Ascomycota, genera » incertae sedis » Didymochaeta

Didymella camporesii

Didymella camporesii Manawasinghe & K.D. Hyde, sp. nov.

Index Fungorum number: IF556895

Facesoffungi number: FoF 06802

Etymology: Name reflects the collector of the specimens, Mr Erio Camporesi

Holotype: JZBH380040

Saprobic or necrotrophic on Amorpha fruticosa. Sexual morph: Undetermined. Asexual morph: Conidiomata 125–149 μm diam. ( ̄x = 74.5 μm, n = 20) on host submerged, pycnidial, solitary or confluent, pycnidial solitary or confluent, subglobose, glabrous or with some hyphal outgrows, produced on the agar surface or immersed. Pycnidial walls 11–16.8 μm ( ̄x = 13.4 μm, n = 10) textura angularis, 5–8 layered, thick, outer walls pigmented. Conidiophores reduced to conidiogenous cells. Conidiogenous cells phialidic, hyaline, smooth, ampulliform. Conidia 8–4 × 1.5–2.6 μm ( ̄x = 1.9 × 5.2 μm, n = 40), on host cylindrical, smooth- and thin-walled, hyaline, aseptate. On culture allantoid to fabiform, smooth- and thin-walled, hyaline, aseptate.

Culture characteristics: Colonies on PDA, reach 40 mm diam. after 7 days of incubation at 25 °C, margin regular, densely covered by floccose, and yellowish-green mycelia, immersed to submersed thin mycelial mat. Reverse initially yellowish, with age it becomes black, yellowish at margins.

Material examined: ITALY, Province of Forlì-Cesena, Fiumana di Predappio, on the dead aerial branch of Amorpha fruticosa L. (Fabaceae), 15 December 2015, E. Camporesi, IT 2743 (ZB380040, holotype), ex-type living culture, JZB380040.

GenBank numbers: ITS = MN648211, LSU = MN640406, RPB2 = MN984253, TUB2 = MN537432.

Notes: Didymella camporesii was isolated from dead and dying twigs and branches of Amorpha fruticosa in Forlì- Cesena, Italy. The characters of conidia and colony match the species concept of Didymella (Chen et al. 2015). The species identified in the present study is sister to Didymella macrophylla Qian Chen, Crous & L. Cai (CGMCC 318357) with 99% ML and 1.00 BYP. Didymella macrophylla has larger conidia (3.5–5.5 × 1.5–2.5 μm) than the current taxon (Chen et al. 2017). In pairwise nucleotide comparisons of type species of Didymella macrophylla and current taxon (JZB380040), there are 1.25% nucleotide differences in LSU (882 nucleotides) and 1.64% nucleotide difference in ITS (486 nucleotides). However, in the protein-coding genes, 2.12% nucleotide difference was observed for TUB2 across 330 nucleotides and 2.34% nucleotide difference was observed in RPB2 across 597 nucleotides. This is the first report of Didymella on Amorpha fruticosa (Farr and Rossman 2020).