February 16, 2009

The University of Delaware (UD) and DuPont Co has ventured for a commercial deal to develop a disease-resistant corn.

DuPont's Pioneer Hi-Bred seed business is in charge of marketing hybrid corn that has a gene that helps resist a disease called anthracnose stalk rot. The disease, which rots the stalks of corn plants, is blamed for an estimated US$1 billion in annual losses in North America.

The university, on the other hand, will receive royalties from sales of the corn seed, although specific terms of the deal were not disclosed.

The commercial introduction of the hybrid corn is the culmination of decades of work by UD professor of plant and soil sciences James Hawk tracing back in the 1980s with a line of "tropical" corn from Mississippi that was resistant to the fungus that causes anthracnose stalk rot, but difficult to grow.

Hawk and research associates used standard breeding techniques to help introduce the gene responsible for anthracnose resistance to grow lines of corn. The researchers tested the corn by injecting spores into the stalk and observing the plant's response, a difficult and time-consuming process.

The university entered a collaborative research agreement with DuPont in 1999 wherein research teams from UD and DuPont teamed up on the anthracnose-resistant corn few years later.

DuPont scientists helped "map" the gene by identifying molecular markers -- small pieces of genetic material that point to particular genes. Pioneer uses those markers to introduce the gene for anthracnose resistance into commercial corn seed.

Enno Krebbers, a research director at the DuPont Experimental Station in Wilmington and a supervisor on the anthracnose research, said conventional breeding is a powerful tool but the trait is not powerful enough to move the trait into a wide variety of germplasm.

With molecular markers, Hawk said it is easier to precisely pick up the gene of interest and not bring in the undesirable aspects of tropical corn.

Hawk and UD's corn breeding program participate in a US Department of Agriculture program called Germplasm Enhancement of Maize, an effort to diversify the genetic base of corn grown in the United States.

Hawk said the gene for anthracnose resistance isn't found in most North American corn seed. The UD-DuPont research effort demonstrates the importance of conserving and studying a diverse group of seeds and plants, he said.