Obsolete

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.

The new form of charlock was growing among many others in a field which had been used to grow GM rape. When scientists treated it with lethal herbicide it showed no ill-effects.

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: "The frequency of such an event [the cross-fertilisation of charlock] in the field is likely to be very low, as highlighted by the fact it has never been detected in numerous previous assessments."

However, he adds: "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."

I'm not going to pretend that I completely understand the science behind GM crops and foods. In fact, I don't even moderately understand it. What I do understand is that these crops and foods pose a multiude of risks, as these trials and experiments in Canada and America have shown. Before we even consider planting them commercially here, we need to do a lot more experimentation. The advantages have not yet overcome the disadvantages.