Phaeoisaria aquatica Z.L. Luo, X.J. Su & K.D. Hyde, Mycol. Progr. 17(5): 514 (2018)

Index Fungorum number: IF821837; MycoBank number: MB 821837; Facesoffungi number: FoF 03411; Fig. 1

Saprobic on submerged decaying wood. Sexual morph Undetermined. Asexual morph Hyphomycetous. Colonies effuse, solitary, dark brown to black, hairy, covered by white conidial mass. Mycelium immersed in the substrate. Synnemata 313–727×11–23 µm (x̅=470×16 µm, n=5), erect, straight to flexuous, dark brown to black, composed of compact parallel conidiophores, wide at the base, wide at the apical fertile region. Conidiophores macronematous, synematous, septate, branched, dark brown, smooth. Conidiogenous cell 12–21×2–5 µm (x̅=17×3.5 µm, n=10), polyblastic, integrated, terminal and intercalary, sympodial, cylindrical or attenuated towards tip, hyaline to light brown, denticulate, denticle conspicuously cylindrical. Conidia 4.5–8×2–3 µm (x̅=5.5×2 µm, n=30), ellipsoid to obovoid or sub-spatulate, straight, aseptate, hyaline, smooth-walled.

Culture characteristics – Conidia germinating on PDA within 24 h and germ tubes arising from both ends. Colonies on malt extract agar (MEA), reaching 2 cm diam. after 2 weeks at room temperature, flat, circular, surface slightly rough with crenated edge, white mist at the middle region, surrounded by greenish brown towards white grey at the margin, olivaceous dark green at the reverse with surrounded by white grey at the margin.

Material examined – THAILAND, Chiang Rai Province, Muang, Mae Yao Village, saprobic on submerged decaying wood, 23 September 2019, N. Huanraluek, MY01 (MFLU 21-0071, new record), living culture, MFLUCC 21-0094.

GenBank number – ITS=MZ538522, LSU=MZ538556, TEF1-α=MZ567098.

Notes – Phaeoisaria aquatica was introduced as a new species by Luo et al. (2018), which was found on decaying submerged wood in Jinsh River in China. The strain MFLUCC 21-0094 that was isolated and described in this study, is phylogenetically related to the type strain MFLUCC 16-1298 with 94% MLBS, 1.00 BYPP support (Fig. 2). Furthermore, our strain (Fig. 1) shares similar features of dark brown synematous, compact parallel conidiophores and ellipsoid to obovoid, aseptate, hyaline conidia with Ph. aquatica (MFLUCC 16-1298), the type strain and both strains were found in freshwater habitats. Therefore, based on morphology and phylogenetic affinity, our strain MFLUCC 21-0094 is identified as Ph. aquatica and it is reported here as a new geographical record from Thailand.

Figure 1 – Phaeoisaria aquatica (MFLU 21-0071, new record). a Conidiomata synnemata on wood. b, c Conidiophores. d–f Conidiogenous cells. g, h Conidia. i Germinated conidium. j, k Culture on MEA from surface and reverse. Scale bars: b, c=300 µm, d–f=50 µm, g, h=5 µm, i=10 µm

Figure 2 – Maximum likelihood phylogenetic tree based on a combined LSU, ITS, SSU and RPB2 sequence data of genera in Pleurotheciaceae. Conioscypha peruviana CBS 137657 and C. pleiomorpha FMR 13,134 were selected as the outgroup taxa. 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 95% are given above the nodes. Ex-type strains are in bold and newly generated sequences are in blue