Disease-resistant elms aim of Canadian research
Cloning technique offers hope for cities battling Dutch elm disease
Scientists at the University of Guelph are cloning elm trees they believe are resistant to Dutch elm disease, a fungus that has devastated the North American elm tree population.
Their work features a method that is the first of its kind for replicating elms that have survived the onslaught of the European tree sickness.
"I was surprised myself that American elms are very, very difficult to clone," said Dr. Praveen Saxena, the head of the university's research project. Saxena explained there was a lack of research on this type of procedure so it took him and his team two years to develop a successful cloning method.
The centrepiece of his research is a nutrient-enriched growing gel.
"That's the innovation. Of knowing what exactly is needed to multiply these plants and for a long term, especially if the bud is coming from a mature tree," Saxena added.
Research backed by brewer with a love for birds
Prof. Saxena's work would not have been possible without the help of Philip Gosling. He is a Guelph entrepeneur and the benefactor of the Gosling Foundation which is devoted to environmental education.
The founder of the Wellington Brewery is also an avid birder. Every year, a family of orioles would nest in an elm tree in his yard. When the tree died, the birds disappeared.
"It was very sad. In fact, for years we felt the loss was tragic," explained Gosling before adding, "you have this helplessness that you can't do anything about it."
But Gosling and his wife Susan didn't allow themselves to be overcome by emotion. They decided to approach the problem scientifically and found that Saxena was more than willing to help.
"[Saxena] captured it instantly. And we were absolutely thrilled that in no time at all he was growing those samples," Gosling reminisced. He eventually donated enough money to fund the Gosling Research Institute of Plant Preservation.
"The knowledge gained [from the institute] will spread across the world in how to approach the treatment of diseased trees," said Gosling.
The American elm is now mostly used as a cover tree, shading many Canadian avenues. But it also has medicinal uses and the wood was once prized for making hockey sticks.
Dutch elm disease has wreaked havoc on elm forests across North America since it arrived in the 1920's. Cities and provinces in Canada go to huge extents — and expense — to halt its spread.
The disease is a fungal infection, carried on the legs of beetles, that blocks a tree's ability to take in nutrients, slowly starving the plant over a two- to five-year period.
It begins with a yellowing of the leaves at the top of the tree and eventually spreads through every branch, rotting the tree from within and leaving the wood brittle and the entire tree suscrptible to being blown over in a high wind. A tree is usually cut down before it reaches that stage.
The fungus reached eastern Canada in the 1940s and has progressively spread as far west as Saskatchewan. It reached Manitoba in 1975. Winnipeg immediately set about protecting its urban forest which is made up mostly of elms, believed to be the largest population in North America. Even with its preventive program, the city is losing 6,000 trees this year.
"Even after being in this industry for the years that I've been in, it's still devastating for me to see those orange marks on the elms, particularly when it's on those big majestic elms. I feel the loss every time," said Martha Barwinsky, Winnipeg's city forester.
Dr. Saxena's research won't stop Winnipeg from continuing with its current program of detecting and removing diseased trees, but it could provide the city with disease-resistant replacements.
"We would see it as just another tool in our tool box to help preserve our elm trees," explains Barwinsky.
And that is just fine with Saxena. In his opinion, the landscape would be incomplete without the elm. "There is an emotional connection with the American elm. I think that's the driving force."