Fungalpedia – Note 112 Achrochaeta
Achrochaeta Réblová & Hern. -Restr.
Citation when using this entry: Silva et al., in prep – Fungalpedia, Sordariomycetidae. Mycosphere.
Achrochaeta was introduced by Réblová et al. (2021) as a monotypic genus to accommodate Achrochaeta talbotii (S. Hughes, W.B. Kendr. & Shoemaker). Réblová & Hern.-Restr., isolated from decaying wood collected from New Zealand (Réblová et al. 2021). The phylogenetic analysis using ITS and 28S sequences revealed that their isolate clustered with Chaetosphaeria talbotii, representing a novel lineage in the Chaetosphaeriaceae separating it from Dictyochaeta. Therefore, C. talbotii was synonymized under a new genus Achrochaeta (Réblová et al. 2021). Morphologically, it is characterized by its sexual and asexual morphs. The sexual morph is a perithecial, astromatic ascomata with a carbonaceous ascomatal wall and periphysate ostioles. Paraphyses are hyaline and septate, while asci are short-stipitate and unitunicate with 8-spores. The shape of the asci varies from cylindrical to cylindrical-fusiform and have a nonamyloid apical annulus. The ascospores are ellipsoidal to ellipsoidal-fusiform in shape (Réblová et al. 2021, Hughes et al. 1968). The asexual morph has macronematous and mononematous conidiophores that are unbranched or rarely simply branched. The conidiogenous cells are phialidic, terminal, and integrated with single or several lateral openings. The collarettes are narroautowly funnel-shaped and do not become apically incurved. They are also hyaline. The conidia are smooth, cylindrical to clavate in shape, and gradually taper towards the basal end (Réblová et al. 2021). Achrochaeta can be distinguished from Dictyochaeta by its cylindrical-clavate conidia tapering more progressively towards the basal end and narrowly funnel-shaped collarettes (Réblová et al. 2021).
Type species: Achrochaeta talbotii (S. Hughes, W.B. Kendr. & Shoemaker) Réblová & Hern.-Restr.
Figure 1 – Achrochaeta talbotii. a, b Conidiophores. c-g Conidia. Scale bars: a-g = 10 μm
Hughes SJ, Kendrick WB. 1968. New Zealand fungi 12. Menispora, Codinaea, Menisporopsis. New Zealand Journal of Botany 6, 323–375.
(Edited by Roberto Farias & Kevin D. Hyde)