A group of scientists have completed a genetic map of the late blight organism that should aid plant breeders and chemical developers.


Phytophthora infestans, the late blight fungus that caused the Irish potato famine in the 1840s, causes about $7 billion in annual losses worldwide, according to a news release. The pathogen also attacks tomatoes.


The genetic sequencing work was led by the Broad Institute of Harvard University and MIT. The work also included collaborators from dozens of other institutions.


“Scientists have studied this pathogen for 150 years and there’s still a great deal we don’t know about it,” James Carrington, professor and director of the Center for Genome Research and Biocomputing at Corvallis-based Oregon State University, said in the news release. “It caused one of the most important famines in history and is still a major problem that costs billions of dollars to fight.”


The researchers discovered the pathogen has 240 million base pairs of DNA, which is huge.


Abut 75 percent of the genome has repetitive DNA, which researchers say may explain why the pathogen can be so aggressive and virulent.


Now researchers and breeders will work to identify genes they can turn off, or silence, to help control the pathogen and reduce its severity.