Alloscorias syngonii Haituk & Cheew., 2021

Haituk, Sukanya, Suwannarach, Nakarin, Hongsanan, Sinang, Senwanna, Chanokned & Cheewangkoon, Ratchadawan, 2021, New genus of epiphytic sooty mold: Alloscorias syngonii (Readerielliopsidaceae) from Thailand, Phytotaxa 507 (4), pp. 271-282 : 276-280

Alloscorias syngonii Haituk & Cheew. , sp. nov. (FIGURE 2,3)

Index Fungorum number: IF558108

Etymology—Refers to the host, on which the sexual morph of the taxon was collected.

Ex-type culture—SDBR-CMU355

Epiphytic on the upper surface of Syngonium podophyllum leaves. Thallus very thin, superficial, pale brown to brown walls. Sexual morph Ascomata 47–66 μm diam., 38–64 μm high, (x̅ = 54.9 × 54.4 μm, n = 20), gregarious to scattered, superficial, globose to subglobose, brown to dark brown, with indistinct ostiole. Peridium 20–24 μm. wide (x̅ = 21 μm, n = 10), composed of two sections, arranged in textura angularis, outer layer of brown to dark brown, thickwalled cells, inner layer of light brown thin-walled cells. Setae 30–41 μm long × 3–4 μm wide (x̅ = 36.1 × 3.7 μm, n = 20) abundant, corniform, brown, 4–7-septate, constricted at septa, smooth-walled. Asci 27–33 × 14–16 μm (x̅ = 29.7 × 15.4 μm, n = 10), 8-spored, bitunicate, obpyriform sessile, rounded at the apex. Ascospore 14–17 × 2–5 μm (x̅ = 16 × 3.6 μm, n = 10), overlapping 2–3-seriate, hyaline, smooth-walled, fusoid, narrowly rounded at the ends, 3–4-septate, upper cells wider and shorter than lower cells, constricted at the septa, with a conspicuous mucilaginous sheath. Asexual morph Mycelium pale brown to brown at the apex, septate, constricted at the septa, rough, thickwalled. Coelomycetous : Conidiomata 42–92 μm high × 32–76 μm diam. (x̅ = 73 × 49 μm, n = 10), solitary, brown to dark brown, globose to subglobose. Pycnidial walls composed of pseudoparenchymatous cells of textura angularis, thick-walled, outer layer brown to dark brown, inner layer with hyaline cells. Conidiophores reduced to conidiogenous cells. Conidiogenous cells enteroblastic, phialidic, integrated, terminal, smooth, hyaline, thin-walled. Conidia 4.7–7.4 × 1.7–2.6 μm (x̅ = 5.8 × 2.2 μm, n = 30), oblong to ellipsoid, hyaline, aseptate, guttulate, smooth-walled.

Culture characteristics: Ascospores germinated on PDA within 20–24 hr at 25−30°C, colonies on PDA reaching 2.5–5 mm diam. after one month, greenish brown, leathery, circular, dense, aerial, reverse dark brown, filamentous. Mycelium , brown, pale brown at the apex, septate, constricted at the septa, rough and thick-walled, with a mucilaginous outer wall layer. Colonies on OA reaching 6–10 mm diam, producing dense, irregular, flat or effuse, slightly raised, olivaceous grey. Asexual morph sporulated after two months on OA at 25°C, visible as water drop-like on colony.

Materials examined:— THAILAND, Mae Hong Son Province, Mueang District, Mok Champae Sub-district, on living leave of Syngonium podophyllum (Araceae) , 16 September 2019, Sukanya Haituk, Culture number SDBR- CMU 355 (Holotype and Ex-type), TBRC 14598.