Apiognomonia erythrostoma (All Fungi)
Ascomata 200-320 µm diam., neck straight 100-250 x 60-130 µm and wider at the base. Peridium 20-30 µm thick, composed of ca 3 layers of cells with yellow-brown walls. Asci 65-95 x 10-13 µm, ± cylindrical, with tapering base and apical ring, eight-spored, becoming free within the ascoma at maturity. Ascospores 14.5-20 x 4-6 µm, septum dividing the spore 3:1, the larger upper cell is usually 2-guttulate, occasionally with a hyaline bristle-like appendage at each end.
Anamorph: conidiomata pycnidial, 100-160 µm diam, spherical or subspherical, immersed in leaf tissue, unilocular, ostiole emerging on the lower surface of the leaf. Conidiogenous cells phialides formed from the hyphae of the inner pycnidial surface in chains of 2-4, the terminal conidiogenous cell is longest 11-20 x ca 3 µm and acute, the intermediate phialides are shorter 5-9 x ca 3 µm and form conidia laterally. Conidia 17-25 x ca 1 µm, filiform.
Not formally assessed, the paucity of records despite the fairly conspicuous symptoms suggests that the species may be rare.
No sequences are available for this species, and the atypical biology and anamorphic structures suggest that the species may be mis-placed.
Causing reddish spots on living leaves and fruits of Prunus species. Serious infections can cause premature leaf fall and yield loss.
Scattered throughout GBI, probably under-recorded. Widespread throughout Europe (including Austria, Denmark, France, Germany, Russia, Serbia, Sweden and Switzerland).
The species has been listed as a quarantine pest (see Chalkley et al., 2010)