Paramacroventuria ribis Crous & Bulgakov, sp. nov.

MycoBank number: MB 841788; Index Fungorum number: IF 841788; Facesoffungi number: FoF12734;

Etymology. Name refers to the host genus Ribes from which it was isolated.

Leaf spots superfial, round, merging, 1– 6 mm diam, firstly medium brown, later fair grey, with raised, dark brown-purple edge. Conidiomata pycnidial, globose, brown, 150 – 250 µm diam, with central periphysate ostiole; wall of 3 – 6 layers of medium brown textura angularis. Conidiophores reduced to conidiogenous cells lining inner cavity, hyaline, smooth, ampul- liform, 5 – 8 × 4 –7 µm, proliferating percurrently at apex. Conidia solitary, brown, finely roughened, medianly septate, guttulate, ellipsoid, apex obtuse, base with truncate hilum, 2 – 3 µm diam, (9 –)10 –12(–15) × 5(– 6) µm.

Culture characteristics — Colonies flat, spreading, with sparse aerial mycelium and smooth, even margin, reaching 35 mm diam after 7 d at 25 °C. On MEA surface umber, reverse isabelline; on PDA surface and reverse isabelline; on OA sur- face isabelline.

Typus. RUSSIA, Rostov region, Shakhty city district, urban street greenery, on Ribes aureum (Grossulariaceae), 18 July 2020, T.S. Bulgakov, HPC 3326 = PC 107 (holotype CBS H-24885, isotype LE F-332405, culture ex-type CPC 39692 = CBS 148443, ITS, LSU, rpb2 and tub2 sequences GenBank OK664706.1, OK663745.1, OK651160.1 and OK651204.1).

Notes — Paramacroventuria clusters close to Juxtiphoma and Macroventuria. Juxtiphoma was introduced to accommodate Phoma eupyrena reported on stems of Solanum tuberosum (Valenzuela-Lopez et al. 2018), while the sexual genus Macroventuria is based on M. anomochaeta, which was described from decayed canvas (Hou et al. 2020b). Para­ macroventuria is an asexual phoma-like genus, distinct from Juxtiphoma in that it lacks chlamydospores, and has percurrently proliferating conidiogenous cells.

Based on a megablast search of NCBIs GenBank nucleotide database, the closest hits using the ITS sequence had highest similarity to Briansuttonomyces eucalypti (strain CBS 114879, GenBank NR_153618.1; Identities = 535/541 (99 %), no gaps), Macroventuria wentii (strain CBS 526.71, GenBank MH860250.1; Identities = 534/540 (99 %), no gaps), and Leptosphaerulina australis (strain CBS 297.54, GenBank MH857342.1; Identities = 536/543 (99 %), one gap (0 %)). Closest hits using the LSU sequence are Microsphaeropsis hellebori (strain CBS 569.82, GenBank MH873273.1; Identities = 820/821 (99 %), no gaps), Didymella aurea (strain CBS 269.93, GenBank NG_069042.1; Identities = 819 / 821 (99 %), no gaps), and Microsphaeropsis ononidicola (strain MFLUCC 15-0459, GenBank MG967668.1; Identities = 819 /821 (99 %), no gaps). Closest hits using the rpb2 sequence had highest similarity to Macroventuria anomo­ chaeta (strain CBS 525.71, GenBank GU456346.1; Identities = 691/ 751 (92 %), no gaps), Paraboeremia adianticola (strain CBS 187.83, GenBank KP330401.1; Identities = 693 / 760 (91 %), no gaps), and Juxtiphoma eupyrena (as Phoma eu­ pyrena; strain CBS 374.91, GenBank LT623268.1; Identities = 692/760 (91 %), no gaps). Closest hits using the tub2 sequence had highest similarity to Ascochyta pilosella (strain CBS 583.97, GenBank MT005696.1; Identities = 316/333 (95 %), no gaps), Paramicrosphaeropsis ellipsoidea (strain CBS 197.97, GenBank MT005680.1; Identities = 314 / 333 (94 %), no gaps), and Stagonosporopsis helianthi (strain CBS 200.87, GenBank KT389848.1; Identities = 314/334 (94 %), three gaps (0 %)).