Diaporthe nigra Brahmanage & K.D. Hyde, in Hyde et al., Fungal Diversity 100: 185 (2020)
Index Fungorum number: IF556927; Facesofungi number: FoF 07202
Etymology: Name refers to the host epithet, [Ballota] nigra.
Saprobic on dead aerial stem of Ballota nigra L., visible as raised, black spots or, black necks immerging through the host surface. Sexual morph: Undetermined. Asexual morph: Conidiomata pycnidial or multi-loculate, scattered, semi-immersed, globose or irregular, black. Pycnidia walls consisting brown cells of textura angularis in surface view. Conidiophores reduce to conidiogeneous cells or rarely short, 8–25 × 1–3 μm (x̄ = 20 × 1.5 μm), compressed cylindrical, aseptate, branched, densely aggregated, cylindrical, straight to sinuous rarely reduced to conidiogenous cells, hyaline, smooth-walled. Alpha conidiogenous cells 190–295 × 120–175 μm (x̄ = 270 × 160 μm), phialidic, subcylindrical to ampulliform, hyaline, with visible periclinal thickening, and a flared collarette. Alpha conidia 17–28 × 7–7.5 μm (x̄ = 25 × 7.2 μm), enteroblastic, ovate to ellipsoidal, base obtuse to subtruncate, aseptate, straight, biguttulate, hyaline, smooth-walled. Beta and Gamma conidia not observed.
Culture Characteristics: Colonies on PDA, reaching 30 mm diam. after 2 weeks at 25 °C, flat, circular, margin entire, white with radially arranged minute mycelium clots later becoming pale yellow, reverse whitish. Odour not pronounced. Sporulated on PDA after 2 months incubation period in dark, at 25 °C.
Material examined: ITALY, Province of Forlì-Cesena [FC], Predappio, Tontola, on dead aerial stem of Ballota nigra L. (Lamiaceae), 13 March 2018, E. Camporesi, IT 3773 (JZBH320170, holotype), ex-type living culture, JZB320170.
GenBank Numbers: ITS: MN653009, TEF1-α: MN892277, TUB2: MN887113.
Note: Asexual morphs of Diaporthe have mostly similar morphologies (Dissanayake et al. 2017; Perera et al. 2018). Based on multi-gene phylogenetic analysis of combined ITS, TUB2, CAL and TEF1-α sequence data of Diaporthe species (85% ML, 0.90 BYPP), our strain (JZB320170) clusters with D. baccae (CBS 136972), but differs in alpha conidial size (17–28 × 7–7.5 μm) compared to the ex-type strain D. baccae (CBS 136972) ((6–)7–9 × 2–3 μm).