The vast majority of Britain’s 80 million ash trees are expected to be lost over coming decades due to the spread of the Chalara fraxinea virus, which was first spotted in the UK in 2012.
Scientists at the Queen Mary University of London are working to sequence the genome of different species of ash tree from around the world to try to identify genes that make some varieties, such as those found in East Asia, resistant to the disease.
The screening work, which is backed by £1 million of public funding, could enable scientists to one day insert the resistant genes into Britain’s native ash species, through a process known as “cis-genetics”.
Research of public opinion being carried out by the University of Oxford, in tandem with the screening work, suggests this option would be more palatable than “trans-genetics” form of GM, which would involve adding in genes from other plants or animal species.
Dr Richard Buggs, one of the scientists carrying out the genome sequencing, said his work could also enable non-GM methods for overcoming ash dieback, such as accelerated breeding of resistant trees.
The scientists have suggested six options, ranging from “doing nothing” to GM.
One option would be conventional breeding, crossing the more resilient specimens of the native UK ash species in the hope the offspring will be even more resistant.
A second would accelerate the breeding process by using “genetic methods to select the offspring which seem to be more resistant”, Dr Buggs said.
Under a third option, the species could be cross-bred with resistant species from Asia to create a hybrid.
The cis-genetics GM option would effectively accelerate that process, Dr Buggs said. “We would try to take a gene from a different species of ash and put it into our native ash. We would be doing something which we could do naturally by hybridising the two species, but we would be accelerating that process by using GM methods. It could potentially save you decades of breeding.”
He said he could not see any reason why the trans-genetics GM option, using genes from non-ash plant species, would be necessary given resistant ash trees were available.
Dr Buggs said he was “agnostic” about what method was used and wanted to see what was acceptable to the public.
“We don’t want to go down a route to develop a tree that no one wants,” he said. “Even if we have to spend extra 30 years developing a tree that someone wants, we would rather do that than put money and effort into producing something that is resistant to has dieback but no-one wants planted in the countryside.”