Microdochium Syd. & P. Syd., Annls mycol. 22(3/6): 267 (1924)
Xylariomycetidae, Delonicicolales, Microdochiaceae, Microdochium
Pathogenic or saprobic on plants. Sexual morph: Monographella-like, on natural substrate. Ascomata pale brown to black, perithecial, immersed, subepidermal, and solitary or in clusters, globose, subglobose to oval, with central, papillate and acute ostiole. Ostioles usually more distinctly pigmented than the perithecial body, filled with slightly clavate periphyses. Peridium brown, thin-walled, coagulated and darker around the ostiole, in surface view, composed of cells of textura angularis-epidermoidea. Paraphyses filamentous, apically free, thin-walled. Asci unitunicate, oblong to clavate with 8 bi- to multi-seriate ascospores, apex with an amyloid, refractive, flat, funnel-shaped ring. Ascospores hyaline to brownish, clavate, fusoid or oblong, straight or curved, smooth-walled and septate. Asexual morph: Coelomycetous. Mycelium diverged and septate. Sporodochia, if present, epidermal, subepidermal to erumpent over stromata; hyaline, pseudoparenchymatic, spreading after egress. Conidiophores hyaline, more or less verticillate, reduced to conidiogenous cells, smooth. Conidiogenous cells hyaline, holoblastic, discrete, smooth, solitary or aggregated in small sporodochia; two kinds: with sympodial proliferation, cylindrical or slightly narrowing, or clavate, denticulate with one or more apical denticles. Or with percurrent proliferation (annellidic), subcylindrical, obpyriform, ampulliform to lageniform. Conidia hyaline, dry or slimy in bulk, unicellular or multi-septate, smooth, lunate, falcate, fusiform, filiform, obovoid or subpyriform, straight or curved, apex rounded, base flattened. Occasionally the conidia originate directly from hyphae. Chlamydospores terminal or intercalary, solitary, in chains or grouped in clusters, brown (adapted from Maharachchikumbura et al. 2016).
Type species: Microdochium phragmitis Syd. & P. Syd., Annls mycol. 22(3/6): 267 (1924)
Notes: Microdochium (asexual morph, Monographella - sexual morph) is the type genus of Microdochiaceae and was established by Sydow (1924) with M. phragmitis as the type species, found on living leaves of Phragmites australis in Germany. Since Microdochium has more species and is more commonly encountered, and the name is more frequently used in literature, Hernández-Restrepo et al. (2016) suggested to use Microdochium over Monographella. Microdochium species are economically important plant pathogens on grasses and cereals worldwide (Hernández Restrepo et al. 2016, Wijayawardene et al. 2017, Farr & Rossman 2018). However, species identification mainly depends on multi-gene phylogenetic analyses, with priority to the protein coding region tub2. Thirty-seven species have been accepted under Microdochium (Hernández-Restrepo et al. 2016, Zhang et al. 2017, Crous et al. 2018, 2019).
Microdochium phragmitis, the type species of Microdochium was isolated from leaves of Phragmites communis. Hernández-Restrepo et al. (2016) epitypified the species and provided an ex-epitype with molecular data. However, variations among the strains and polymorphisms make it difficult to delimit species in Microdochium. This entry is illustrated with Microdochium phragmitis.
Species illustrated in this entry:
Microdochium phragmitis Syd. & P. Syd.
Crous PW, Schumacher RK, Akulov A, Thangave R et al. 2019 – New and Interesting Fungi. 2. Fungal Systematics and Evolution 3, 57–134
Crous PW, Schumacher RK, Wingfield MJ, Akulov A et al. 2018 – New and Interesting Fungi. 1. Fungal Systematics and Evolution 1, 169–215
Farr DF, Rossman AY. 2018 – Fungal Databases, U.S. National Fungus Collections, ARS, USDA. Retrieved
Hernández-Restrepo M, Groenewald JZ, Crous PW. 2016 – Taxonomic and phylogenetic reevaluation of Microdochium, Monographella and Idriella. Persoonia: Molecular Phylogeny and Evolution of Fungi 36, 57–82
Maharachchikumbura SSN, Hyde KD, Jones EBG, McKenzie EHC et al. 2016 – Families of Sordariomycetes. Fungal Diversity 79, 1–317
Sydow H. 1924 – Sydow, Mycotheca germanica. Fasc. XLII –XLV (No. 2051–2250). Annales Mycologici 22, 257–268
Wijayawardene NN, Hyde KD, Rajeshkumar KC, Hawksworth DL et al. 2017 – Notes for genera: Ascomycota. Fungal Diversity 86, 1–594
Zhang ZF, Liu F, Zhou X, Liu et al. 2017 – Culturable mycobiota from Karst caves in China, with descriptions of 20 new species. Persoonia: Molecular Phylogeny and Evolution of Fungi 39, 1–31