Cytospora phialidica W.J. Li, Camporesi & K.D. Hyde, sp. nov.
Index Fungorum number: IF557146
Etymology: Name refers to its phialidic conidiogenous cells.
Saprobic on dead stems of Alnus glutinosa. Sexual morph: undetermined. Asexual morph: Conidiomata 950–1100 µm diam., 400–500 µm high, brown, eustromatic, pycnidial, solitary to gregarious, at maturity furfuraceous, immersed to erumpent, globose to subglobose in section view, multilocular, convoluted, thick-walled, glabrous, ostiolate. Ostiole 200–250 × 70–100 µm, single to each locule, circular, prominent, centrally located. Conidiomatal wall 35–120 µm wide, composed of dark brown, thick-walled cells of textura angularis to textura intricta in outer layer, becoming hyaline towards conidial hymenium. Conidiophores arising from inner wall layer of locules, hyaline, cylindrical, branched at base, septate, smooth-walled. Conidiogenous cells 6–15 × 1–2 µm, hyaline, enteroblastic, polyphialidic, cylindrical to subcylindrical, usually integrated, indeterminate, smooth-walled, with 2 conidia formed sympodially in a very restricted area at the apices. Conidia 3.5–5 × 1–2 µm ( = 4 × 1.5 µm; n = 50), hyaline, allantoid, aseptate, smooth-walled, eguttulate.
Culture characters: Colonies on PDA, reaching 4–5 mm diam. after 14d at 25–30 °C, white to brown with age, velutinous to felty, flattened, dense, with rounded margin, reverse greyish red (10C4), sporulation after 4 weeks.
Material examined: Italy, Province of Forlì-Cesena, Bagno di Romagna, Lago Pontini, on dead aerial stems of Alnus glutinosa (Betulaceae), 11 August 2016, Erio Camporesi, IT3067 (MFLU 16-2442, holotype), ex-type living culture MFLUCC 17-2498, (KUM, HKAS 101662).
Notes: Phylogenetic analyses based on LSU, ITS and rpb2 shows that collection MFLUCC 17-2498 grouped with Cytospora sp. I126, C. melanodiscus (Jimslanding2, Worrall2b), but it formed a separated branch above Cytospora sp. I126. Our collection MFLUCC 17-2498 has polyphialidic conidiogenous cells, while other Cytospora species have monophialidic conidiogenous cells (Sutton 1980, Adams et al. 2006, Norphanphoun et al. 2017,2018, Fan et al. 2020). The ostiole in many Cytospora species unite as a single channel in the upper region, but our collection has a single ostiole to each locule. Therefore, our collection is introduced as new taxon.
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.