Population structure and natural selection in the Chalara ash dieback fungus

Fruit bodies of H FraxineusThe research will investigate the ecological genetics of the ash dieback pathogen Hymenoscyphus fraxineus and its ability to evolve in response to natural selection.

Research objectives

The initial objectives of this research are to:

  • Examine variation in the genetic diversity and pathogenicity of H. fraxineus between populations and within trees using a number of different approaches.
  • Explore the relationship between the recently arrived H. fraxineus and its cousin H. albidus, which is native to the UK and harmless to our native ash species Fraxinus excelsior.
  • Determine if viruses might offer a control for ash dieback disease.

Results so far

The work is in its early stages but by gaining vital information about the ash dieback pathogen and its native relative, we hope to contribute to work on the breeding and management of natural and commercial ash populations to control this aggressive disease.
The research will also provide insights into the operation of natural selection on this recently arrived pathogen as it infects native ash trees.


ACTIVE until March 2017


Dr Joan Webber

Funders and partners

This research is being undertaken with the John Innes Centre and is led by Prof James Brown. It is 80% funded under the auspices of the Living With Environmental Change Partnership with support from the Biotechnology and Biological Sciences Research Council, Department for Environment, Food and Rural Affairs, Economic and Social Research Council, Forestry Commission, Natural Environment Research Council and the Scottish Government and 20% funded through the Forestry Commission Advice and Scientific Support for Tree Health Programme

Forestry Commission policy

This research underpins the evidence base for the delivery of healthy and resilient forests and wider ecosystems (see Tree Health management plan)