A research team lead by Sainsbury Laboratory in the U.K. has identified the pathogen that may have caused the Irish Potato Famine 168 years ago, Mother Nature Network reported.
This is the first time scientists have decoded the genome of a plant pathogen from a dried herbarium sample, reported a news release by the Science Daily.
According to research to be published in eLife Journal the famine that killed about 1 million people was caused by a strain of fungus-like pathogen called Phytophthora Infestans.
Scientists were aware that this pathogen had caused the events in Ireland, but they believed that it was linked to a strain called US-1.
The Sainsbury research team extracted DNA from infected potato leaves that had been collected as museum samples in the 1840's and compared the pathogen to the modern strain. The team concluded that the strain was not US-1, but something that may not have been seen before. The team named the strain HERB-1.
"This strain was different from all the modern strains that we analyzed - most likely it is new to science," Sainsbury Laboratory's Sophien Kamoun told BBC News.
The team believes that HERB-1 may be extinct, while US-1 is still found around the world.
In the abstract of their paper the researchers wrote, "HERB-1 is distinct from all examined modern strains, but it is a close relative of US-1, which replaced it outside of Mexico in the 20th century." They believe that the strain originated in Mexico.
Science Daily reported the scientists have linked the spread of the pathogen with historic events. The first introduction of Americans and Europeans in Mexico resulted in a drastic increase in the genetic diversity of Phytophthora.
The study suggests that some of the first potatoes may have been bred at the beginning of the 20th century, which would have resulted in the extinction of HERB-1.
"What is for certain is that these findings will greatly help us to understand the dynamics of emerging pathogens," said Kentaro Yoshida from The Sainsbury Laboratory. "This type of work paves the way for the discovery of many more treasures of knowledge hidden in herbaria."
