Diaporthe eres Nitschke, 1870

Yang, Qin, Fan, Xin-Lei, Guarnaccia, Vladimiro & Tian, Cheng-Ming, 2018, High diversity of Diaporthe species associated with dieback diseases in China, with twelve new species described, MycoKeys 39, pp. 97-149 : 97

Diaporthe eres Nitschke, 1870 Figure 12

= Diaporthe biguttusis Y.H. Gao & L. Cai, 2015.

= Diaporthe camptothecicola C.M. Tian & Qin Yang, 2017.

= Diaporthe ellipicola Y.H. Gao & L. Cai, 2015.

= Diaporthe longicicola Y.H. Gao & L. Cai, 2015

= Diaporthe mahothocarpus (Y.H. Gao, W. Sun & L. Cai) Y.H. Gao & L. Cai, 2015.

= Diaporthe momicola Dissan., J.Y. Yan, Xing H. Li & K.D. Hyde, 2017.

Description.

Conidiomata pycnidial, immersed in bark, erumpent through the bark surface, serried, with a single locule. Ectostromatic disc obviously, brown to black, with one ostiole per disc, 245-572 μm diam. Ostiole medium black, up to the level of disc. Locule circular, undivided, 335-450 μm diam. Conidiophores 10.5-19 × 1-1.5 μm, cylindrical, hyaline, unbranched, straight or slightly sinuous. Conidiogenous cells phialidic, cylindrical, terminal. Alpha conidia hyaline, aseptate, ellipsoidal to lanceolate, one guttulate at each end, 6-7.5 × 1.5-2.5 μm (av. = 6.5 × 2 μm, n = 30). Beta conidia not observed.

Culture characters.

Cultures on PDA incubated at 25 °C in darkness. Colony with white felty aerial mycelium, becoming white felted aerial mycelium in the centre and grey-brown mycelium at the marginal area, conidiomata irregularly distributed over agar surface.

Specimens examined.

CHINA. Beijing: Pinggu district, on symptomatic branches of Castanea mollissima , 1 Nov. 2016, N. Jiang, living culture CFCC 52576 (BJFC-S1489); ibid. living culture CFCC 52577 (BJFC-S1490). Heilongjiang Province: Liangshui Nature Reserve, on symptomatic twigs of Acanthopanax senticosus , 29 July 2016, Q. Yang, living culture CFCC 52580 (BJFC-S1493). Heilongjiang Province: Harbin city, Botanical garden, on symptomatic twigs of Sorbus sp., 2 Aug. 2016, Q. Yang, living culture CFCC 52575 (BJFC-S1488). Shaanxi Province: Zhashui County, on symptomatic branches of Juglans regia , 29 July 2016, Q. Yang, living culture CFCC 52579 (BJFC-S1492). Zhejiang Province: Yangzhou city, on symptomatic twigs of Melia azedarace , 8 July 2017, N. Jiang, living culture CFCC 52578 (BJFC-S1491). Zhejiang Province: Tianmu Mountain, on symptomatic twigs of Rhododendron simsii , 20 Apr. 2017, Q. Yang, living culture CFCC 52581 (BJFC-S1494).

Notes.

Diaporthe eres , the type species of the genus, was described by Nitschke (1870) on Ulmus sp. collected in Germany, which has a widespread distribution and a broad host range as a pathogen, endophyte or saprobe causing leaf spots, stem cankers and diseases of woody plants ( Udayanga et al. 2014b). Fan et al. (2018) indicated that D. biguttusis , D. ellipicola , D. longicicola and D. mahothocarpus should be treated as synonyms of D. eres using cal, tef1 and tub2 gene regions. In this study, we extended the work presented in Fan et al. (2018) and found seven additional strains belonging to D. eres . Additionally, the phylogenetic tree demonstrated that D. camptothecicola and D. momicola should also be treated as synonyms of D. eres (Fig. 2). Diaporthe camptothecicola from Camptotheca acuminate and D. momicola from Prunus persica are described and illustrated based on the combined ITS, cal, his3, tef1 and tub2 regions ( Dissanayake et al. 2017a, Yang et al. 2017c). Both of the two species are embedded in the D. eres complex. However, ITS analysis resulted in an unresolved phylogenetic tree without definitive bootstrap at the internodes, highly discordant to the trees resulting from the other four genes ( Udayanga et al. 2014b). Therefore, the ITS region was not used in the combined analysis in the current study. To further investigate this complex, a second set of four (cal, his3, tef1 and tub2), three (cal, tef1 and tub2), two (tef1 and tub2) and one (tef1) data matrices were performed following Santos et al. (2017) and Fan et al. (2018). The results showed that the three genes analyses (cal, tef1 and tub2) appeared to be a better species recognition (Fig. 2). When it comes to this species complex, sequences supported by Udayanga et al. (2014b) are necessary to perform a more robust phylogenetic tree, clarifying the real species boundaries in this group in the future work.