Diplodia sapinea
Diplodia sapinea (Fr.) Fuckel 1870
≡Sphaeria sapinea Fr., Syst. mycol. (Lundae) 2(2): 491. 1823
=Diplodia rosacearum S. Giambra et al., Mycosphere 7: 983. 2016
=Diplodia italica Wijayaw. et al., Fungal Diversity 77: 110. 2016
=Diplodia intermedia A.J.L. Phillips et al., Persoonia 29:33. 2012
Index Fungorum number: IF 146913; Facesoffungi number: FoF 05292
Saprobic or pathogenic on a dead aerial branch of Prunus sp. Sexual morph: Undetermined. Asexual morph: Conidiomata 250–300 μm diam., 240–270 μm high (x̄ = 270 × 250 μm, n = 5), pycnidial, stromatic, immersed, solitary, scattered, becoming erumpent at maturity, globose to subglobose, unilocular, ostiolate, dark brown to black. Ostioles papillate, central, circular, single. Conidiomata wall 30–40 μm wide at the sides, 40–45 μm wide at the base, composed of several layers, outermost layers with thick-walled brown cells, innermost layers with thin-walled, pale brown to hyaline cells, arranged in textura angularis. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 3–10 × 2–3 μm, cylindrical, long, sometimes slightly swollen at the base, enteroblastic, phialidic, periclinal thickening, and producing single conidia at the tip, determinate, and hyaline. Paraphyses lay between and intermingled with conidiogenous cells, wide at the base (1.8–2.2 μm) and gradually becoming thinner towards the apex (0.6–0.7 μm). Conidia 12–14 × 5–8 μm (x̄ = 12.5 × 7.5 μm, n = 20; l/w = 1.6), oblong to ovoid, widest in the middle, obtuse apex or slightly rounded, truncate at base, aseptate, thick or smooth-walled, guttulate, initially hyaline, brown to dark brown at maturity before releasing from the pycnidia.
GenBank Accession Numbers: ITS: OQ401051; tef1-α: OQ437907.
Material examined: Italy, Province of Forlì-Cesena [FC]), near Meldola, on a dead aerial branch of Prunus sp. (Rosaceae), 23 May 2016, Erio Camporesi, IT 978 (MFLU 16-1443).
Notes: Based on the similar morphologies and phylogenetic relationships, Wijesinghe et al. (2023) confirmed that this collection is D. sapinea. In the past, D. sapinea was found on Crataegus sp. by Wijayawardene et al. (2016) (as D. italica), on Eriobotrya japonica by Giambra et al. (2016) (as D. rosacearum), and as D. sapinea on Pinus nigra, P. sylvestris, P. halepensis, P. pinaster and P. resinosa by Luchi et al. (2014) in Italy. Additional known distribution of the fungus on P. persica is in Western Cape and South Africa (Jami et al. 2017). This collection is the first report of this fungus on Prunus sp. in Italy.
Figure x. Diplodia sapinea (MFLU 16-1443, new host record in Italy). a–b Conidiomata on the dead host surface of Prunus sp. (Rosaceae, Rosales). c–d Longitudinal sections of a conidioma. e Conidiomatal wall. f–j Developmental stages of conidiogenesis. k–m Conidia. Scale bars: a = 1 mm, b, c = 200 μm, d = 50 μm, e = 20 μm, f–m = 10 μm.
References
Wijesinghe SN, Samarakoon MC, Camporesi E, Hyde KD et al. 2023 – Over the footprints of Italian mycology with emphasis on plant-associated Ascomycota. Current Research in Environmental & Applied Mycology (Journal of Fungal Biology), 13, 162–276.
N.B - The data has been directly extracted from the original publication (Wijesinghe et al. 2023) with the permission of the journal Current Research in Environmental & Applied Mycology' (Journal of Fungal Biology).
Last Update: 25 October 2023