Additions to the genus Kirschsteiniothelia (Dothideomycetes); Three novel species and a new host record, based on morphology and phylogeny Author Tang, Xia 0000-0003-2705-604X Engineering and Research Center for Southwest Biopharmaceutical Resource of National Education Ministry of China, Guizhou University, Guiyang, 550025, Guizhou Province, China & Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand Author Jeewon, Rajesh 0000-0002-8563-957X School of Science, Mae Fah Luang University, Chiang Rai, 57100, Thailand Author Jayawardena, Ruvishika S. 0000-0001-7702-4885 Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand Author Gomdola, Deecksha 0000-0002-0817-1555 Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand Author Lu, Yong-Zhong 0000-0002-1033-5782 Department of Health Sciences, Faculty of Medicine and Health Sciences, University of Mauritius, Reduit, Mauritius Author Xu, Rong-Ju 0000-0002-3968-8442 Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand Author Alrefaei, Abdulwahed Fahad 0000-0002-3761-6656 School of Food and Pharmaceutical Engineering, Guizhou Institute of Technology, Guiyang, Guizhou Province 550003, China Author Alotibi, Fatimah 0000-0003-3629-5755 School of Food and Pharmaceutical Engineering, Guizhou Institute of Technology, Guiyang, Guizhou Province 550003, China Author Hyde, Kevin D. 0000-0002-2191-0762 Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand & School of Food and Pharmaceutical Engineering, Guizhou Institute of Technology, Guiyang, Guizhou Province 550003, China Author Kang, Ji-Chuan 0000-0002-6294-5793 Engineering and Research Center for Southwest Biopharmaceutical Resource of National Education Ministry of China, Guizhou University, Guiyang, 550025, Guizhou Province, China text MycoKeys 2024 2024-10-28 110 35 66 journal article 10.3897/mycokeys.110.133450 Kirschsteiniothelia bulbosapicalis X. Tang, K. D. Hyde, Jayaward. & J. C. Kang , sp. nov. Fig. 3 Etymology. The specific epithet ‘ bulbosapicalis ’ refers to the bulbous area of the conidia at the apex. Holotype . GZAAS 23-0808. Description. Saprobic on unidentified decaying wood. Sexual morph : Undetermined. Asexual morph : Colonies on the natural substrate superficial, effuse, gregarious, hairy, black, glistening. Mycelium semi-immersed, on the substrate, pale brown to dark brown. Conidiophores (– 47) 58–128 (– 199) μm × 7.5–12.5 (– 16.5) μm (x ̄ = 86.7 × 10.6 μm, n = 15), macronematous, mononematous, solitary, straight or slightly flexuous, cylindrical, unbranched, septate, smooth, brown to dark brown, truncate at the apex and wider at the base. Conidiogenous cells 6–17 μm × 7–10.5 μm (x ̄ = 10.6 × 8.6 μm, n = 15), monoblastic, holoblastic, terminal, determinate, proliferating, cylindrical, brown to dark brown. Conidia 118–236.5 μm × 15–27 μm (x ̄ = 174.8 × 21 μm, n = 30), solitary, acrogenous, cylindrical, ovoid to obclavate, rostrate, smooth, straight or slightly curved, 8–13 - septate, slightly constricted at the septa, olivaceous to reddish-brown to dark brown, bulbous at the apex and / or third or fourth cell, truncate at the base, with a spherical hyaline mucilaginous sheath. Kirschsteiniothelia bulbosapicalis ( GZCC 23-0732, holotype) a, b colonies natural substrate c – f conidiophores, conidiogenous cells bearing conidia (red arrows indicate mucilaginous sheaths) g, h conidiophores i – o conidia (red arrows indicate mucilaginous sheaths) p a germinated conidium q upper surface view of culture r lower surface view of culture. Scale bars: 100 μm ( c – f ); 20 μm ( g, h ); 50 μm ( i – p ). Culture characteristics. Conidia germinating on PDA within 24 hours, producing germ tubes from the apex. Colonies displayed a circular morphology with an umbonate elevation, dense growth and a filiform margin. The surface appeared greyish-green, occasionally exhibiting paler mycelium in the bulge region. The reverse colonies exhibited a circular shape with a filiform margin, displaying a dark brown colour, becoming olivaceous towards the periphery. Material examined. China • Hainan Province , Jianfengling National Forest Park , saprobic on unidentified decaying wood, 23 August 2021 , Zili Li, JBT 04 ( GZAAS 23-0808, holotype ), ex-type living culture GZCC 23-0732 . Note. Kirschsteiniothelia bulbosapicalis exhibits sporidesmium-like characteristics and shares similar morphologies with other Kirschsteiniothelia species. However, K. bulbosapicalis can be distinguished from other Kirschsteiniothelia species in having different sizes of conidiophores, conidiogenous cells and the unique feature of its conidia, which comprises one or two bulbous structures at or near the apex, with a spherical hyaline mucilaginous sheath. Phylogenetically, K. bulbosapicalis is sister to K. dujuanhuensis ( KUNCC 22-12671) with 85 % ML and 0.99 PP support (Fig. 1 ). Similar to our new species, K. dujuanhuensis also comprises a spherical hyaline mucilaginous sheath. Kirschsteiniothelia bulbosapicalis is characterised by larger conidiophores [(– 47) 58.5–128 (– 199) μm × 7.5–12.5 (– 16.5) μm, L / W ratio = 8.2] compared to K. dujuanhuensis [29–74 (– 119) × 9–11 μm, L / W ratio = 5.1] and larger conidia (118–236.5 μm × 15–27 μm, L / W ratio = 8.3) compared to K. dujuanhuensis [(114 –) 122–155 (– 170) × 10–13 (– 16) μm, L / W ratio = 11.5]. In addition, K. bulbosapicalis exhibits cylindrical to ovoid or obclavate conidia with 8–13 septa and often consist of bulbous structures at the apex and / or the third or fourth cell, as well as a spherical hyaline mucilaginous sheath. In contrast, K. dujuanhuensis typically contains obclavate to subcylindrical conidia that are 6–15 septate. In addition, the comparison of the nucleotides between the sequences of K. bulbosapicalis and K. dujuanhuensis showed differences of 9 % (47 / 512 bp) across ITS , 1 % (8 / 812 bp) across LSU and 0.1 % (2 / 1003 bp) across SSU , excluding gaps. Based on these findings, we introduce K. bulbosapicalis as a novel species, in accordance with the guidelines established by Jeewon and Hyde (2016) and Maharachchikumbura et al. (2021) .