Norwich Research Park scientists help identify ash dieback tolerance in trees
PUBLISHED: 16:00 27 December 2016 | UPDATED: 13:30 04 January 2017
Researchers at the John Innes Centre and the Earlham Institute have helped to identify genetic markers for disease tolerance that suggest UK ash trees may have a fighting chance against a fungal infection that has the potential to wipe out 90pc of the European ash tree population.
The disease, called ash dieback, was first identified in Poland, where it devastated the native ash tree population. It rapidly spread across northern Europe and was discovered in the UK in 2012.
Results from the latest study published in Nature, a UK collaboration between Queen Mary University of London (QMUL), University of York, Earlham Institute (EI), John Innes Centre (JIC), NIAB and the University of Copenhagen, could contribute to breeding new varieties of ash that are tolerant to the disease.
Much like Dutch elm disease, ash dieback is aggressive, spreads quickly through the ash tree population, and has no cure, other than individual natural tolerance to the infection. It is spread on the wind or via the transfer of infected saplings between areas. Symptoms include loss of leaves and lesions, which are a useful way to diagnose fungal ash dieback, as they leave a characteristic diamond-shaped scar on the bark.
The York team had previously tested a genetic screening process on Danish trees identified by collaborators at the University of Copenhagen as having a range of different levels of disease susceptibility. Using this data alongside information from the ash tree genome, which was sequenced by researchers at QMUL by utilising EI’s reference gene models, they were able to improve the genetic markers for disease tolerance, and use them to predict the tolerance of a sample of trees from across the UK.
Dr David Swarbreck, Regulatory Genomics Group Leader at EI, said: “Having a more comprehensive annotation of ash genes has improved the identification of markers for ash dieback and will aid future functional studies into this prevalent disease.”
Professor Mario Caccamo, previously at EI, now Head of Crop Bioinformatics at NIAB, added: “This effort is a great example of teamwork across several leading UK research organisations responding to the devastating threat of ash dieback. The identification of markers for tolerance will be a very important tool in the toolbox that complements other ongoing efforts to manage the threat of this disease. We have also generated important genomic resources that will support other studies and offer the foundations for more research into tackling the epidemic.”
Professor Allan Downie, Emeritus Fellow at JIC and coordinator of the NORNEX programme, commented: “This work represents significant new progress in our understanding of ash dieback disease and the patterns of inheritance of tolerance to this disease. Our success has been built on excellent national and international collaborations. These have brought the strengths of genomics and transcriptomics research in the UK together with the excellent analyses of disease susceptibility done in Denmark, to enhance our research into UK ash trees. This progress has been breathtaking in its speed and as a research coordinator based at JIC, I have been delighted by the spirit of collaboration and determination brought to this project by my Danish and UK collaborators.
Early indications suggest that the proportion of UK trees with tolerance to ash dieback is greater than that of the Danish and Polish trees, but it is still unknown whether the UK trees have previously been infected with the disease and built tolerance or whether this is due to their genetic tolerance, is yet to be tested.
The study, “Genome sequence and genetic diversity of European ash trees” is published in the journal, Nature.