Uniappendiculata kunmingensis Tibpromma, sp. nov. Fig. 7

MycoBank number: MB 558616; Index Fungorum number: IF 558616; Facesoffungi number: FoF 10422;

Etymology – Named after Kunming, from where the species was first collected.

Holotype – HKAS 115530

Saprobic on dead stem of Acer palmatum. Sexual morph: Undetermined. Asexual morph: Conidiomata acervuli, superficial, solitary, scattered, setae formed on cushions of brown to black, masses of spores all over the dead stem surfaces of the host. Conidiophores 5–20 × 1–3 μm (x̅ = 16.35 × 2.14 μm, n = 40), hyaline, simple or septate, branched, smooth-walled. Conidiogenous cells 3–8 × 1–3 μm (x̅ = 5.35 × 2.12 μm, n = 40), enteroblastic, phialidic, produce only one spore each conidiogenous cells, hyaline, smooth-walled, cylindrical, ellipsoidal, sometimes extending to form new conidiogenous loci (percurrent). Conidia 20–35 × 2.5–5 μm (x̅ = 13.94 × 3.85 μm, n = 40), subcylindrical, slightly curved, obtuse at apex, 3–7-septate, sometimes constricted at septum, hyaline, guttulate, thick-walled, with one appendage at each end, 4–10 μm long and without mucilaginous.

Material examined – China, Yunnan Province, Kunming Institute of Botany garden, dead stem of Acer palmatum Thunb. (Sapindaceae), 25 May 2020, S. Tibpromma, ST57 (HKAS 115530, holotype).

GenBank numbers – LSU: MZ822227; ITS: MZ822229; tef1-α: MZ889430; RPB2: MZ889431.

Notes – Maximum likelihood analysis using the alignment of LSU, tef1-α and ITS rDNA sequences shows the new isolate as a well-separated lineage from other genera in Sulcatisporaceae with 97% in ML, 1.00 PP support (Fig. 6). The results from blast searches of the LSU regions of our new isolate matched 98.3% with Pseudobambusicola thailandica (MG926560), the ITS regions matched 89.71% with Pseudobambusicola thailandica (MG92655) and the tef1-α regions matched 93.55% with Sulcatispora acerina (LC014615). We consider our new isolate as a new species based on such significant differences in morphology and molecular data.

Figure 6 – The best scoring RAxML tree with a final likelihood value of -9124.516643 for combined dataset of LSU, tef1-α and ITS sequence data. The tree is rooted with Montagnula aloes (CBS 132531) and Didymosphaeria rubi-ulmifolii (MFLUCC 14-0024). The matrix had 547 distinct alignment patterns with 24.64% undetermined characters and gaps. Estimated base frequencies were as follows: A = 0.228527, C = 0.263570, G = 0.278846, T = 0.229057; substitution rates: AC = 1.094587, AG = 1.973297, AT = 1.123227, CG = 0.720850, CT = 5.866173, GT = 1.000000; gamma distribution shape parameter α = 0.165842. The newly generated sequence is in blue. Bootstrap support values for ML equal to or greater than 60% and BYPP equal to or greater than 0.90 are given above and below the nodes, respectively.

Figure 7 Uniappendiculata kunmingensis (HKAS 115530, holotype). a Conidiomata on substrate. b Conidiomata with setate. c, d Conidiophore and conidiogenous cell. e–g Developing conidia attach to conidiogenous cells. h–k Conidia (j, k conidia under a SEM). Scale bars: a = 1 mm, b, d = 40 μm, c = 20 μm, e–i = 10 μm, j, k = 2 μm.