Diaporthe hunanensis Q. Yang, 2021

Yang, Qin, Tang, Jie & Zhou, Guo Y., 2021, Characterization of Diaporthe species on Camellia oleifera in Hunan Province, with descriptions of two new species, MycoKeys 84, pp. 15-33 : 15

Diaporthe hunanensis Q. Yang sp. nov.

Figure 4

Diagnosis.

Distinguished from its phylogenetically closely-related species, D. chrysalidocarpi , D. drenthii , D. searlei and D. spinosa based on DNA sequence data.

Etymology.

In reference to the Hunan province, from where the fungus was first collected.

Description.

Asexual morph: pycnidia on PDA 180-300 μm in diam., superficial, scattered, black, globose, solitary in most. Conidiophores reduced to conidiogenous cells. Conidiogenous cells (8-)9-15(-16.5) × 1.7-2.1 μm (n = 30), aseptate, cylindrical, phiailidic, straight or slightly curved. Alpha conidia 6.5-7.5(-8.5) × 2.4-2.9 μm (n = 30), aseptate, hyaline, ellipsoidal, biguttulate, both ends obtuse. Beta conidia not observed.

Culture characters.

Culture incubated on PDA at 25 °C, originally flat with white fluffy aerial mycelium, becoming pale brown with age, with visible solitary conidiomata at maturity after 18 days.

Specimens examined.

China. Hunan Province: Zhuzhou City , on leaves of Camellia oleifera , 27°2'41"N, 113°19'17"E, 14 Aug. 2020, Q. Yang (holotype CSUFT 023; ex-type living culture: HNZZ023; living cultures: HNZZ025 and HNZZ033) .

Notes.

Three isolates representing D. hunanensis cluster in a well-supported clade (ML/BI=100/1) and appear most closely related to D. chrysalidocarpi on Chrysalidocarpus lutescens , D. drenthii and D. searlei on Macadamia sp., and D. spinosa on P. pyrifolia cv. Cuiguan. Diaporthe hunanensis can be distinguished from D. chrysalidocarpi based on ITS, cal, his3 and tub2 loci (7/457 in ITS, 28/448 in cal, 8/455 in his3 and 5/401 in tub2); from D. drenthii based on ITS, tef1 and tub2 loci (9/457 in ITS, 13/328 in tef1 and 23/401 in tub2); from D. searlei based on ITS and tub2 loci (10/457 in ITS and 12/401 in tub2); from D. spinosa based on ITS, cal, his3, tef1 and tub2 loci (8/458 in ITS, 31/448 in cal, 5/455 in his3, 8/328 in tef1 and 19/401 in tub2). Morphologically, D. chrysalidocarpi produces only beta conidia, while D. hunanensis produces alpha conidia ( Huang et al. 2021); D. hunanensis differs from D. drenthii and D. searlei in wider alpha conidia (2.4-2.9 μm in D. hunanensis vs. 1.5-2.5 μm in D. drenthii vs. 1.5-2 μm in D. searlei ) ( Wrona et al. 2020); from D. spinosa in shorter alpha conidia (6.5-7.5 × 2.4-2.9 μm vs. 5.5-8 × 2-3.5 μm) ( Guo et al. 2020). Therefore, we establish this fungus as a novel species.

Figures

Figure 4. Diaporthe hunanensis (HNZZ 023) A Culture on PDA B conidiomata C conidiogenous cells D alpha conidia. Scale bars: 500 μm (B); 10 μm (C-D).