Polluted pollen's 'limited impact'

Pollen from GM rapeseed crops has certainly escaped

By environment correspondent Alex Kirby

The news that United Kingdom farmers have unwittingly been growing genetically-modified (GM) crops for two years has caused alarm.

The crops were grown from seeds imported from Canada. The seeds were taken from plants that had accidentally been exposed to GM material from nearby fields.

The UK Government has ordered three years of farm trials to test GM seeds for their possible impact on wildlife and the environment, before they can be sold to farmers.

But it seems very unlikely that the Canadian seeds will affect native plants in any noticeable way.

The species concerned is oilseed rape, which has been modified to make it resistant to a herbicide.

Escape

When the crop is processed, the herbicide-tolerant gene protein is destroyed.

But before that happens, some pollen will escape from the crop and be carried into nearby fields by the wind, or by bees.

Beekeepers face problems

The concentration of pollen lessens as it travels further, and it also gradually loses its potency over time. But in any case, the chances of the GM pollen establishing a foothold in British plants seem vanishingly small.

Dr Brian Johnson, of English Nature, the government's wildlife advisers, told BBC News Online: "The GM pollen will certainly escape into the surrounding countryside.

"It may land on the stigmas of native plants like wild mustard or wild radish, and it may pollinate them.

"But the chance is very low, and the chance of a viable hybrid developing is lower still.

"If one or two per cent of the rapeseed crop contains GM material, then you're talking of something orders of magnitude less than that when it comes to the chance of the modified gene getting into another species.

Lingering survivors

"And even if it does it won't matter, because the herbicide-tolerant gene confers no advantage on that species, so it will die out very quickly."

Lab research showed Monarch butterflies could be harmed

Dr Johnson said there could be a problem with "volunteer" rapeseed growing the following year, plants originating from seed which went astray at the time of sowing.

"Rape seeds are like small greasy ball bearings, and they escape quite easily. So they could perpetuate the gene flow.

"The answer is to spray the volunteers with another herbicide next spring, and then there should be no problem."

Insects harmed

But other concerns will persist. Organic farmers whose land abuts GM crops, or bee-keepers whose hives are within flying distance of them, probably cannot avoid GM material getting into their produce.

And there may be effects on non-plant species as well. US researchers found that pollen from a GM crop could, in certain circumstances, harm caterpillars of the monarch butterfly.

It was a different crop, incorporating a different gene. But it is not yet possible to be certain that the GM rapeseed will not produce similar effects in other animal species.

The government says that only through larger trials can the true impact of GM on the countryside be tested.