UK Wrong culprit blamed for potato famine Potato blight is still a problem in many parts of the world DNA analysis of ancient potato leaves has forced scientists to re-think their theories about the origin of the Irish potato famine. More than one million people starved and another two million emigrated to America when Ireland's potato crop was devastated in the 184Os. Until now, scientists believed the crop failure was caused by a particular strain of fungus, originating in Mexico. Our work indicates that these historic collections can be valuable to epidemiologists and population geneticists who study plant diseases.
Experts now know that a fungus causes the disease.
When plants become infected, lesions appear on their leaves and stems. Eventually the potatoes rot and become inedible. Until now, scientists had always believed that a common strain of the fungus that arose in Mexico caused the Irish potato famine. But DNA analysis shows that this is not the case. By finding where the disease arose, it might be possible to find plants that are naturally resistant to the disease and use them to breed more resistant varieties of potato.