A genetically modified grass has passed a RoundUp-resistance transgene on to a related species growing 14 km away and to wild-growing plants of the same species 21 km away, according to a group from the US Environmental Protection Agency. A novel sampling method, employing widespread sentinel plants placed at different locations, found evidence of gene flow from transgenic bent-grass (Agrostis stolonifera) into the related species, Agrostis gigantea.

But, there was no evidence that the gene crossed into a grass in a different genus, Polypogon monspeliensis. Bentgrass, an amenity grass usually grown on golf courses and as a forage crop, is also listed as a weed in parts of the world, including some parts of the United States. Charles F. Chilcutt at Texas A&M University says there is no risk of crossing with other species when growing corn or cotton in the mainland United States because no...