Ascochyta medicaginicola Q. Chen & L. Cai (2015)

≡ Phoma medicaginis var. medicaginis Malbr. & Roum., Rev. Mycol. 8: 91. 1886.

MycoBank number: MB 814129; Index Fungorum number: IF 814129;  Facesoffungi number: FoF 08216;

Pathogenic on living branches of Prunus cerasifera Ehrh. noticeable as black, circular dots on the host surface. Asexual morph: Conidiomata 165–190 μm high, 170–210 μm wide, black, scattered or gregarious, superficial to immerse on the substrate, black, subglobose to globose, uniloculate. Ostiolar neck 25–50 lm long, 3–5 lm wide, covered with 1-celled, thick-walled, dark brown to almost black. Peridium 15–25 lm wide at the base, 30–80 lm wide at the sides, thick, comprising 3–4 layers, outer most layer heavily pigmented, thick-walled, comprising blackish to dark brown loosely packed cells of textura angularis, inner layer composed 3–5 layers, pale brown to hyaline, cells towards the inside lighter, flattened, thick-walled cells of textura angularis.  Sexual morph: Not observed.

Material examined: RUSSIA, Rostov region, Shakhty, near railroad, on dead twigs of wild tree of Prunus cerasifera Ehrh. (Rosaceae), 11 May 2017, Timur S. Bulgakov, T-1832 (MFLU 17-2138,); living cultures MFLUCC 18–0453.

Known distribution:

GenBank ITS: ***; LSU: ****.

Notes: Our collection shares similar morphological characters with the ex-type strain of A. medicaginicola (Boerema et al. 2004, Chen et al. 2015). The multigene phylogenetic analysis shows that our collection groups in the Ascochyta medicaginicola clade with 52 MLBS support (Fig. *). Several Ascochyta species have been recorded from different host plants in Russia (Farr and Rossman 2022). However, on Rosaceae, the only record available is the Ascochyta sorbina on Sorbus torminalis, based on morphological characters. Therefore, our collection provides the first host record of Ascochyta medicaginicola on Rosaceae based on both morphological and phylogenetic data.

Ascochyta medicaginicola var. medicaginicola a, b, c Conidia observed on host substrate. d, e Conidiomata. f, g, h Conidia i, k, l Conidia j Conidiodenous cell. Scale bars: a = 500 µm, b, c, d, e, g = 100 µm, f,h = 50 µm, i, j, k, l = 10 µm.