Kirschsteiniothelia chiangmaiensis J. Louangphan, AR. Gomes de Farias & R.H. Perera, 2024

Louangphan, Johnny, Perera, Rekhani H. & Gomes De Farias, Antonio R., 2024, A new addition to Kirschsteiniotheliaceae: Kirschsteiniothelia chiangmaiensis sp. nov. from Northern Thailand, Phytotaxa 634 (1), pp. 49-62 : 54-56

Kirschsteiniothelia chiangmaiensis J. Louangphan, AR. Gomes de Farias & R.H. Perera , sp. nov.

Index Fungorum number: IF901120, Facesoffungi number: FoF 14883

Etymology: The name refers to Chiang Mai Province, where the holotype was collected.

Holotype: MFLU 23–0358

Saprobic on decaying wood. Sexual morph: Ascomata 133–247 μm high, 150–307 μm diam. (x̄ = 180.7 × 232.4 µm, n = 6), scattered, immersed to semi-immerse, black, sub-globose or hemispherical to broadly conical with the base flattened, apex plane or papillate, rounded to truncate, sometimes split. Ostiole 40–70 µm wide with short papilliform, Peridium 25–70 µm thick on sides but thin and pale, immersed in host tissue at the base, comprising several layers of textura angularis with pale brown inner layer cells and dark brown to black outer layer cells. Hamathecium composed of dense filiform pseudoparaphyses, 1.5–2.6 µm wide, branched, septate, hyaline, embedded in a gelatinous matrix. Asci 76–119 × 24–30 µm (x̄ = 93.8 × 27.2 µm, n = 13), bitunicate, 8-spored, cylindrical-clavate with a short stalk up to 5 µm long, straight or slightly curved, apically rounded, with a small ocular chamber. Ascospores 20–31 × 9–12 µm (x̄ = 25.6 × 10.7 µm, n = 45), bi- or tri-seriate in the middle and uniseriate in the top of the ascus, ellipsoid to fusiform, narrowly to broadly ellipsoidal with rounded or slightly pointed at the ends, 1-septate, septum submedian and deeply constricted, the upper cell distinctly larger than the lower cell, each cell containing a distinct large guttule and densely pluri-guttulate, brown, thick-, smooth-walled, with a mucilaginous sheath. Asexual morph: Undetermined.

Culture characteristics: Ascospores germinating on PDA within 24–48 hours. Colonies growing on PDA dense, reaching 1 cm diam. after a week at room temperature and 3–4 cm diam. within a month. In the first week, the surface was covered with a pale white mat of aerial hyphae, then became greyish-green and dark green, composed of brown to dark brown, reverse at the first dark green with a white margin, then dark brown to black.

Specimens examined: THAILAND, Chiang Mai Province, MaeTaeng District, Pha Deng Village, Mushroom Research Center (MRC), on decaying wood in a forest spot, 10 December 2022, Johnny Louangphan, MC4.1 (MFLU 23–0358, holotype), ex-type living culture MFLUCC 23–0209.

Notes —The phylogenetic analyses revealed that K. chiangmaiensis formed an independent lineage, sister to K. puerensis (ZHKUCC 22-0271 and ZHKUCC 22-0272), but with low bootstrap support 68% ML/0.76 BYPP (<75% ML and 0.95 BYPP) ( Figure 1 ). The comparison of the base pairs between K. chiangmaiensis and the three closely related species is shown in Table 3. Kirschsteiniothelia chiangmaiensis is reported from its sexual morph, while K. puerensis , K. thailandica , and K. xishuangbannaensis , are reported from their asexual morphs ( Hyde et al. 2023, Sun et al. 2021, Xu et al. 2023). Therefore, we could not compare the morphology between the above species. When considering the sexual morph, K. chiangmaiensis is morphologically similar to K. aethiops (= K. atra ), the type species and K. thujina from their ascospore shape and septation. However, K. chiangmaiensis differs primarily from K. aethiops by smaller immerged ascomata (150–307 μm vs 300–600 μm diam.), wider asci (24–30 µm vs 12–15 μm), pluri-guttulate ascospores, and deviates from K. thujina by smaller ascomata (150–307 μm vs 300–500 μm diam.), smaller ascospore (20–31 × 9–12 µm vs 36–50 × 15–17 μm), and mucilaginous sheath in ascospores ( Table 4), confirming the taxonomic placement within the Kirschsteiniothelia . Thus, we introduce K. chiangmaiensis as a new species based on morphology and phylogeny.

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Figures

FIGURE 1. Phylogenetic tree generated from ML analysis based on the combined ITS, LSU, and SSU sequence data for selected Dothideomycetes families. The tree was rooted to Stemphylium vesicarium (CBS 191.86 and MFLUCC 14–0920). Newly generated sequence is indicated in red, and holotype/ex-type strains are symbolic by T. Ultrafast ML bootstrap values ≥ 75% and BYPP ≥ 0.95 are given at the nodes. Strain numbers are noted after the species names.