Good news about ash dieback
In the park, we have lost many of our ash saplings to ash dieback and the disease is spreading rapidly.
Ash dieback is caused by an invasive alien fungus (Hymenoscyphus fraxineus) that came originally from Asia. In its native range, H. fraxineus causes little damage to trees, but when it was introduced into Europe about thirty years ago, it caused widespread destruction.
It was first identified in Britain in 2012 and recent estimates suggest that the seemingly unstoppable disease will kill up to 70% of British ash trees.
Hymenoscyphus fraxineus fruiting bodies and ash seedlings (Google images)
However, a small number of trees are showing some natural resistance to ash dieback and researchers at Kew Gardens have identified the parts of their genomes that are responsible. They believe that ash dieback resistance is a polygenic trait that should respond well to selective breeding.
Professor Richard Buggs of the Botanic Gardens at Kew said:
“ We hope to bring together all of the genetic differences that are contributing to resistance into a single population of ash trees that will have higher resistance than any of the ash trees that we currently have.“
This will not save the park’s ash trees that are currently infected, but if the project is successful, they could soon be replaced by saplings specially bred to be resistant to the disease.
More about ash dieback in the park: