Nodulosphaeria guttulatum

Nodulosphaeria guttulatum Tibpromma, Camporesi & K.D. Hyde, in Tibpromma et al., Fungal Diversity 83: 89 (2017)

Index Fungorum number: IF 552699; Facesofungi number: FoF 2790

            Etymology: ‘guttulatum’ referring to ascospore containing numerous guttules.

Holotype: MFLU 14-0712

Saprobic on dead stem of Scabiosa sp. Sexual morph: Ascomata 197–218 μm high × 163–244 μm diam. (x̄ = 206 × 199 μm, n = 5), immersed, solitary, or in small groups, uniloculate, globose to subglobose, conical at the base, black, hairy. Ostiole papillate, protruding, with numerous, short, brown to dark brown setae. Peridium 15– 30 μm wide, comprising 6–7 layers of hyaline to reddish-brown cells of textura angularis. Hamathecium 2.1–3.9 μm wide, comprising dense, numerous, aseptate, distinctly guttulate pseudoparaphyses. Asci 40–89 × 10–15 μm (x̄ = 71 × 13 μm, n = 20), 8-spored, bitunicate, fissitunicate, cylindric-clavate, with long, club-shaped pedicel, thick-walled at the apex, with a minute ocular chamber. Ascospores 29–38 × 5–6.5 μm (x̄ = 33 × 6 μm, n = 15), overlapping 1–2-seriate, hyaline when young, becoming golden yellow at maturity, fusiform, 4-septate, slightly constricted at the septum, enlarged at the second cell from apex, conical and narrowly rounded at the ends, with numerous guttulate, with circular sheath at both ends. Asexual morph: Undetermined.

            Culture characteristics: Colonies on MEA reaching 3–4 cm diam., after 7 days in the dark at 16 °C, white–gray to dark, cottony, flat, dense, with sparse aerial mycelium on the surface.           

Material examined: ITALY, Predappio Province, Rocca delle Caminate, on dead stem of Scabiosa sp. (Caprifoliaceae), 21 April 2014, Erio Camporesi, IT1826 (MFLU 14-0712, holotype); ex-type living culture MFLUCC 15-0069 (HKAS bis, paratype).

GenBank Numbers LSU:KY496726, ITS:KY496746, SSU:KY501115, RPB2:KY514405, TEF1:KY514394.

Notes: Nodulosphaeria guttulatum differs from N. aconita, N. modesta, N. scabiosae, and N. spectabilis in having ascospores that are slightly constricted at the septa, enlarged at the second cell from the apex, numerous guttules, and with a circular sheath at both ends. Phylogenetic analyses indicate that N. guttulatum is closely related to N. multiseptata with high support (90% in ML/0.98 in BYPP), but is morphologically different (Tibpromma et al. 2017).