“Whodunnit” of Irish potato famine solved
It is the first time scientists have decoded the genome of a plant pathogen and its plant host from dried herbarium samples. This opens up a new area of research to understand how pathogens evolve and how human activity impacts the spread of plant disease.
Phytophthora infestans changed the course of history. Even today, the Irish population has still not recovered to pre-famine levels. “We have finally discovered the identity of the exact strain that caused all this havoc”, says Hernán Burbano from the Max Planck Institute for Developmental Biology.
For research to be published in eLife, a team of molecular biologists from Europe and the US reconstructed the spread of the potato blight pathogen from dried plants. Although these were 170 to 120 years old, they were found to have many intact pieces of DNA.
“Herbaria represent a rich and untapped source from which we can learn a tremendous amount about the historical distribution of plants and their pests - and also about the history of the people who grew these plants,” according to Kentaro Yoshida from The Sainsbury Laboratory in Norwich.
There are so many reasons why herbaria, like the NYBG’s William and Lynda Steere Herbarium, are important, and now there’s one more!
But first a reminder of what a herbarium is: It is a physical record of the plants of the world. Each specimen has been gathered in the field by a scientist who has also taken detailed notes and photographs, as well as notes on the plant’s location and the time of year. The specimens are brought back to the herbarium where they are described and indexed. Herbarium specimens have been gathered and stored for centuries.
Herbarium specimens are used to describe new species and to determine species relationships. Technology is having a huge impact on herbaria, including genomics which is helping to sort out some sticky cladistic situations. And now, herbaria are providing fascinating new research materials for geneticists and historians working on the history of agriculture, disease, and human migration. Seriously good stuff. ~AR