MEXICO CITY – Wild cotton in Mexico has been contaminated with genetically modified material, posing a risk to biodiversity, experts say.

This worrying conclusion was reached by six scientists at the National Autonomous University of Mexico (UNAM) and the National Commission for Knowledge and Use of Biodiversity (CONABIO) in a research study published this month in Molecular Ecology, an international journal.

In their article "Recent long-distance transgene flow into wild populations conforms to historical patterns of gene flow in cotton (Gossypium hirsutum) at its centre of origin", the experts showed that cotton genes and transgenes can be transferred between populations thousands of kilometres apart by seed dispersal.

They also found that varieties of Mexican wild cotton that harbour transgenes (genes from one species introduced artificially into another) undergo rapid evolution, with unpredictable consequences.

"The genetic diversity of wild populations is very high, and that of cultivated cotton is very low. Gene flow can reduce the differentiation between populations, but we have no idea what impact that might have," the head of the research project, Ana Wegier of UNAM’s Ecology Institute and the National Institute of Forestry, Agriculture and Livestock Research (INIFAP) told IPS.

"What we are seeing is the effect on biodiversity of 15 years of growing transgenic crops under permits," she said.

In order to boost cotton cultivation, in decline because of the collapse of international prices and the growing dominance of synthetic fibres, in 1996 the Mexican government authorised experimental planting of genetically modified cotton, without paying heed to studies of its biological interactions in the country.

Since 2009, transgenic cotton has been grown on a commercial scale on an area of over 100,000 hectares, producing harvests of 500,000 tonnes, according to the Mexican agriculture ministry.

Cottonseed is used mainly for oil and meal for animal feed, and transport of animal feed products might explain how transgenic seeds arrived in wild cotton populations.

The six authors collected 336 plants from 36 populations between 2002 and 2008. They also analysed seeds from three Mexican locations, the U.S. states of Texas and Virginia, and from Argentina, Brazil, India and Egypt. Of the 270 samples analysed, 66 were positive for transgenes.

The scientists found that 1.4 percent of 5,985 permits to plant genetically modified cotton issued by the Mexican authorities between 1996 and the beginning of 2008 fell within the area of distribution of two wild cotton metapopulations, as collections of interacting populations of the same species are called.

A further 4.2 percent of the authorised transgenic crops were within a 300-km radius from three metapopulations. The remaining 94.4 percent were over 300 km away from all wild cotton metapopulations.

As has already happened with native maize, contamination of wild strains could occur with other transgenic crops, which are slowly spreading in this Latin American country.

This concern is shared by 16,000 beekeepers in the southeastern state of Yucatán, where U.S. agribusiness giant Monsanto has a pilot plantation of genetically modified soy covering 30,000 hectares.

Monsanto’s soy has been genetically modified to confer resistance to an herbicide, glyphosate, which is sprayed on the crop to kill off non-resistant weeds.

"In the soyfields, the bees turn very aggressive and instead of returning to the hive, they die on the way back, as the glyphosate applied to the crops damages their intestines," the local coordinator of the National Union of Autonomous Regional Campesino Organisations, Pablo Duarte, told IPS.

"Our fear is that not only will the bees die, but we will not be able to sell our honey," he said.

In Mexico, some 45,000 beekeepers collect approximately 56,000 tons of honey a year. Their main market is the European Union, followed by the United States and Canada.

But the EU Court of Justice has already banned the sale of honey containing pollen contaminated by unauthorised transgenes.

The first plots of genetically modified soy were evaluated in 2008. Currently 60,000 hectares of Mexican soil are producing transgenic soy.

The government received 110 applications to grow transgenic maize on an experimental basis, and 11 applications since 2009 for pilot-scale projects, the stage before commercial cultivation. The agriculture ministry authorised 67 experimental fields covering 70 hectares in the north of the country, and at least 12 experimental transgenic wheat fields.

The 2005 Biosecurity Law for Genetically Modified Organisms states that the centres of origin of seeds must be defined before any permission can be given for transgenic crops.

The environmental watchdog Greenpeace reported the presence of transgenic maize in six out of Mexico’s 32 states, as well as imports of genetically modified seeds of this staple food, which is profoundly symbolic in Mesoamerican cultures from central Mexico to Costa Rica.

"Each case needs to be analysed separately, to the highest scientific standards," said Wegier, who is also a member of the Union of Socially Committed Scientists (UCCS) and is currently working on the genetics of avocados and green tomatoes.

"So far, decisions have been made without the benefit of scientific research done in Mexico, but now we have the opportunity to take decisions based on the precautionary principle (that activities that present an uncertain potential for significant harm should be avoided until they are proved to be harmless)," said the head of research.

Although seed migration out of fields of genetically modified crops may be low, the study warns that once a single or a few transgenic individuals are dispersed into particular wild populations, they produce pollen that may fertilise local wild plants.

"Since transgenes are inserted within the nuclear genome, they can be dispersed both via pollen or seed," the document says.

Genetically modified organisms "are going to contaminate all the varieties we have, and then we will have to depend on seeds from the big companies," Duarte warned.

"If we lose our native seeds, we won’t have seeds to plant. That’s why we are asking the government to stop the sowing of transgenic maize and soy," he said. (END)