Brussels, 21 Sep 2004
Pollen from a genetically modified (GM) grass has travelled up to 21 kilometres on the wind before pollinating other grasses, a new study in the US has found.
According to the researchers from the US Environmental Protection Agency (EPA), cross-pollination over such a distance is much further than previously measured and is believed to be a record for any GM pollen.
The grass in question is an experimental variety of GM creeping bentgrass, which is commonly used for putting greens on golf courses due to the smooth surface it provides. The grass was modified in order to make it resistant to herbicides, allowing for weed-free greens, and has been grown in experimental fields in Oregon, US, for the past two years, reports New Scientist.
Lidia Watrud and colleagues from EPA's national health and environmental effects research laboratory in Corvallis, Oregon, collected seeds from wild grasses growing in an area stretching tens of kilometres in every direction from the experimental fields. They then grew the seeds in greenhouses and tested the resulting grasses for signs of contamination by the GM variety.
The team recorded significant levels of cross-pollination in samples from seeds collected within two kilometres downwind of the GM plots, but were more surprised to find contaminated seeds covering an area of 310 square kilometres, with the furthest example 21 kilometres from the GM source.
Few studies have previously investigated cross-pollination from crops - GM or traditional - at distances of more than a few hundred metres. In light of this latest data, it has been suggested that windblown pollen from certain crops could travel hundreds of kilometres from its source.
Scotts, the Ohio-based seed company that developed the GM bentgrass, collaborated on the EPA study. They had already filed an application to the US government for permission to sell their product to golf courses, but a decision has been held up over fears that the GM grass could invade surrounding wild lands.
'Our concern is that if it was to escape onto public land, we wouldn't know how to control it,' Gina Ramos of the Bureau of Land Management told New Scientist.