Clues Found to Block Late Blight’s Blitz on Potatoes, Tomatoes

Late blight is the bane of potato and tomato growers around the globe. To the tune of being a $6 billion a year problem, this notorious disease has devastated many a crop far and wide. However, new findings by UF/IFAS researchers, published in the journal Molecular Ecology, could help prevent more genetic strains of the deadly pathogen from entering the U.S.

Late blight shown in a tomato

Photo courtesy of UF/IFAS

Erica Goss, a UF/IFAS Assistant Professor of plant pathology, who published a study in 2014 showing Toluca, Mexico, as the origin of the late-blight pathogen, has now discovered the pathogen in other parts of Mexico. Goss and her team also found that each strain varies genetically.


Goss and her research team analyzed the genes of potato late-blight pathogens and found the pathogen in western Mexico (Michoacan) differs genetically from the one in central (Toluca) and eastern Mexico (Tlaxcala and Puebla).

“This genetic difference allowed us to track the potential source of strains that show up in the U.S., just like genetic analysis of an American person of European ancestry would tell you if their family was more likely to have originated from western Europe or eastern Europe,” Goss said. “What our study shows is that there is more potential trouble that could make its way here, replacing the existing genetic types of the pathogen in the U.S., and affecting disease control.”

According to Goss, to increase U.S. food security, scientists should study the genetic variation in Mexico and try to track how the strains are coming to America so they can prevent future introductions.