Apiospora magnispora H.J. Zhao, Manawas. & K.D. Hyde, sp. nov.  Fig 2

MycoBank number: MB; Index Fungorum number: IF; Facesoffungi number: FoF 12961;

Etymology – In reference to the large conidia.

DiagnosisSaprobic on dead a dead twig of Bambusa textilis. Sexual morph: undetermined. Asexual morph: coelomycetous. Conidiomata 700–1000 μm high, 300–500 μm diam., scattered to gregarious, immersed in host substrate, becoming erumpent when mature, dark brown to black, raised, pustulate. Conidiomatal wall 20–50 µm thick, composed of dark brown, thin-walled cells of textura angularis. Conidiophores 20–35 × 4–7 μm ( = 28 × 5 μm, n = 20), hyphoid, subcylindrical, brown, barely septate, unbranched, curved, verrucose. Conidiogenus cells 3–5× 2–5 μm ( = 4 × 3 μm, n = 15), holoblastic, monoblastic, integrated, determinate, terminal, doliiform or lageniform, brown, verrucose. Conidia 20–35 × 15–25 μm ( = 26 × 21 μm, n = 40), solitary, irregular-shaped, oval, subglobose, brown to medium brown or reddish brown, smooth, easily become wizened and showing a hollow on the surface.

Culture characteristics – conidia germinated on PDA within 12 hours at 25°C. Colonies on PDA reach 6–8 cm diam. after 7 days at 25°C. Colonies circular, medium dense, flattened, white radial, margin undulate. Reverse white, becoming tawny from the center.

Material examined – China, Guangdong Province, Shaoguan City, Renhua County, Danxia Mountain, isolated from a dead twig of Bambusa textilis McClure (Poaceae), E 113°44′22″, N 25°2′39″, 17 November 2020, H.J. Zhao & Y.R. Xiong ZHJ001 (ZHKU 22-0001, holotype); living cultures, ZHKUCC 22-0001.

Notes – In our multi-locus phylogeny, the new collection ZHKUCC 22-0001 is affiliated with A. chromolaenae, A. italica, A. thailandica and A. vietnamensis (Fig. 1). They share similar characteristics in having pale brown to dark brown and generally subglobose conidia, but they can be easily distinguished by conidial morphology and dimension (Dai et al. 2016, Wang et al. 2017, Pintos et al. 2019, Mapook et al. 2020). The four species are hyphomycetes, while the new collection is a coelomycetes. The four species have subglobose to globose and lenticular conidia with a slit, while the new collection has irregular-shaped conidia which easily become wizened and show a hollow on the surface and lack an obvious slit. In addition, the new collection has larger conidia measured as 20–35 × 15–25 μm, while they are 4–6 × 4.5–6.5 μm in A. chromolaenae, 4–6 × 3–4 µm in A. italica, 5–9 × 5–8 μm in A. thailandica and 5–6 μm diam. in A. vietnamensis. Given the above reasons, Apiospora magnispora sp. nov. is established for the new collection ZHKUCC 22-0001.

Fig. 2 Apiospora magnispora (ZHKU 22-0001, holotype). a, b Conidiomata on the host substrate. c Section through conidioma. d Conidiomatal wall. e, f Conidiophore bearing conidium. g–m Conidia. n, o Culture on PDA from the front and below. – Scale bars: c, e–m = 10 μm, d = 20 μm.