Pleosporales

Corynesporascaceae

Corynesporascaceae Sivan

Index Fungorum number: IF 81981

 

Pathogenic and saprobic on leaves. Sexual morph: Ascomata cleistothecial with conidiophores arising form cleistothecial walls, sphaerical, solitary to aggregated, superficial on mycelia, or immersed when grown in agar. Peridium thin, composed of pale brown, compressed cells, forming a texura globosa or angularis, covered by mycelia and conidiophores. Hamathecium comprising paraphysoids, with branched, septate, apically free, cylindrical hyphae, which break up when asci mature. Asci 8-spored, thick-walled, bitunicate, obovoid, deliquescent, short-stalked, fasciculate and arising to form a hymenium among deliquescent paraphysoids. Ascospores 2–3-seriate, oblong, pale to dark brown, 1-euseptate at the centre and indistinctly 1-distoseptate in the upper and lower cell, constricted at the median septum, smooth, with a somewhat slightly longer basal cell, which possesses an indistinct, hyaline area, at or near its centre, with three lenticular to globose, granular lumena, the central lumen occupying both the central cells. Asexual morph: Conidiophores formed on the superficial, floccose mycelium and cleistothecial wall, macronematous, mononematous, single or caespitose, erect, simple, straight or flexuous, subhyaline to pale brown, none to few septate, smooth, cylindrical. Conidiogenous cells monotretric, integrated, terminal, percurrently proliferating, subhyaline to pale brown, smooth, cylindrical, becoming spathulate towards the apex. Conidia solitary, obclavate, wide at the truncate base, tapering towards the apex, subhyaline to pale brown, acrogenous, unbranched, smooth-walled, straight to curved, multi to distoseptate, germinating from the apical end of the terminal cell by means of 1–4 germ tubes (Sivanesan 1996).

 

Type genus:Corynesporasca Sivan., Mycol. Res. 100(7): 786 (1996)

 

Notes: The family Corynesporascaceae was introduced by Sivanesan (1996) with Corynesporasca caryotae Sivan. as the type species, isolated from a decaying leaf of Caryota urens collected in Sri Lanka. Sivanesan (1996) linked the sexual (Corynesporasca caryotae) and asexual (Corynespora) state in culture. The Corynesporascaceae differ from Testudinaceae by its cephalothecioid peridium and hamathecium with cellular pseudoparaphyses (Hawksworth and Booth 1974; Hawksworth 1979). Didymosphaeria resembles Corynesporasca in having brown, 1-septate ascospores, but are rather small, smooth to echinulate and uni-seriately arranged inside the persistent, usually cylindrical asci, which are provided with a narrow, ocular chamber. The ascomata are immersed and clypeate unlike those in Corynesporasca. Corynesporasca has asci with a wide ocular chamber and lacks a refractive ring. Immature ascospores are 1-septate almost in the middle and appear to be faintly distoseptate in each cell. The ascospore cells have lenticular to globose lumina. The ascospores lack a mucilaginous sheath. While Massariaceae have asci with a wide ocular chamber but often surrounded by refractive, non-amyloid ring; the ascospores are usually distoseptate in some state of their development, often with lenticular to globose lumina and surrounded by a mucilaginous sheath.

 

Pyrenulaceae and Requienellaceae are similar with Corynesporasca in having distoseptate and euseptate ascospores with lumina but are distinguishable from Corynesporasca by their lichenized habit and peridium comprised of textura intricata in Pyrenulaceae, or cellular pseudoparaphyses in Requienellaceae (Aptroot 1991a, b). The Trypetheliaceae differ from Corynesporasca in having lichenized ascomata, which may be aggregated in a pseudostroma, a peridium of textura intricata and a pycnidial asexual state (Aptroot 1991a, b). Tubeufiaceae differ from Corynesporasca in having a hamathecium with cellular pseudoparaphyses and submedianly 1-septate, hyaline to yellowish brown, sheathed ascospores (Rodrigues and Samuels 1994).

 

References:

Aptroot A (1991a) A monograph of the Pyrenulaceae (excluding Anthracothecium and Pyrenula) and the Requienellaceae, with notes on the Pleomassariaceae, the Trypetheliaceae and Mycomicrothelia (lichenized and non–lichenized Ascomycetes). Bibl Lichenologica 44:1–178

Aptroot A (1991b) Monoblastia pellucida: a remarkable new lichen species from tropical coastal areas, with comments on the Monoblastiaceae. Bryologist 94:404–406

Hawksworth D.L., Booth C. (1974) A revision of the genus Zopfia Rabenh. Mycol Pap 135:1–38

Hawksworth DL (1979) Ascospore sculpturing and generic concepts in the Testudinaceae (syn. Zopfiaceae). Can J Bot 57:91–99

Hyde, K. D., Jones, E. G., Liu, J. K., Ariyawansa, H. et al. (2013). Families of dothideomycetes. Fungal diversity, 63(1), 1-313.

Rodrigues K.F., Samuels G.J. (1994) Letendraeopsis palmarum, a new genus and species of Loculoascomycetes. Mycologia 86: 254–258

Sivanesan A. (1996) Corynesporasca caryotae gen. et sp. nov. with a Corynespora anamorph, and the family Corynesporascaceae. Mycological Reseach 100:783–788

 

Recent Genus

1
Neochlamydotubeufia
Neohelicomyces

Recent Species

Neohelicomyces submersus
Neohelicomyces hyalosporus
Neohelicomyces grandisporus