Scientists Identify Irish Potato Famine Culprit

An international team of scientists has identified the pathogen that caused the Irish potato famine of the mid-ninetheenth century. The scientists said that a strain of Phytophthora infestans called HERB-1 triggered the disaster, and not the US-1 strain that was long thought to have been the culprit.

A team of molecular biologists from USA and Europe reconstructed the pathogen's spread from dried plants. They studied the historical spread of P. infestans, and compared samples with modern strains from Europe, Africa, and the Americas, and estimated that the HERB-1 strain likely emerged during the early 1800s, while US-1 came up only during the twentieth century, after new potato varieties were introduced.

The international team decoded the complete genomes of 11 samples of P. infestans from potato leaves collected over more than 50 years from Europe and North America, preserved by the Botanical State Collection Munich and Kew Gardens in London.

Kentaro Yoshida of The Sainsbury Laboratory in Norwich said, "These findings will greatly help us to understand the dynamics of emerging pathogens. This type of work paves the way for the discovery of many more treasures of knowledge hidden in herbaria."

More information about this research is available at http://www.mpg.de/7258079/potato_blight?filter_order=L&research_topic=.