Cryphonectriaceae Gryzenh. & M.J. Wingf., Mycologia 98: 246 (2006)
Index Fungorum number: IF510585; 91 species.
Saprobic or pathogenic in forest trees and economic crops. Sexual morph: Ascostromata scattered, immersed or erumpent, aggregated, oval to circular from above, comprising two layers, with the upper layer of yellowish-orange to pale brown cells, purpling in KOH and the inner layer of hyaline cells, mixed with plant cells. Ascomata immersed, aggregated, several in one stroma, globose to subglobose, fuscous black to umber, with a long neck, sometimes ostiolar canal immersed in stromatic tissues or superficial, with necks covered in umber stromatic tissue of texture porrecta, the inner wall of the necks or ostiolar canal with hyaline, filamentous periphyses. Peridium comprising the inner layer of small, hyaline cells of textura angularis and the outer layer of small, brown cells of textura angularis. Paraphyses few, cellular, parenchymatous cells, attached at the base of asci and dissolving at maturity. Asci 8-spored, unitunicate, cylindrical-fusoid to clavate, pedicellate, with distinct, J-, refractive apical ring. Ascospores overlapping uniseriate to biseriate, hyaline, sometimes brown, ellipsoid, fusoid to cylindrical, aseptate to multi-septate, not constricted at septa, smooth-walled. Asexual morph: Coelomycetous. Conidiomata occurring as part of ascostromata, as conidial locules or solitary structures, uni- to multi-loculate, pyriform, subglobose to pulvinate, ostiolar necks absent or present; if present, with one to several attenuated necks, superficial or semi-immersed, orange to fuscous-black. Conidiophores cylindrical, aseptate, hyaline, sometimes reduced to conidiogenous cells. Conidiogenous cells lining the inner cavity of the conidiomata, phialidic, sometimes within the flattened base, ampulliform, conspicuous, with attenuated or truncate apices, hyaline, smooth. Conidia minute, sometimes both micro-and macro-conidia present, sigmoid, broadly ellipsoid to fusoid, obovoid-cylindrical to allantoid, aseptate, hyaline.
Type genus – Cryphonectria (Sacc.) Sacc. & D. Sacc.
Notes – Cryphonectriaceae comprises mostly tree and plant pathogens (Vermeulen et al. 2011) and rarely saprobes and endophytes. They cause diseases in economically important plants and forest trees. Cryphonectriaceae was established by Gryzenhout et al. (2006b) to accommodate the Cryphonectria-Endothia complex based on nrLSU sequence data.
Ecological and economic significance of Cryphonectriaceae
Cryphonectriaceae comprises highly virulent plant pathogens such as Cryphonectria parasitica which is the causal agent of chestnut blight (Anagnostakis 1987, Heiniger & Rigling 1994). Some species are pathogenic on Myrtales tree species, especially forms causing stem canker disease (Chen et al. 2016). Species in Cryphonectriaceaeare commonly associated with serious cankers and leaf spots diseases (Crous et al. 2015a). Very few species are saprobes.