Dendrostoma donglinensis H.Y. Zhu & X.L. Fan

Zhu, Haiyan, Pan, Meng, Bonthond, Guido, Tian, Chengming & Fan, Xinlei, 2019, Diaporthalean fungi associated with canker and dieback of trees from Mount Dongling in Beijing, China, MycoKeys 59, pp. 67-94 : 67

Dendrostoma donglinensis H.Y. Zhu & X.L. Fan sp. nov. Fig. 7

Etymology.

Named after the location where it was collected, Mount Dongling.

Holotype.

CHINA, Beijing City, Mentougou District, Mount Dongling, Xiaolongmen Forestry Centre (39°58'19.62"N, 115°26'51.27"E), from branches of Quercus mongolica Fisch. ex Ledeb., 18 Aug. 2017, H.Y. Zhu & X.L. Fan, deposited by X.L. Fan, holotype CF 2019903, ex-type living culture CFCC 53148.

Description.

Sexual morph: not observed. Asexual morph: Pycnidial stromata immersed in the bark, scattered, erumpent through the surface of bark, unilocular, with a conspicuous central column. Central column beneath the disc more or less conical, yellow. Conceptacle absent. Ectostromatic disc hyaline, circular to ovoid, 750-1190 µm in diam., with a single ostiole per disc. Ostiole grey to black, at the same level as the disc surface, 240-270 μm in diam. Locule single, circular to irregular, undivided, 550-750 µm in diam. Conidiophores hyaline, unbranched, approximately cylindrical. Conidiogenous cells enteroblastic, phialidic. Conidia hyaline, fusoid, acute at each end, smooth or occasional not smooth, aseptate, 16.5-20.5 × 2-3.5 (av. = 18 ± 1.1 × 3 ± 0.3, n = 30) μm.

Culture characteristics.

Cultures on PDA are initially white, growing slowly to 2 cm in diam. after 3 days and 4 cm after 14 days, becoming salmon in the center after 7-10 days. Growth stops when colony reaches 8 cm and cultures becoming salmon to honey after the 30 days. Colonies are felty with a uniform texture; sterile.

Additional material examined.

CHINA, Beijing City, Mentougou District, Mount Dongling, Xiaolongmen Forestry Centre (39°58'19.62"N, 115°26'51.27"E), from branches of Quercus mongolica Fisch. ex Ledeb., 18 Aug. 2017, H.Y. Zhu & X.L. Fan, deposited by X.L. Fan, CF 2019887, living culture CFCC 53149; ibid. CF 2019805, living culture CFCC 53150.

Notes.

Dendrostoma donglinensis is associated with canker disease of Quercus mongolica in China. It can be distinguished from its closest relative D. parasiticum by its fusoid, acute at each end and larger conidia (16.5-20.5 × 2-3.5 vs. 9.3-11.7 ×2.8– 3.3 μm). The isolates are phylogenetically distinct from all other available strains of Dendrostoma included in this study and we therefore describe this species as new, based on DNA sequence data and morphology.

Figures

Figure 7. Morphology of Dendrostoma donglinensis from Quercus mongolica (CF 2019903). A-E Habit of conidiomata on twig F transverse section of conidioma G longitudinal section through conidioma H conidiophores and conidiogenous cells I conidia J colonies on PDA at 3 days (left) and 30 days (right). Scale bars: 1 mm (A); 500 μm (B-G); 10 μm (H, I).