Wheat producers work to avoid the yellow dwarf virus, carried by cereal aphids, by planting winter wheat after the insects' fall flight. The strategy can carry some costs. Delayed seeding may reduce yield potential in the absence of disease. But the risk is better than the almost-all or nothing gamble of planting too early and suffering devastating losses if the aphids find a field of freshly emerged seedlings. UI researcher Bob Zemetra works with virus-resistant wheat varieties in a UI greenhouse.
Mites carry the wheat streak mosaic virus.
Wheat growers must try to break the green bridge of live wheat or grasses growing nearby that permit the mites to move into a newly emerged field. UI scientists have taken up the gene gun in hope of an alternate defense. Although the two viruses are particular targets, the researchers also want to insert generic viral resistance into wheat. DNA carrying the resistance is shot into wheat embryos using a gene gun. The genetic engineering techniques used offer a greater chance that the event, in this case wheat developing viral resistance, will take place.