Fungalpedia – Note 1665, Thyronectria
Thyronectria Sacc.
Index Fungorum, Facesoffungi, MycoBank, GenBank.
Classification: Incertae sedis, Incertae sedis, Incertae sedis, Sordariomycetes, Pezizomycotina, Ascomycota, Fungi
Saprobic or parasitic on the host plant in terrestrial habitat or fungicolous (Jaklitsch et al. 2014, Checa et al. 2015). Sexual morph: see Hirooka et al. (2012), Jaklitsch & Voglmayr (2014). Asexual morph: Conidiomata orange to bay, stromatic, pycnidial, erumpent through epidermis or developing in stroma with ascomata, solitary or aggregated in groups, superficial or immersed, subglobose to discoidal or irregularly in shape, unilocular or multilocular, often convoluted, glabrous, thick-walled, KOH+ slightly darker, LA+ slightly yellow. Conidiomatal wall composed of thick-walled, pale brown cells of textura angularis to textura globulosa or textura prismatica. Conidiophores arising from the innermost layer of wall cells of conidiomata, hyaline, densely branched, generally verticillately 1–3 branched, septate, smooth-walled, with acropleurogenous conidiogenous cells or sterile hyphae. Sterile hyphae occasionally present, hyaline, filiform, unbranched or branched, straight or curved, septate, smooth-walled. Conidiogenous cells hyaline, enteroblastic, phialidic, subcylindrical to lageniform, integrated or discrete, determinate, smooth-walled. Conidia hyaline, ellipsoidal to cylindrical, oblong to allantoid, straight or slightly curved, unicellular, smooth-walled (adapted from Hirooka et al. 2012, Jaklitsch and Voglmayr 2014).
Notes: Thyronectria species are commonly saprobic and show a degree of host-specificity (Jaklitsch and Voglmayr 2014), some are fungicolous (Jaklitsch and Voglmayr 2014), while a few are plant pathogens (Seeler 1940a, Crandall 1942, Hudler and Oshima, 1976, Crowe, Starkey and Lengkeek 1982, Bedker and Wingfield 1983, Hirooka et al. 2012). Thyronectria shares a similar characters with Nectria in having light to bright-coloured, soft-textured, uniloculate perithecia, but can be distinguished by its yellowish green scurf which is absent in Nectria species, as well as the asexual morph. The asexual morph of Thyronectria has been connected to Gyrostroma (Seeler 1940b) and Zythiostroma (Rossman et al. 1999). However, Hirooka et al. (2012) re-examined the generic type of Gyrostroma, and excluded it from Hypocreales. They circumscribed the asexual morph of Thyronectria to those species which are characterized by having superficial and immersed, aggregarious or caespitose pycnidia, branched 1−3 times conidiophores, monophialidic conidiogenous cells and hyaline, ellipsoidal to cylindrical, oblong or allantoid conidia. The taxonomy, phylogeny and nomenclature of Thyronectria were studied in detail by Hirooka et al. (2012) and Jaklitsch & Voglmayr (2014). To data, 34 species are recognized in Thyronectria (Checa et al. 2015, Zeng & Zhuang 2016).
Type species: Thyronectria rhodochlora (Mont.) Seeler, J. Arnold Arbor. 21: 455 (1940)
For illustration see Hirooka et al. (2012), Jaklitsch and Voglmayr (2014).
Other accepted species: Species Fungorum – search Thyronectria.
References
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD 2020 – Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.