The Mexican region where modern corn originated shows no traces of a genetically engineered contamination that caused an international uproar and created tension over U.S. corn imports, researchers said Monday.
WASHINGTON The Mexican region where modern corn originated shows no traces of a genetically engineered contamination that caused an international uproar and created tension over U.S. corn imports, researchers said Monday.
"If they were there, they are gone," Exequiel Ezcurra, a former Mexican official who is now with the San Diego Natural History Museum in California, said in a telephone interview.
He said an educational campaign to make farmers in Oaxaca state aware of the issue evidently has worked, and the farmers apparently were able to eliminate the undesirable corn imports.
Ezcurra worked on the original study and the new analysis published in this week's issue of the Proceedings of the National Academy of Sciences.
When the genetically modified corn was discovered in September 2001 deep in mountainous Oaxaca, it raised alarms around the world and sparked protest from global activist groups like Greenpeace.
The culprit was clear -- Mexico imports between 5 million and 6 million tons of maize from the United States each year, and close to half of all U.S. corn is genetically modified.
Most is altered to produce a naturally occurring toxin known as Bacillus thuringiensis, or Bt, to ward off pests.
Mexico allows GM cotton and soybeans, but not corn.
The government says it wants to protect the biodiversity of Mexico's corn because the nation is home to the world's richest corn gene pool.
Ezcurra, Allison Snow of Ohio State University and colleagues did another sampling and found no evidence of gene-engineered corn.
"We sampled maize seeds from 870 plants in 125 fields and 18 localities in the state of Oaxaca during 2003 and 2004," they wrote in their report published in the Proceedings of the National Academy of Sciences.
They tested more than 150,000 seeds and found no evidence of transgenes -- the spliced-in genes used to engineer the corn.
"We now know that transgenic maize isn't growing in Oaxaca," Snow said in a statement. "Mexican farmers who don't want transgenes in their crops will be relieved to find out that these uninvited genes seem to have disappeared."
Ezcurra said he also was relieved by the findings.
"We were incredibly surprised when we found nothing," he said.
"If transgenic material had got into the community because people were planting imported grain inadvertently, then from 2001 onwards, the communities were well-informed and they knew how to avoid planting grain of unknown origin."
This finding suggests that even if gene-engineered crops escape the fields they are intended for, the problem can be corrected quickly, Ezcurra and Snow said.
"There is great potential for transgenes to come across the U.S. border, with millions of tons of GM grain imported each year for processed food and animal feed," Snow said.
"If farmers think that their highly revered native plants have been altered by transgenes, they might even stop planting them," she added.