GM crops created superweed, say scientists 

  Modified rape crosses with wild plant to create tough pesticide-resistant strain 

  Modified genes from crops in a GM crop trial have transferred into local wild
  plants, creating a form of herbicide-resistant "superweed", the Guardian can reveal.

  The cross-fertilisation between GM oilseed rape, a brassica, and a distantly related
  plant, charlock, had been discounted as virtually impossible by scientists with the
  environment department. It was found during a follow up to the government's three-year
  trials of GM crops which ended two years ago.

  Unlike the results of the original trials, which were the subject of large-scale press
  briefings from scientists, the discovery of hybrid plants that could cause a serious
  problem to farmers has not been announced.

  The scientists also collected seeds from other weeds in the oilseed rape field and
  grew them in the laboratory. They found that two -  both wild turnips - were herbicide
  resistant.

  The five scientists from the Centre for Ecology and Hydrology, the government research
  station at Winfrith in Dorset, placed their findings on the department's website last
  week.

  A reviewer of the paper has appended to its front page: "This unusual occurrence merits
  further study in order to adequately assess any potential risk of gene transfer."

  Brian Johnson, an ecological geneticist and member of the government's specialist
  scientific group which assessed the farm trials, has no doubt of the significance.
  "You only need one event in several million. As soon as it has taken place the new plant
  has a huge selective advantage. That plant will multiply rapidly."

  He said: "There is every reason to suppose that the GM trait could be in the plant's
  pollen and thus be carried to other charlock in the neighbourhood, spreading the GM genes
  in that way. This is after all how the cross-fertilisation between the rape and charlock
  must have occurred in the first place."

  Since charlock seeds can remain in the soil for 20 to 30 years before they germinate,
  once GM plants have produced seeds it would be almost impossible to eliminate them.

  To assess the potential of herbicide-resistant weeds as a danger to crops, a French
  researcher placed a single triazine-resistant weed, known as fat hen, in maize fields
  where atrazine was being used to control weeds. After four years the plants had multiplied
  to an average of 103,000 plants, Dr Johnson said.

  Although the government has never conceded that gene transfer was a problem, it was fear
  of this that led the French and Greek governments to seek to ban GM rape.

  The findings mirror the Canadian experience with GM crops, which has seen farmers and
  the environment plagued with severe problems.

  Paul Brown, environment correspondent
  Monday July 25, 2005
  The Guardian 

http://www.guardian.co.uk/gmdebate/Story/0,2763,1535428,00.html

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