Palmiascoma gregariascomum Phookamsak & K.D. Hyde, in Liu et al., Fungal Diversity: https://doi.org/10.1007/s13225-015-0324-y, [65] (2015).
MycoBank number: MB 550927; Index Fungorum number: IF 550927; Facesoffungi number: FoF 00429; Fig. 1
Saprobic on dead twigs of Rosa sp. Sexual morph: See Liu et al. (2015). Asexual morph: Conidiomata 140–200 μm high, 130–220 μm diam. (x̅=172×165 μm, n=5), pycnidial, solitary or aggregated, immersed, erumpent neck, visible as black, uni- to multi-loculate, globose to subglobose, rarely irregular, glabrous, ostiole central, with minute papilla. Conidiomata walls 14–38 μm (x̅=27 μm, n=8), wide, thick-walled, of equal thickness, composed of several layers of hyaline to dark brown, pseudoparenchymatous cells, outer layers comprising 4–5 cell layers of 6–12×2–5 μm (x̅=8.7×3.4 μm, n=15), thick-walled, dark brown to black, organized in a textura angularis to textura prismatica cells, inner layers comprising 2–3 layers of 3–8×2–4 μm (x̅=5.3×3.2 μm, n=15), thin-walled, hyaline, organized in a textura angularis. Conidiophores arising from basal cavity of conidiomata mostly reduced to conidiogenous cells. Conidiogenous cells 5–7×1–2 μm (x̅=5.8×1.6 μm, n=25), holoblastic, phialidic, discrete, ampulliform to cylindrical, hyaline, aseptate, smooth-walled, guttulate. Conidia 3.2–4.5×1.7–2.4 μm (x̅=3.7×2.1 μm, n=35), in culture Conidia 3.4–4.7 × 1.6–2.5 μm (x̅=4.1 × 2.1 μm, n=35), solitary, one-celled, oblong to ellipsoidal, with rounded or obtuse ends, initially hyaline, becoming brown at maturity, smooth-walled.
Culture characteristics – Colonies on PDA fast growing, 33–37 mm diam. after 2 weeks at 25–30 °C, greenish-grey to grey, forming white tufts on surface, slightly radiating; reverse brown to dark brown at the margin, dark brown to black in the centre; medium dense, circular, flattened to slightly raised, dull to rough with entire edge, fairy fluffy to velvety, slightly radially furrowed.
Material examined – Thailand, Mueang, Chiang Rai District, Chiang Rai 57100, (20° 03′ 24.7′′ N, 99° 52′ 23.5′′ E), dead twigs of Rosa sp. (Rosaceae), 20 August 2017, MC. Samarakoon, SAMC070 (MFLU 18–0845, HKAS 102350), living culture MFLUCC 18-0505.
Hosts – on dead frond of palm (Liu et al. 2015), Rosa sp. (this study)
Distribution – Thailand (Liu et al. 2015; this study)
GenBank numbers – OM293742 (LSU), OM293753 (SSU), OM305060 (tef1), OM305066 (tub2)
Notes – Our new collection of Palmiascoma gregariascomum is described on dead twigs of Rosa species from Thailand. We found the asexual morph of the taxon with a similar range of conidiogenous cells (5–7 × 1–2 μm vs 5–12 × 2–4 μm) and conidia (3.2–4.5 × 1.7–2.4 μm, 3.4–4.7 × 1.6–2.5 μm vs 4–6 × 2–3 μm) in morphologies compared to the type species (MFLU 11-0211). In multigene phylogeny, our strain clusters with MFLU 11–0211 with high statistical (81/ML, 1.00 BYPP) support. Based on similar morphology and phylogenetic analyses, here we provide a new host record of Palmiascoma gregariascomum on Rosa sp. from Thailand (Fig. 2).
Figure 1 – Palmiascoma gregariascomum (MFLU 18–0845, new host record) a-c Conidiomata on the substrate. d Vertical section of conidioma. e Peridium. f–h Conidiogenous cells and conidiogenesis. i,o Conidia (o in culture), j Top view of culture in PDA. k Reverse view of culture. l,m Conidiomata on PDA. n Peridium. Scale bars: a,l=1000 µm, b=500 µm, c,m=200 µm, d=50 µm, e=20 µm, n=10 µm, f-i,o=5 µm
Figure 2 – Phylogram generated from maximum likelihood analysis based on combined LSU, SSU and tef1 sequenced data for Bambusicola and allied genera Twenty-two strains are included in the combined sequence analyses, which comprise 2761 characters with gaps. Murilentithecium clematidis (MFLUCC 14–0562) is used as the outgroup taxon. Tree topology of the ML analysis was similar to the BYPP. Bootstrap support values for ML≥50% and BYPP≥0.95 are given above the nodes. New strain is in red. Ex-type and representative strains are in bold