Diaporthe arecae (H.C. Srivast., Zakia & Govindar.) R.R. Gomes, Glienke & Crous, Persoonia 31: 16. (2013)

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 arecae (H.C. Srivast., Zakia & Govindar.) R.R. Gomes, Glienke & Crous, Persoonia 31: 16. (2013) Figure 2

Subramanella arecae H.C. Srivast., Zakia & Govindar., in Srivastava, Banu and Govindarajan (1962). Basionym.

Description.

Asexual morph: Conidiomata pycnidial, several pycnidia grouped together, globose, black, erumpent, exuding creamy to yellowish conidial droplets from ostioles. Conidiophores hyaline, septate, branched, cylindrical, straight to sinuous, 25.0-32.0 × 1.4-2.5 μm. Conidiogenous cells 10.5-20.7 × 1.4-2.0 μm, phialidic, cylindrical, swollen at base, tapering towards apex, slightly curved. Alpha conidia hyaline, smooth, aseptate, ellipsoidal, guttulate, apex subobtuse, base subtruncate, 7.5-10.0 × 1.8-3.0 µm (mean = 8.2 × 2.4 μm, n = 20). Beta conidia hyaline, aseptate, filiform, slightly curved, tapering towards base, 18.5-26.5 × 1.0-1.8 µm (mean = 24.3 × 1.4 μm, n = 20). Gamma conidia not observed. Sexual morph not observed.

Culture characteristics.

Cultures incubated on PDA at 25 °C in darkness, growth rate 11.2-13.3 mm diam/day. Aerial mycelium white, cottony, feathery, abundant in center, sparse in margin, white on surface, reverse yellowish to tan.

Specimen examined.

China, Yunnan Province: Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, on diseased leaves of Persea americana ( Lauraceae ). 19 April 2019, S.T. Huang, HSAUP194.18, living culture SAUCC194.18.

Notes.

Diaporthe arecae (CBS 161.64) was originally described as Subramanella arecae on fruit of Areca catechu in India ( Srivastava et al. 1962) and placed in Diaporthe by Gomes et al. (2013). The Diaporthe isolate from fruits of Citrus sp. (CBS 535.75) in Suriname was also placed in D. arecae by Gomes et al. (2013). In the present study, strain (SAUCC194.18) from symptomatic leaves of Persea americana was congruent with D. arecae based on morphology and DNA sequences data (Fig. 1 ). We therefore consider the isolated strain as D. arecae .

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 2. Diaporthe arecae (SAUCC 194.18) a infected leaf of Persea americana b, c surface and reverse of a colony after 15 days on PDA d conidiomata e-g conidiophores and conidiogenous cells h beta conidia i alpha conidia j alpha conidia and beta conidia. Scale bars: 10 μm (e-j).