha river, April 2015, X.J. Su, JSJ H 28-1-1 (MFLU 17-1430

paratype, HKAS 92861), living culture MFLUCC 16-1290; saprobic on decaying wood submerged in a stream in Cangshan Mountain , June 2016, S.M. Tang, 3XP H 2-22-1, living culture DLUCC 0805 .

Notes:—Three isolates of Helminthosporium submersum were isolated from three different locations (mentioned above) along the stream. The phylogenetic analysis based on combined ITS, LSU, SSU, RPB 2 and TEF1α sequence data coupled with the morphological characters show that they are one species. Helminthosporium submersum is agrees with the generic concept of Helminthosporium in having tretic conidiogenesis, distoseptate conidia with narrow,

truncate, basal conidial scars, conidiogenous cells with simple, flat-ringed pores and conidia are borne on septate,

erect or curved conidiophores. Helminthosporium submersum is morphologically similar to H. velutinum but can be distinguished by phylogenetic analysis ( FIG. 1 ).

Figures

FIGURE 1. Phylogram generated from maximum likelihood analysis (RAxML) based on combined ITS, LSU, SSU, RPB2 and TEF1α sequence data for the families Corynesporaceae, Massarinaceae and Periconiaceae. Bootstrap support values for maximum likelihood (ML) greater than 75% and Bayesian posterior probabilities (PP) greater than 0.95 are given above the nodes. The tree is rooted to Cyclothyriella rubronotata (TR9, TR). Newly generated sequences are indicated in red and ex-type strains are in bold.

FIGURE 2 Helminthosporium submersum (MFLU 17-1429, holotype) a Colonies on decaying wood. b–d Conidiophores and conidia. e–g Conidiogenesis. h–m Conidia. n–o Culture on PDA after 21 days (o from below). Scale bars: b, d =100 μm, c = 200, e–g = 50, h–m = 30 μm.