Diaporthales » Gnomoniaceae » Apiognomonia

Apiognomonia errabunda

Apiognomonia errabunda (Roberge ex Desm.) Höhn., Annls mycol. 16(1/2): 51 (1918)

Facesoffungi number: FoF 07116

Saprobic or parasitic on the host plant. Sexual morph: see Sogonov et al. (2007). Asexual morph: Conidiomata 9001000 µm diam., 450500 µm high, black, stromatic, pycnidial, solitary, deeply immersed when young, becoming erumpent at maturity, dehiscing by an irregular break in the apical wall, multilocular, convoluted, with locules 200450 µm diam., 200400 µm high, ovoid to subglobose, thick-walled, glabrous, smooth-walled. Conidiomatal wall 85180 µm wide, composed of relatively thick-walled, hyaline cells of textura angularis to textura intricata in the upper part, and thin-walled, hyaline cells of textura angularis in the basal and lateral part. Conidiophores arising from the inner layer cells of the conidiomata, hyaline, cylindrical, branched at the base, septate, smooth-walled. Conidiogenous cells 1020 × 25 µm hyaline, enteroblastic, annellidic, ampulliform to subcylindrical, integrated or discrete, indeterminate, thick- and smooth-walled, tapered towards apex, with several indistinct percurrent proliferations. Conidia 10–15 × 35 µm (mean = 12 × 4 µm; n = 50), hyaline, fusiform to oval or cylindrical, rounded at both ends, straight or slightly curved, unicellular, smooth, guttulate.

Culture characters: colonies on MEA, reaching to 90 mm diam. after 14 d at 25°C, forming concentric circles, white, flattened, with dense, filamentous, aerial, fluffy hyphae on the surface; margin entire, circular; reverse pale brown; colonies on PDA, reaching 3040 mm diam. after 14 d at 25°C, without forming concentric circles, whitish, plane to slightly convex, velutinous to felty, dense in the middle zone, becoming sparse in the marginal zone; margin entire to undulate; reverse whitish to pale brown with age.

Material examined: Italy, Province of Forlì-Cesena, Passo la Calla, on dead branch of Fagus sylvatica (Fagaceae), 5 April 2016, Erio Camporesi, IT2571 (MFLU 16-1148), living culture MFLUCC 16-1318 = ICMP 21528 = KUMCC 16-0073, (KUN, HKAS 93598).

Notes: Conidia of strain (MFLUCC 161318) share a similar form (fusiform to oval or cylindrical) and dimension (av. 12.7 × 3.8, Sogonov et al. 2007) to those of the asexual morph of Apiognomonia errabunda. Phylogenetic tree reconstruction based on combined genes of LSU, ITS, rpb2 and tef1 sequence dataset of Apiognomonia and related genera show that MFLUCC 161318 clustered with epitype strain (CBS 775.79) of A. errabunda. Therefore, it is identified as the asexual morph of A. errabunda, and a detailed description and plate are provided.