Ash trees are rapidly developing the same resistance to Ash Dieback disease

Ash trees in the UK are rapidly evolving resistance in response to Ash Dieback disease, DNA sequencing of hundreds of trees has shown.

Found is good news, says Richard Buggs in Royal Botanic Gardens, Kew, in the UK, but ash trees are unlikely to be complied with in the near future. “We probably need a breeding program so we can help nature and finish the job,” he says.

Ash Dieback is caused by a sponge (Hymenoscyphus frxineus) resident in Asia, which is slowly destroying the ability of the trees to transport water. It began to spread in Europe in the 1990s and reached the UK in 2012.

The death of ash trees leads to the release of carbon dioxide and places hundreds of species that depend on these for their habitats. Falling trees are also a threat to people and property. “There are a lot of ash close to paths and roads that are now danger,” says Buggs.

Becuse fungus takes much longer to kill large trees than young, Buggs’ team was able to compare the genomes of 128 adult European ash trees (Fraxinus excelsior) and 458 plants at a place called Marten Park in Surrey. This revealed that thousands of variants that his team had previously proven to be associated with resistance were more common in the young trees – probably because it lacked them was dead.

It is the most detailed genetic image of evolution in action ever achieved in nature. “What is original about this study is that we have been able to characterize the genetic basis and then demonstrate a shift that happens in a single generation,” says Buggs.

However, each of the gene variant has only a small effect instead of giving complete resistance. The speed of evolutionary change will also slow down in the future as large ash trees die offers and fewer fungal spores are produced, which means young ash trees will have a better chance of survival, Buggs says.

“It’s a massive problem, but they are not to disappear,” he says. “I think our results encourage us that these young ash trees will hopefully turn it into adults and hopefully have another generation of natural selection.”

Ash Dieback has not yet spread to North America, but an introduced insect damage animal, emerald ash bore (Agrilus Planipennis), spreading and killing ash trees there. It is not clear what will happen if Ash Dieback and Emerald Ash Boots both arrive in the same region, but it can make the situation much worse.

“Globalization mixes the world’s insects and microbes, and so we see these new wooden memories, and it is very difficult for the trees to keep up with it,” says Buggs. “Trees face threats that they never face before come to those at speeds they never have before.”

He believes we need to step in to help trees survive the attack, for example by crossing native trees with exotic species to create resistant hybrids.

“One of the answers is to move the genetic diversity of trees also surround the world to keep up with all the pests and pathogens that we move,” he says.