Interbreeding GM crops 'raises risk of superweeds'

Genes from genetically modified crops are interbreeding with other crops and weeds, a government report has found.

Evidence of contamination between engineered oilseed rape and non-GM plants has been discovered after a six-year research programme. The genes in the research could migrate up to 200 metres, the research found.

A spokesman for Friends of the Earth, Peter Riley, said the report highlighted the potential threat of "superweeds" in the British countryside.

A summary of the results was published by the Department for the Environment, Food and Rural Affairs (Defra) on 24 December. The department was criticised by Friends of the Earth for not posting the full report on its website.

Defra defended the decision to release the report on Christmas Eve, with a spokesman admitting it was not the "ideal time" to publish but that "there has been no attempt to mislead".

"It's 100 pages long. It's very detailed and very scientific – that's why it's not on the website," he said.

He also said the results were as expected – showing low levels of contamination.

The research found the weed wild turnip (Brassica rapa) was affected by gene flow when planted next to GM oilseed rape, prompting fears it could become resistant to herbicides.

Mr Riley said: "These results should cause the Government to think again about the long-term implications on the commercial growing of oilseed rape."

The work focused on GM oilseed rape crops at sites including official farm-scale trials.

In some samples, the GM oilseed rape contaminated normal crops 200 metres away.

The report said commercial scale releases of GM oilseed rape in the future could pollinate other crops and wild turnip.

It said: "There may be a need to review isolation requirements in keeping with current legislation on contamination thresholds in crops, in light of this research."