Ageratinicola kunmingensis Lu L., K.D. Hyde & Tibpromma, sp. nov.
Index Fungorum number: IF 559943; MycoBank number: MB 559943; Facesoffungi number: FoF 10845; Fig. 1
Etymology – based on the location where fungus was collected.
Saprobic on dead stem of Ageratina adenophora (Spreng.) King & H. Rob. Sexual morph: Undetermined. Asexual morph: Coelomycetous. Conidiomata 100–240×90–180 μm (x=180×140 µm, n=10), pycnidial, globose to subglobose, or irregular, immersed, ostiolate, with a short neck, black. Pycnidial walls 10–16 μm thick, comprised 2–4-layers of brown cells of textura angularis. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 3.7–5×3–3.7 μm (x=4×3 µm, n=10), enteroblastic, cylindrical, hyaline. Conidia 8–17×6–14 μm (x=12×10 µm, n=20), oval to ellipsoid, or ovoid, muriform, hyaline when young, becoming pale yellow to brown when maturity, multi-septate at maturity.
Culture characteristics – Colonies on PDA reaching 15 mm diam. after 4 weeks in room temperature at 20 °C, flat, slightly raised, circular, smooth, dense, front gray with white aerial mycelia at the margin; reverse sunken, from the inside to the outside, dark gray, dark brown to white, not produced pigments in culture.
Material examined – China, Yunnan Province, Kunming City, Chang Chong Mountain, on dead stem of Ageratina adenophora (Asteraceae), 20 June 2021, Li Lu, CCS 18, (HKAS 122688, holotype); ex-type culture KUMCC 21-0217.
GenBank numbers – ITS: ON359920, ON359921; LSU: ON340721, ON340722; SSU: ON359915, ON359916.
Notes – The combined ITS, LSU, and SSU gene analyses (Fig. 2) showed that our collection (HKAS 122688) forms a distinct sister clade with Foliophoma with ML/BI=100%/1.00 bootstrap support. The nucleotide differences of ITS and LSU sequences among our collections and the type species of Foliophoma, F. fallens (CBS 161.78) revealed 5.22% and 0.7% respectively. Besides, morphological characteristics of our collection are also very different from Foliophoma by larger and multi-septate conidia (Hyde et al. 2020a). Therefore, we introduce our collection as Ageratinicola kunmingensis.
Figure 1 – Ageratinicola kunmingensis (HKAS 122688, holotype). a Examined material. b–c Close view of conidiomata. d–e Cross sections of conidioma. f Pycnidial wall. g–h Conidia attached to conidiogenous cells. i–k Conidia. l Germinated conidium. m–n Culture on PDA from surface and reverse. Scale bars: d=100 µm, e=80 µm, f–i, l=20 µm, j–k=5 µm
Figure 2 – Phylogram generated from maximum likelihood analyses based on combined ITS, LSU and SSU sequence data. Thirty taxa were included in the combined analyses, which comprised 2538 characters (ITS=594, LSU=905, SSU=1039). The matrix had 506 distinct alignment patterns, with 24.52% of undetermined characters or gaps. Estimated base frequencies were as follows: A=0.251501, C=0.216231, G=0.272433, T=0.259835; substitution rates: AC=1.610597, AG=3.537196, AT=2.613191, CG=0.671725, CT=6.148363, GT=1.0; gamma distribution shape parameter α=0.084053 with a final likelihood value of − 8485.427171. Bootstrap support for maximum likelihood (ML)≥50% and clade credibility values≥0.90 from Bayesian inference analyses are labelled at each node. Ex-type strains are in bold, while the new isolate is indicated in blue bold. The tree is rooted to Ascochyta pisi (CBS 126.54) and Didymella exigua (CBS 183.55)