|Wednesday, 28 November, 2001
Genetic diversity is at stake, say campaigners
GM corn infects wild Mexican maize 62 miles away
By BBC News Online's Ivan Noble
Scientists have found DNA from genetically modified crops in wild
maize growing on remote mountains in Mexico.
The authors of the study say they found the results hard to believe,
but saw them verified by a Mexican Government follow up.
Now, they are worried that genes from GM crops are unintentionally
threatening the valuable diversity of native wild maize.
The wild maize in question was growing around 100 kilometres (62
miles) from the nearest GM crops.
Mexico has had a moratorium on new plantings of GM maize since 1998
but allows the import of GM crops for consumption.
Ignacio Chapela and David Quist of the University of California,
Berkeley, US, compared wild maize from the Sierra Norte de Oaxaca
mountains in Mexico with GM varieties from the Monsanto company in the
US and with samples known to be uncontaminated.
They found that some of the wild samples were contaminated with
telltale sections of DNA from GM crops.
"This is very serious because the regions where our samples were taken
are known for their diverse varieties of native corn, which is
something that absolutely needs to be protected," Dr Chapela said.
"Originally I was very surprised and concerned about the danger of
false positives. I was very alarmed and hoping it wasn't true," his
colleague David Quist told BBC News Online.
"It was initially hard to believe that corn in such a remote region
would have tested positive," he said, explaining that tests were
carried out in two labs in Mexico and one in the US.
It is not entirely clear how the DNA from the GM crops got into the
wild plants, but David Quist has a theory.
"It's more likely that the contamination came from food aid brought in
to these regions. A lot of it comes from the United States and a lot
of it is transgenic," he said.
Mr Quist believes measures should be taken to counter the spread of GM
genes. "Once the DNA is in the population, you can't just go and fish
it out," he said.
But a well-enforced ban on imported GM corn and a programme to
encourage traditional habits of swapping and testing wild seeds would
dilute the influence of the GM genes, he said.
The publication of the study coincides with the issue of a report by a
UK coalition calling for further restrictions on GM crops.
"The issue... has amounted to a public relations disaster for a
government whose support for the agri-biotechnology industry has been
seen to clash with its responsibility to the public interest," the
Five Year Freeze campaign said on Wednesday.
The campaign, which encompasses a range of pressure groups and
companies, wants to see a five-year ban on the planting, import and
patenting of GM crops.
"Today's report in Nature shows evidence of GM contamination of wild
maize in Mexico, the origin of all maize varieties, posing a potential
threat to vital diversity essential for future global food security,"
said the campaign's coordinator, Clare Devereux.
"Here in the UK the issue of genetic pollution not only threatens
biodiversity, but also the livelihoods of non-GM and organic farmers,
and the right of consumers to choose GM-free food," she said.
Guy Poppy of CropGen, an association backed by the UK biotech
industry, described the study as "a good piece of research" but said
it contained no real surprises.
"It's better to acknowledge that a minimum of cross-pollination cannot
be avoided and not to panic: after all, nowhere in the world has a GM
product been found to be unhealthy and no adverse environmental effect
has ever been substantiated," he said.
Further studies were required to evaluate the impact of genetic
transfers, he said, adding: "Let's not forget that the benefit from GM
is already being felt around the world.
"In Mexico, they've used GM technology to address the problem of high
levels of aluminium in the soil, which in the developing world reduces
yields by as much as 80%.
"By transferring a gene from a bacterium called Pseudomonas into
maize, the crop can be made resistant to this toxic metal."
The Mexican maize study appears in the journal Nature.