The Irish potato famine that caused mass starvation and approximately 1 million deaths in the mid-19th century was triggered by a newly identified strain of potato blight that has been christened "HERB-1," according to a new study.
An international team of molecular biologists studied the historical spread of Phytophthora infestans, a funguslike organism that devastated potato crops and led to the famine in Ireland. The precise strain of the pathogen that caused the devastating outbreak, which lasted from 1845 to 1852, had been unknown.
"We have finally discovered the identity of the exact strain that caused all this havoc," study co-author Hernán Burbano, a researcher at the Max Planck Institute for Developmental Biology in Germany, said in a statement. [Microscopic Worlds Gallery: Fascinating Fungi]
Previously, a Phytophthora strain called US-1 was thought to have triggered the potato famine, but by sequencing the genomes of preserved samples of the plant pathogen, the researchers discovered that a different strain — one that is new to science — was the real culprit.
"Both strains seem to have separated from each other only years before the first major outbreak in Europe," Burbano said.
The researchers studied 11 historic samples from potato leaves that were collected about 150 years ago in Ireland, the United Kingdom, Europe and North America.
The scientists found these ancient samples, which were preserved at the Botanical State Collection Munich and the Kew Gardens in London, still had many intact pieces of DNA. In fact, the DNA quality was so good the researchers were able to sequence the entire genome of Phytophthora infestans and its host, the potato, within just a few weeks.
"The degree of DNA preservation in the herbarium samples really surprised us," study co-author Johannes Krause, a professor of paleogenetics at the University of Tübingen in Germany, said in a statement.
Taken from http://news.yahoo.co...-140830483.html