Diaporthe hainanensis Q. Yang, 2024

Liu, Hong Y., Luo, Dun, Huang, Han L. & Yang, Qin, 2024, Two new species of Diaporthe (Diaporthaceae, Diaporthales) associated with Camellia oleifera leaf spot disease in Hainan Province, China, MycoKeys 102, pp. 225-243 : 225

Diaporthe hainanensis Q. Yang sp. nov.

Fig. 2

Diagnosis.

Distinguished from D. cercidis in narrower alpha conidia; from D. guangxiensis in shorter beta conidia.

Etymology.

In reference to the Hainan Province, from where the fungus was first collected.

Description.

Asexual morph: Conidiomata on PNA pycnidial, globose or rostrated, black, erumpent in tissue, erumpent at maturity, 450-600 μm diam., often with pale yellowish conidial drops exuding from the ostioles. Conidiophores reduced to conidiogenous cells. Conidiogenous cells (10.5-)14.5-20(-21.5) × 1.4-1.8 μm (n = 30), aseptate, cylindrical, phialidic, straight or slightly curved. Alpha conidia (5.5-)7-8(-8.5) × 2.1-2.9 μm (n = 30), aseptate, hyaline, ellipsoidal, biguttulate. Beta conidia (21.5-)23-25 × 1.1 µm (n = 30), hyaline, aseptate, filiform, sinuous at one end, eguttulate.

Culture characters.

Culture incubated on PNA at 25 °C, originally white, fluffy aerial mycelium, becoming pale yellow with age, with visible solitary conidiomata pine needles after 15 days.

Specimens examined.

China. Hainan Province: Chengmai County, on leaves of Camellia oleifera , 19°34'10"N, 110°18'09"E, 25 July 2022, Q. Yang (holotype CSUFT055; ex-type living culture: HNCM049; other living cultures: HNCM050, HNCM051 and HNCM052) .

Notes.

Four isolates representing D. hainanensis cluster in a well-supported clade (ML/BI = 100/1) and appear most closely related to D. cercidis on Cercis chinensis and D. guangxiensis on Macadamia sp. Diaporthe hainanensis can be distinguished from D. cercidis , based on ITS, his3, tef1 and tub2 loci (13/458 in ITS, 5/455 in his3, 33/341 in tef1 and 5/401 in tub2); from D. guangxiensis , based on ITS, tef1 and tub2 loci (5/457 in ITS, 2/339 in tef1 and 16/403 in tub2). Morphologically, D. hainanensis differs from D. cercidis in narrower alpha conidia (2.1-2.9 μm vs. 3-3.5 μm) ( Yang et al. 2018); from D. guangxiensis in shorter beta conidia (23-25 μm vs. 20-32 μm) ( Manawasinghe et al. 2019).

Figures

Figure 2. Diaporthe hainanensis (HNCM 049) A culture on PNA B, C conidiomata D conidiogenous cells E alpha conidia F beta conidia. Scale bars: 500 μm (B, C); 10 μm (C, F), 20 μm (E).