FOR the first time, scientists have been able to extract fungal DNA from
dried potato leaves left over from the infamous famine in 19th-century Ireland.
The genetic material could one day help farmers control potato blight.
Over a million people died in Ireland when a fungus-like pathogen called
Phytophthora infestans devastated the potato crop. Because modern farmers
also grapple with the disease, Jean Beagle Ristaino of North Carolina State
University in Raleigh and her colleagues developed a DNA fingerprinting test to
spot the fungus. And she thought she might try her test on specimens from the
Irish potato famine stored at arboretums such as the Royal Botanic Gardens
Mycological Herbarium in Kew.
Ristaino managed to amplify and sequence a small one hundred-base pair region
of the pathogen鈥檚 DNA from eight important specimens collected in Britain,
France and Ireland from 1845 to 1847. These sequences will help her to see how
the pathogen has evolved over the last century and a half. She also plans to use
them to help work out where potato blight began and to track its migration
around the world.鈥漈he big question is where did it come from,鈥� she says.
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