Dictyosporium thailandicum M.J. D’souza, Bhat & K.D. Hyde
Index Fungorum number: IF551063; Facesoffungi number: FoF 00394
Etymology: The specific epithet thailandicum refers to Thailand the country of origin. Holotypus: MFLU 14–0240
Sexual morph Undetermined. Saprobic on submerged wood in flowing stream. Mycelium partly superficial, partly immersed, composed of smooth, septate, branched, light brown 1.5–3.2 μm wide, hyphae. Asexual morph Sporodochia 350–500 μm wide, black, scattered. Conidiophores 6.8–11 × 4.3–10.6 μm, micronematous, mononematous, cylindrical, light brown, smooth-walled. Conidiogenous cells 4.2–5 × 5–5.7 μm terminal, integrated. Conidia 15.4–34.5 × 14.5–20.6 μm (30.6 × 19 μm, n = 50), acrogenous, solitary, dictyoseptate, cheiroid, smooth-walled, complanate, light brown when young, turning dark brown to black at maturity, with 28–32 cells per conidium and 6–9 cells per row, consisting of 5 rows of cells; outer rows shorter than inner rows, with 6–8 cells, with two hyaline, smooth, tubular, elongated appendages in the above half, 20.6–26 × 5.1–6.1 μm. (Descriptions from Luo et al. 2015)
Culture characters: Conidia germinate on water agar (WA) within 24 h. Colonies on PDA, slow growing, covering 9 cm Petri-dish in 2 months at 24–28 °C, yellow to pale brown, sporulating in 45 days.
Material examined: THAILAND. Chiang Rai Province, Mae Fah Luang University stream, on submerged wood, 15 September 2013, M. D’souza, MJD-2 (MFLU 14–0240, holotype); ex-type living culture, MFLUCC 13-0773. GenBank ITS: KP716706; LSU: KP716707.
Notes: Morphologically D. thailandicum is comparable to D. alatum Emden, D. bulbosum Tzean & J.L. Chen, D. elegans Corda and D. strelitziae Crous & A.R. Wood. Dictyosporium thailandicum is very similar to D. alatum in having the same-sized conidia, appendages, shape and rows of cells, but differs in the number of cells per row. Dictyosporium alatum has 4–6 cells in a row, whereas D. thailandicum has 6–9. Further, the rows of cells in D. alatum may vary from 4–7 and, in contrast, D. thailandicum has consistently 5 rows of cells except when in culture; D. thailandicum may occasionally possess 3 or 4 rows of cells. In our phylogenetic analysis, D. thailandicum was nested in a clade together with D. alatum, D. bulbosum, D. elegans and D. strelitziae with a strong bootstrap support. Dictyosporium thailandicum is phylogenetically close to D. strelitziae, but morphologically this species differs from D. thailandicum in having longer conidia, and a larger number of cells in the conidium. (Notes from Liu et al. 2015)
Freshwater distribution: Thailand (Liu et al. 2015)
Liu JK, Hyde KD, Jones EBG, Ariyawansa HA, Bhat DJ, Boonmee S, Maharachchikumbura SSN, McKenzie EHC, Phookamsak R, Phukhamsakda C, Shenoy BD, Abdel-Wahab MA, Buyck B, Chen J, Chethana KWT, Singtripop C, Dai DQ, Dai YC, Daranagama DA, Dissanayake AJ, Doilom M, Dsouza MJ, Fan XL, Goonasekara ID, Hirayama K, Hongsanan S, Jayasiri SC, Jayawardena RS, Karunarathna SC, Li WJ, Mapook A, Norphanphoun C, Pang KL, Perera RH, Peršoh D, Pinruan U, Senanayake IC, Somrithipol S, Suetrong S, Tanaka K, Thambugala KM, Tian Q, Tibpromma S, Udayanga D, Wijayawardene NN, Wanasinghe D, Wisitrassameewong K, Zeng XY, Abdel-Aziz FA, Adamčík S, Bahkali AH, Boonyuen N, Bulgakov T, Callac P, Chomnunti P, Greiner K, Hashimoto A, Hofstetter V, Kang JC, Lewis J, Li XH, Liu XZ, Liu ZY, Matsumura M, Mortimer PE, Rambold G, Randrianjohany E, Sato G, Sri-Indrasutdhi V, Tian CM, Verbeken A, von Brackel W, Wang Y, Wen TC, Xu JC, Yan JY, Zhao RL, Camporesi E (2015) Fungal diversity notes 1–110: taxonomic and phylogenetic contributions to fungal species. Fungal Divers 72:1–197
Fig 1. Dictyosporium thailandicum (holotype). a, b. Condiomata on the substrate, c-f. conidia. Scale bars: a = 500 μm, b = 100 μm, c-f = 20 μm. (Luo et al. 2015)