Pleosporales » Didymellaceae » Neomicrosphaeropsis

Neomicrosphaeropsis minima

Neomicrosphaeropsis minima W.J. Li & K.D. Hyde, in Hyde et al., Fungal Diversity 80: 39 (2016)

Index Fungorum number: IF 552213; Facesofungi number: FoF 02348

Etymology: Named for the small conidiomata.

Holotype: MFLU 16-1490.

Saprobic on dead stems of Verbascum sp. (Scrophulariaceae), forming numerous, conspicuous, rounded, black conidiomata. Sexual morph: Undetermined. Asexual morph: Coelomycetous. Conidiomata 60–80 μm diam., 60–95 μm high, black, solitary to gregarious or confluent, pycnidial, globose to subglobose, immersed or semi-immersed, unilocular, thick-walled, smooth, ostiolate. Ostiole single, short, centrally located. Wall of conidiomata 8–15 μm wide, composed of thick-walled, brown to hyaline cells of textura angularis. Conidiophores 2.7–5.5 μm long × 3.2–5.5 μm wide, occasionally present, hyaline, doliiform to ampulliform, arising from inner layers of the  pycnidial wall. Conidiogenous cells 2.6–5.5 μm long × 2–3.5 μm wide, hyaline, enteroblastic, phialidic, doliiform or cylindrical to ampulliform, with a periclinal wall thickening at the tip, smooth. Conidia 2.8–5.4 × 2–3.6 μm (x̄ = 4.1 × 2.8 μm, n = 30), hyaline when young, becoming brown at maturity, oval, rounded at both ends, unicellular, thick-walled, smooth, guttulate.

Culture characteristics:  Colonies on PDA attaining 15–20 mm diam. after 7d at 20–25 °C with circular margins, white to dark brown, flattened, with felt-like, dense, aerial mycelium on the surface, reverse with dark brown in the central zone, white on the edge, sporulating.

Material examined: ITALY, Province of Arezzo [AR], near Montemignaio, on dead stems of Verbascum sp. (Scrophulariaceae), 1 October 2012, Erio Camporesi, IT-765 (MFLU 16-1490, holotype); ex-type living culture, MFLUCC 13-0394; ibid. IT-765B (HKAS 95027, isotype); living culture, KUMCC 16-0024.

GenBank:

Notes: Phylogenetic tree based on multi-gene (LSU, ITS, RPB2 and b-tubulin) shows that the three collections (MFLUCC 13-0394, MFLUCC 13-0396, KUMCC 15-0557) cluster with newly introduced genus Neomicrosphaeropsis (Thambugala et al. 2016). However, these strains formed a separate branch, basal to N. rossica Thambugala, Bulgakov & K.D. Hyde. Morphologically, they share similar conidia characters with the type species N. italica. Neomicrosphaeropsis minima is closely related to N. cytisi in the phylogenetic tree from Hyde et al. (2016), but can be easily distinguished by the dimensions of the conidiomata. Neomicrosphaeropsis minima has immersed to semi-immersed conidiomata smaller than these of N. cytisi which has conidiomata 75–155 μm diam. × 75–130 μm high. In addition, N. minima has conidiogenous cell walls, thickened at the apex, while this character is not observed in N. cytisi. (Hyde et al. 2016).