Pleosporales » Leptosphaeriaceae » Leptosphaeria

Leptosphaeria doliolum

Leptosphaeria doliolum (Pers.) Ces. & De Not., Comm. Soc. crittog. Ital. 1(fasc. 4): 234 (1863)

Index Fungorum number: IF 161618; Facesofungi number: FoF 00391

Saprobic on decaying stem of Urtica dioica L. Sexual morph: Ascomata 154–211 μm high × 160–225 μm diam. (x̄ = 177 × 201 μm, n = 6), superficial, semi-immersed at the base, solitary, scattered, globose to subglobose, apically conical, wider and flattened at the base, carbonaceous, glabrous, black, ostiolate, with a shiny papilla. Peridium 24–39 μm, thick-walled, multi-layered, comprising cells of textura angularis, cells thick-walled at external layers, inner layer of thin-walled cells, surface heavily pigmented. Hamathecium comprising numerous, 1–2 μm wide, long cylindrical, cellular, branched, septate, hyaline, pseudoparaphyses, anastomosing above the asci. Asci 52–71 × 4–5 μm (x̄ = 63 × 4 μm, n =15), 8-spored, bitunicate, fissitunicate, narrowly cylindrical, short pedicellate or apedicellate, rounded at the apex, with a small ocular chamber. Ascospores 15–19 × 2–3 μm (x̄ = 18 × 3 μm, n = 15), overlapping uni-seriate, 3-septate, straight or slightly curved, constricted at the septa, yellowish brown to brown, guttulate, lacking a mucilaginous sheath, smooth-walled. Asexual morph: Undetermined.

Culture characters: Ascospores germinate on MEA at 18 °C within 24 h and germ tubes produced from both ends of ascospores. Colonies on MEA fast growing, white-gray. Mycelium septate, branched, hyaline to light brown, and smooth..

Material examined: ITALY, Province of Forlì-Cesena [FC], Monte Fumaiolo, on stems of Urtica dioica L. (Urticaceae), 3 July 2013, E. Camporesi IT661 (MFLU 14-0565), living culture, MFLUCC 13-0740.

GenBank: ITS: KP729444, LSU: KP729445..

Notes: Leptosphaeria was introduced by Cesati and De Notaris (1863) and included 26 species, with L. doliolum selected as the lectotype species for the genus (Shearer et al. 1990). Confusion surrounding the type of L. doliolum has been discussed in Hyde et al. (2013). Due to the uncertainty of the placement of this genus, several authors have included it under different families, such as Leptosphaeriaceae (Barr 1987, Eriksson and Hawksworth 1991) or Phaeosphaeriaceae (Eriksson and Hawksworth 1986). Previous studies based on multi-gene analysis showed that Leptosphaeria clustered within the order Pleosporales, in the family Leptosphaeriaceae. Species of Leptosphaeria (including the type of Leptosphaeriaceae) and Neophaeosphaeria form a paraphyletic clade with moderate bootstrap support (Schoch et al. 2009, Zhang et al. 2012a, b). In our study, we signify an additional collection for the type of L. doliolum to stabilize the placement of the genus in Leptosphaeriaceae which is morphologically and phylogenetically identical to the epitypified strain of L. doliolum (CBS 541.66).