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Perspectives on Novelty
Unintended effects from non-rDNA plant breeding
Alan McHughen
University of California
Riverside, Ca 92521
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Assumption:
GE is inherently higher
risk than non-GE
- GE is
"unnatural"
- Nature does not mix genes across species
- Conventional breeding -- ditto –
- GE invariably spans the
"species barrier"
Natural inter-species gene flow
- Wheat
- Agrobacterium
- Various Brassicas are inter-fertile
- Retroviruses
Conventional breeding interspecies
- Wheat chromosome engineering (esp. rye)
- Tomato with 100+ L.
peruvianum genes
- Triticale
- Potato hybrids (e.g. S. brevidens)
GE need not involve
"foreign" DNA
- Flavr Savr tomato
- High oleic soybean
- RNAi
applications
- "Self-cloning"
- Within species DNA
transfer
- Genomics guided breeding
- (Xa21 in rice)
Unintended effects: non-rDNA
- Potato with high solanine (several)
- Celery with excessive psoralen
- Tomatoes with high tomatine
- Kiwifruit with allergens
- Squash with high curcurbitacin
- Likely many unknown, unnoticed and undocumented.
Environmental damage caused by:
| Source |
Example of problem |
Prior regulatory scrutiny |
| |
Entire Genotypes |
|
| Naturally occurring invasions |
Ordinary Successions |
none |
| Unintentional introductions |
Russian thistle in NA |
none |
| ? Intentional introduction; |
Purple loosestrife; Eurasion milfoil |
low/none |
Intentional introductions,
Unintended displacements |
Prickly Pear cactus in Australia
Johnsongrass in NA |
low |
Intentional introductions,
Intentional displacements |
Soybean in NA |
low |
| |
Single Genes |
w |
| Intentional introductions |
Rht genes in wheat |
low/moderate |
| intentional displacements: |
Canola from rapeseed |
moderate |
| GMOs |
None recorded |
high |
Similar products, similar risks ?
| HT Canola |
Group |
| Sulfonylurea |
2. ALS/AHAS inhibitor |
| Trifluralin |
3. Mitotic inhibitor |
| Bromoxynil |
4. PGR |
| Triazine |
5. Photosynthetic inhibitor |
| Glyphosate |
9. EPSP
Synthase inhibitor |
| Glufosinate |
10. Glutamine Synth. Inhibitor |
Conclusion
- Unexpected effects can occur with any method of breeding
- Unexpected result does not by itself invoke hazard
- Inter-species gene transfer is common and innocuous
- Risk analysis demands a consideration of:
- the host species,
- the novel trait, and
- the environment in which it will be released.
- Method of breeding is immaterial
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