First report of Hymenoscyphus fraxineus on Phillyrea spp. and Chionanthus virginicus in the United Kingdom
In May 2018, Hymenoscyphus fraxineus (formerly EPPO Alert List) was detected on a non-Fraxinus host in South East England, United Kingdom. Symptomatic hosts comprised trees of Phillyrea latifolia, part of a hedge in a private property. The trees had been planted in August 2011 but had recently developed symptoms of dying branches and showed discolouration of the wood in the cross section of the affected branches. The identification of H. fraxineus was confirmed by isolation, ITS sequencing and real-time PCR. Two additional findings of H. fraxineus were detected on P. angustifolia and Chionanthus virginicus in a tree collection in South West England. The location of these findings on non-ash hosts was in the vicinity of many native ash trees affected by H. fraxineus. Both Phillyrea and Chionanthus belong to the Oleaceae family, as does Fraxinus. P. angustifolia is native to the western and central Mediterranean Basin, from Portugal to Albania. P. latifolia is native to the entire Mediterranean Basin, from Portugal to Syria. C. virginicus is native to southern North America. The findings of infection by H. fraxineus on Phillyrea spp. and C. virginicus are the first non-ash host records worldwide. Koch’s postulates and the susceptibility of different hosts within the Oleaceae family are ongoing at the Forest Research UK.
Sources
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Forest Research (2018-08-07) Chalara ash dieback on different ash species and non-ash hosts. https://www.forestresearch.gov.uk/news/chalara-ash-dieback-different-ash-species-and-non-ash-hosts/
GOV.UK (2018-08-07) Ash dieback found on three new host species of tree in the UK. https://www.gov.uk/government/news/ash-dieback-found-on-three-new-host-species-of-tree-in-the-uk--2