Science in Society Archive

Transgenic Contamination of Certified Seed Stocks

Yet more evidence that transgenic contamination is inevitable and unavoidable. Prof. Joe Cummins reports.

The spread of transgenes from genetically modified crops is a great threat to the quality of certified seed. Canola (oilseed rape in the UK) (Brassica napus, B. rapa, B. campestris) is the second most valuable crop in Canada. The Canadian Food Inspection Agency (CFIA), a sub department of Agriculture Canada, requires a distance of 200 metres separation between fields growing certified seeds from any other Brassica, and a distance of 50 metres from weedy relatives. Recently, however, producers of hybrid canola seed have required a separation of 2 kilometers from a Brassica crop, in recognition that pollen from a Brassica crop may travel as far as a kilometer or more. CFIA separation distances are evidently inadequate for insuring the purity of certified seeds.

Friesen, Nelson and Van Acker in the University of Manitoba in Winnipeg, Manitoba, Canada, studied certified canola seed stocks for contamination due to transgenes for herbicide tolerance to glyphosate, glufosinate or thifensulfuron [1]. Certified seed stocks were studied in field plots to which herbicides were applied. The results showed that 95% of 27 certified seed lots were contaminated with herbicide tolerance transgenes; with 52% of the seed lots exceeding the 0.25% maximum contamination standard set for certified seed. Some lots were tolerant to both glyphosate and glufosinate.

A year earlier, Downie and Beckie from AgriFood Canada in Saskatoon, Saskatchewan [2], examined 70 certified canola seed lots using a laboratory Petri dish assay. They found 59% of the seed lots had detectable herbicide tolerance and 25% had contamination levels exceeding the maximum acceptable standard for certified seeds. The standard for cross contamination was established for conventional not transgenic cultivars, and presently, there are no standards for transgenic contamination of certified cultivars in Canada. Standards for transgene contamination of canola oil or oilseed cake for animal feed would be desirable, and even necessary for export purposes, given the requirements for labeling and traceability in Europe.

The extensive contamination of certified canola seed with transgenes for herbicide tolerance is staggering. The Canadian canola crop extends over some 5 million hectares, of which roughly 60% are planted with transgenic varieties. The extensive cross contamination by transgenic varieties could have been foreseen and predicted at the time field trials of transgenic crops were carried out. By now, it seems unlikely that transgene- free canola can be produced in western Canada. It is disturbing that CFIA appears to be totally unconcerned over the extensive contamination, which is evidence of gross negligence in oversight on its part.

  1. Friesen LF, Nelson AG and Van Acker RC. Evidence of contamination of pedigreed canola (Brassica napus) seedlots in western Canada with genetically engineered herbicide resistance traits. Agron. J. 2003, 95.
  2. Downey RK, and Beckie H. 2002. Isolation Effectiveness in Canola Pedigree Seed Production. Internal Research Report, Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, Saskatchewan, S7N 0X2, Canada, 2002, 14 pp.

Article first published 10/06/03

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