Iodosphaeria thailandica L.S. Dissan., Marasinghe, & K.D. Hyde, sp. nov.

Dissanayake, Lakmali S., Marasinghe, Diana S., Samarakoon, Milan C., Maharachchikumbura, Sajeewa S. N., Mortimer, Peter E., Hyde, Kevin D., Kuo, Chang-Hsin & Kang, Ji-Chuan, 2022, Three new species of Iodosphaeria (Xylariomycetidae): I. chiayiensis, I. jinghongensis and I. thailandica, MycoKeys 86, pp. 1-17 : 1

Iodosphaeria thailandica L.S. Dissan., Marasinghe, & K.D. Hyde, sp. nov.

Figure 5

Etymology.

The specific epithet Iodosphaeria thailandica refers to the country where the fungus was collected.

Holotype.

MFLU 21-0041

Description.

Saprobic on dead leaves of unidentified host. Sexual morph: Ascomata 250-285 × 250-295 μm (x̅ = 267.3 × 272 μm, n = 10), globose to subglobose, superficial, black, solitary to gregarious, consisting of numerous long, flexuous setae. Setae 4.5 μm wide, arising from cells at the peridium surface, dark brown to brown, unbranched, septate. Ostiole periphysate, apapillate. Peridium 40-50 μm wide (x̅ = 44.6 μm, n = 10), comprising two layers of cells of textura angularis, outer layer of dark brown to black thick-walled cells and an inner layer of flattened, hyaline cells. Paraphyses 5-8 μm wide, length as longer than asci, septate, hyaline, branched, embedded in a gelatinous matrix. Asci 65-100 × 8-10 μm (x̅ = 84.3 × 8.9 μm, n = 30), 8-spored, unitunicate, cylindrical, short pedicellate, apex rounded, with a J+ apical ring. Ascospores 20-35 × 2-4 μm (x̅ = 29.1 × 3.2 μm, n = 30), overlapping uni-seriate, cylindrical to allantoid, aseptate, hyaline to pale brown, guttulate, slightly curved. Asexual morph: Undetermined.

Material examined.

Thailand, Chiang Mai, Mushroom Research Centre , on dead leaves of an undetermined species, 11 September 2020, D.S Marasinghe, DMRC011 (MFLU 21-0041, holotype)

Notes.

Iodosphaeria thailandica shares similar characteristics with I. honghensis in having globose to subglobose, superficial, solitary to gregarious ascomata, cylindrical, short pedicellate, J+, apical ring and cylindrical to allantoid asci with aseptate, guttulate ascospores (Marasinghe et al. 2019). However, I. thailandica differs from I. honghensis in having long, narrow (20-35 × 2-4 μm) and hyaline to pale brown ascospores versus short, broad (18.5-22.5 × 4.5-6.5 μm) and hyaline ascospores. In the phylogenetic analyses, I. thailandica is distinct from other species in the genus by 100 % ML and 1.00BYPP and sister to the I. chiayiensis . Iodosphaeria thailandica has larger ascomata (250-285 × 250-295 μm), cylindrical to allantoid asci and hyaline to pale brown ascospores, while the ascomata of I. chiayiensis are smaller (150-190 × 160-200 μm) and ascospores are hyaline and ellipsoidal to allantoid. Iodosphaeria thailandica is the first report of Iodosphaeria from Thailand.

Figures

Figure 5. Iodosphaeria thailandica (MFLU 21 - 0041, holotype) a substrate b, c ascomata on the host surface d peridium e section of ascomata f appearance of setae (black arrow) on peridium g setae h paraphyses i, j asci k J + apical ring (in Melzer's reagent) l-q ascospores (p, q stained in Lactophenol Cotton Blue). Scale bars: 10 μm (d); 100 μm (e); 5 μm (f-h); 20 μm (i, j); 10 μm (k-q).