FAMINE PLANT TO SOLVE NEW DISEASE MYSTERY; DNA taken from 150yr-old leaves in blight probe.
For the first time an American expert has been able to extract DNA samples from the dried Irish potato leaves which have been safely store for 150 years.
The research by Professor Jean Beagle Ristaino is similar to the plot of the blockbuster dinosaur movie Jurassic Park.
She believes the plants will help unlock the mysteries of a fungus which has re-emerged with a vengeance around the world in recent years.
The blight fungus - phytopthora infestans - laid siege to the Irish potato crop in 1845.
Specimens of the infected plants were sent to London where experts at the Royal Botanic Gardens in Kew tried to find a way to fight the disease.
The shrivelled Irish potato plants, collected between 1845 and 1847, remained stored in Kew's dried plant collection with seven million other specimens.
But it was 25 years before the Bordeaux mixture fungicide was developed - too late to stop the ravages of the great hungers of 1845-50.
The result was more than one men, women and children died of starvation.
And millions more were forced to emigrate from Ireland to America to escape the famine brought on by the disease.
Now, using the unique "time capsules'', Prof Ristaino has extracted and amplified strands of DNA from the Famine plants.
With the aid of recent advances in molecular biology, the university team plan to track the migration of the fungus around the world and detect its presence more rapidly and accurately in potatoes before they are stored or planted.
"This research opens a window to epidemics of the past," said Prof Ristaino.
"There are so many unsolved mysteries that this DNA should finally help us answer.
"Where did the blight pathogen originate? How did it spread around the world? How has it evolved over the past 150 years?
"Ultimately, if we can learn how the late blight pathogen has evolved, we can develop new control measures that could help eradicate future outbreaks," he said.
In recent years, blight has hit crops in Mexico, Ecuador, Ireland, Canada and 23 American states.
The disease causes most problems in developing countries where control measures may be too costly to use.
In Russia, where potatoes are a sustaining food crop and are known as "the second bread", new blight varieties are causing havoc.
Russia grows between 35 and 40 million tons of potatoes a year but some parts of the country have experienced blights every year for the last decade.
And tonnes of potatoes shipped to Mexico from Russia after a 1976 drought caused shortages have led to a new strain that can survive in Russian soil despite the harsh winters.