Many homeowners spend a lot of time and money on planting trees. The hope is that the trees will grow and last a long time.
But many trees that come from nurseries across the country are clones – they are all genetically the same – and it could be a problem.
“If you have something that’s all genetically the same and a disease or pest comes through that’s attacking them, they have no resistance,” said Cynthia Morton, a botanist at Carnegie Museum of Natural History in Pittsburgh.
Using genetic testing, Morton and a colleague found that many cloned trees come from a limited stock of parental trees from the West Coast.
“They’re taking cuttings of one tree and they’re reproducing it over and over again,” Morton explained.
To find out a tree’s genetic makeup, the scientists grind up a leaf in a lab and extract its DNA for testing, and then they look for DNA patterns within different tree samples.
The researchers found that “all the nurseries came out to [have] a very low genetic diversity,” said Morton.
Older trees with more variety may be more resilient because they have survived through pollution, pests and bad weather. These time-tested trees are often more genetically diverse as well and have a better chance of a long, healthy life.
Morton suggests asking a nursery where the trees came from before buying and look for a good variety of trees. “When we plant those plants we’re expect we’re getting something that’s going to last for 50 to 100 years,” said Morton.
Karin Heineman is the executive producer of Inside Science TV. She has produced over 600 video news segments on science, technology, engineering and math in the past 13 years for Inside Science TV and its predecessor, Discoveries and Breakthroughs Inside Science.
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