Torula sundara (Subram.) Y.R. Sun, Yong Wang bis & K.D. Hyde, comb.nov.

≡ Dwayabeeja sundara Subram., J. Indian Bot. Soc.37: 56 (1958)
= Pseudotorula sundara (Subram.) J.L. Crane & A. Mill

Index Fungorum number: IF 559464; MycoBank number: MB 559464; Facesoffungi number: FoF 09933; Fig. 1

Saprobic on decaying bamboo culms in terrestrial habitat. Asexual morph: Hyphomycetous. Colonies on natural substrate superficial, powdery, dark brown to black. Mycelium immersed, composed of branched, septate, pale brown to brown hyphae. Conidiophores 2.5–4 μm wide, micronematous to semi-macronematous, mononematous, solitary, erect, sample, straight or slightly flexuous, unbranched, paler brown to brown, thin-walled, septate, with ampulliform cells, arising from prostrate hypha. Conidiogenous cells polyblastic, terminal, with the apex thin-walled and freuently collapsing and becoming coronate, dark brown to black, ellipsoid to coronal. Conidia two types, short conidia and long conidia. Short conidia 41–60×9–15 μm (x̄ =53×12 μm, n=30), acrogenous, phragmosporous, single or in chains, broadly fusiform, yellow brown to dark brown, 5–10-septate, slightly constricted at some septa, verruculose. Long conidia acrogenous, phragmosporous, single, straight or flexuous, cylindrical, up to 50-septate, constricted at the septa, brown to dark brown, up to 200 μm long. Sexual morph: Not observed.

Culture characteristics – Conidium germinated on PDA within 12 h. Colonies on PDA reaching 20 mm in two weeks at 26 °C. Mycelia superficial, circular, entire, flat, white from above, pale brown from below.

Material examined – Thailand, Chiang Mai Province, Mae Taeng District, MRC, on bamboo culms, 10 September 2020, H.W. Shen, M55 (MFLU 21-0089); living culture, MFLUCC 21-0067).

GenBank numbers – OM276824 (ITS), OM287866 (LSU)

Notes – Dwayabeeja sundara as the type species in Dwayabeeja was introduced by Subramanian (1958). It has dark blackish-brown colonies and two types of conidia. Crane and Miller (2016) transferred D. sundara to Pseudotorula based on catenate phragmoconidia. It was recollected and isolated from bamboo culms in Chiang Mai Province, Thailand. Here, we provided sequences for it. Phylogenetic analyses show it is a distinct clade in Torula and sister to T. acaciae with high support (ML 100% and 1.00 BYPP). According to the similarities in morphology along with phylogenetic analyses, we propose Pseudotorula sundara as a synonym of Torula sundara.

Figure 1 – Torula sundara (MFLU 21–0089, new combination). a, b Colonies on the host c–e Conidiophores and conidia f–l Conidia m Germinated conidium. Scale bars: c=10 μm, d–m=20 μm