Corn is one of the most widely grown crops in the United States, which produces 40 percent of the world crop. But as with all crops, diseases threaten corn production.
Three diseases, southern corn leaf blight, northern leaf blight, and gray leaf spot, all cause lesions on corn leaves. In the U.S. Midwest Corn Belt, northern leaf blight and gray leaf spot are significant problems.
Agricultural Research Service scientists and university colleagues have found a specific gene in corn that seems to confer resistance to all three of these leaf diseases. This discovery, published in 2011 in the Proceedings of the National Academy of Sciences, could potentially help plant breeders build disease-resistance traits into future corn plants.
The researchers examined 300 corn varieties from around the world, making sure to have a genetically diverse representation. No corn variety has complete resistance to any of these diseases, but varieties differ in the severity of symptoms they exhibit.
When they tested corn lines for resistance to these three diseases, they found that if a corn variety was resistant to one disease, chances were favorable that it was also resistant to the other two.
Source: Agricultural Research magazine, February 2012