Pseudomultiseptospora thysanolaenae (Phookamsak, Ariyawansa & K.D. Hyde) Phookamsak, Rajeshk., Karun. & Wijayaw., comb. nov.

Basionym – Multiseptospora thysanolaenae Phookamsak, Ariyawansa & K.D. Hyde, in Li et al., Fungal Diversity 78: 1–237 [46] (2016)

Index Fungorum number: IF 559659; MycoBank number: MB 559659; Facesoffungi number: FoF 01660; Fig. 1

Prologue and illustration – in Fungal Diversity 78: 1–237, 46 pp, 2016; Fig. 27, 47pp

Holotype – MFLU 11-0238

Saprobic on Thysanolaena maxima Kuntze. Sexual morph: Ascomata 190–270 μm high, 300–350 μm diam., gregarious, scattered, immersed, visible as raised, black dots on host surface, uni-loculate, globose to subglobose, glabrous, ostiole central, with minute papilla. Peridium 12–40 μm wide, thin- to thick-walled, slightly thick at the sides towards apex, composed of several layers of flattened, pseudoparenchymatous cells, inner layers comprising flattened, hyaline cells, arranged in a textura prismatica, outer layers comprising brown to dark brown cells, arranged in a textura angularis. Hamathecium composed of dense, 1.8–4 μm wide, cellular pseudoparaphyses, slightly constricted at the septum, anastomosing among the asci, embedded in a hyaline gelatinous matrix. Asci (93–)100–120(–143) × (26–)28–32(–35) μm (x = 114.3 × 30.4 μm, n=30), 8-spored, bitunicate, fissitunicate, broadly cylindricclavate to clavate, subsessile to short pedicellate, apically rounded, with an indistinct ocular chamber. Ascospores (55–)60–65(–73)×(8–)9–11(–13) μm (x=64.6×10.5 μm, n=30), overlapping 3–4-seriate, initially hyaline, becoming brown to dark brown at maturity, fusiform, with slightly rounded ends, slightly curved, (6–)7-septate, not constricted at the septa, smooth-walled, surrounded by thin, mucilaginous sheath, with small appendages at both ends. Asexual morph: Undetermined.

Material examined – Thailand, Chiang Mai Province, Doi Suthep-Pui, on dead leaf sheath of Thysanolaena maxima (Poaceae), 5 June 2011, R. Phookamsak, RP0118 (MFLU 11-0238, holotype), ex-type culture MFLUCC 11-0202.

GenBank numbers – LSU: NG_059655; SSU: NG_063600; tef1-α: KU705658

Notes – Both Multiseptospora thysanolaenae and M. thalandica comprise multi-septate ascospores and host association with Thysanolaena maxima. However, M. thysanolaenae significantly differs from M. thailandica by its glabrous ascostromata with brown ascospores. Pseudomultiseptospora thysanolaenae has larger ascomata, asci and ascospores than Multiseptospora thailandica, but has less ascospore septation (10–11-septate in M. thailandica, 6–7-septate in P. thysanolaenae). A concatenate analysis of LSU and tef1-α formed a paraphyletic lineage of M. thysanolaenae (distant from its type M. thailandica) that endorse the recombination of new genus as Pseudomultiseptospora that typified by P. thysanolaenae comb. nov.

Figure 1 – Pseudomultiseptospora thysanolaenae (MFLU 11-0238, holotype). a Appearance of ascomata on host substrate. b Vertical cross-section of ascoma. c Section of peridium. d–f Asci. g–j Ascospores. Scale bars: b=50 μm, c=20 μm, d=5 μm, e–f=20 μm, g–j=10 μm