New species and records of Botryosphaeriales (Dothideomycetes) associated with tree dieback in Beijing, China Author Wu, Yingying https://orcid.org/0009-0007-5095-2738 The Key Laboratory for Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, China Author Peng, Cheng The Key Laboratory for Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, China Author Yuan, Rong https://orcid.org/0009-0006-5597-7531 The Key Laboratory for Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, China Author Zhang, Mingwei The Key Laboratory for Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, China Author Hu, Yang The Forestry Protection Station of Tonghzou Strict in Beijing, Beijing 101100, China Author Tian, Chengming 0000-0002-3352-7664 The Key Laboratory for Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, China text MycoKeys 2024 2024-06-27 106 225 250 journal article 299051 10.3897/mycokeys.106.122890 c1609dc8-7d30-4bb0-815a-74c459f25412 Dothiorella hortiarborum Y. Y. Wu & C. M. Tian sp. nov. Fig. 5 Etymology. “ Hort ” means “ garden, ” and “ arbor ” means “ tree ” in Latin. Collected from Fraxinus chinensis and Lagerstroemia indica , both of which are landscaping and greening trees. Holotype . China , Beijing City , Tongzhou District , Central Green Forest Park , 39 ° 52 ' 16 " N , 116 ° 42 ' 04 " E , on the dead branches of Fraxinus chinensis , 19 April 2023 , C. M. Tian , C. Peng , R. Yuan , M. W. Zhang & Y. Y. Wu ( holotype BJFC - S 1951 , ex-type cultures CFCC 70756 ). Description. Sexual morph : Not observed. Asexual morph : Conidiomata pycnidial, scattered to aggregated, immersed to semi-immersed in bark, globose to subglobose, dark gray to black, unilocular, 260–450 μm diam. Disc black, ovoid, 310–330 μm diam. Ostioles single, light gray, circular, central, papillate, 30–45 μm diam. Locules single, black, oval, 100–380 μm, Conidiophores reduced to conidiogenous cells. Conidiogenous cells : hyaline, smooth, thin-walled, holoblastic, cylindrical to subcylindrical, 4.5–11.0 × 2.0–4.0 μm (av. ± S. D. = 6.8 ± 1.3 × 2.9 ± 0.5 µm). Conidia initially hyaline, then producing light yellow pigmentation, uneven surface, thick-walled, dark brown when matrues, 1 - septate, constricted at the septum, smooth, ovoid with a broadly rounded apex, truncate base. 10.0–19.0 × 6.0–11.0 μm (av. ± S. D. = 14.9 ± 2.6 × 8.1 ± 1.0 µm). Dothiorella hortiarborum ( BJFC - S 1951 ) A, B habit of conidiomata on branch C transverse section of conidioma D longitudinal section through conidioma E, F conidiogenous cells and conidia G top (left) and bottom (right) sides of colonies on potato dextrose agar ( PDA ) H, I conidia. Scale bars: 1000 μm ( A ); 200 μm ( B – D ); 10 μm ( E – F, H – I ). Culture characters. Colonies on PDA with aerial mycelium gray-green, thick and dense, fluffly, margin with undulate and irregular, reverse with inky blue pigment accumulation, reaching 60 mm diam in 7 days at 25 ° C. Other material examined. China , Beijing City , Tongzhou District , Central Green Forest Park , 39 ° 52 ' 16 " N , 116 ° 42 ' 04 " E , on the dead branches of Fraxinus chinensis , 19 April 2023 , C. M. Tian , C. Peng , R. Yuan , M. W. Zhang & Y. Y. Wu , BJFC - S 2366 , living culture CFCC 70757 ; China , Beijing City , Tongzhou District , Central Green Forest Park , 39 ° 52 ' 16 " N , 116 ° 42 ' 04 " E , on the dead branches of Lagerstroemia indica , 19 April 2023 , C. M. Tian , C. Peng , R. Yuan , M. W. Zhang & Y. Y. Wu , BJFC - S 1952 , living culture CFCC 70758 ; ibid . BJFC - S 2367 , living culture CFCC 70759 . Notes. Dothiorella hortiarborum formed an independent clade with 87 % MP , 97 % ML , and 0.99 BYPP values and is distinct from Do. acericola and Do. plurivora in the multi-locus analyses (Fig. 3 ). Morphologically, Do. hortiarborum can be distinguished from Do. acericola by shorter conidia ( Phookamsak et al. 2019 ) and Do. plurivora by smaller conidia (10.0–19.0 × 6.0–11.0 μm vs. 22.3–22.7 × 10.8–11.2 μm) ( Abdollahzadeh et al. 2014 ). Additionally, Do. hortiarborum differs from Do. acericola in tef 1 - α (five bp difference from 170 characters, with 97.1 % similarity, including no gaps) sequences, and Do. plurivora in tef 1 - α (one bp difference from 254 characters, with 99.6 % similarity, including one gap), tub 2 (three bp difference from 370 characters, with 99.2 % similarity, including one gap) sequences.