Cytospora cedri
Cytospora cedri Syd., P. Syd. & E.J. Butler, Annls mycol. 14(3/4): 193 (1916)
Index Fungorum number: IF 184521; Facesofungi number: FoF 05104
Saprobic on the bark. Sexual morph: Stromata 1048–1422 µm wide, with the poorly developed
interior, solitary to gregarious, immersed, becoming raised to erumpent the bark by the ostiolar canal, dark brown to black, glabrous, circular in shape, arranged with conspicuous, clustered, roundish to cylindrical prominent ostioles. Ascomata (excluding necks) 212–334 μm high, 222–373 µm diam. (x̄ = 273 × 297 μm, n = 30), perithecial, immersed in a stroma, dark brown to brown, globose to subglobose, glabrous, individual ostiole with the neck. Ostiolar canal 287–493 μm high, 59–90 μm diam. (x̄ = 390 × 75 μm, n = 18), cylindrical, sulcate, periphysate. Peridium 25–38 μm wide, composed of two section layers, outer section comprising 3–5 layers, of relatively small, brown to dark brown, thick-walled cells, arranged in textura angularis, the inner part comprising 2–3 layers of hyaline cells of textura angularis. Hamathecium comprising only asci. Asci (30–)32–39(–42) × (4–)4.5–6(–6.5) μm (x̄ = 35 × 5.2 μm, n = 35), 8-spored, unitunicate, clavate, sessile, apically rounded to truncate, with a J- apical ring. Ascospores (5.5–)7–8.5(–10) × (1.5–)1.8–2.5(–3) μm (x̄ = 7.6 × 2 μm, n = 110), overlapping 1–2-seriate, hyaline, allantoid, aseptate, smooth-walled. Asexual morph: Undetermined.
Culture characteristics: Ascospores germinating on PDA within 24 hrs. Germ tubes produced from all sides. Colonies on PDA reaching 5–5.5 cm diam. after 15 days at room temperature, colonies circular to irregular, medium dense, flat or effuse, slightly raised, with edge fimbriate, fluffy to fairy fluffy, dark brown from above, dark brown to black from below; not producing pigments in agar
Material examined: ITALY, near Galeata (Province of Forlì-Cesena [FC]), on a dead land branch of Ostrya carpinifolia (Betulaceae), 13 April 2017, E. Camporesi, IT 3289C (MFLU 18-1387, KUNHKAS 100917), living culture, MFLUCC 18-1219.
Notes: Cytospora cedri was reported by Sydow et al. (1916) as a coelomycete which is characterized by having black stromata and allantoid conidia. There are no records of the sexual morph (Adams et al. 2002, 2005, 2006). The phylogenetic result in the study of Shang et al. (2020) shows that the isolates of MFLUCC 18-1219a and MFLUCC 18-1219b cluster together with C. cedri (CBS 196.50). The single gene comparison of ITS showed that there is no sequence difference among these three isolates. Therefore, based on the guidelines of Jeewon & Hyde (2016), MFLUCC 18-1219a and MFLUCC 18-1219b were identify as isolates of C. cedri and Shang et al. (2020) provided the first sexual morph description for the species.
Figure 1. Cytospora cedri (MFLU 18-1387). a Appearance of stromata on substrate. b Stroma. c Cross section through stroma. d Vertical section through stroma. e Ostiolar canal. f Peridium.g Ascospores. h Germinating ascospore. i–l Asci. m, n Culture characteristic on PDA after 10 days(m = colony from above, n = colony from below). Scale bars: a = 1 mm, b, c = 200 µm, d = 100µm, e = 50 µm, f = 20 µm, g, i–l = 5 µm, h = 10 µm.
References:
Sydow H, Sydow P, Butler EJ. 1916 – Fungi Indiae orientalis pars V. Annales Mycologici 14, 177–220.
Adams GC, Roux J, Wingfield MJ. 2006 – Cytospora species (Ascomycota, Diaporthales, Valsaceae): introduced and native pathogens of trees in South Africa. Australasian Plant Pathology 35, 521–548.
Adams GC, Surve-Iyer RS, Iezzoni A. 2002 – Ribosomal DNA sequence divergence and group I introns within Leucostoma species, L. cinctum, L. persoonii, and L. parapersoonii sp. nov.,
ascomycetes that cause Cytospora canker of fruit trees. Mycologia 94, 947–967.
Adams GC, Wingfield MJ, Common R, Roux J. 2005 – Phylogenetic relationships and morphology of Cytospora species and related teleomorphs (Ascomycota, Diaporthales, Valsaceae) from Eucalyptus. Studies in Mycology 52, 1–144.
Jeewon R, Hyde KD. 2016 – Establishing species boundaries and new taxa among fungi: recommendations to resolve taxonomic ambiguities. Mycosphere 7, 1669–1677
Shang QJ, Hyde KD, Camporesi E, Maharachchikumbura SSN et al. 2020 – Additions to the genus Cytospora with sexual morph in Cytosporaceae, Mycosphere 11, 189–224.
Last Update: 23 September 2021