Bartalinia bidenticola Htet, Mapook & K.D. Hyde, sp.nov.
Index Fungorum number: IF 559553; MycoBank number: MB 559553; Facesoffungi number: FoF 10766; Fig. 1
Etymology – The name refers to the host plant from which it was collected Bidens pilosa.
Holotype – MFLU 22-0103
Saprobic on dead stems of Bidens pilosa. Sexual morph: Not observed. Asexual morph: Conidiomata 120–130 × 190–200 μm ( x̄ = 123 × 196 μm, n = 5), uniloculate, solitary, immersed to semi-immersed, globose to subglobose. Ostiole absent. Peridium 23–30 μm wide, 3–4 layered, comprised of brown cells of textura globulosa. Conidiogenous cells 1–2 μm wide, filiform, hyaline. Conidia 23–27 × 4–6 µm, (x̄ ±SD =24.9±0.8 × 4.9±0.3 µm), fusoid to ellipsoid, straight to slightly curved at the apex, 4-septate, constricted ate the septa, brown in three middle cells and hyaline at the basal and apical cells; basal cells 2–4 µm long, hyaline, obconic to conic with a truncate base, thin-walled; three median cells 14–18 µm long, (x̄ ±SD =15.8±0.8 µm), (second cell from the base pale brown, 6–7 μm long; third cell pale brown, 4–6 μm long; fourth cell pale brown, 4–7 μm long), doliiform, wall rugose, versicoloured; apical cells 3–6 µm long, hyaline, subcylindrical, smooth-walled; with 2–3 tubular appendages (mostly 2), unbranched, filliform (13–)17–24(–24) µm long, (x̄ ±SD =22.7±2.7 µm); basal appendage single, tubular, unbranched, centric 4–8(–10) µm long.
Culture characteristics – Spores germinating on MEA within 24 h, reaching 50 mm after 7 days at room temperature, irregular, undulate, concentric, flat, leathery surface, grey.
Material examined – Thailand, Chiang Rai Province, Doi Pui, on the dead stems of Bidens pilosa Linn var radiata (Asteraceae), 10 July 2020, Zin Hnin Htet SW35 (MFLU 22-0103, holotype), ex-type living culture (MFLUCC 22-0008).
GenBank numbers – ON715467(LSU), ON715520(ITS).
Notes – Bartalinia bidenticola (MFLUCC 22-0008) resembles Bartalinia in having subcylindrical to fusoid, pale yellow septate conidia, with an apical cell modified into branched appendages. According to the BLASTn results, the closest match for the LSU sequence of Bartalinia bidenticola (MFLUCC 22-0008) was Bartalinia kevinhydei (MFLUCC 12-0384) with 97.32% similarity and the closest match for ITS sequence was Bartalinia pondoensis (CCTU 459) with 98.85% similarity. Phylogenetic analyses of a combined ITS and LSU sequence dataset (Fig. 2) show that Bartalinia bidenticola (MFLUCC 22-0008) is phylogenetically well distinguished and branched off from all other species in Bartalinia with ML=100% and BYPP=1.00 support. We, therefore, identify our isolate as a new species which was found from Bidens pilosa.
Figure 1 – Bartalinia bidenticola (MFLU 22–0103, holotype). a,b Appearance of conidiomata on host substrate. c Section through conidioma. d Peridium. e Conidia on the conidiogenous cells. f–i Conidia. j–k Germinating conidia. l–m Culture on MEA from surface and reverse. Scale bar a=300 µm, b=200 µm, c=50 µm, d=20 µm, e=10 µm, f,g,h,I,j,k,l,m=20 µm
Figure 2 – Phylogram generated from maximum likelihood analysis based on combined LSU and ITS sequence data for Bartalinia. Twenty taxa were included in the combined analyses, which comprised 1479 characters (LSU=897 bp, ITS=582 bp) after alignment. Bootstrap support values for maximum likelihood (ML)≥50% and clade credibility values≥0.90 from Bayesian inference analysis are labelled at each node. Ex-type strains are in bold and the new isolate is indicated in blue bold. Hymenopleella endophytica (APBSWTPF108, EML AS5-1, EML AS5-2) were used as the outgroup taxa