Corynespora Güssow, Z. PflKrankh
Index Fungorum number: IF 7795
Pathogenic and saprobic on leaves or submerged wood. Sexual morph: Ascomata solitary to aggregated, superficial or immersed, uniloculate, globose, dark brown to black, lacking ostioles. Peridium comprising several layers of thin-walled, brown cells of textura globosa or angularis. Pseudoparaphyses cylindrical, branched, septate, apically free, disintegrate when asci mature. Asci 8-spored, bitunicate, obovoid, deliquescent. Ascospores oblong, pale to dark brown, usually asymmetric, 1-euseptate near the center, with or without indistinctly 1-distoseptate in the upper and lower cell, constricted at the central euseptum (Sivanesan 1996; Hyde et al. 2013). Asexual morph: Hyphomycetous. Colonies on the natural substrate effuse, hairy, amphigenous, brown. Mycelium superficial to immersed in the substrate, composed of branched, septate, thin-walled, smooth, subhyaline to brown hyphae. Conidiophores macronematous, mononematous, erect to procumbent, simple, none to few septate, smooth. Conidiogenous cells monotretic, integrated, terminal, determinate or percurrent proliferation. Conidia acrogenous, solitary, obclavate, wide at the truncate base, tapering towards the apex, pale brown to pale olivaceous brown, multi-distoseptate, smooth-walled, usually with a slightly melanized basal scar (Hyde et al. 2013).
Type species: Corynespora cassiicola (Berk. & M.A. Curtis) C.T. Wei, Mycol. Pap. 34: 5 (1950)
Notes: Corynespora is characterized by obclavate, brown, multi-distoseptate conidia with slightly melanized basal scar (Hyde et al. 2013). Sivanesan (1996) linked C. caryotae Sivan. as the sexual morph of Corynespora based on cultural method. Based on the extensive use of the name Corynespora for plant pathogenic fungi and its priority, Rossman et al. (2015) formally synonymized Corynesporasca Sivan. under Corynespora. Corynespora is therefore the only genus in Corynesporascaceae (Sivanesan 1996; Wijayawardene et al. 2018). Corynespora was revealed as polyphyletic (Schoch et al. 2009; Voglmayr and Jaklitsch 2017). Two freshwater species C. lignicola Z.L. Luo et al. and C. submersa Z.L. Luo et al. formed a well-supported clade with the type species C. cassiicola, which was represented by a strain CBS 100822 (Hyde et al. 2020). Corynespora aquatica R.F. Castañeda et al. was reported from freshwater habitats, but not confirmed by molecular data (Castañeda-Ruiz et al. 2004).
Key to freshwater Corynespora species (Dong et al. 2020)
1. Conidia cylindrical................................ C. lignicola
1. Conidia obclavate................................. 2
2. Conidia 100–150 μm long...................... C. submersa
2. Conidia 34–46 μm long......................... C. aquatica
Castañeda-Ruiz R.F., Heredia G.P., Arias R.M., Saikawa M. et al. (2004) Two new hyphomycetes from rainforests of Mexico, and Brainsuttonia, a genus to accommodate Corynespora alternarioides. Mycotaxon 89:297–305
Hyde K.D., Jones E.B.G., Liu J.K., Ariyawansa H. et al. (2013) Families of Dothideomycetes. Fungal Divers 63:1–313
Voglmayr H. and Jaklitsch W.M., (2017). Corynespora Exosporium and Helminthosporium revisited–new species and generic reclassification. Studies in Mycology 87: 43–76.
Fig 1. Corynespora smithii. A, B. Colony in face view, C, D. Conidiophore bases, E. Stroma cells in section, F, J, K. Conidiophore apices (F. with wide apical pore (arrow), J. with apical conidium, K. proliferating), G–I. Conidiophores (I. with young apical conidium), L–T. Vital conidia (L. young, R, S. proliferating apically). All in water. A, B. WU 38824; C–F. WU 38822; G, K, M–P. WU 38820; H–J, L, Q–T. WU 38821. Scale bars: A = 2 mm; B = 500 μm; C–E, H–T = 10 μm; F = 5 μm, G = 20 μm. (Photo grabbed by Voglmayr & Jaklitsch 2017)