Nemania guangdongensis Senan., sp. nov.

Index Fungorum number: IF 900463; MycoBank number: MB 900463; Facesoffungi number: FoF 14216; Fig. 1

Etymology – in reference to the region where sample has been collected.

Saprobic on dead wood. Sexual morph: Ascostromata 750–1,100×750–1,450 μm (x=950×1,200 μm, n=15), superficial with immersed base, solitary or rarely aggregated, scattered, globose, black, carbonaceous. Ascomata 720–850×625–1,270 μm (x=770×751 μm, n=15), globose, covered with thin stromata, ostiolate, papillate. Ostioles centric, surrounding area slightly flattened, shiny, black, conspicuous. Paraphyses 1.2–2 μm (x = 1.6 μm, n=25) wide, cellular, long, numerous, septate, smooth-walled. Asci 65–105×7–10 μm (x=88.5×8.6 μm, n=20), 8-spored, unitunicate, cylindrical, short pedicellate, with a 1.7–2.5 × 2.4–3.3 μm (x = 2 × 2.8 μm, n = 8), discoidshaped, apical ring, J+in Melzer’s reagent, apex rounded. Ascospores 9.5–14.5×5–7.5 μm (x=12.5×6.2 μm, n=35), uniseriate to overlapping uniseriate, hyaline, when immature, turning pale brown and dark brown when mature, 1–2-guttulate, oblong to ellipsoid, symmetrical to slightly inequilateral, aseptate, smooth-walled, with a straight germ slit along the entire spore length. Asexual morph: Undetermined.

Culture characteristics – Colonies on PDA reaching 4 cm diam., after seven days at 25 °C, circular, umbonate, entire, undulate, rough, wooly aerial mycelia, white from above, off-white from below.

Material examined – China, Guangdong Province, Guangzhou City, Xiaogang Park, dead bark of unidentified plant, 18 July 2021, I.C. Senanayake, S3-13 (MHZU 22-0079, holotype), ex-type cultures ZHKUCC 22-0136, ZHKUCC 22-0156.

GenBank numbers: – ITS: OR164916, OR164917, rpb2: OR166293, OR166294.

Notes: The sequence data of ITS, LSU, rpb2 and β-tubulin of our isolate (ZHKUCC 22-0136) gives species in Nemania as the closest matches with NCBI. The phylogenetic analysis (Fig. 2) showed that our isolate is phylogenetically close to Nemania paraphysata Samarak. & K.D. Hyde and N. pouzarii J.D. Rogers & Y.M. Ju, but distinct from them forming a subclade with MP/BI=94%/0.90 support. Comparison of the sequence of ITS, LSU, and rpb2 locus of our isolates (ZHKUCC 22-0136, ZHKUCC 22-0156) with Nemania paraphysata and N. pouzarii revealed the base pair differences of 1.02%, 5.66%, 1.5%, 0.3%, 2.5%, and N/A respectively. No β-tubulin sequences are available for both Nemania paraphysata and N. pouzarii. Our collection (MHZU 22-0079) is morphologically different from Nemania paraphysata by carbonaceous, superficial stromata with immersed base, and absence of mucilaginous sheath or knob-like structure at the base of ascospores while N. paraphysata has mammiform stromata with broad base, ascospores often with a knob at base and with a thick, mucilaginous sheath (Samarakoon et al. 2021).

Figure 1 – Nemania guangdongensis (MHZU 22-0079, holotype). a–c Ascomata on substrate. d Vertical cross section through ascoma. e J+apical ring. f Paraphyses. g–j Asci. k Ascospores. l Cultures on PDA from above. m Cultures on PDA from below. Scale bars: c=500 μm, d–f=5 μm, g–i=30 μm, j–p=15 μm

Figure 2 – Phylogram generated from maximum likelihood analysis based on combined ITS and LSU sequence data of 37 taxa, which comprised 1479 characters (ITS=612 bp, LSU=866 bp). The best scoring RAxML tree with a final likelihood value of − 8948.691975 is presented. The matrix had 590 distinct alignment patterns, with 10.36% of undetermined characters or gaps. Estimated base frequencies were as follows: A=0.233892, C=0.254026, G=0.301847, T=0.210236; substitution rates: AC=1.841685, AG=3.640707, AT=1.708445, CG=1.248451, CT=8.476357, GT=1.0; gamma distribution shape parameter α=0.583881. Bootstrap support for maximum likelihood (ML) equal to or greater than 50% and clade credibility values greater than 0.90 (the rounding of values to 2 decimal proportions) from Bayesian inference analysis are labelled at each node. Ex-type strains are in bold, while the new isolates are indicated in blue bold. The tree is rooted to Sporocadus trimorphus (CBS 114203)