Multigene phylogeny and morphology reveal three new species of Cytospora isolated from diseased plant branches in Fengtai District, Beijing, China Author Jia, Aoli https://orcid.org/0009-0004-0265-5454 State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China Author Chen, Baoyue Key Laboratory for Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, China Author Lu, Hongyan Key Laboratory for Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, China Author Xing, Yu Key Laboratory for Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, China Author Li, Bin Key Laboratory for Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, China Author Fan, Xinlei https://orcid.org/0000-0002-4946-4442 State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China xinleifan@bjfu.edu.cn text MycoKeys 2024 2024-01-18 101 163 189 http://dx.doi.org/10.3897/mycokeys.101.116272 journal article http://dx.doi.org/10.3897/mycokeys.101.116272 1314-4049-101-163 B3407E32182D54A38A90C118F97C94A5 Cytospora haidianensis X. Zhou & X.L. Fan, Forests 11: 524 (2020) Fig. 7 Description. Sexual morph : not observed. Asexual morph : Conidiomata pycnidial , immersed in the bark, scattered, producing black area on bark, circular to ovoid, with multiple locules, occasionally slightly erumpent through the surface. Conceptacle absent. Ectostromatic disc isabelline to dark brick, conspicuous, circular to ovoid, 130-350 µm in diam, with one ostiole per disc. Ostiole in the centre of the disc, black, conspicuous, 90-180 µm in diam. Locules numerous, subdivided frequently by invaginations with common walls, circular to ovoid, 500-1200 µm in diam. Conidiophores hyaline, branched at the base or unbranched, approximately cylindrical, 12-19 x 1-1.5 (av. = 15.5 +/- 4.3 x 1.1 +/- 0.4, n = 50) µm . Conidiogenous cells enteroblastic, phialidic, subcylindrical to cylindrical. Conidia hyaline, elongate-allantoid, smooth, aseptate, thin-walled, 4.8-6 x 1.5-2 (av. = 5.3 +/- 0.7 x 1.7 +/- 0.3, n = 50) µm . Cultural characteristics. Colonies on PDA are initially white after 3 d, becoming light brown after 14 d. The colonies are thin with a uniform texture, lacking aerial mycelium. Pycnidia were randomly observed on the surface of the colony after 30 d. Figure 7. Cytospora haidianensis from Salix babylonica (BJFC CF20230411) A, B habit of conidiomata on branch C transverse section through conidiomata D longitudinal section through conidiomata E, F conidiophores and conidiogenous cells G conidia. Scale bars: 1 mm ( A ); 200 µm ( B-D ); 10 µm ( E-G ). Materials examined. China , Beijing City , Fengtai Distinct , Beigong National Forest Park , 39°52'20.46"N , 116°7'47.60"E , from branches of Euonymus japonicus , 12 Apr 2023 , A.L. Jia & X.L. Fan (BJFC CF20230409, living culture CFCC 59450); Beigong National Forest Park, 39°52'20.46"N , 116°7'47.60"E , from branches of Malus ' American ', 12 Apr 2023 , A.L. Jia & X.L. Fan (BJFC CF20230410, living culture CFCC 59475); Century Forest Park, 39°49'43"N , 116°14'27"E , from branches of Acer pictum subsp. mono , 18 May 2023 , A.L. Jia & Y.X. Li (BJFC CF20230411, living culture CFCC 59471; BJFC CF20230412, living culture CFCC 59536) . Notes. Cytospora haidianensis was first introduced by Zhou et al. (2020) and which was isolated from Euonymus alatus in Beijing, China. This species has numerous locules with a central column of ostiolar tissue ( Zhou et al. 2020 ). In this study, four isolates grouped together with C. haidianensis in ML and BI trees (ML/BI = 100/1). Therefore, they are identified as Cytospora haidianensis . The current study extends its host range to Buxus megistophylla , Malus ' American ' and Acer pictum subsp. mono .