Neofusicoccum parvum (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips, Stud. Mycol. 55: 248 (2006).

Index Fungorum number: IF 500879; MycoBank number: MB 500879; Facesoffungi number: FoF 02411

Saprobic on dead twigs of Camellia sinensis. Sexual morph: Ascomata 185-280 μm high × 205-210 μm diam. (x̄ = 230 × 207 μm, n = 10), solitary to aggregated, semi-immersed to erumpent under epidermis, coriaceous, uniloculate, globose to subglobose, black, papillate. Peridium 20-80 μm wide, two-layered, outer layer composed of thick-walled, brown to dark brown cells of textura angularis, inner layer composed of thin-walled, hyaline cells of textura angularis. Hamathecium comprising numerous, 2-4 µm wide, hypha-like, septate, slightly constricted at septum, cellular pseudoparaphyses. Asci 90-120 × 17-21 μm (x̄ = 105 × 20 μm, n = 15), 8-spored, bitunicate, fissitunicate, clavate, short-pedicellate, apically rounded, with well-developed ocular chamber. Ascospores 17-25 × 8-10 μm (x̄ = 21×9 μm, n = 30), uniseriate at the base, overlapping 2–3-seriate at the apex, hyaline, aseptate, ellipsoid to fusiform, broad at the middle, thick and rough-walled. Asexual morph: Undetermined in this study.

Culture characters – Ascospores germinating on PDA within 6 hours, and germ tubes produced from one end of the ascospore. Colonies on PDA reaching 3-5 cm diam. after 3 days at 25°C, circular, flattened, fluffy, fairly dense, aerial, white in both upper and lower sides.

Material examined – Taiwan, Fenghuang Mountain, Lugu Township, Nantou County, on dead twigs of Camellia sinensis, 17 September 2019, Achala Rathnayaka (MFLU 20-0525; living culture NCYUCC 19-0415).

Notes – Morphology of the specimen examined here is similar to the holotype of Neofusicoccum parvum, collected from dead branches of Populus nigra in New Zealand [9,47]. Size of the asci (75-143 long × 17-21 width μm) and ascospores (x̄ = 20.8 × 9.2 μm, n=73) of the holotype (PDD 45438) and the specimen examined here are in the same range. According to the phylogenetic analysis, strain NCYUCC 19-0415 clustered with the ex-type strain of N. parvum (CMW 9081) with moderate bootstrap and posterior probability support (87% ML, 0.94 PP). Neofusicoccum parvum has been recorded from Taiwan on Mangifera indica, Persea americana, Pyrus bretschneideri, Pyrus pyrifolia, and Wollemia nobilis. This is the first record of N. parvum on Camellia sinensis in Taiwan.

Figure 1 – Neofusicoccum parvum (MFLU 20-0525) on dead twigs of Camellia sinensis: (a, b) Appearance of ascostromata on host substrate; (c, d) Sections through ascostromata; (e) Peridium; (f) Pseudoparaphyses; (g-i) Asci; (j-l) Ascospores; (m) Germinating ascospore; (n, o) Colony on PDA after four days; (n = upper, o = lower surface). Scale bars: a= 200 μm; b, d= 100 μm; c= 50 μm; e, f, j-m= 10 μm; g-i= 20 μm.