Angustimassarina kunmingense H.D. Yang & K.D. Hyde, sp. nov. 

Index Fungorum number: IF 559764; MycoBank number: MB 559764; Facesoffungi number: FoF 11804; Fig. 1

Etymology – Referring to the collecting site, Kunming City, Yunnan, China.

Holotype – HKAS123210 

Saprobic on dead aerial stem of Camellia semiserrata. Sexual morph: Ascomata (162–)190–332(–333)×(119–)142–289(–300) μm (x̅=261×221 μm, n=5), scattered, gregarious, immersed to semi-immersed in the host tissue, black, globose to subglobose, ostiolate. Ostiole in the centre, crest-like, rounded, papillate, with a pore-like opening. Peridium 27–56 μm thick, comprised of 5–10 layers of cells of textura angularis, cells smaller at the base and the apex, and larger at the side, brown to hyaline. Hamathecium composed of 1.2–2 μm (x̅=1.6 μm, n=30) wide, numerous, septate, clamped, unbranched, hyaline, pseudoparaphyses, embedded in a gelatinous matrix, longer than asci. Asci (56–) 60– 74(–77)×(7.2–)7.5–8.7(–9.3) μm (x̅=68×8.1 μm, n=20), 8-spored, bitunicate, fissitunicate, cylindric-clavate, with short pedicel at the base, rounded at the apex with a minute ocular chamber. Ascospores (18–)20–22(–23)×(3.1)3.3–3.8(–4.1) μm (x̅=20×3.5 μm, n=30), 1–2 overlapping seriate, hyaline, fusiform, dimidiate, widest at the centre and tapering toward the ends, with 1–3 constricted septate septum, filled with 1–2 guttules per cell, smooth-walled and surrounded by a mucilaginous sheath. Asexual morph: Not observed.

Culture characteristics– Ascospores germinating on PDA within 24 h and producing germ tubes from both ends and sides. Colonies on PDA reaching 28 mm diam. after 33 days at 20 °C, nearly circular, flat, dense, radial sulcate, edge entire, smoke grey to grey-white on the surface, dark brown on the reverse and becoming grey-white at the margin.

Material examined – China, Yunnan Province, Kunming City, Panlong District, on Camellia semiserrata C.W. Chi (Theaceae), 25° 8′ 29.27″ N, 102° 44′ 16.03″, 17 Dec 2021, Hongde Yang, (HKAS123210, holotype); ex-type living culture, KUNCC22-10799.

GenBank numbers – ON352672 (ITS); ON352671 (LSU); ON352675 (SSU); ON364144 (tef1); ON791602 (act); ON791682 (tub2)

Notes – Species of Angustimassarina are broadly distributed in Belgium, Germany and Italy (Hyde et al. 2020a, b, c; Phukhamsakda et al. 2020), but, have never been reported from China. Our collections from China are morphologically and phylogenetically related to Angustimassarina. Our new species Angustimassarina kunmingense resembles other Angustimassarina species in terms of ascomata, asci and ascospores (Table 1) and the new species was isolated from similar habitat to other Angustimassarina species (Thambugala et al. 2015). However, the taxon is charactered by slender asci and ascospores. The megablast search of the ITS and tef1 sequences show the highest similarity with Angustimassarina populi (457/463, 98%) and Angustimassarina populi (827/830, 99%), respectively. In the phylogenetic analysis, Angustimassarina kunmingense formed a well-supported monophyletic clade basal to Angustimassarina species (97ML/1.00BYPP). Our phylogenetic tree was constructed using multi gene loci (ITS, SSU, LSU and tef1, Fig. 2). However, most taxa were not strongly supported. This could suggest that additional markers are required to achieve a more accurate identity, thus we also provide protein gene act and tub2 herein.

Figure 1  – Angustimassarina kunmingense (YHD216, holotype). a, b Ascomata immersed on host surface. c Section through ascoma. d, e Peridium. f, g Mature bitunicate asci (g. asci stained with Congo red). h–k Ascospores. l Gemmating ascospores. m, n Colonies on PDA. Scale bars: c–d=100 μm, e=50 μm, l=30 μm, f–g=20 μm, i–k=10 μm, h=5 μm

Figure 2  – Phylogram generated from maximum likelihood analysis based on combined ITS, SSU, LSU and tef1 sequence data of Angustimassarina. Twenty strains were included in the analysis of the combined loci which comprised 2700 characters. The tree is rooted with Guttulispora crataegi (MFLUCC 13–0442) and Lophiostoma caulium (KT794). Bootstrap support values≥50% in ML and BYPP≥0.95 are given at the nodes. The ex-types and reference strains are in bold; the new isolate is in blue

Table 1 – Synopsis of mainly morphological characteristics of Angustimassarina species