Using the new gene in combination with other genes is expected to extend resistance time to the most economically damaging insect of wheat by as much as six times. Scientists from Purdue University and the U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS) mapped the new gene and two closely linked markers, or bits of DNA, that indicate its presence in soft red winter wheat.

Results of the study are published in this month's issue of the journal Theoretical and Applied Genetics.

"Although 30 other genes resistant to the Hessian fly are known, this is the first resistance gene found on this particular chromosome," said Christie Williams, Purdue entomology assistant professor and USDA-ARS scientist. "The unique chromosomal location is important because it will allow us to easily pyramid the gene with other resistance genes to extend the durability of resistance against this pest."

When several genes are combined in one plant to create the desired effect, in this case better resistance to the Hessian fly, it is called pyramiding. In order to pyramid genes successfully, they must be in different locations in the genome.

Now that Purdue researchers have discovered the gene, called H31, and know that it's on a different chromosome than previously known Hessian fly resistance genes, they will intentionally breed wheat plants with three different Hessian fly resistance genes, Williams said. This should be especially effective because all of the genes to be used are strong genes - in other words, 100 percent of the plants containing them would be resistant under almost any stress, such as drought.

Conventional agricultural crossbreeding and selection is used to transfer the Hessian fly resista
'"/>

Contact: Christie Williams
cewilliams@entm.purdue.edu
765-494-6763
Purdue University
22-Sep-2003