GE sterile and disease resistant trees (Scion)
Issue
- Concerns over wilding conifers are leading to afforestation restrictions, especially in the South Island, as well as increasing costs for controlling wilding spread from existing plantations.
- NZ has a recent foliage disease outbreak (red needle cast). Resistance to this disease (and possibly others) will be important in maintaining and improving plantation productivity.
- Using standard breeding methods to create a more disease resistant seed stock is likely to take many years, and is also likely to leave some trees still susceptible. Similarly, removing reproductive structures on wilding conifers to prevent spread is unlikely to be effective in the near term, and it will be challenging for a chemical or similar approach, controlling this risk as well.
- Using clonal material is one method of risk mitigation possibly ensuring resistant trees, but will not address reproductive sterility as well.
- Both issues can be addressed by creating transgenic trees (clonal) where each issue can be targeted directly without other modifications to the tree. In addition both traits can be combined in one tree.
- GE or biotech trees are currently not commercialised in NZ, but in order to determine if the gain in value outweighs other considerations, field trials need to be in place to assess performance. Decisions can then be made on proceeding to a commercial outcome.
Research
A project could be established to create a combination of sterile and disease resistant trees.
The approach would be to separately identify sterility genes and make transgenics in the glasshouse with a model system, while also screening seedling transgenics for resistance to red needle cast.
Once successful genes were found these could be combined in pine (and/or Douglas-fir) trees and plants grown for field trial evaluation.
The project would have go/no go milestones and would require up to 10 years before commercial decision making.
Costs and who pays?
Arborgen estimated that working with Scion they could deliver new sterile and disease-resistant planting stock to the market within six years at a cost of $3m. It was suggested FOA/govt could share the costs, but because of the political risks, a case could be made that government should be the main funder.
Outcome
New plantations do not produce wildings.
Resistance to RNC can be engineered into any genotypes.
New plantations will be resistant to red needle cast while still performing well in other traits.
Conclusion
Research into transgenic options to deal with two challenges to plantation forestry provides alternatives with a high likelihood of success. Deployment and use of these trees commercially should be assessed for cost/benefit.
