Can we manage GM contamination of food and seed?

1
Can we manage GM contamination of food and seed?

• Sue Mayer
• GeneWatch UK
• www.genewatch.org

2
Outline

• How contamination arises
• Management
• Gene flow to neighbouring crops
• Other sources of contamination
• Implications
• Terminator and other proposals for biological
  containment

3
Sources of contamination

• Gene flow from GM to non-GM crop
• Volunteer weeds from previous crops - GM seed
  persists
• Mixing during or after harvesting
• Contaminated seed planted

4
Gene flow crop-crop

• Initial decline vs distance then very long tail
• Wind or insect transport
• insects found to be more important than
  previously though for oilseed rape
• Landscape and prevailing wind direction affects
  movement
• Size of pollen source
• Characteristics of crop

5
GM Crop
GM Crop
Organic
GM Crop
Non-GM crop
6
Non-GM Crop
Non-GM Crop
Organic
GM Crop
GM crop
7
Managing gene flow

• Separation distances
• will need to be context specific
• no absolute cut-off distance
• Pollen barriers - crops/hedges etc - untested
• Management of volunteers - oilseed rape seed can
  persist for 10 years
• Dependent on seed purity
• Communication with neighbours

8
Post-harvest management

• Cleaning equipment between crops
• Record keeping
• Quality control and testing - assumes know what
  to test for and burden on non-GM farmer/producer
• Critically dependent on human practices

9
Biological control a solution?

• Genetic modification being proposed to reduce
  contamination from pollen or seed including
• Terminator technology chloroplast
  transformation
• all experimental
• Terminator - sterile seed, pollen flow continues
• Chloroplast transformation - difficult low rates
  escape to wild/crop possible

10
Conclusions

• Extremely complex may not be practicable
• Policing needed
• Strict liability needed
• Contamination inevitable at some level