Fungalpedia – Note 813, Chaetosphaerella
Chaetosphaerella E. Müll. & C. Booth
Citation when using this data: Huang SK et al. 2021 (in prep.) – Fungalpedia, Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig. 1
Classification: Chaetosphaerellaceae, Coronophorales, Hypocreomycetidae, Sordariomycetes, Pezizomycotina, Ascomycota, Fungi
Saprobic on wood. Sexual morph: Subiculum extensive, composed of densely clustered, abundant, dark brown to black, septate, rigid, branched, spinulose hyphae with dichotomously branched, tapering ends. Ascomata perithecial, scattered or densely gregarious, superficial or sitting on or in a subiculum, turbinate, globose to subglobose, carbonaceous, tuberculate, black, glabrous or with brown, cylindrical, spinous setae, ostiolate with papilla, periphysate. Peridium carbonaceous to membranaceous, composed of dark brown to brown to hyaline cells of textura angularis to textura prismatica, Munk pore present. Paraphyses broadly cylindrical, septate, inflated, sometimes present only in young ascomata. Asci 8-spored, unitunicate, cylindrical, apical ring indistinct, with short pedicel. Ascospores bi-seriate, hyaline, aseptate, becoming brown median cells and hyaline end cells, 3-septate, slightly constricted at the middle septum, ellipsoidal to cylindrical, slightly curved, smooth-walled, mostly with guttules. Asexual morph: Hyphomycetous. Conidiophores macronematous, mononematous, brown to dark brown, pale brown towards the apex, occasionally pale towards the base, branched, septate. Conidiogenous cells terminal and intercalary, polyblastic, holoblastic, brown, swollen, globose to subglobose. Conidia solitary, multiple conidia are produced serially from a retrogressive locus, usually central cell dark brown and end cell subhyaline to hyaline, 1–3-septate, oval to ellipsoidal (adapted from Müller & Booth 1972, Réblová 1999a).
Notes – Chaetosphaerella was introduced as a genus similar to Chaetosphaeria in having turbinate ascomata with hyphal subiculum and septate ascospores. However, the latter has enteroblastic conidiogenesis, while the former is holoblastic (Müller & Booth 1972). Réblová (1999a) clarified two Chaetosphaerella species, C. fusca and C. phaeostroma (type), based on their characteristics. Subsequently, the molecular data showed that these two species clustered in Chaetosphaerellaceae, which is distinct from Chaetosphaeria (Chaetosphaeriaceae) (Huhndorf et al. 2004b, Mugambi & Huhndorf 2010). Its asexual morphs Oedemium and Veramycina were synonymised as Chaetosphaerella (Réblová et al. 2016). We found that the sexual morphs of C. fusca and C. phaeostroma are similar, but their conidiogenesis differs. Chaetosphaerella phaeostroma has polyblastic conidiogenous cells (Fig. 1 t) whereas C. fusca has the multiple conidia produced serially from a retrogressive locus of hyphae (Fig. 1 u–y). Phylogenetically, these two species form Chaetosphaerella clade, sister to Crassochaeta (100%ML/1.00BY) in Chaetosphaerellaceae.
Type species: Chaetosphaerella phaeostroma (Durieu & Mont.) E. Müll. & C. Booth, Trans. Br. mycol. Soc. 58(1): 77 (1972).
Other accepted species: Species Fungorum – search Chaetosphaerella.
Figure 1 – Chaetosphaerella phaeostroma: a–b, e, g, m–n, p–s (PC-MNHN-PC-PC0167645); c, i (S-F133811); d, o (PC-MNHN-PC-PC0167641); f, h, j (S-F133805); k (S-F133806); l, t (redrawn from Réblová 1999a). a Material. b–d Ascomata on the host. e–f Ascoma with setae. g–h Ascoma cross section. i Ostiole with periphyses. j Branched hypha. k–l Setae. m–o Asci. p–r Ascospores. s Munk pores (arrow). t Conidiophores with polyblastic conidiogenous cells; Chaetosphaerella fusca: u–aa (UPS-UPS:BOT:F-671626; Russia, Saint Petersburg, Botanical Garden of the Komarov Botanical Institute (lat. 59.96778 long. 30.33167), on dead branches of unknown deciduous tree lying on the surface of ground, 27 August 2009, V. Mel’nik). u–y Conidiophores and conidia produced serially from a retrogressive locus. z–aa Conidia. Scale bars: b–c, e–f = 500 µm, d, g = 200 µm, h, j = 100 µm, i, m–o, s–v = 50 µm, k–l, p–r, w–aa = 20 µm.
References
Entry by
Shi-Ke Huang, State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang 550025, China, The Engineering Research Center of Southwest Bio-Pharmaceutical Resources, Ministry of Education, Guizhou University, Guiyang 550025, Guizhou Province, China, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand, School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand, The Mushroom Research Centre, Guizhou University, Guiyang 550025, China
Published online 14 September 2021