Menisporopsis pirozynskii Varghese & V.G. Rao, Bot. Notiser 131(2): 215 (1978)

Index Fungorum number: IF 317565; MycoBank number: MB 317565; Facesoffungi number: FoF 17089; Fig. 1, 2

Saprobic on dead stems of Cyclosorus interruptus. Sexual morph: undetermined. Asexual morph: Colonies on plant substrate effuse, scattered, white to pale brown. Mycelium partly immersed, composed of brown hyphae. Setae central, solitary, erect, straight, unbranched, dark brown, septate, smooth, thick-walled, subulate, the lower part of each seta encased by tightly compacted conidiophores (170–280 × 5–10.5 µm) at the base. Synemata 75–150 × 8.5–22.5 µm. Conidiophores 147 × 5.5–16 µm, macronematous, synnematous, encasing lower part of setae; separate filaments unbranched, straight or slightly flexuous lower part narrow, upper part wider, pale brown, smooth. Conidiogenous cells monophialidic, integrated, terminal, cylindrical, with collarettes. Conidia 16.0–22 × 3–4 µm (x̄ = 20.0 × 3.0 µm, n = 30), aggregated in slimy heads, acrogenous, semi-endogenous, appendiculate with one or two setulae at each end, setulae 3–11 µm long, aseptate, curved, cylindrical or fusiform, hyaline, smooth.

Culture characteristics – colonies on PDA reaching 25 mm diam. at 25 °C after 6 days, full, moist, rough, felty, with margin undulate and irregular; from above, creamy white at the margin and white in the middle; from below, creamy white edges and dark brown in the middle with a circle of yellow between the two colors; no pigmentation is produced in culture.

Material examined – CHINA, Yunnan Province, Xishuangbanna City, on dead stems of Cyclosorus interruptus (Thelypteridaceae), January 2024, H. Li & I.S. Manawasinghe, YX5-008 (MHZU 24–0584), living cultures ZHKUCC 24–1063, ZHKUCC 24–1064.

GenBank – ZHKUCC 24–1063: PQ203229 (ITS), PQ206193 (LSU); ZHKUCC 24–1064: PQ203230 (ITS), PQ206194 (LSU).

Note – The phylogenetic results showed that our isolate clustered with Menisporopsis pirozynskii with 98% ML bootstrap values (Fig. 1). Conidia of our isolation is similar to M. pirozynskii (MFC-SK082-02) type description, which is aseptate, lunate, hyaline conidia with 1–2 setula at each end, and small differences sizes in Conidia (Tsui et al. 1999). Based on these, we identified our isolate as M. pirozynskii. This is the first report of M. pirozynskii associated with of Cyclosorus interruptus.

Figure 1 – Maximum Likelihood consensus tree inferred from the combined ITS and LSU sequence alignments. Bootstrap support values for Maximum Likelihood (ML, first value) equal to or greater than 75% and Bayesian posterior probabilities from MCMC analyses (BYPP, second value) equal to or greater than 0.95 are given above the nodes. The scale bar indicates expected changes per site. The tree is rooted to Thozetella bambusicola (SC025) and T. hunanensis (053378). Ex type strains are indicated with “T”. The newly generated sequences are indicated in red.

Figure 2 – Menisporopsis pirozynskii (MHZU 24–0584). a Decaying branch of host. b Colonies on natural substrate. c, d Conidiophores, conidiogenous cells and conidia. e–g Conidia. i Germinated conidium. j, k Colony on PDA (front and below). Scale bars: a = 2 mm, b = 0.2 mm, c, d, i = 25 µm, e–g = 10 µm.