Diaporthe pandanicola Tibpromma & K.D. Hyde, MycoKeys 33: 44 (2018)

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 pandanicola Tibpromma & K.D. Hyde, MycoKeys 33: 44 (2018) Figure 8

Description.

Asexual morph: Conidiomata pycnidial, 3-5 pycnidia grouped together, superficial to embedded on PDA, erumpent, thin-walled, dark brown to black, globose or subglobose, exuding white creamy conidial mass from ostioles. Conidiophores hyaline, aseptate, cylindrical, smooth, straight to sinuous, unbranched, aggregated, 17.0-26.5 × 2.0-3.0 µm. Conidiogenous cells phialidic, cylindrical, terminal, 10.0-20.0 × 1.5-1.8 µm. Alpha conidia hyaline, smooth, aseptate, ellipsoidal, eguttulate, apex subobtuse, base subtruncate, 6.5-9.0 × 1.8-2.5 µm (mean = 7.5 × 2.0 μm, n = 20). Beta conidia hyaline, aseptate, filiform, curved, tapering towards apex, base truncate, 26.0-32.8 × 1.0-1.6 µm (mean = 29.0 × 1.3 μm, n = 20). Gamma conidia infrequent, aseptate, smooth, straight, hyaline, 12.5-14.5 × 1.3-1.8 µm (mean = 13.5 × 1.6 μm, n = 6). Sexual morph not observed.

Culture characteristics.

Cultures incubated on PDA at 25 °C in darkness, growth rate 12.8-15.0 mm diam/day, flat, cottony in centre, with aerial mycelium sparse toward margin, white on surface, white to pale yellow on reverse.

Specimen examined.

China, Yunnan Province: Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, on diseased leaves of Millettia reticulata ( Fabaceae ). 19 April 2019, S.T. Huang, HSAUP194.82, living culture SAUCC194.82.

Notes.

Diaporthe pandanicola was originally described by Tibpromma et al. (2018) on healthy leaves of Pandanus sp. ( Pandanaceae ) as an endophytic fungus. Our strain (SAUCC194.82) is closely related to Diaporthe pandanicola based on phylogenetic analyses (Fig. 1 ). The differences of nucleotides in the concatenated alignment (19/533 in the ITS region and 11/351 in the TUB region) are less than 3%. Morphologically, our strain produces alpha conidia, beta conidia and gamma conidia, while Diaporthe pandanicola did not sporulate. We therefore identify our strains as Diaporthe pandanicola .

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 8. Diaporthe pandanicola (SAUCC 194.82) a infected leaf of Millettia reticulata b, c surface and reverse of colony after 15 days on PDA d conidiomata e-g conidiophores and conidiogenous cells h beta conidia i alpha conidia and gamma conidia j alpha conidia, beta conidia and gamma conidia. Scale bars: 10 μm (e-j).