Helminthosporium velutinum 2021

Helminthosporium velutinum Link [as ‘Helmisporium’], Mag. Gesell. naturf. Freunde, Berlin 3(1–2): 10, tab. 1:9 (1809) 2021

Index Fungorum Number: IF250075

Holotype:

Morphological description

Sexual morph: Undetermined.

Asexual morph: Mycelium immersed, composed of branched, septate, thick-walled hyphae. Conidiophores mononematous, macronematous, mostly unbranched, proliferating, dark brown, 96–296 × 5–7 µm (x̅ = 153 × 6 µm, n = 10), 7–12 septate, erect or flexuous, tapering towards apex, bulbous at base with cells near apex of conidiophore guttulate and fertile. Conidiogenous cells polytretic integrated, intercalary and terminal. Conidia 99–131 × 20–36 µm (x̅ = 115 × 28 µm, n = 20)single, obclavate, pale brown to brown, 6–9 distoseptate, smooth, straight or curved, base slightly truncate, cicatrized and wider than apex, dark brown, apical cell paler than other cells, rounded at apex, guttulate when young, non-guttulate at maturity.

Cultures: Colonies on PDA, reaching 21 mm diam., after 2 weeks at 20–25 oC, medium dense, circular to slightly irregular, slightly raised and cottony surface, colony from above: at first white, becoming buff; from below: blackish white at the margin, black to ash at the center; mycelium blackish.

Habitat: on a dead branch of Platanus

Distribution: : Guizhou province, China (this study), Yunnan Province, Dali, WanHua stream, China (Zhu et al. 2016)

GenBank Accession: : LSU: MW273148, SSU: MW273295, ITS: MW273144

Notes: Helminthosporium velutinum, the type species of Helminthosporium was re-visited by Voglmayr & Jaklitsch (2017) and designated the epitype and the ex-epitype. The genus was reported with the sexual morph however, Helminthosporium velutinum lacks the sexual morph (Voglmayr & Jaklitsch 2017). According to Voglmayr & Jaklitsch (2017), distribution of the species was reported as ‘Widespread and common in temperate Eurasia and America, probably almost cosmopolitan’. Zhu et al. (2016) reported Helminthosporium velutinum from submerged wood from Yunnan Province, China. In this study, we collected Helminthosporium velutinum on dead branches of Platanus sp. from Guizhou Province, China. According to Farr & Rossman (2021), a taxon named Helminthosporium spiciferum (Nicot 1953) (current name: Curvularia spicifera Index Fungorum 2021) was reported from Platanus occidentalis. Besides this record, as far as we know, Helminthosporium species have not been reported from Platanus species. Moreover, this is the first record of this genus from terrestrial habitats from China.

Reference: [1] Chen, C. ,  Zhao, L. ,  Zhu, C. ,   Wang, J. ,  Jiang, J. , &  Yang, S. . (2014). Response of diatom community in lugu lake (yunnan–guizhou plateau, china) to climate change over the past century. Journal of Paleolimnology, 51(3), 357-373.

Helminthosporium velutinum (HKAS 107064, new host record and a new record from Guizhou Province) a–c. Colony on the substrate. d. Conidiophores. e–g. Conidiophore and conidia. h–l. Conidia. m. Germinating conidium. n, o. Culture on PDA from. n. above o. below after 4 weeks. Scale bars: d = 100 μm, e–g =50 μm, h–m = 20 μm