Since arriving in North America from Europe in 1930, Dutch elm disease has wiped out 95 per cent of this continent’s population of American elms, the immense and towering trees that, particularly in the U.S., once provided shady relief to the heroes of history—from the original members of the Boston Tea Party to George Washington. In Canada, the scourge continues its march westward, killing the elms of Alberta and beyond. But now scientists at the University of Guelph may have found a sci-fi method of preserving these majestic giants: cloning the few hearty elm specimens that have managed to survive repeated Dutch elm disease epidemics, and preserving them for study in a controlled lab environment.
In a groundbreaking paper published this week in the Canadian Journal of Forest Research, the scientists describe how they used cutting-edge techniques to generate the first-ever American elm clones produced from mature trees, growing them in test tubes and tanks. The clones derive from 17 old Ontario trees, one a centenarian specimen on the Guelph campus. “These trees have proven themselves over the last 60 years,” says Max Jones, one of the authors of the journal article. “While we don’t know the mechanism of how they survived, cloning them is the best way to replicate that and preserve the genetic code.” By studying the clones, the team hopes to isolate the genetic components that helped the trees survive. “We can produce thousands of them under lab conditions and experiment with their level of resistance,” says Guelph plant scientist Praveen Saxena. Similar techniques could be used to safeguard the Ontario maple, now threatened by the Asian longhorn beetle.