Diaporthe eres Nitschke, Pyrenomyc. Germ. 2: 245 (1870)

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

Diaporthe eres Nitschke, Pyrenomyc. Germ. 2: 245 (1870) Fig. 6

Description.

Sexual morph: not observed. Asexual morph: Pycnidial stromata immersed in bark, scattered, slightly erumpent through the bark surface, unilocular, with a conspicuous central column. Central column beneath the disc more or less conical, pale grey with yellow. Ectostromatic disc orange, elliptical, 160-300 μm in diam., with one ostiole per disc. Ostiole dark brown to black, at the same level as or slightly above the disc surface, 70-80 μm in diam. Locule single, 210-260 μm in diam. Conidiophores cylindrical, hyaline, unbranched, straight or slightly curved, tapering towards the apex, 12-13.5 × 2-3 μm. Conidiogenous cells enteroblastic, phialidic. Alpha conidia hyaline, aseptate, smooth, ellipsoidal, biguttulate, rounded at both ends, 6.5-8.5 × 2.5-3 (av. = 7.3 ± 0.5 × 2.8 ± 0.3, n = 30) μm. Beta conidia were not observed.

Culture characteristics.

Cultures on PDA are initially white, growing up to 4 cm in diam. after 3 days, and becoming yellow green to brown after 7-10 days. Colonies are flat felty with a thick texture at the marginal area, with a thin texture at the center, abundant aerial mycelium, sterile.

Material examined.

CHINA, Beijing City, Mentougou District, Mount Dongling, Xiaolongmen Forestry Centre (39°58'06.45"N, 115°26'48.36"E), from branches of Prunus davidiana (Carr.) Franch., 20 Aug. 2017, H.Y. Zhu & X.L. Fan, deposited by X.L. Fan, CF 2019808, living culture CFCC 53146; ibid. CF 2019858, living culture CFCC 53145. CHINA, Beijing City, Mentougou District, Mount Dongling, Xiaolongmen Forestry Centre (39°57'47.49"N, 115°29'20.52"E), from branches of Juglans regia L., 20 Aug. 2017, H.Y. Zhu & X.L. Fan, deposited by X.L. Fan, CF 2019801, living culture CFCC 53147.

Notes.

Diaporthe eres is the type species of Diaporthe , and is also the most common species causing canker disease on a wide range of hosts ( Gomes et al. 2013, Udayanga et al. 2014, Dissanayake et al. 2017, Yang et al. 2018). Our isolates are associated with canker disease of Prunus davidiana in China, which belong to the Diaporthe eres species complex ( Fig. 4 ). Fan et al. (2018c) treated many Diaporthe species as D. eres , and showed the combined cal, tef1-α and tub2 genes provide a better topology than the combined five-gene phylogeny for the D. eres complex. Both sequence data and morphology confirm that our isolates belong to this species ( Fig. 4 ).

Figures

Figure 4. Phylogram of Diaporthe eres complex based on combined cal, tef 1 - α and tub 2 genes. The MP and ML bootstrap support values above 50 % are shown at the first and second positions, respectively. Thickened branches represent posterior probabilities above 0.95 from BI. Ex-type strains are in bold. Strains from the current study are in blue.

Figure 6. Morphology of Diaporthe eres from Prunus davidiana (CF 2019808). A, B Habit of conidiomata on twig C, D transverse section of conidioma E longitudinal section through conidioma F conidiophores and conidiogenous cells G alpha conidia H colonies on PDA at 3 days (left) and 30 days (right). Scale bars: 1 mm (A); 250 μm (B-E); 10 μm (F, G).