Helminthosporium velutinum Voglmayr & Jaklitsch, Stud. Mycol .

Helminthosporium velutinum Voglmayr & Jaklitsch, Stud. Mycol. View in CoL 87: 43–76. (2017)

MycoBank number: MB 250075; Facesoffungi number: FoF 01053. Fig. 3 View FIGURE 3

Saprobic on dead twigs of Camellia sinensis . Sexual morph: Undetermined. Asexual morph: Colony on natural substrate superficial, effuse, hairy, dark brown to black. Mycelium superficial, numerous, hairy, black, scattered, solitary or fasciculate, septate, unbranched, smooth, thick‐walled hyphae. Conidiophores 402–723 µm long ( x = 660 µm, n = 20), 12–24 µm wide ( x = 21 µm, n = 20), macronematous, mononematous, erect, straight or flexuous, solitary or in groups of 2-4, thick‐walled, subcylindrical, septate, brown to black, obtuse at apex. Conidiogenous cells monoto poly‐tretic, integrated, terminal and intercalary, cylindrical, brown, smooth. Conidial secession schizolytic. Conidia 45–96 µm long ( x = 65 µm, n = 40), 16–29 µm wide ( x = 21 µm, n = 40), tapering to 5.8–10.2 µm ( x = 7.7 µm, n = 20) at the distal end, with a blackish-brown 4–7 µm ( x = 5.5 µm, n = 40) wide scar at the base, 6–12 distoseptate; with an angular lumina, wall up to 3.6–4.9 µm ( x = 4.3 µm, n = 20) thick. cylindrical, obclavate, phragmoconidia, acropleurogenous, verruculose, straight or flexuous, uneven width, rounded at apex, thick-walled, pale taupe brown to dark brown.

Culture characteristics:— Conidia germinating on PDA within 24 h and germ tubes arising from cells of the arms. Colonies growing on PDA reached a diam. of 22 mm after 2 weeks at 25 °C. Velvety, white to pale green, raised in center, with denser mycelium at the center; reverse dark brown to black with white edges.

Material examined:— CHINA, Sichuan Province, Qionglai City, Tiantaishan Town , 30°15′58''N, 103°6′25''E, 1,000–1,250m, on dead twigs of tea ( Camellia sinensis ), 18 September 2023, M.F. Chi, X.D. Liang, T03 (HUEST 24.0219; living culture UESTCC 24.0202) GoogleMaps ; ibid., Sichuan Province, Leshan City, Muchuan County, Muxi Town , Jianhe Township , 28°53′45''N, 103°49′58''E, 1,000–1,200 m, on dead twigs of tea ( Camellia sinensis ), 24 October 2023, M.F. Chi, X.D. Liang, LJ03 (HUEST 24.0220; living culture UESTCC 24.0203) GoogleMaps ; ibid., Sichuan Province, Meishan City, Hongya County, Wawushan Town , Fuxing Village , 29°64′29’’N, 102°93′22’’E, 1,000-1,500 m, on dead twigs of tea ( Camellia sinensis ), 17 July 2023, M.F. Chi, X.D. Liang, EM18 (HUEST 24.0221; living culture UESTCC 24.0204) GoogleMaps .

Notes: — Helminthosporium velutinum is the most widely distributed and frequently recorded species in this genus, which has been documented on a broad range of woody and herbaceous substrates, with over 110 known host records ( Farr 2022). Zhu et al. (2016) was the first to report H. velutinum from a freshwater habitat in China, which is an uncommon environment for this species. Currently, H. velutinum has been observed in both freshwater and terrestrial environments in China ( Voglmayr et al. 2017, Chen et al. 2022, Tian et al. 2024). Multi-locus analysis of combined ITS, LSU, SSU, rpb 2, and tef 1-α sequence data indicate that our collection groups with H. velutinum strains (CBS 139923), supported by 99% ML and 1.00 BPP statistical values. Additionally, our collection (UESTCC 24.0202, UESTCC 24.0203, UESTCC 24.0204) exhibit morphological characteristics similar to the type strain of H. velutinum strains (CBS 139923), with the shape and color of colonies. Colonies on natural substrates are effuse, black, hairy while the conidiophores are simple, straight or flexuous, cylindrical, smooth, brown to dark brown, with well-defined small pores at the apex. Conidia are with blackish-brown to black scars at the base, obclavate to rostrate, smoothwalled, pale golden brown to brown, 6-18 distoseptate ( Voglmayr et al. 2017). Hence, based on both morphological comparison and phylogenetic analysis, we report our collection as a new host record on Camellia sinensis .