Tretospeira cheirospora N. G. Liu & Jian K. Liu 2023, sp. nov.
Creators: name: Liu, Ning-Guo
name: Liu, Jian-Kui
name: Sun, Ya-Ru
name: Jumpathong, Juangjun
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Fungi
Ascomycota
Dothideomycetes
Pleosporales
Phaeosphaeriaceae
Tretospeira
Tretospeira cheirospora

description: Tretospeira cheirospora N.G. Liu & Jian K. Liu, sp. nov.
Index Fungorum number: IF900053
Etymology: in reference to its cheiroid conidia
Holotype: MFLU 22-0204
Saprobic on decaying wood in terrestrial habitat. Sexual morph: Unknown. Asexual morph: Hyphomycetous. Colonies on natural substrate superficial, effuse, dark brown to black, velvety. Mycelium partly superficial, partly immersed, composed of septate, branched, brown hyphae. Conidiophores 34–61 × 5.5–9.5 μm (= 44.5 × 8 μm, n = 15), macronematous, mononematous, gregarious, erect, short, cylindrical, rounded at apex, straight or broadly curved, septate, unbranched, brown to dark brown, thick-walled. Conidiogenous cells 6.5–10.5 × 8–10.5 μm (= 8.5 × 9 μm, n = 15), monotretic, terminal, integrated, slightly swollen, dark brown, thick-walled. Conidia 64–77 × 15.5–24.5 μm (= 68.5 × 19 μm, n = 20), solitary, dry, cheiroid, obclavate to narrowly obpyriform, composed of 4 narrowly obclavate columns, fused laterally except at the apex, olivaceous brown to brown, distoseptate, slightly constricted at the septa, verrucose, with a circular, hyaline, gelatinous sheath around the hyaline tip.
Culture characteristics: Conidia germinate on water agar within 72 hrs. Germ tubes are produced from the apex or base. Colonies superficial, irregularly circular, with raised surface and undulate edge, from above grey to whitish grey in the center, brownish gray at the edge, and from below, pale grey in the middle, brownish grey at the edge
Material examined: THAILAND, Chiang Mai province, Mae Taeng, Mushroom Research Center, on decaying wood in terrestrial habitat, 18 July 2020, Y. R. Sun, MRCS9 (MFLU 22-0204, holotype), ex-type living culture, MFLUCC 22-0171.
Notes: Tretospeira cheirospora resembles the type species in having erect, cylindrical, short conidiophores and monotretic conidiogenous cells bearing obclavate to narrowly obpyriform conidia composed of four columns (Pirozynski 1972). However, Tretospeira cheirospora has slightly longer conidiophores (34–61 μm vs. 15–50 μm) and larger conidia (64–77 × 15.5–24.5 μm vs. 40–60 × 17 μm) than those of T. ugandensis (Pirozynski 1972). Besides, conidia of T. cheirospora have a circular, hyaline, gelatinous sheath at the apex which is absent in T. ugandensis. Therefore, we introduce Tretospeira cheirospora as a new species based on morphology.
In our phylogenetic analysis, Tretospeira cheirospora has close affinity with Banksiophoma australiensis (FIGURE 1). Banksiophoma is a monotypic genus represented by its coelomycetous asexual morph, which has pycnidial conidiomata and ellipsoid to globose or subglobose, hyaline, aseptate conidia (Crous et al. 2017). Thus their morphology can not be appropriately compared. Further discoveries of sexual morphs of both Banksiophoma and Tretospeira may bring a clearer understanding of the two genera.
description: Published as part of Liu, Ning-Guo, Liu, Jian-Kui, Sun, Ya-Ru & Jumpathong, Juangjun, 2023, Phylogenetic placement of Tretospeira cheirospora in Phaeosphaeriaceae, pp. 175-186 in Phytotaxa 579 (3) on page 180, DOI: 10.11646/phytotaxa.579.3.3, http://zenodo.org/record/7550325