Neodeightonia subglobosa

Neodeightonia subglobosa C. Booth, in Punithalingam, Mycol. Pap. 119: 19 (1970) [1969] (Fig. 1)

MycoBank number: MB318601, Facesoffungi number: FoF01966.

Saprobic on a dead culm of bamboo, forming conspicuous, black spots on the host surface. Sexual morph: not observed. Asexual morph: Conidiomata 95–185 μm diam., 60–170 μm high (n = 20), semi-immersed or immersed in the substrate, uni-locular to multilocular, solitary or aggregated, globose or subglobose to obpyriform, dark brown to black. Peridium up to 10–38 μm wide, consisting of brown, small cells of textura angularis, becoming thin-walled and hyaline towards the inner region. Ostiole 17–20 μm diam., centrally located, occasionally observed. Paraphyses absent. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 6–20 μm long, 3–5 μm wide (n = 20), subcylindrical, hyaline. Conidia (10–)11–12(–13) × (6–)8–9(–12) μm ( x = 12 × 9 μm, n = 50), subglobose to oval, rounded at the apex, initially hyaline, aseptate, granulate, without longitudinal striations or mucilaginous sheath, becoming brown when mature.

Culture characteristics:—Conidia germinating on PDA within 12 h. Colonies reaching 90 mm diam. after 4–5 days at 20–23 °C, circular, white during the first few days, sparse, aerial, smooth surface with crenate edge, filamentous, after 2 weeks becoming black.

Material examined:—THAILAND. Chiang Rai: Amphoe Mueang, Tambon Nang Lae, Mae Fah Luang University garden, 20°02’22.7’’N, 99°53’38.1’’E, on a dead bamboo culm, 17 July 2019, Na Wu, YW101 (MFLU 22-0004), living culture MFLUCC 22-0005.

Notes:—Neodeightonia subglobosa, the type species of the genus Neodeightonia, was originally collected from Bambusa arundinacea in Africa (Punithalingam 1969). Liu et al. (2012) and Dai et al. (2017) found the sexual morph of N. subglobosa from Bambusa sp. in Thailand. The phylogenetic result showed that our strain (MFLUCC 22-0005) clustered with the ex-type strain of N. subglobosa (CBS 448.91) with the absolute bootstrap support (100% ML, 100% MP and 100% BYPP) and we identify it as this species. This is the first time that its asexual morph was observed from a natural substrate, as previous studies reported it only from sporulation of the culture.