Diaporthe osmanthi H. Long, K.D. Hyde, & Yong Wang bis, MycoKeys 57: 120. (2019)

Huang, Shengting, Xia, Jiwen, Zhang, Xiuguo & Sun, Wenxiu, 2021, Morphological and phylogenetic analyses reveal three new species of Diaporthe from Yunnan, China, MycoKeys 78, pp. 49-77 : 49

Diaporthe osmanthi H. Long, K.D. Hyde, & Yong Wang bis, MycoKeys 57: 120. (2019) Figure 7

Description.

Conidiomata pycnidial, globose, 5-10 pycnidia grouped together, dark brown to black, exuding creamy to yellowish conidial droplets from central ostioles. Conidiophores hyaline, smooth, densely aggregated, branched, cylindric-clavate, 20.5-32.0 × 1.8-2.4 μm. Conidiogenous cells phialidic, hyaline, terminal, cylindrical, straight, 14.0-20.5 × 1.5-2.0 μm, tapered towards apex. Alpha conidia hyaline, aseptate, fusiform, tapering towards both ends, guttulate, 7.3-9.3 × 1.8-2.3 μm (mean = 8.5 × 2.0 μm, n = 20). Beta conidia hyaline, aseptate, filiform, curved, 22.0-28.5 × 1.0-2.0 μm (mean = 27.2 × 1.3 μm, n = 20). Gamma conidia not observed. Sexual morph not observed.

Culture characteristics.

Cultures incubated on PDA at 25 °C in darkness, growth rate 12.0-13.5 mm diam/day, cottony with abundant aerial mycelium, sparse at margin. With several concentric rings of dense hyphae, white on surface, white to pale brown on reverse.

Specimen examined.

China, Yunnan Province: Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, 19 April 2019, S.T. Huang. On diseased leaves of Litchi chinensis ( Sapindaceae ) HSAUP194.21, living culture SAUCC194.21.

Notes.

Diaporthe osmanthi was originally described from the leaves of Osmanthus fragrans ( Oleaceae ) in Guangxi province, China ( Long et al. 2019). In the present study, phylogenetic analyses (Fig. 1 ) indicated that the strain SAUCC194.21 is closely related to Diaporthe osmanthi and D. podocarpi-macrophylli ( Gao et al. 2017). Morphological comparison indicated that this strain was most similar to D. osmanthi by the size of alpha conidia and beta conidia. We therefore identify this strain as belonging to D. osmanthi .

Figures

Figure 1. Phylogram of Diaporthe spp. based on combined sequence data of ITS, TUB, TEF, CAL and HIS genes. The ML and BI bootstrap support values above 50 % and 0.90 BYPP are shown at the first and second position, respectively. Strains marked with " * " are ex-type or ex-epitype. Codes referring to strains from the current study are written in red. Some branches were shortened to fit them to the page as indicated by two diagonal lines with the number of times a branch was shortened indicated.

Figure 7. Diaporthe osmanthi (SAUCC 194.21) a infected leaf of Litchi chinensis b, c surface and reverse of colony after 15 days on PDA d conidiomata e-g conidiophores and conidiogenous cells h, i beta conidia j, k alpha conidia. Scale bars: 10 μm (e-k).