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MARIN COUNTY'S NEWS MONTHLY - FREE PRESS
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October, 2004
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Wind Carries GM Pollen Record
Distances
Wildland Invasion Feared
By New Scientist
Pollen from a
genetically modified grass has blown on the wind and pollinated other grasses
up to 21 kilometres away, says a new study. This distance is "much further
than previously measured", say the authors, and is thought to be a record
for any GM pollen.
The discovery comes as regulators decide whether to allow the planting of
the GM creeping bentgrass on golf course putting greens across the US.
Scientists from the US Environmental Protection Agency (EPA) focused on
fields that have been growing GM varieties of creeping bentgrass near Madras in central Oregon, US, for two years. The
experimental grasses are genetically modified to resist popular herbicides,
such as Roundup.
Lidia Watrud and colleagues from the EPA's National Health and Environmental
Effects Research Laboratory in Corvallis, Oregon, collected seeds from wild
grasses growing tens of kilometres around the experimental plots.
They then grew the seeds in greenhouses and tested the growing grasses for
transgenes and resistance to Roundup, which would reveal cross-pollination with
the GM bentgrass.
Extensive Contamination
Watrud's team found extensive gene contamination within 2 km downwind of the
experimental plots. But some pollen went much further. Contaminated grass seeds
turned up across 310 square km, with the most distant find 21 km from the
source.
Only a handful of studies have ever investigated gene flow from crops - GM
or otherwise-at distances greater than a few hundred metres. Studies have found
radish and sunflower genes travelling 1 km, marrow (or squash) genes travelling
1.3 km and oil-seed rape (or canola) genes travelling up to 3 km.
But the suspicion is that pollen from many crops could travel hundreds of
kilometres on the winds.
"To my knowledge, this is the longest distance reported for GM pollen
dispersal," says David Quist, whose research into the genetic spread of GM
maize in Mexico caused a row after its publication
in Nature in June 2002.
Creeping bentgrass is a favourite of golf course managers, who say it
provides a uniquely smooth surface for putting greens. But weeds can interrupt
the smoothness, so course managers want a grass that is resistant to the herbicides
that kill the weeds.
Wild-Land Invasion
GM creeping bentgrass has exactly that characteristic and has been tested in
Oregon by seed company Scotts, of Marysville, Ohio, which collaborated on the EPA study.
But the findings now threaten to derail a bid from Scotts for government
permission to sell the product to golf courses and more widely. Their efforts
have been held up by government agencies who fear that the GM putting-green
grass could invade the country's wild lands.
Creeping bentgrass grows naturally in many habitats and cross-pollinates
with other grasses of the Agrostis genus. "It is one of the first
wind-pollinated transgenic crops being developed for commercial use," says
Watrud.
Gina Ramos of the Bureau of Land Management says: "Our concern is that
if it was to escape onto public land, we wouldn't know how to control it."