Moesziomyces bullatus (J. Schröt.) Vánky, Bot. Notiser 130(2): 133 (1977)

Index Fungorum number: IF 317784; Mycobank number: MB 317784; Facesoffungi number: FoF 15929, Fig. 1

Parasitic on Echinochloa oryzoides. Infection local.  Sori in single ovaries of infected plant, visible between spreading glumes, subglobose, broadly ellipsoidal or ovoid, 3–5×2–4 mm, covered by a thick greenish brown  to yellowish brown peridium that later ruptures exposing a powdery, very dark brown mass of spore balls. Spore balls variable in shape and size, broadly ellipsoidal, subglobose, ovoid or globose, sometimes irregular, (55–)80–240(–290) × (40–)60–160(–200) μm, very dark reddish brown, opaque, composed of hundreds, rather firmly united spores and sterile cells. Spores irregularly polygonal, subglobose, ovoid or broadly ellipsoidal, (6.5–)7–10(–11)×6.5–8(–9) (8.7±0.8 × 7.4±0.6) μm (n=100), light yellow–brown, attached together by cylindrical protuberances, 1.5–2.5 μm wide, 1–2 μm high; spore wall 0.5–0.8 μm thick, with irregular meshes and wings, representing remnants of broken sterile cells.

Material examined – GREECE, Central Macedonia Region, Thessaloniki, in a rice field near Axion, 40°30′N 22°34′E, 10 msl, on Echinochloa oryzoides (Ard.) Fritsch (Poaceae), 8 October 1992, Th. Raus & Ch. Schiers, s.n. (B s.n.).

GenBank numbers – ITS: PP860524.

Notes – Moesziomyces bullatus is a cosmopolitan species known on Echinochloa spp. Echinochloa oryzoides is reported here as a new host for M. bullatus. The phylogenetic analysis of Moesziomyces, based on ITS sequence data (Fig. 2), confirmed previous phylogenetic relationships within the genus. The newly studied specimen of M. bullatus groups together with other M. bullatus specimens from other hosts. This species was inferred as sister taxon to a group containing M. antarcticus and M. kimberleyensis.

Figure 1 – Moesziomyces bullatus on Echinochloa oryzoides (B s.n.). a Habit (sori in single ovaries). b Spore ball in LM. c Spores attached together by remnants of broken sterile cells. Scale bars: a=1 cm, b=20 μm, c=10 μm

Figure 2 – Most likely tree generated using maximum likelihood analysis (RAxML-NG, Kozlov et al. 2019) implemented in RAxMLGUI (Edler et al. 2021) based on a MAFFT v7.450 (Katoh and Standley 2013) alignment of ITS. The tree is rooted with Triodiomyces altilis (Syd.) McTaggart & R.G. Shivas and Ustilago echinata J. Schröt. Values at nodes indicate bootstrap values inferred by 1000 replicates; only values≥60% are shown