GM Superweeds Inevitable/Ban GM Oilseed Rape Now (9/10/2003)

"Cross-pollination between GM plants and their wild relatives is inevitable and could create hybrid superweeds resistant to the most powerful weedkillers, according to the first national study of how genes pass from crops to weeds." - The Independent (item 2)

The paper referred to is Wilkinson et al., Hybridization Between Brassica napus and B. rapa on a National Scale in the United Kingdom, Science 9 October 2003, Science 0: 10882001-0

1.Ban GM Oilseed Rape Now
2.Study Reveals First Evidence that GM Superweeds Exist
Ban GM Oilseed Rape Now
Oct 9
Friends of the Earth called for GM oilseed rape to be banned from the UK as new evidence reveals widespread cross breeding with wild flowers.

The paper [1], published in the journal Science today, presents research into the hybridisation of oilseed rape and its relative wild turnip or bargeman's cabbage.

The researchers found that cross breeding between the crop and its relatives continued for at least 3,000 metres from the nearest oilseed rape field and the rate of hybridisation declined very slowly. They estimate that more than 3,2000 hybrids would be created every year along rivers and 17,000 in arable areas (where the wild turnip is less common).  River banks where bargeman's cabbage is most common are the main place for the hybrids.

Commenting on this story, Friends of the Earth Real Food Campaigner Pete Riley said: This research shows that oilseed rape and wild turnip frequently cross-breed   over a wide area and this means that GM traits will rapidly find their way into wild plants.  The long-term consequences of this for agriculture and wildlife are difficult to predict, so if we allowed the commercial growing of oilseed rape, we would be starting a huge outdoor experiment.  The Government has no other choice than to ban GM oilseed rape and keep Britiain GM-free.

1.  M.J.Wilkinson et al, 2003.  Hybridisation between Brassica napus and B.rapa on a National Scale in the United Kingdom, Science 9 October 2003
See www.sciencexpress.org/9October/page 1/10.1126/science.1088200
2.Study Reveals First Evidence that GM Superweeds Exist
Steve Connor, Independent (UK), 10 Oct. 2003

Cross-pollination between GM plants and their wild relatives is inevitable and could create hybrid superweeds resistant to the most powerful weedkillers, according to the first national study of how genes pass from crops to weeds.

Its findings will raise concerns about the impact of GM crops. Next week the results will be published of farm-scale trials which have studied the impact on the countryside of three types of crop.

The government-funded scientists said the latest findings "contrast" with previous assessments of gene flow between farm crops and weeds. They had suggested that the danger of hybridisation - where two types of plant cross-pollinate to create another, for example a superweed - was limited. Superweeds are considered to be a threat because, in some cases, they might absorb resistance to weedkillers from GM crops engineered to be herbicide-tolerant.

But the results of the research, which involved analysing satellite images of the British countryside and patrolling 180 miles of river banks, reveal that hybridisation is both more widespread and frequent than previously anticipated.

Mike Wilkinson of Reading University, who led the study published today in the journal Science, said physical barriers such as isolation distances - buffer zones designed to stop pollen spreading from GM crops into the wild - would have only a limited impact on preventing hybridisation.

"This [study] shows that isolation distances will reduce hybrid numbers but not prevent hybridisation. It depends on what level of hybridisation you deem acceptable but if you want to absolutely prevent hybrids then isolation distances will not do so," Dr Wilkinson said. "Hybridisation is more or less inevitable in the UK context," he added.

The study concentrated on non-GM oilseed rape and assessed how easily it cross-bred with a near-relative in the wild called bargeman's cabbage, also known as wild turnip, which typically grows along river banks. Although the research was based on conventional oilseed rape, Dr Wilkinson said the conclusions applied to any flow of genes that could be expected from the GM varieties of oilseed rape that were undergoing farm-scale trials.

"Our findings are directly transferable to almost all sorts of genetically modified oilseed rape," he said. "The only exceptions will be ones where there is male sterility introduced into the crop." Researchers scoured the countryside for sites where bargeman's cabbage grew near to oilseed rape fields and they used DNA techniques to assess whether any hybrids between the crop and the wildflower had been produced as a result of pollen transfer.

The scientists, from the Natural Environment Research Council and the Centre for Ecology and Hydrology in Dorset, calculated the frequency of hybridisation and used it to estimate the number of hybrids that would form each year across the UK.

They concluded that typically there would be 32,000 hybrids produced annually in wild riverside populations of bargeman's cabbage, and a further 17,000 hybrids growing among a weedier variety of the wildflower which tends to infest farmland. This represents a relatively small fraction of the 88 million wild bargeman's cabbage plants estimated to grow along British riverbanks, but if the hybridisation involved a GM gene that conferred a significant advantage on the weed, the hybrid could quickly spread to pose a superweed threat.

An important outcome of the work is that it will allow scientists to assess what needs to be done to limit the spread of genes and pollen from GM crops. One possibility is to make the male plants sterile so they do not produce pollen.

"If we know how many hybrids to expect then we can test methods that people put forward hoping to prevent hybrid formation. In order to prevent hybrid formation you need to know how many to expect in the first place," Dr Wilkinson said.

"One of the main reasons for doing the work is that this sort of data represents a starting point for us to do predictive modelling, to predict how particular different sorts of genes will behave across the country. "It's important to know how many hybrids to expect, to know how efficient it has to be to prevent hybrids. The key question is whether the gene that they contain is going to cause a change [to the countryside] or not," he said.

Although the latest study stands in contrast to previous work attempting to predict gene flow between farm crops and wild flowers, Dr Wilkinson said the findings were not totally surprising. "The level of hybrid formation is more or less in keeping with what we expected on a national level," he said. "What's surprised us slightly is the variability between the regions."
Tearing Down Biotech's 'Berlin Wall'

EXCERPT: "Proponents of GM crops claim that public fears over GM risks are exaggerated and way beyond what is justified by 'scientific' risk assessments. But that is exactly the type of situation where attractive highly profitable insurance business can be done. Yet the insurance sector is deliberately avoiding such business. Why? It seems clear that they are well aware that the science is immature and that the assessment of GM related risks may be operating well beyond the capacity of science to identify them in advance of their widespread use. It is that scientific immaturity which goes to the heart of the debate and concern about GMOs. Why are we unwilling to recognise that reality politically when the de facto actions of commerce and industry confirm that internally they recognise it economically?"
Tearing Down Biotech's 'Berlin Wall' - 4 May 2003

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