Tackling ash dieback

Chalara-induced ash dieback is causing severe disease on more than 90% of European ash trees. The arrival of the disease in the UK prompted an inter-institutional/university research effort into the pathogen and its host.

Nornex is a network of scientists from eleven research institutions aiming to make tools to help understand how to deal with ash dieback, caused by Chalara fraxinea (Hymenoscyphus pseudoalbidus)



The aims of the Nornex partners can be split into five streams:


Genomics of the pathogen Hymenoscyphus pseudoalbidus

Understand the diversity of the population of the pathogen infecting UK and European ash trees, and determine the likely source of the disease.
Nornex is establishing the genome sequence of a reference genome from the UK (isolate KW1) and will determine diversity by comparing this with DNA sequences from other isolates of the pathogen.


Pathology of Hymenoscyphus pseudoalbidus

Why is H.pseudoalbidus so pathogenic on ash?
Nornex hopes to generate laboratory-based tests to understand how it infects trees and what steps can reduce infection.
Analysis of the DNA sequence and the genes it expresses on ash will give insights into why it is such a virulent pathogen.


Chalara-resistant ash genome project

The genome sequence of the Chalara-resistant ash tree 35 will be used in conjunction with genetic mapping to generate DNA-sequence-based genetic map of Fraxinus excelsior.
This map is needed to understand inheritance of low susceptibility to the disease.


Mapping inheritance of low susceptibility in ash

By sequencing the genes expressed by trees with low susceptibility, Nornex hopes to map the locations of the genome that confer tolerance to the pathogen.
The knowledge will enable crosses to be done between ash trees to optimise the chances of progeny that can grow well, even if infected by the pathogen.
The approach Nornex are using is associative transcriptomics, which was recently developed to identify inheritance of useful traits in crop plants.


Open access website

The research partners are committed to making their findings rapidly available on OpenAshDieback.
Other scientists from around the world are helping to analyse the data and contribute new ideas via the website.
For more on OpenAshDieback, head to http://oadb.tsl.ac.uk.


Nornex partners




Nornex is named after ‘The Three Norns’, female Nordic mythological spirits who watered and sustained the roots of the tree Yggdrasil, an immense and holy ash tree-of-life which extends its branches to the heavens.