Wrong Culprit Blamed for Irish Potato Famine: ScientistsUS Scientists probing 150-year-old plant samples have cast doubt on the prevailing theory of what strain of potato blight caused the Irish potato famine of the 1840s, and from where this devastating pest originated.Considered the most serious potato disease, late blight caused the Irish potato famine, in which one million people died. Today the pathogen costs the developing world alone up to 3 billion US dollars a year. Until now, scientists believed the crop failure was caused by a particular strain of fungus, originating in Mexico. But DNA analysis shows that this is not the case, reported the British science journal Nature to be published on Thursday. Jean Ristaino of North Carolina State University and her team performed DNA fingerprinting on dried British and Irish potato leaves infected with Phytophthora infestans, the pest that causes late blight in potatoes. The researchers discovered that DNA isolated from the minute amounts of the pest still lurking on the leaves did not match DNA from the strain of P. infestans, known as US-1, thought to have caused the famine. Work is now under way to find out exactly which strain did kill Ireland's potato plants, 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. |
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