Tubeufia roseohelicospora Y.Z. Lu, Boonmee & K.D. Hyde, Fungal Diversity 80: 128 (2016)

Index Fungorum number: IF 552222; MycoBank number: MB 552222; Facesoffungi number: FoF 02362; Fig. 1

Saprobic on submerged decaying wood. Sexual morph Undetermined. Asexual morph Hyphomycetous, helicosporous. Colonies on wood substrate superficial, effuse, hyaline to white of crowded conidiospore masses. Mycelium composed of superficial and partly immersed, anastomosing, branched, septate, brown hyphae, smooth-walled. Conidiophores (19–)59–90(–158)×3–7.5 µm, macronematous, mononematous, erect, arising from repent mycelium, flexuous, branched, septate, brown, smooth-walled. Conidiogenous cells (8–)18–40×3–6 µm, holoblastic, mono- to polyblastic, terminal or intercalary, integrated, subhyaline, bearing lateral minute denticles each with single conidium. Conidia 20–44 µm diam., with conidial filament 3–6 µm wide, with 318–563 µm long, loosely coiled 1½–4½ times, becoming loosely uncoiled in water, rounded at apical ends, indistinctly multi-septate, not constricted at the septa, hyaline, guttulate, smooth-walled.

Culture characteristics – Conidium germinating on MEA within 24 h and many germ tubes produced from conidium cells. Colonies growing on MEA, reaching greater than 10 mm diam. in 7 days at room temperature, effuse, sparsely hairy, radially striate, with fimbriate edge, dark brown, with yellow brown pigmented in the medium after 45 days. Mycelium superficial, composed of branched, septate, brown to dark brown hyphal filaments, conidial spores formed on hyphae in culture at 60 days.

Material examined – THAILAND, Chiang Rai Province, Muang, Mae Yao, Huay Mae Sai, on submerged decaying wood in a small freshwater stream, 17 March 2016, S. Boonmee, HMS14 (MFLU 21-0101, new record), living culture, MFLUCC 16-0729.

GenBank numbers – ITS=MZ538532, LSU=MZ538566, TEF1-α=MZ567107.

Notes – Tubeufia roseohelicospora was introduced by Hyde et al. (2016) to accommodate a taxon that is characterized by tightly helicoid with light pink conidia. Phylogenetic analysis of the combined LSU, ITS and TEF1-α dataset indicates that our strain MFLUCC 16-0721 is related to T. roseohelicospora isolates (MFLUCC 15-1247, MFLUCC 17-1797 and MFLUCC 17-2024) with 99% MLBS, 1.00 BYPP support (Fig. 2). Furthermore, our taxon also shares similar morphological characters (Fig. 1) with the ex-type strain MFLUCC 15-1247 provided in Hyde et al. (2016). We therefore, identify our taxon as Tubeufia roseohelicospora a new record from Chiang Rai Province, Thailand.

Figure 1 – Tubeufia roseohelicospora (MFLU 21-0101, new record). a Colony on decaying wood. b–d Conidiophores with lateral minute polyblastic denticles and attached conidia. e–j Conidia. k Germinated conidium. l, m Culture on MEA from surface and reverse after 1 month. Scale bars: a=200 µm, b, c=50 µm, d–k=20 µm

Figure 2 –  Maximum likelihood phylogenetic tree based on a combined LSU, ITS and TEF1-α sequence dataset of Tubeufia taxa and related genera in Tubeufiaceae. Eighty-four strains are included in the combined analyses which comprise a total of 2395 characters. Pseudohelicomyces talbotii (MFLUCC 17-2021) is selected as the outgroup taxon. The best RAxML tree with a final likelihood value of − 11543.960875 is presented. RAxML analysis yielded 680 distinct alignment patterns and 15.58% of undetermined characters or gaps. Estimated base frequencies were as follows: A=0.238955, C=0.251270, G=0.256785, T=0.229079, with substitution rates AC=0.670086, AG=4.164732, AT=3.398524, CG=0.528840, CT=7.628422, GT=1.000000; gamma distribution shape parameter alpha=0.148685. Bootstrap support values for maximum likelihood (MLBS, left) equal to or greater than 70% is given above the nodes. Bayesian posterior probabilities (BYPP, right) equal to or greater than 0.95 are given above the nodes. Ex-type strains are in bold and newly generated sequences are in blue