Torula fici Crous, IMA Fungus 6: 192 (2015).

Index Fungorum number: IF 816154; MycoBank number: MB 816154; Facesoffungi number: FoF 02712, Fig. 1

Saprobic on the dead pseudo stem parts of Musa sp. Sexual morph: Not observed. Asexual morph: Colonies effuse, black, powdery and thread-like. Mycelium slightly immersed, septate, branched, smooth, with pale brown hyphae. Conidiophores 2–3 μm long × 1–3 μm diameter ( x̄ = 2.77 × 1.91 μm, n = 10), macronematous, mononematous, solitary, erect, thick–walled, consisted of 2 distinct cells, first cell from the bottom is pale brown to sub hyaline, wide at the base and narrow at apex, the second cell is pale brown to brown, different from the first cell by shape, cylindrical to subcylindrical at the base and globose to subglobose at apex, conidiophore arising from prostrate hypha. Conidiogenous cells 2–3 μm long×1–2 μm diam, (x̄ =2.18×1.33 μm, n=10) polyblastic, and terminal, dark brown to black, verruculose, thick-walled, ellipsoid, paler or sub hyaline at apex, dark and black at the bottom. Conidia 19– 25 μm long 2–3.5 μm wide (x̄ =18.56×2.88 μm, n=10) solitary to catenate, acrogenous, simple, phragmosporous, dark brown, apical cell often pale brown, minutely verruculose, often 3–4 septate, rounded at both ends, composed of subglobose cells, slightly constricted at some septa. Immature conidia are sub hyaline to pale brown and arising to multi-angles from mature conidia. Conidial secession is rheixolytic.

Culture characteristics – Conidia germinating on PDA within 18 h and germ tubes produced from the tip cell. Colonies growing on PDA, reaching 5 cm in 5 days at 25 °C, mycelium partly immersed to superficial, slightly effuse, hairy, with regular edge, pink or pale brown.

Material examined – Thailand, Chiang Mai, Mushroom Research Center, on dead plant material of Musa sp. (Musaceae), 30 December 2018, Binu Samarakoon, E001 (MFLU 22-0251), living culture MFLUCC 22-0176.

Other material examined – Taiwan, Ali shan mountain, Fanlu Township area, Dahu forest, dead leaves of Ficus septica (Moraceae), 20 September 2018, D. S. Tennakoon, HAY029A (MFLU 19-2775); living culture, MFLUCC 20-0167, ibid., 10 July 2019, HAY029B (NCYU 19-0367); living culture, NCYUCC 19-0248.

Known hosts – Chromolaena odorata (Asteraceae), Ficus septica (Moraceae), Ficus religiosa (Moraceae), Garcinia sp. (Clusiaceae), Magnolia grandiflora (Magnoliaceae), Olea europaea (Oleaceae), Pandanus sp. (Pandanaceae),  Musa sp. (Musaceae) (Crous et al. 2015a, b, c, Li et al. 2017a, b; Tibpromma et al. 2018; Jayasiri et al. 2019; Mapook et al. 2020; Samarakoon et al. 2021; Tennakoon et al. 2021; this study).

Known distribution – Taiwan (this study), Cuba, South Africa, Thailand (this study) (Crous et al. 2015a, b, c, Li et al. 2017a, b; Tibpromma et al. 2018; Jayasiri et al. 2019; Mapook et al. 2020; Samarakoon et al. 2021; this study).

GenBank numbers – MFLUCC 22-0176 – OP099550 (LSU), OP097673 (SSU), OP099562 (ITS), OP113821 (tef1) MFLUCC 20-0167 – MZ317501 (LSU); MZ317506 (ITS); MZ326657 (tef1); MZ326659 (rpb2) NCYUCC 19-0248 – MZ317502 (LSU); MZ317507 (ITS); MZ326658 (tef1); MZ326660 (rpb2)

Notes – In the multi-gene phylogeny, our strain (MFLUCC 22-0176) grouped with T. fici strains with moderate statistical support in ML analysis and a higher support in Baysian analysis (81% ML, 0.98 BYPP) (Fig. 2). Morphological comparisons revealed that our collection is similar to the holotype of T. fici (Crous et al. 2015a, b, c) by the distinct shape of the conidiophores and having 3–4 celled conidia. In addition, the conidiogenous cells of the type specimen are identical in shape with our collection. Therefore, based on both morphology and phylogeny evidence, we identify our specimen (MFLU 22-0251) as T. fici from Chiang Mai, Thailand. Torula fici was previously found from China on Musa sp. by Samarakoon et al. (2021). In this study, we report T. fici on Musa sp. for the first time from Thailand as a new collection. In addition, our strains (MFLU 19-2775 and NCYU 19-0367) share the size range of the conidial characters with T. fici (Crous et al. 2015a, b, c; Tibpromma et al. 2018; Mapook et al. 2020). The phylogeny also indicates that both strains were nested with other Torula fici strains in a 100% ML, 1.00 BYPP supported clade (Fig. 2). We conclude that our stains (MFLU 19-2775 and NCYU 19-0367) also belong to T. fici which was reported on Ficus septica from Taiwan as a new host record.

Figure 1 – Torula fici (MFLU 22-0251, new collection). Fungal colonies on host surface, b, c, e–p Budding, conidial formation and mature conidia, d Conidiogenous cell. Scale Bars: a=500 μm, b, i, k, m=20 μm, e–h, j, l, n–p=15 μm, c, d=5 μm

Figure 2 –  The best scoring RAxML tree for combined dataset of LSU, SSU, ITS, tef1 and rpb2 sequence data. The topology and clade stability of the combined gene analyses was compared to the single gene analyses. The tree is rooted with Neooccultibambusa chiangraiensis (MFLUCC 12–0559) and Occultibambusa bambusae (MFLUCC 13–0855). Ex-type strains are in bold and newly generated sequences are in red. Bootstrap support values for ML≥60% and BYPP≥0.90 are given above the nodes