Torula mackenziei J.F. Li, Phookamsak & K.D. Hyde, Mycol Progress 16: 447–461 (2017)

Index Fungorum number: IF 819537; MycoBank number: MB 819537; Facesoffungi number: FoF 02714; Fig. 1

Saprobic on submerged wood in a freshwater habitat. Sexual morph Undetermined. Asexual morph Colonies on the substrate superficial, effuse, hairy, powdery, black. Mycelium immersed on the substrate, composed of septate, branched, smooth, light brown hyphae. Conidiophores 7–20(–48)×3–5 μm (x̅=13×4 μm, n=15), macronematous, mononematous, solitary, erect, minutely verruculose, thick-walled, without apical branches, brown, ellipsoid to subglobose. Conidiogenous cells 5–7×4–6 μm (x̅=6×5 μm, n=15), polyblastic, terminal, dark brown to black, paler at apex, smooth to minutely verruculose, thick-walled, globose to ellipsoid, discrete. Conidia 13–20 × 6–7 μm (x̅=16 × 7 μm, n=50) acrogenous, catenated, yellowish brown to dark brown, minutely verruculose, 3–5-septate, rounded at both ends, paler yellowish at apex, composed of moniliform cells, slightly constricted at septa, doliiform to globose, in beadlike chains, with conidial chains in branches. Conidial secession schizolytic.

Culture characteristics – Conidia germinated on PDA within 24 h, and the germ tube produced by a certain conidial cell at either end or in the center. Colonies grow on PDA, and after incubating at room temperature for 1 month, the diameter reaches about 5 cm. Hyphae are initially white to light grey, and then gradually become grey to brown, with convex middle, flocculent, gray to brown, smooth edges and dark grey; reverse light grey in the middle, dark gray to black, smooth edges.

Material examined – CHINA, Yunnan Province, Kunming City (103°08′59″ E 24°37′53″ N, 1790 msl), on submerged wood, 13 May 2018, H.W. Shen and X. He, S-1837 (HKAS 112705, new record), living culture, DLUCC 1837.

GenBank numbers – ITS = MW723058, LSU = MW879525, SSU = MW774581, RPB2=MW729779, TEF1-α: MW729784.

Notes – In the phylogenetic analyses our strain clustered with the type of Torula mackenziei (MFLU 16-2820) with 100% ML, 1.00 BYPP support (Fig. 2). Torula mackenziei was collected from a dead branch of Bidens pilosa in Doi Mae Salong, Chiang Rai Province, Thailand (Li et al. 2017). Compared with T. mackenziei, our strain has larger conidiophores (7–20 × 3–5 μm vs. 3–4.3 × 3.4–3.7 μm),

Figure 1 – Torubla mackenziei (HKAS 112705, new record). a Colonies on submerged wood. b–f Conidiophores with conidiogenous cells and conidia. g, h Conidia. i–k Conidia in catenated chain. l–o Branched chains of conidia. p Germinated conidium. q Culture on PDA from surface and reverse. Scale bars: a–p=10 μm

Figure 2 – Phylogram generated from maximum likelihood analysis based on combined LSU, SSU, TEF1-α, RPB2 and ITS sequence dataset representing genera of Torulaceae and other related families in Pleosporales. The updated sequence dataset was derived from Hyde et al. (2020b) and Li et al. (2020a). Forty-seven strains are included in the combined analyses which comprise a total of 4193 characters. Paeadictyoarthrinium diffractun MFLUCC 13-0466 and P. hydei MFLUCC 17-2512 are selected as the outgroup taxa. The best RAxML tree with a final likelihood value of − 20632.568415 is presented. RAxML analysis yielded 1256 distinct alignment patterns and 34.11% of undetermined characters or gaps. Estimated base frequencies were as follows: A=0.246275, C=0.259573, G=0.270969, T=0.223183, with substitution rates AC=1.544243, AG=3.270041, AT=1.437706, CG=0.944551, CT=7.854806, GT=1.000000; gamma distribution shape parameter alpha=0.178530. 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