Dictyosporium duliujiangense L. L. Liu & Z. Y. Liu 2023

Dictyosporium duliujiangense L. L. Liu & Z. Y. Liu, Phytotaxa 606: 266 (2023) Fig. 4 Description. Saprobic on submerged decaying wood. Sexual morph: Undetermined. Asexual morph: Hyphomycetous. Colonies on natural substrate punctiform, sporodochial, scattered, dark brown to black, velvety, glistening. Mycelium mostly immersed, composed of septate, branched, hyaline to pale brown hyphae. Conidiophores macronematous, branched, septate, cylindrical, hyaline to pale yellow, rough-walled, 3–5 μm wide, sometimes reduced to conidiogenous cells. Conidiogenous cells 11–18 × 3–5 μm (x ̄ = 15 × 4 μm, n = 17) monoblastic, integrated, terminal, determinate, pale yellow to yellow. Conidia 38–45 × 22–26 μm (x ̄ = 41.5 × 24 μm, n = 30), acrogenous, solitary, cheiroid, smooth-walled, complanate, yellowish-brown to pale brown, range from moderate orange at the base to pale yellow at the apex when immature, consisting of five closely adpressed rows of cells 33–38 × 4–6 μm (x ̄ = 35.5 × 5.5 μm, n = 30), side rows shorter than middle rows, 4–10 - euseptate in each row of cells, constricted at septa, with one or two hyaline, tubular, elongated appendages, narrower in the middle, 42–59 × 6–9 μm (x ̄ = 50.2 × 7.2 μm, n = 28) containing small guttules, suspended from the apical part of the outer rows of cells. Cultural characteristics. Conidia germinating on PDA within 24 h and germ tubes produced from the apex. Colonies grew on PDA at 22 ° C, circular, with fluffy, dense, white mycelium. The reverse side has a pale-yellow edge and an orange center. Material examined. China • Yunnan Province, Dulongjiang River, on submerged decaying wood, 2 May 2023 (Altitude: 1516 m, 27.686450°N, 98.349933°E), Ying Wang, S 4923 (KUN-HKAS 135956), living culture, KUNCC 23-15949. Notes. The conidia in Dictyosporium are complanate and not closely clustered at the apex (Boonmee et al. 2016; Yang et al. 2018). The morphological characteristics of the newly collected strain (KUNCC 23-15949) match with Dictyosporium species (Boonmee et al. 2016, Yang et al. 2018). Based on the phylogenetic analyses of the combined ITS, LSU, and tef 1 - α sequence data, our new strain (KUNCC 23-15949) shows a close affinity to Di. duliujiangense (GZCC 19-0426). There is a 1.56 % (8 / 512) difference in ITS sequence data between KUNCC 23-15949 and GZCC 19-0426, but the LSU and tef 1 - α sequences of these two species are identical. Morphologically, our collection differs from the type material in the size of conidia (41.5 × 24 μm vs. 33 × 20 μm) and the length of the appendages (50.2 × 7.2 μm vs. 27 × 6 μm) (Liu et al. 2023). Di. duliujiangense was first reported on a decaying branch submerged in a freshwater river in Dushan County, Guizhou Province, China (Liu et al. 2023). Based on these findings, we identified our collection as Di. duliujiangense.