Pleosporales » Didymosphaeriaceae » Montagnula

Montagnula graminicola

Montagnula graminicola Chethana, Thambug., Camporesi & K.D. Hyde, in Liu et al., Fungal Diversity: 10.1007/s13225-015-0324-y, [88] (2015)

Index Fungorum number: IF 550763; Facesofungi number: FoF 00379

Etymology: The specific epithet graminicola was given after the host family Graminae in which the fungus was collected.

Holotype: MFLU 14-0622.

Saprobic on a dead stem of grass. Sexual morph: Ascomata 37–117.22 μm diam. (x̄ = 56.67 μm, n = 20), pseudothecia, mostly solitary, semi-immersed to erumpent, black, globose to subglobose, coriaceous, with a minutely papillate ostiole. Peridium 14.9 μm thick at sidewalls, up to 16 μm thick near the apex and 9 μm thick at the base, consisting of a 3–4 layers of cells, outer 3–4 layers of thick-walled, dark brown cells of textura angularis and 2–3 layers of hyaline to pale brown inner cells. Hamathecium comprising 2–3μm wide, filiform, hyaline, septate, pseudoparaphyses, anastomosing above the asci, embedded in a gelatinous matrix. Asci (45–)50–132(–137) × (6–)8–13(–15) μm (x̄ = 81.3 × 10.10 μm, n = 10), 8-spored, bitunicate, fissitunicate, cylindrical to clavate, long pedicellate and apically rounded with a small ocular chamber distinct at immature asci. Ascospores (7.8–)9.8–13(– 15) × (2.8–)3.8–5.5(–6.5) μm (x̄ = 11.3 × 4.9 μm, n = 25), partially overlapping, biseriate, ellipsoidal, tapering towards the ends, brown, two-celled, septate median, slightly constricted at the septum, wall verruculose, surrounded by a mucilaginous sheath. Asexual morph: Undetermined.

Culture characters: Ascospores germinated on water agar within 48 h with 3–4 μm diam. germ tubes. Colonies slow-growing on PDA, attaining 6 mm diam. after 14 days at 28 °C, entire edged, white to pale white, dense, cottony mycelium on the surface and reverse pale white colour mycelium.

Material examined: ITALY, Province of Forlì-Cesena [FC], Montebello, Modigliana, on dead stem of grass (Graminae), 27 May 2013, E. Camporesi (MFLU 14-0622, holotype); ex-type living cultures, MFLUCC 13-0352.

GenBank: ITS: KM658314, LSU: KM658315, SSU: KM658316.

Notes: Montagnula was established by Berlese (1896), with M. infernalis and M. gigantea based on the presence of hyphal stromatic tissue over the ascomata and long pedicellate asci. Montagnula infernalis was selected as the lectotype species and the genus was characterized by immersed to erumpent, globose to subglobose ascomata, bitunicate, cylindro-clavate to clavate, pedicellate asci and reddish-brown to dark yellowish-brown, muriform, or phragmosporous ascospores (Ariyawansa et al. 2014b). Leuchtmann (1984) and Aptroot (1995) included some phragmosporous and didymosporous species, making it heterogenous (Hyde et al. 2013; Ariyawansa et al. 2014a). Previous phylogenetic analyses have shown the robust clustering of M. opulenta with Bimuria, Didymocrea, Letendrea, Paraphaeosphaeria, Didymosphaeria, Pseudocamarosporium, Paracamarosporium, Paraconiothyrium, Tremateia, Deniquelata, Neokalmusia, Phaeodothis, Alloconiothyrium and Kalmusia forming the family clade (Zhang et al. 2009, Hyde et al. 2013, Ariyawansa et al. 2014b, Wijayawardene et al. 2014). Ariyawansa et al. (2014a) synonymized Montagnulaceae under the older family name Didymosphaeriaceae.

In the current study, a new species, Montagnula graminicola is introduced in the genus Montagnula based on the morphological and phylogenetic evidence. Our new species Montagnula graminicola is distinct from M. infernalis in having smaller ascomata, and smaller, ellipsoidal, one-celled ascospores with a sheath. Montagnula graminicola resembles M. opulenta, but differs in having smaller ascomata, and spores with verruculose wall.