27/11/2007

GE Plants Spread Genes into Wild Relatives

 



A recent study by Warrick (1) has confirmed that genetically modified Ready Roundup (RR) Brassica can escape and outcross with wild relatives.


The study conducted in Canada with GE RR Canola (Brassica napus) and the weedy relative Wild Mustard (Brassica rapa). Scientists reported that the RR Canola transgene outcrossed readily and persisted in the weedy mustard relative and was passed on to further generations. This supports earlier findings in England that outcrossing is very common in brassica species.


The findings add to concerns about the risks of GE brassica being developed and trialled by Crop and Food Research in New Zealand. Brassica is the name given to plants belonging to the Cabbage family from cauliflower, broccoli, to turnips and forage kale. Brassica are highly promiscuous and readily transfer genes between plant relatives.


The study was carried out over 6 years and found that the transgene was stably integrated into the weedy descendants over that time. However, the transgenic Brassica plants had reduced male fertility and reduced pollen viability.

One FI GM hybrid plant still produced 480 seeds of which 22 carried the transgene. The plants persisted regardless of Roundup spraying and fitness costs associated with selection pressure.


'This transgenic escape into wild weedy relatives supports concerns that GE brassica are a threat here,' said Claire Bleakley of GE Free (NZ) in food and environment 'Once released out of laboratory containment, GM pollen will spread to other brassica species both weedy and food plants, contaminating the environment and food chain'.


'The worst part of this is the plants may contain mixtures of GM insecticidal and herbicide resistant toxins that could affect pollinating insects and the wider food chain and it will be the farmers, market gardeners and Councils who will be liable for cleanup and compensation costs.


GE Free (NZ) in food and environment believe that ERMA and Crop and Food Research must look into the new information on the ability of transgenes to outcross, integrate and survive in the wild under competitive selection pressure.


There are no studies on human safety and if levels of toxins cannot be controlled there may be long term health effects on animals and people. The research is reason to re-assess their approval of the Bt GM Brassica trial.

References:

(1)The case of an herbicide resistance transgene in a weedy Brassica rapa population To cite this article: S. I. WARWICK, A. LEGERE, M.-J. SIMARD, T. JAMES Molecular Ecology 2007 Oct 29 2007; http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-294X.2007.03567.x


Wilkinson M., Elliott L., Allainguillaume J., Shaw M., Norris C., Welters R., Alexander M., Sweet J., and Mason D. Hybridization Between Brassica napus and B. rapa on a National Scale in the United Kingdom Science 17 October 2003: Vol. 302. no. 5644, pp. 457 459 DOI: 10.1126/science.1088200 http://www.sciencemag.org/cgi/content/short/302/5644/457

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