No stopping GM seeds
April 4, 2008
Scientists discovered seeds from certain genetically modified crops can endure in the soil for at least 10 years in some cases.
A field planted with experimental oilseed rape (canola) a decade ago found transgenic specimens were still growing there despite intensive efforts over the years to remove the seeds, according to researchers in Sweden. This is the first time a genetically modified crop has endured so long and critics say it shows that genetically modified organisms cannot be contained once released.
Tina D’Hertefeldt and a team of researchers from Lund University searched a small field that hosted the GM trial 10 years ago looking for “volunteers” – plants that have sprung up spontaneously from seed in the soil. “We were surprised, very surprised,” said D’Hertefeldt. “We knew that volunteers had been detected earlier, but we thought they’d all have gone by now.” A larger French study, published at the same time as the Swedish research was submitted, also found survival of volunteer plants for eight years after a GM trial.
The researchers presented their findings in the journal ‘Biology Letters’ and found that after the trial of herbicide-resistant GM rape, the Swedish Board of Agriculture covered the field with chemicals that should have killed all the remaining plants. Inspectors searched specifically for two years to find and kill volunteer plants — more effort than would usually be deployed on a normal farmer’s field. However, 15 plants had sprung up 10 years later carrying the genes that scientists had originally inserted into their experimental rape variety to make them resistant to the herbicide glufosinate.
Rapeseed is the fourth most commonly grown GM crop in the world, after soya beans, maize and cotton. According to the International Service for the Acquisition of Agri-biotech Applications (ISAAA), an industry organization, more than one million square kilometers (approximately 250 million acres) of land across the world are now dedicated to growing GM plants.
“I think for oilseed rape we may have to be aware that there will always be some contamination and therefore we may need labeling to tell the consumer,” added D’Hertefeldt.
Professor Mark Westoby, a plant ecologist from Macquarie University in Australia, had a more blunt assessment. “This study confirms that GM crops are difficult to confine,” he said.”We should assume that GM organisms cannot be confined, and ask instead what will become of them when they escape.”