Diaporthe litchii S.T. Huang, J.W. Xia, X.G. Zhang, Z. Li, 2021

Sun, Wenxiu, Huang, Shengting, Xia, Jiwen, Zhang, Xiuguo & Li, Zhuang, 2021, Morphological and molecular identification of Diaporthe species in south-western China, with description of eight new species, MycoKeys 77, pp. 65-95 : 65

Diaporthe litchii S.T. Huang, J.W. Xia, X.G. Zhang, Z. Li sp. nov. Figure 6

Etymology.

Named after the host Litchi chinensis on which it was collected.

Diagnosis.

Diaporthe litchii differs from D. collariana R.H. Perrera & K.D. Hyde in smaller alpha conidia and shorter conidiophores.

Type.

China, Yunnan Province: Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, on infected leaves of Litchi chinensis . 19 April 2019, S.T. Huang, HSAUP194.22, holotype, ex-holotype living culture SAUCC194.22.

Description.

Asexual morph: Conidiomata pycnidial, 3-5 pycnidia grouped together, globose, black, erumpent, coated with white hyphae, creamy to yellowish conidial droplets exuded from central ostioles. Conidiophores hyaline, branched, densely aggregated, cylindrical, 10.5-15.0 × 1.8-2.5 μm. Conidiogenous cells 7.5-9.5 × 1.5-2.0 μm, cylindrical, terminal, straight to sinuous. Alpha conidia, hyaline, smooth, aseptate, ellipsoidal to fusiform, biguttulate, 3.8-5.0 × 1.5-2.3 µm (mean = 4.7 × 2.0 μm, n = 20). Beta conidia hyaline, aseptate, filiform, few guttulate, slightly curved, tapering towards both ends, 20.0-28.0 × 1.2-1.8 µm (mean = 23.2 × 1.2 μm, n = 20). Gamma conidia and sexual morph not observed.

Culture characteristics.

Pure culture was isolated by subbing hyphal tips growing from surface sterilized plant material. Colonies on PDA cover the Petri dish diameter after incubation for 15 days in dark conditions at 25 °C. Aerial mycelium abundant, white, cottony on surface, reverse white to pale brown with two concentric zonation.

Additional specimen examined.

China, Yunnan Province: Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, on diseased leaves of Elaeagnus conferta . 19 April 2019, S.T. Huang, HSAUP194.12 paratype; living culture SAUCC194.12.

Notes.

Diaporthe litchii comprises strains SAUCC194.12 and SAUCC194.22 can be distinguished from the closely related species D. collariana by 63 nucleotides difference in the concatenated alignment (9 in the ITS region, 34 TUB, 5 TEF and 15 CAL). Diaporthe litchii differs from D. collariana in smaller alpha conidia (3.8-5.0 × 1.5-2.3 vs. 4.7-5.6 × 1.7-2.2 μm) and shorter conidiophores (10.5-15.0 × 1.8-2.5 vs. 12-20 × 2.4-3.2 μm) ( Perera et al. 2018).

Figures

Figure 6. Diaporthe litchii (SAUCC 194.22) a leaf of host plant b, c surface (b) and reverse (c) sides of colony after incubation for 15 days on PDA d conidiomata e, f conidiophores and conidiogenous cells g, h beta conidia i alpha conidia and beta conidia j alpha conidia. Scale bars: 10 μm (e-j).