Seeds the big threat in GM study

LONDON - Genetically modified crops could crossbreed via their seeds - not just pollen, scientists warned yesterday.

Humans and vehicles could inadvertently carry seeds from GM crop sites into neighbouring fields, which had crucial implications for the siting of such crops, the French research shows.

The new study, released by the Royal Society, deviates from common thinking that pollen dispersal is the main route and worry for potential GM cross-breeding.

Other GM critics have separately voiced concern about engineered gene constructs spreading or re-combining through horizontal gene transfer in soil organisms.

New Zealand's Government intends in October to lift a moratorium on commercial releases of GM crops and animals. Some regions, such as Marlborough, and farming sectors, such as kiwifruit, are interested in blocking specific GM crops from specific regions to avoid the risk of engineered genes "contaminating" conventional crops.

"Gene flow and interbreeding from cultivated to wild plant populations has important and ecological consequences," said researcher Dr Jean-Francois Arnaud, of the Universite de Lille, in France.



His findings follow a study of cultivated and wild sugar beets in northern France. Researchers monitored weed beets, commercially grown sugar beet and wild sea beet in three separate fields, one more than 1km away. They matched DNA in all three.

But, contrary to expectations, the gene flow through pollen was limited. Rather, Arnaud said, the weed beet had acted as a bridge between the wild and commercial crops via "accidental seed flow" - most likely spread in soil caught on vehicles.

None of the beets was genetically engineered but, the findings "highlighted the likelihood for transgene (GM) escape" and hybridisation through seed dispersal, Arnaud said.

They reinforced economic issues caused by "increased invasiveness" of any future GE crops in the agricultural system and that location of such crops had to be done cautiously.

- NZPA