IU biologist Loren Rieseberg and former postdoctoral fellow John Burke (now at Vanderbilt University) reported in the May 23 issue of Science that a wheat transgene synthetically inserted into sunflowers has little or no effect on crop sunflowers' wild relatives and is not likely to impact the environment.
"We found that a certain transgene that gives crop sunflowers resistance to white mold is unlikely to spread rapidly to the wild because the transgene doesn't affect the seed-producing abilities of wild sunflowers in nature," said Rieseberg, who led the study. "We need to examine each transgene and crop on a case-by-case basis. Some transgenes will have major ecological impacts and others probably won't."
For example, another study co-authored by Rieseberg, published last month in Ecological Applications, showed that a bacterial transgene inserted into sunflowers significantly increases seed production of wild sunflowers and therefore may incur ecological costs.
A common worry about genetically modified (GM) crops is that new, highly advantageous genes will seep through wild populations as crop plants mingle and reproduce with their wild cousins.
While the new report by Rieseberg and Burke does not refute that worry, the researchers believe that the movement of certain genes from GM crops into the wild may occur at a glacial pace, meaning wild plants in locations far from their alter egos in farm crops will not encounter the transgenes for a long time.