Diversity of Distoseptispora (Distoseptisporaceae) taxa on submerged decaying wood from the Red River in Yunnan, China Author Shen, Hong-Wei https://orcid.org/0000-0003-2508-1970 College of Agriculture and Biological Science, Dali University, Dali 671003, Yunnan, China & Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand Author Bao, Dan-Feng https://orcid.org/0000-0002-5697-4280 College of Agriculture and Biological Science, Dali University, Dali 671003, Yunnan, China Author Boonmee, Saranyaphat https://orcid.org/0000-0001-5202-2955 Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand Author Lu, Yong-Zhong https://orcid.org/0000-0002-1033-5782 School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand Author Su, Xi-Jun https://orcid.org/0000-0002-6357-7750 College of Agriculture and Biological Science, Dali University, Dali 671003, Yunnan, China Author Li, Yun-Xia https://orcid.org/0009-0007-5645-8861 College of Agriculture and Biological Science, Dali University, Dali 671003, Yunnan, China Author Luo, Zong-Long https://orcid.org/0000-0001-7307-4885 College of Agriculture and Biological Science, Dali University, Dali 671003, Yunnan, China luozonglongfungi@163.com text MycoKeys 2024 2024-02-05 102 1 28 http://dx.doi.org/10.3897/mycokeys.102.116096 journal article http://dx.doi.org/10.3897/mycokeys.102.116096 1314-4049-102-1 B41B42084B3E53689FCD1BF6D9013E68 Distoseptispora suae H.W. Shen & Z.L. Luo sp. nov. Figs 6 , 7 Etymology. "suae" (Lat.) in memory of the Chinese mycologist Prof. Hong-Yan Su (4 April 1967-3 May 2022), who kindly helped the authors in many ways. Description. Saprobic on submerged decaying wood in a freshwater stream. Anamorph: Colonies on wood effuse, brown, solitary or in small group. Mycelium immersed, septate, brown hyphae, smooth-walled. Conidiophores (21-)25-41(-53) x 4-5 µm (x̄ = 33 x 5 µm , n = 20), macronematous, mononematous, solitary or in groups, erect, straight or slightly flexuous, cylindrical, 1-3-septate, brown, unbranched, smooth-walled. Conidiogenous cells (11-)13-15(-16) x 5-6 µm (x̄ = 14 x 5 µm , n = 20), monoblastic, terminal, determinate, subcylindrical, brown, smooth-walled. Conidia (77-)81-101(-109) x 8-10 µm (x̄ = 91 x 9 µm , n = 30), acrogenous, solitary, obclavate to rostrate, truncate at base, tapering towards the apex, straight or slightly curved, bent at the second or third cell at the base, brown to dark brown, 3-12-euseptate, guttulate, verrucose, thin-walled. Teleomorph : Undetermined. Figure 6. Distoseptispora suae (HKAS 125819, holotype) a, b colonies on woody substrates c-e conidiophores and conidiogenous cells f-k conidia l germinated conidium m culture on PDA. Scale bars: 10 μm ( c-l ). Culture characteristics. Conidia germinating on PDA within 12 hrs and germ tubes produced from the apex. Colonies growing on PDA reaching 4-5 cm in one month at 26 °C in the dark, with dense, velvety, brown to dark brown mycelium from above; dark brown from below. Sporulation on PDA after two months, Mycelium hyaline to brown, septate, branched, smooth-walled. Conidiophores (15-)16-56(-110) x 4-6 µm (x̄ = 36 x 5 µm , n = 30), usually form at the end of the hyphae, cylindrical, straight or slightly curved, yellowish brown to olivaceous-brown, septate. Conidiogenous cells (9-)11-14(-16) x 4-5 µm (x̄ = 12 x 5 µm , n = 30) monoblastic, terminal, determinate, cylindrical, brown, sometimes reduce conidiophores. Conidia (31-)47-90(-124) x 6-8 µm (x̄ = 68 x 7 µm , n = 40) acrogenous, obclavate, elongated, truncate at base, straight or slightly curved, brown, euseptate, thin-wall, sometimes with a gelatinous sheath around the septum (Fig. 7 ). Figure 7. Distoseptispora suae (ex-type culture KUNCC 22-12476) a culture on PDA, obverse (left) and reverse (right) b, c colonies on PDA d mycelium from PDA e mycelium, conidiophores and conidia f conidiophore g-j conidiophores with conidia (Arrow in i, j indicate the gelatinous sheath) k conidia. Scale bars: 10 μm ( d ); 40 μm ( e ); 20 μm ( f-k ). Material examined. China , Yunnan Province , Yuxi City , Xinping Yi and Dai Autonomous County , Yuanjiang River , 24°02′16"N , 101°34′05" E , on submerged decaying branches in a freshwater stream, 22 February 2022 , H.W. Shen & Q.X. Yang YJ 14-35-2 (HKAS: 125819, holotype , ex-type, CGMCC3.24262 = KUNCC 22-12476) . Notes. Distoseptispora suae clusters with D. hyalina (MFLU 21-0137) with 100% ML/1.00 PP support whereas D. yunnanensis (MFLUCC 20-0153) state in a basal lineage (Fig. 1 ). A comparison of the LSU, ITS, tef 1-α and rpb 2 nucleotide bases between D. suae and D. hyalina revealed differences of 8 bp (8/832, including one gap), 11 bp (11/540, including 3 gaps), 21 bp (21/934), and 54 bp (54/1087) sequence similarity, respectively. Morphologically, D. suae resembles other species in the genus with its euseptate structure, characterized by acrogenous, solitary, obclavate to rostrate conidia. D. hyalina , D. suae and D. yunnanensis cluster in a stable lineage (Fig. 1 ). Since only teleomorphs were found in D. hyalina ( Yang et al. 2021 ), and only anamorphs were found in D. suae (this study), the morphological characteristics of D. suae and D. yunnanensis were compared here. D. suae can be distinguished from D. yunnanensis by its shorter conidiophores (25-41(-53) µm vs. 131-175 µm ) and guttulate, verrucose conidia ( Li et al. 2021 ). Based on phylogenetic analysis and morphological evidence, following the guidelines of Jeewon and Hyde (2016) , we therefore introduce D. suae as a new species.