Much of Dr. Ristaino’s work has been on the Oomycete pathogens in the genus Phytophthora. She works on the population genetics of historical potato famine epidemics and studies the population structure of present day late blight outbreaks. Ristaino’s lab was the first to develop pioneering research techniques to recover DNA from 150-year-old historic herbarium specimens and determine that the strain that caused the potato famine was a Ia mt haplotype. Her work documented an Andean origin for P. infestans and tracked it migration to the US and Ireland. She has also described new species of Phytophthora including P. andina the closest relative of P. infestans found in South America and she has developed taxonomic keys for identification. Her research has been published in Nature, Science, and Proceedings of the National Academy of Sciences. Her research uses molecular tools for addressing basic ecological questions concerning the spread of microorganisms in nature. She conducts Phytophthora diagnostics workshops in Latin America. Dr. Ristaino’s late blight research has been featured on CNN, Discovery Channel, radio (NPR, BBC, Voice of America) and in newspaper and magazine articles. Dr. Ristaino’s research has not only impacted the understanding and direction of plant pathology, but has also influenced how the general public and policy makers view science and scientists. She serves as a Senior Science advisor and Jefferson Science Fellow at USAID Washington in the Bureau of Food Security.