CROSSES between genetically modified oilseed rape and a wild relative produce hybrid plants that are as toxic to insects as the original crop. Though it is still unclear how such hybrids would fare in the wild, the finding is likely to be seized on by environmentalists as proof that field trials of GM crops are unsafe.
In lab experiments, Matthew Halfhill at the University of North Carolina in Greensboro and colleagues took oilseed rape (canola) that had been modified to contain the insect resistance gene Bt and crossed it with a related weed, birdseed rape (Brassica rapa). They made 11…
