The ash dieback invasion of Europe was founded by two genetically divergent individuals

Mark McMullan, Maryam Rafiqi, Gemy Kaithakottil, Bernardo J. Clavijo, Lorelei Bilham, Elizabeth Orton, Lawrence Percival-Alwyn, Ben J. Ward, Anne Edwards, Diane G.O. Saunders, Gonzalo Garcia Accinelli, Jonathan Wright, Walter Verweij, Georgios Koutsovoulos, Kentaro Yoshida, Tsuyoshi Hosoya, Louisa Williamson, Philip Jennings, Renaud Ioos, Claude HussonAri M. Hietala, Adam Vivian-Smith, Halvor Solheim, Dan MaCclean, Christine Fosker, Neil Hall, James K. M. Brown, David Swarbreck, Mark Blaxter, J. Allan Downie, Matthew D. Clark

Research output: Contribution to journalArticlepeer-review

73 Citations (Scopus)
12 Downloads (Pure)


Accelerating international trade and climate change make pathogen spread an increasing concern. Hymenoscyphus fraxineus, the causal agent of ash dieback, is a fungal pathogen that has been moving across continents and hosts from Asian to European ash. Most European common ash trees (Fraxinus excelsior) are highly susceptible to H. fraxineus, although a minority (~5%) have partial resistance to dieback. Here, we assemble and annotate a H. fraxineus draft genome, which approaches chromosome scale. Pathogen genetic diversity across Europe and in Japan, reveals a strong bottleneck in Europe, though a signal of adaptive diversity remains in key host interaction genes. We find that the European population was founded by two divergent haploid individuals. Divergence between these haplotypes represents the ancestral polymorphism within a large source population. Subsequent introduction from this source would greatly increase adaptive potential of the pathogen. Thus, further introgression of H. fraxineus into Europe represents a potential threat and Europe-wide biological security measures are needed to manage this disease.

Original languageEnglish
Pages (from-to)1000-1008
Number of pages9
JournalNature Ecology and Evolution
Issue number6
Early online date23 Apr 2018
Publication statusPublished - Jun 2018

Cite this