First national study to quantify GM hybrids across the UK

9 October 2003

Joint press release from BBSRC and NERC.

Pioneering research that quantifies cross-fertilisation between crops and their wild relatives will help to assess the risk of hybridisation associated with growing GM crops in the UK, according to a report published today in the journal Science.

The researchers, led by Dr Mike Wilkinson from the University of Reading, carried out the largest survey of its kind to examine hybridisation between commercially grown non-GM oilseed rape crops and Bargeman's cabbage (also known as the Wild Turnip, Brassica rapa) which are known to frequently cross fertilise.

Using these data, the researchers have been able to predict, for the first time, the number, frequency and location of hybrids likely to occur on a national scale. They report that the numbers of hybrids will fluctuate widely between years, but predict around 32,000 hybrids annually in wild riverside populations and some 17,000 in weed populations growing in fields across the UK - given current crop numbers.

"Our method for predicting where these hybrids are most likely to occur, combined with continuing research on the consequences of hybridisation, will be a valuable tool in carrying out environmental risk assessments on areas where GM oilseed rape and other GM crops might be grown in the future," says Dr Wilkinson. "We have known for some time that these two species will hybridise, but until now there has been no way of predicting the total number of hybrids or where they can be found most frequently in the UK," he says.

A further key finding from the survey confirms that isolation of crops reduces, rather than prevents, gene flow from oilseed rape, even over large distances. The study identifies eastern central England as the region of the UK most likely to contain hybrids and Northern Ireland as the least. The study will also provide a foundation for developing methods of testing other types of crops.

Further information

NERC Press Office
Natural Environment Research Council
Polaris House, North Star Avenue
Swindon, SN2 1EU
Tel: 01793 411561
Mob: 07917 557215

Dr Mike Wilkinson
University of Reading
Tel: 0118 378 8075

Andrew McLaughlin
BBSRC
Tel: 01793 413301
mob: 0790 058 0098

Notes

1. Using satellite imagery and data from the Centre for Ecology & Hydrology's Countryside survey, combined with samples taken from riverbanks and fields, the researchers developed methods to predict when and where cross-fertilisation is most likely to occur. They estimate that 1·8 million - around 2% - of all waterside B. rapa plants are found within 30m of rapeseed fields. Interestingly, no Bargeman's cabbage were found along any of the Scottish rivers tested in the survey.

2. Bargeman's cabbage is usually found in abundance along riverbanks in many parts of England, so fields of rapeseed growing near rivers will cross-pollinate more frequently with these populations.

3. Another form of Bargeman's cabbage also grows in arable fields and particularly in oilseed rape crops. This weedy form hybridises more frequently with oilseed rape but appears to be mostly restricted in its distribution to fields in Humberside.

4. There have been several previous studies that propose techniques to stop hybrids from forming and so avoid gene flow from GM crops. None will be 100% effective. Prediction of total hybrid numbers in the UK sets targets for how efficient these methods must be to effectively prevent gene flow during the lifespan of a GM variety.

5. Estimates show that around 32,000 hybrids appear annually in wild riverside populations and some 17,000 arise in weed populations across the UK. The number of GM hybrids will be very much lower for the foreseeable future and will depend on the amount of GM oilseed rape grown.

6. This research was funded as part of BBSRC-NERC joint initiative on gene flow from GM crops.

Press release: 21/03

First national study to quantify GM hybrids across the UK

External links

Press links

Recent press news