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 xinpingensis H.W. Shen & Z.L. Luo sp. nov. Fig. 8 Etymology. " xinpingensis " refers to the Xinping Yi and Dai Autonomous County, Yunnan Province, China, where the species was collected. Description. Saprobic on submerged decaying wood in a freshwater stream. Anamorph: Colonies on wood effuse, brown to dark brown, solitary or gregarious. Mycelium immersed, composed of septate, hyaline to brown hyphae, smooth-walled. Conidiophores (97-)105-149(-175) x 4-5 µm (x̄ = 127 x 5 µm , n = 40), macronematous, mononematous, solitary or in groups, erect, straight or slightly flexuous, cylindrical, brown, unbranched, slightly paler at the apical cell, slightly enlarged at the base, septate, smooth-walled. Conidiogenous cells (7-)13-23(-25) x 4-5 µm (x̄ = 18 x 4 µm , n = 30), mono- or poly- blastic, terminal, determinate, subcylindrical, pale brown, smooth-walled. Conidia (95-)107-139(-155) x (7-)8-9(-10) µm (x̄ = 123 x 8 µm , n = 40), acrogenous, solitary, obclavate, truncate at base, tapering towards the apex, straight or slightly curved, brown, 8-12-euseptate, smooth, thin-wall, sometimes a second conidium proliferates at the top of the conidia. Teleomorph : Undetermined. Figure 8. Distoseptispora xinpingensis (HKAS 125818, holotype) a, b colonies on woody substrates c, d conidiophores e, f conidiogenous cells g-k conidia (Arrow in i-k indicate proliferating conidia) l germinating conidium m culture on PDA. Scale bars: 40 μm ( c, d ); 10 μm ( e, f ); 30 μm ( g-l ). Culture characteristics. Conidia germinating on PDA within 24 hrs and swollen germ tubes produced from both ends and some septate. Colonies growing on PDA reaching 2-3 cm in two weeks at 26 °C in the dark, with dense, velvety, dark brown mycelium on the surface; in reverse brown to dark brown with entire margin. Material examined. China , Yunnan Province , Yuxi City , Xinping Yi and Dai Autonomous County , Yuanjiang River , 23°48′12"N , 101°47′21"E , on submerged decaying branch in a freshwater stream, 22 February 2022 , S. Luan & W.P Wang YJ 17-2-2 (HKAS: 125818, holotype ), ex-type, KUNCC 22-12667 ; ibid, 23°48′12"N , 101°47′21"E , on submerged decaying branches in a freshwater stream, 22 February 2022 , H.W. Shen & Z.Q. Zhang YJ 17-5-2 (HKAS: 125821, paratype ), ex-paratype, KUNCC 22-12669 . Notes. Phylogenetic analysis showed that the two strains of Distoseptispora xinpingensis (KUNCC 22-12669 and KUNCC 22-12667) clustered together and formed a sister clade to D. lignicola (MFLUCC 18-0198) and D. menghaiensis (HJAUP C2045) with low support (Fig. 1 ). Based on a megablast search of NCBIs GenBank nucleotide database, the best matching result for ITS sequence of KUNCC 22-12667 is Distoseptispora sp. (isolate SICAUCC 22-0049, sequence ID: ON228626; identities: 499/516 (97%), 4 gaps); the best matching result of LSU sequence is D. lignicola (strain MFLUCC 18-0198, sequence ID: MK849797; identities: 1223/1245 (98%), no gap); the best matching result of rpb 2 sequence is D. bambusae (voucher MFLU 17-1653, sequence ID: MT232882; identities: 1047/1047 (100%), no gap); the best matching result of tef 1-α sequence is D. mengsongensis (strain HJAUP C2126, sequence ID: OP961937; identities: 866/916 (95%), no gap). Distoseptispora xinpingensis conforms to the generic concept of Distoseptispora ( Su et al. 2016 ; Yang et al. 2018 , 2021 ; Luo et al. 2019 ; Zhang et al. 2022 ). The morphological comparison between Distoseptispora xinpingensis and the closely related D. lignicola and D. menghaiensis shows that D. xinpingensis has longer conidiophores (105-149 µm vs. 84-124 µm ) and conidia (107-139 µm vs. 60-108 µm ), and with more conidial septate (8-12 vs. 5-9) than D. lignicola . Distoseptispora xinpingensis can be distinguished from D. menghaiensis by its longer conidiophores (105-149 µm vs. 45.7-82.9 µm ) and conidia (107-139 µm vs. 35.7-48.6 µm ), as well as conidial septation (8-12-euseptate vs. 4-8-distoseptate) ( Hu et al. 2023 ). Given the morphological distinctions and evidence from phylogenetic analysis, we introduce Distoseptispora xinpingensis as a new species from the Red River Basin in Yunnan, China.