In a paper published online in Nature Genetics, North Carolina State University and U.S. Department of Agriculture crop scientists and plant pathologists sift through millions of genetic sequence variations in the set of all genes in maize (corn) to identify 51 gene regions associated with resistance to Southern corn leaf blight disease — an important plant pathogen.

Finding out more about the mechanisms behind complex traits like disease resistance has the potential to help plant breeders build the best traits into tomorrow’s corn plants, including resistance to some diseases, says Jim Holland, North Carolina State professor of crop science, research geneticist for the U.S. Department of Agriculture-Agriculture Research Service (USDA-ARS) and the corresponding author of the paper.

Holland and study co-authors Peter Balint-Kurti, a USDA-ARS research plant pathologist and geneticist who works in North Carolina State’s plant pathology department, and Kristen Kump, a North Carolina State graduate student, joined researchers from Cornell University, the University of Delaware and the University of Missouri to examine a set of 5,000 maize varieties called the maize nested association mapping population. Using this population allowed the researchers to zero in on the parts of the genome responsible for conferring resistance.

The researchers likened the search for Southern corn leaf blight resistance gene regions in maize to looking for specific houses in a large city — without knowing the addresses.