More than 2,000 healthy English elms have been produced from a single tree which survived the devastating disease in the 1970s, the UK’s Telegraph newspaper reports.
Paul King, who runs a tree nursery, stumbled upon the mysteriously unharmed specimen while he worked to clear hundreds of diseased elms and took cuttings from it.
Over the next 23 years, the paper says, he used the samples to nurture hundreds of saplings which have the same resistant traits as the 200-year-old parent tree.
Mr King sent the sample plant tissue off to a laboratory for micropropagation.
Now, nearly 25 years later, the cuttings have produced 2,000 healthy trees which are set to replace the dwindling English elm population.
The trees (Ulmus procera) are believed to repel the beetle which carries the Dutch Elm disease.
The 10ft tall trees are available to buy from Mr King’s business, The Tree Nursery in Rayne, Essex, and cost £120 each.
Mr King said: “We have been working hard on the project for 23 years.
“I was working dismantling and clearing diseased elms when Dutch Elm disease hit, and saw how many were destroyed.
“But as we worked in this particular area, we noticed that there were a few trees which seemed to be resistant to the disease.
“While other trees around them died, these were totally unharmed by the Dutch Elm disease.
“After about 10 years, they were still surviving while every other tree in the area had died and we knew they must be resistant.
“So an expert from the local council took cuttings from one of the mature trees for me, which survived – and then kept surviving.
“We realised we had something on our hands here and I sent them off for micropropagation, and before I knew it I had a production.
“The original trees, which are around 150 to 200 years old, are still surviving less than five miles from the nursery and the first cuttings are still 100% in leaf.
“The trees we have propagated are all still in full leaf, even though there is Dutch Elm disease in the hedges just two or three metres from them.
“We can say they are extremely resistant to Dutch Elm disease.”
Dutch Elm Disease is native to Asia but was accidentally introduced in Europe in 1910, although it only killed a small proportion of trees.
It gets it name after it was isolated in Holland in 1921.
It had largely died out by 1940 but in 1967 a new and deadlier strain of the disease arrived in Britain on a shipment of elm tree logs from North America.
The disease killed an estimated 25 million elm trees throughout the UK.
Source: Telegraph newspaper