1.GM seeds can 'last for 10 years' - BBC
2.GM Crops Can Stay In Soil For Up to Ten Years - AHN
3.Transgenic crops can persist for ten years - Nature
1.GM seeds can 'last for 10 years'
By Richard Black, Environment correspondent BBC News, 1 April 2008 http://news.bbc.co.uk/1/hi/sci/tech/7324654.stm
[image caption: France has recently seen street protests against GM crops]
Seeds of some genetically modified crops can endure in soil for at least 10 years, scientists have discovered.
Researchers in Sweden examined a field planted with experimental oilseed rape a decade ago, and found transgenic specimens were still growing there.
This was despite intensive efforts in the intervening years to remove seeds.
No GM crop has been found to endure so long; and critics say it shows that genetically modified organisms cannot be contained once released.
Tina D'Hertefeldt from Lund University led the team of scientists that scoured the small field which had 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,' she told BBC News. 'We knew that volunteers had been detected earlier, but we thought they'd all have gone by now.'
Presenting their findings in the journal Biology Letters, the researchers note that after the trial of herbicide-resistant GM rape, the Swedish Board of Agriculture sprayed the field intensively with chemicals that should have killed all the remaining plants.
And for two years, inspectors looked specifically for volunteer plants and killed them.
This is much more effort than would usually be deployed on a normal farmer's field.
But even so, 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.
Non-GM varieties were used in the 10-year-old study as well, and some of these had also survived.
'I wouldn't say that the transgenic varieties are able to survive better,' said Dr D'Hertefeldt. 'It's just that oilseed rape is a tough plant.'
Jeremy Sweet, a former head of the UK's National Institute of Agricultural Botany and now an independent consultant on biotech crops, agreed.
'It's been known for some time that oilseed rape is a bit of a problem because of the survival of its seed,' he told BBC News.
'It means that if farmers want to swap [from growing GM rape] to conventional varieties, they will have to wait for a number of years.'
Rapeseed - often known by its Canadian name canola - is the fourth most commonly grown GM crop in the world, after soya beans, maize and cotton.
An industry organisation, the International Service for the Acquisition of Agri-biotech Applications (ISAAA), calculated recently that more than one million square kilometres of land across the world are now dedicated to growing GM plants.
Europe accounts for only about 0.1% of that total, with a single maize variety the single transgenic food plant being grown.
Many European countries, including the UK, have yet to implement legislation on the thorny issue of how fields of genetically modified crops could co-exist with others that farmers are keen to keep free of transgenic material.
The Lund research does not deal with the flow of genes into neighbouring fields, or whether transgenes can transfer into wild plants growing nearby.
But Tina D'Hertefeldt believes legislators do need to take note of her findings.
'What we are saying is they also need to take into account the temporal aspect,' she said.
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.'
2.Genetically Modified Crops Can Stay In Soil For Up to Ten Years
Nidhi Sharma AHN, April 1 2008
London, England (AHN) - Genetically-modified crops such as oilseed rape can survive and produce plants as much as a decade after it was sown, according to a study done in Sweden.
Researchers in Sweden examined a field planted with experimental oilseed rape a decade ago, and found transgenic specimens still growing there. The study raises new concerns that genetically modified organisms cannot be contained once released despite intensive efforts in the intervening years to remove seeds.
Critics are also concerned to find ways to monitor GM crops so that they don't mix with food chains. The persistence of oilseed rape may be an important consideration for non-transgenic oilseed rape strains, such as those grown for use as biofuels.
The persistence of these seeds may lead to contamination of food crops, making them unfit for human consumption. The GM crops also produce chemicals that may pose a danger if they enter the public food chain.
To minimise unwanted mixing of GM and non-GM crops farmers should allow some years to pass before a GM field reverts to non GM, according to the team.
Plant ecologists led by Tina D'Hertefeldt of Lund University made the discovery after studying seedlings found growing at Lönnstorp Experimental Farm. The biotech firm Plant Genetic Systems sowed a plot of various transgenic oilseed rape strains, including a herbicide-resistant variety, in the farm in 1995 as part of a trial.
Since 1996, the plot has been used to grow wheat, barley and sugar beet. The findings were reported Wednesday in the journal Biology Letters.
3.Transgenic crops can persist for ten years Genetically modified oilseed rape springs up a decade after trial crop was sown
NATURE, 1 April doi:10.1038/news.2008.729 http://www.nature.com/news/2008/080401/full/news.2008.729.html
Transgenic oilseed rape can survive and produce plants as much as a decade after it was sown, according to a study done in Sweden.
The discovery that transgenic seeds can survive and germinate on farmland for this length of time raises fresh questions about how to monitor genetically modified (GM) crops. The crops need to be controlled to ensure that genes designed to pump out pharmaceuticals, for example, don't wind up in food, and that crops labelled as 'organic' are pure enough to satisfy consumers and regulators.
Plant ecologists led by Tina D'Hertefeldt of Lund University made the discovery after studying seedlings found growing at Lönnstorp Experimental Farm. The biotech firm Plant Genetic Systems sowed a plot of various transgenic oilseed rape strains, including a herbicide-resistant variety, in the farm in 1995 as part of a trial. Since 1996, the plot has been used to grow wheat, barley and sugar beet instead.
D'Hertefeldt and her colleagues collected seedlings from the plot in 2005, and unexpectedly found 38 oilseed rape plants growing amongst the modern crops. When they tested the plants with herbicides, they found that 15 were resistant and so came from seeds left by the transgenic plants. They report their findings in the journal Biology Letters 1.
Oilseed rape strains, both transgenic and non-transgenic, are known to be persistent. This study confirms that 'some of the seeds will remain viable for an awfully long time', says Les Firbank, head of North Wyke Research in Devon, UK.
With no proven health dangers of herbicide-resistant crops, the issue here is one of living up to labelling standards, Firbank says.
The European Union, for instance, rules that food labelled as 'organic' should contain no more than 0.9% of its material from genetically modified sources. The persistence of transgenic seeds may now make this limit difficult to adhere to, particularly if new crops are planted in the same field where GM crops were once grown.
D'Hertefeldt says that there is no way to tell whether the level of contamination they found would exceed the European Union's limits in fields sown with GM oilseed rape and then used for food production. 'We found quite a low number of plants,' she says.
Some farmers favour herbicide-resistant oilseed rape because it allows them to easily wipe out weeds before sowing other crops. Some seed companies, such as the multinational giant Monsanto, have suggested that transgenic crops could be grown in between seasons of non-GM crops to help manage weeds.
Getting into the food chain
The persistence of oilseed rape may be an important consideration not just for transgenic crops, but also for non-transgenic oilseed rape strains, such as those grown for use as biofuels. The persistence of these seeds may lead to contamination of food crops, making them unfit for human consumption. 'This is an important issue for all crops that have persistent seeds ”” it's not only about GM,' Firbank says.
Other strains of oilseed rape are being engineered as potential 'pharma' crops, producing chemicals that may pose a danger if they enter the public food chain. 'There are potential issues for food safety,' Firbank says.
Persistence might not be such an issue with other transgenic crops, especially those that can be prevented from producing seeds, such as the high-starch potatoes being trialled in Germany, D'Hertefeldt says. But engineering oilseed rape not to produce flowers is out of the question. 'With oilseed rape the crop you're after is the oil, and the oil is in the seeds,' D'Hertefeldt says.
1.D'Hertefeldt, T ., JÃ¸rgensen, R. B. & Petterson, L. B. Biol. Lett. doi:10.1098/rsbl.2008.0123 (2008).