Scientists clone the survivors of Dutch elm disease

Dutch elm disease is a terrible affliction that destroyed elm trees throughout North America and Europe. It is a fungal infection that is spread by the elm bark beetle. It is believed to originate from feline feces in Asia. Unequipped to handle the invading pathogen, the disease devastated massive populations of elms, nearly wiping them out. However, there are a few that survived which are now the foundation for the elm's future. Scientists from the University of Guelph in Canada are working to make genetic copies of the survivors. The clones that they produce, which are resistant to Dutch elm disease, could lead to a revival of the species in their former habitats."This research has the potential to bring back the beloved American elm population to North America," said Prof. Praveen Saxena, a plant scientist who worked on the project with Prof. Alan Sullivan, both with Guelph's Department of Plant Agriculture. "It may also serve as a model to help propagate and preserve thousands of other endangered plant species at risk of extinction across the globe." Elms used to be iconic trees throughout eastern Canada and the United States, recognizable and grand. They were popularly used to line the streets and boulevards of cities, as they created high-tunneled effects, tolerated air pollution, and their fallen leaves decomposed quickly. The invasive fungal disease nearly knocked them all out. According to the researchers, only one in 100,000 are naturally resistant to the pathogen. The genetic makeup of these survivors are what they are after as the key to species survival. Saxena and the team employed new techniques to clone the trees. They used selected tissue samples from a century old survivor in Ontario. They selected germplasm (egg cell cytoplasm) with the desired traits which they were able to conserve in a germplasm repository. The germplasm are believed to be a much more efficient form of conservation than are seed banks. Hundreds of phenotypes can be saved in a small space and easily propogated. The team created genetic copies from the shoot tips and dormant buds. They eventually want to reintroduce the disease-resistant trees back into their former habitat.