Concern that gene biotechnology applied to agriculture could coincide with the arrival of "superweeds" and limit the benefits of a new generation of crops has been heightened by findings published by French scientists.
A research team attached to the National Agricultural Research Institute at Le Rheu confirmed that genes resistant to herbicides can cross from specifically engineered crops to wild species.
Unintentional transfer of genetic material from what are described as "transgenic crops" to the wild, and the likely generation of superweeds resistant to herbicides, are repeatedly cited by environmental interests as the basis for restricting what it considers to be relatively unproven biotechnology.
The French scientists, nonetheless, say the chance of the process happening under normal conditions is rare. They used a genetically modified oilseed rape plant containing a gene conferring resistance to the herbicide glusofinate aluminium and crossed it with an unrelated wild radish weed. Over four generations the resistance gene became incorporated into the weeds until it could spread among non-hybrid weeds.
Their findings, published in Na- ture, suggest that transgenic crops designed to be resistant to a particular herbicide could have a limited useful life before their genetic advantage is passed on to the weeds around them.
Monsanto, which has undertaken the first field trial for genetically modified crops in Ireland, said the finding would have no adverse effect on its use of crops engineered to be resistant to the company's RoundUp herbicide.
Its British technical manager, Mr Colin Meritt, said RoundUp blocks a particular enzyme found only in particular organisms, which makes the process highly specific. "That means resistance to it can't be developed directly. The benefits greatly outweigh the problems associated with this technology."
But Genetic Concern, which opposes Irish trials with genetically modified crops pending more extensive independent evaluation, accused the biotechnology industry of trying to underplay possible negative effects.
Its spokesman, Mr Quentin Gargan, said: "The reason why RoundUp is such a broad spectrum herbicide is because this enzyme exists in almost all weeds. It's a nonsense to claim that the benefits of genetic engineering outweigh the problems without finding out what all the problems are first."
A public debate on genetically modified organisms will be held at the University of Limerick in conjunction with Science Week Ireland later today. Speakers include Mr Sydney Reid, Monsanto's business manager for Ireland; Dr Brian Trench of Dublin City University; Green MEP Ms Nuala Ahern; Mr Quentin Gargan of Genetic Concern, and Father Sean McDonagh of Voice of Concern for the Irish Environment. It takes place at Theatre FB 028 in the Foundation Building at 8 p.m.
