Richard Black BBC News 6 Aug 10;
Researchers in the US have found new evidence that genetically modified crop plants can survive and thrive in the wild, possibly for decades.
A University of Arkansas team surveyed countryside in North Dakota for canola. Transgenes were present in 80% of the wild canola plants they found.
They suggest GM traits may help the plants survive weedkillers in the wild.
The findings were presented at the annual meeting of the Ecological Society of America in Pittsburgh.
"We just drew 11 lines that crossed the state [of North Dakota] - highways and other roads," related research team leader Cindy Sagers.
"We drove along them, we made 604 stops in a total distance of over 3,000 miles (5,000km). We found canola in 46% of the locations; and 80% of them contained at least one transgene."
In some places, the plants were packed as closely together as they are in farmers' fields.
"We found herbicide resistant canola in roadsides, waste places, ball parks, grocery stores, gas stations and cemeteries," they related in their Ecological Society presentation.
The majority of canola grown in North Dakota has been genetically modified to make it resistant to proprietary herbicides, with Monsanto's RoundUp Ready and Bayer's LibertyLink the favoured varieties. These accounted for most of the plants found in the wild.
Two of the plants analysed contained both transgenes, indicating that they had cross-pollinated.
This is thought to be the first time that communities of GM plants have been identified growing in the wild in the US.
Similar findings have been made in Canada, while in Japan, a study in 2008 found substantial amounts of transgenic rape - a close relative of canola - around port areas where GM varieties had been imported.
State-wide
What surprised the Arkansas team was how ubiquitous the GM varieties were in the wild.
"We found the highest densities of plants near agricultural fields and along major freeways," Professor Sagers told BBC News.
"But we were also finding plants in the middle of nowhere - and there's a lot of nowhere in North Dakota."
Canola seeds are especially prone to dispersal, through blowing in the wind or through falling from trucks, as the seeds weigh just a few thousandths of a gram.
Professor Alison Snow, an authority on gene flow from Ohio State University who was not involved in the research, said that authorities had anticipated the existence of GM "volunteers" - plants growing in the wild outside fields - but did not consider it a problem.
"Regulatory agencies in the US have acknowledged that volunteer populations of GM, herbicide-resistant canola are expected to occur, as well as populations of inter-specific hybrids," she told BBC News.
"Over time, however, the build-up of different types of herbicide resistance in feral canola and closely related weeds, like field mustard, could make it more difficult to manage these plants using herbicides."
US policy is not to place a GM crop under any special regulatory regime unless there is a demonstrable difference between it and its conventional equivalent. The varieties in use here were deregulated in 1988 and 1989.
This is very different from the regime that has existed for a decade in the European Union.
But the European Commission recently recommended that nations should now be allowed to make their own decisions on whether to allow the crops or not, once they have passed health and environmental impact assessments at EU level.
Authorisations at EU level have been issued for GM potatoes, sugar beet, soya bean, oilseed rape, cotton and maize products.
Genetically Modified Crop on the Loose and Evolving in U.S. Midwest
GM canola plant refugees from farms in North Dakota bear multiple transgenic traits
David Biello Scientific American 6 Aug 10;
Outside a grocery store in Langdon, N.D., two ecologists spotted a yellow canola plant growing on the margins of a parking lot this summer. They plucked it, ground it up and, using a chemical stick similar to those in home pregnancy kits, identified proteins that were made by artificially introduced genes. The plant was GM—genetically modified.
That's not too surprising, given that North Dakota grows tens of thousands of hectares of conventional and genetically modified canola—a weedy plant, known scientifically as Brassica napus var oleifera, bred by Canadians to yield vegetable oil from its thousands of tiny seeds. What was more surprising was that nearly everywhere the two ecologists and their colleagues stopped during a trip across the state, they found GM canola growing in the wild. "We found transgenic plants growing in the middle of nowhere, far from fields," says ecologist Cindy Sagers of the University of Arkansas (U.A.) in Fayetteville, who presented the findings August 6 at the Ecological Society of America meeting in Pittsburgh. Most intriguingly, two of the 288 tested plants showed man-made genes for resistance to multiple pesticides—so-called "stacked traits," and a type of seed that biotechnology companies like Monsanto have long sought to develop and market. As it seems, Mother Nature beat biotech to it. "One of the ones with multiple traits was [in the middle of] nowhere, and believe me, there's a lot of nowhere in North Dakota—nowhere near a canola field," she adds.
That likely means that transgenic canola plants are cross-pollinating in the wild—and swapping introduced genes. Although GM canola in the wild has been identified everywhere from Canada to Japan in previous research, this marks the first time such plants have been shown to be evolving in this way. "They had novel combinations of transgenic traits," Sagers says. "The most parsimonious explanation is these traits are stable outside of cultivation and they are evolving."
Escaped populations of such transgenic plants have generally died out quickly without continual replenishment from stray farm seeds in places such as Canada, but canola is capable of hybridizing with at least two—and possibly as many as eight—wild weed species in North America, including field mustard (Brassica rapa), which is a known agricultural pest. "Not only is it going to jump out of cultivation; there are sexually compatible weeds all over North America," Sagers says. Adds ecologist-in-training Meredith Schafer of U.A., who led the research, "It becomes a weed [farmers] can't control."
There has been no evidence to show that the herbicide resistance genes will either increase or decrease fitness to date. The finding provides, however, a warning for future genetic modifications that might increase fitness in all kinds of plants; it will be difficult to keep those traits on the farm and out of the wild. "The big concern is traits that would increase invasiveness or weediness, traits such as drought tolerance, salt tolerance, heat or cold tolerance" says weed scientist Carol Mallory-Smith of Oregon State University—all the traits that Monsanto and others are currently developing to help crops adapt to climate change. "These traits would have the possibility of expanding a species' range." In the case of canola, consider it done—at least in North Dakota.
This is not the first transgenic crop to escape into the wild in the U.S.; herbicide-resistant turf grass being tested in Oregon spread as well in 2006. And GM canola is not a regulated plant, "therefore no protocols are required by the regulatory agencies to reduce or prevent escape," notes ecologist Allison Snow of The Ohio State University. "The next question is: 'So what?' What difference does it make if the feral canola or any species that hybridize with it have two transgenes for herbicide resistance?"
Canola modified to resist either the herbicide glufosinate (brand name Liberty) or glyphosate (brand name Roundup) has been available in the U.S. since 1989—and unregulated since 1998 and 1999, respectively for the two herbicides. "These results are not new for Canadian researchers and to be expected if two types of transgenic herbicide-resistant canola are commercially grown," says Suzanne Warwick of Agriculture and Agri-Food Canada, a government agency.
A common source for GM canola in the wild is seed that has scattered during harvest or fallen off a truck during transport. "Because about 90 percent of the U.S. and Canadian canola crop is biotech, it is reasonable to expect a survey of roadside canola to show similar levels of biotech plants," said Tom Nickson, environmental policy lead at Monsanto, in a prepared statement.
Nor does Monsanto claim ownership of the escaped plants, even those with multiple transgenes, according to company spokesman John Combest. "It has never been, nor will it be, Monsanto policy to exercise its patent rights where trace amounts of our patented traits are present in fields as a result of inadvertent means," although researchers would have to obtain a license from the company to work with the GM plant.
It remains to be seen how much sexual mingling such transgenic plants do; U.A.'s Sagers plans to do greenhouse trials starting in a few weeks. But it does provide a compelling example of how genes might move through a given population. "This is a good model for the influence of agriculture on the evolution of native plants," she says. "We can imagine gene flow to native species. If we can imagine it happening, it probably happens."
