Wheat Resistance Genes Failing, Scientists Suggest New Approach to Stop Flies

Scientists from the U.S. Department of Agriculture and Purdue University have reported that some of the wheat resistance genes are no longer effective against Hesian flies. Hesian flies are major pests of wheat that cause million dollar losses every year. Once the wheat resistance genes recognize avirulent Hesian flies, the genes would activate a defense mechanism that kills the fly larvae attacking the plant. However, new strains of flies develop that can overcome resistant wheat.

"The number of genes available to protect wheat is limited. There really aren't that many," said Richard Shukle, a research scientist with the USDA Agricultural Research Service Crop Production and Pest Control Research Unit and Purdue adjunct associate professor of entomology. "In the Southeast, having multiple generations of Hessian fly each year enhances the ability of these flies to overcome wheat's resistance."

On the other hand, USDA entomologist and Purdue assistant professor Brandi Schemerhorn said that a number of Hesian flies in any population can overcome resistant wheat and when these flies survive, they breed and build a population that makes the gene ineffective. Thus, Shukle and Schemerhorn suggest stacking of genes to increase resistance to the pest and slow down adaptation of the flies.

Visit http://www.purdue.edu/newsroom/research/2011/110124ShukleGenes.html for more details.