Morphology and multigene phylogeny reveal three new species of Distoseptispora (Distoseptisporales, Distoseptisporaceae) on palms (Arecaceae) from peatswamp areas in southern Thailand Author Karimi, Omid https://orcid.org/0000-0001-9652-2222 State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang 550004, China & School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand Author Chethana, K. W. Thilini https://orcid.org/0000-0002-5816-9269 School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand Author de Farias, Antonio R. G. https://orcid.org/0000-0003-4768-1547 School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand Author Asghari, Raheleh https://orcid.org/0009-0006-4897-5327 School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand Author Kaewchai, Saithong https://orcid.org/0009-0004-9335-7697 Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand Author Hyde, Kevin D. https://orcid.org/0000-0002-2191-0762 School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand & Princess of Naradhiwas University, 99 Moo 8, Kok Kian, Muang District, Narathiwat Province, 9600 Thailand & Mushroom Research Foundation, 128 M. 3 Ban Pa Deng T. Pa Pae, A. Mae Taeng, Chiang Mai 50150, Thailand Author Li, Qirui https://orcid.org/0000-0001-8735-2890 State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang 550004, China lqrnd2008@163.com text MycoKeys 2024 2024-02-09 102 55 81 http://dx.doi.org/10.3897/mycokeys.102.112815 journal article http://dx.doi.org/10.3897/mycokeys.102.112815 1314-4049-102-55 3A2B04778BE9529EA5726A7C6D88950E Distoseptispora arecacearum O. Karimi, Q.R. Li & K.D. Hyde sp. nov. Fig. 2 Etymology. The epithet '' arecacearum '' refers to host family, Aceraceae . Holotype. MFLU 23-0276. Description. Saprobic on submerged rachis of Licuala paludosa in peatswamp forest. Sexual morph : Undetermined. Asexual morph : Hyphomycetous. Colonies gregarious or scattered, effuse, hairy, dark brown to black. Mycelium mostly immersed, composed of branched, septate, smooth hyphae. Conidiophores 70-140 x 5.1-6.3 µm (x̄ = 110 x 5.5 µm , n = 20), macronematous, mononematous, unbranched, erect, straight or flexuous, cylindrical, smooth, thick-walled, brown, 4-7 septa, sometimes consists a swollen cell in the middle or towards the apex. Conidiogenous cells 13-25 x 4.5-6 µm (x̄ = 17 x 5 µm , n = 20), monoblastic or polyblastic, terminal or subterminal, determinate, cylindrical, brown. Conidia 25-60 x 7-17 µm (x̄ = 44 x 10 µm , n = 30), acrogenous, solitary, cylindrical, obclavate to obpyriform or irregular, straight or curved, 4-10-distoseptate, brown, thick-walled, smooth, round apex, truncated base, sometimes with percurrent regeneration forming a secondary conidium from the conidial apex. Figure 2. Distoseptispora arecacearum (MFLU 23-0276, holotype) a host material b colonies on the substrate c-e conidiophores and conidia f-i conidia j, k culture on PDA. Scale bars: 200 µm ( b ); 50 µm ( c-e ); 10 µm ( f-i ). Culture characteristics. Colonies grown on PDA, reaching 50 mm in diameter after 15 days at 25 °C, under dark conditions, circular, fimbriate edge, flat, dull surface, radiating outwards, felted, medium dense, without pigment diffusion and sporulation, brown on the top, reverse dark brown to black. Material examined. Thailand . Narathiwat Province : Yi-ngo District , peatswamp forest, on submerged rachis of Licuala paludosa , 06 April 2022 , Omid Karimi, S 5PP3SG (MFLU 23-0276, holotype ); ex-type culture MFLUCC 23-0211, additional living culture MFLUCC 23-0212 . Notes. Morphologically, our proposed new species is similar to Distoseptispora dehongensis W. Dong, H. Zhang & K.D. Hyde and D. obpyriformis Z.L. Luo & H.Y. Su in having macronematous, mononematous, unbranched, erect, straight or flexuous, cylindrical, septate conidiophores, terminal, determinate, cylindrical, brown conidiogenous cells and acrogenous, distoseptate, straight or curved conidia ( Luo et al. 2018 ; Hyde et al. 2019 ). However, our isolate differs from D. dehongensis (HKAS 101738) in having longer and wider conidiophores (70-140 x 5.1-6.3 µm vs. 45-80 x 4-5 µm ), with swollen cells, longer and wider conidia (25-60 x 7-17 µm vs. 17-30 x 7.5-10 µm ) and more distosepta (4-10-distoseptate vs. 3-5-distoseptate). Distoseptispora arecacearum (MFLU 23-0276) differs from D. obpyriformis (MFLU 18-0476) in having conidiophores with swollen cells and shorter conidia (25-60 µm vs. 53-71 µm ) ( Luo et al. 2018 ). The BLASTn searches of the ITS sequence of D. arecacearum (MFLUCC 23-0211) resulted in D. aquatica Z.L. Luo, H.Y. Su & K.D. Hyde (MFLUCC 18-0646) with 92.21% similarity across 100% of the query sequence coverage, while the LSU sequence of D. arecacearum has 99.09% similarity across 100% of the sequence coverage with D. phangngaensis J. Yang, Maharachch. & K.D. Hyde (MFLUCC 16-0857). Distoseptispora arecacearum (MFLU 23-0276) is easily distinguishable from D. aquatica (HKAS 83991) in having longer conidiophores (70-140 µm vs. 29-41 μm ) and shorter conidia (25-60 µm vs. 110-157 µm ) with less distosepta (4-10-distoseptate vs. 15-28-distoseptate) ( Su et al. 2016 ). Distoseptispora arecacearum (MFLU 23-0276) differs from D. phangngaensis (MFLU 17-0855) in having longer conidiophores (70-140 µm vs. 18-30(-40) μm ) and shorter conidia (25-60 µm vs. 165-350 µm ) ( Yang et al. 2018 ). Therefore, we introduced D. arecacearum (MFLU 23-0276) as a novel species, based on morphological and phylogenetic analyses.