Advancing white pine blister rust resistance in five-needle pine trees
May 2025
Genomics is unlocking resistance to white pine blister rust (WPBR) – offering hope for Canada’s endangered five-needle pines.
“White pine blister rust can infect and kill more than 95 percent of trees in some populations. Without intervention, less than 10 percent of their seedlings survive. Our molecular tools can accurately identify nearly all resistant trees for breeding.” — Jun-Jun Liu, Molecular Forest Pathologist, Natural Resources Canada.
(left) Seedlings in the lab are being grown to study and identify genetic lines that are particularly resistant to WPBR. (right) A seedling with WPBR.
The seven-second summary:
White pine blister rust poses a severe threat to Canada’s native five-needle pines, with high infection and mortality rates endangering entire ecosystems. In many regions, the volume of white pine has been depleted to the point where it is no longer considered a viable commercial species. Jun-Jun Liu and his team are using advanced genomic tools to identify resistant trees, focusing on resistance to WPBR for long term sustainability. This research, in collaboration with the U.S. Forest Service, aims to accelerate breeding programs and develop DNA-based selection methods to restore and protect Canada’s forests.
Five-needle pine tree species are at risk
- All four native Canadian five-needle pine species in regions across Canada are highly vulnerable to WPBR
- This includes western white pine, eastern white pine, whitebark pine, and limber pine
- The disease has spread and covered all landscapes where these four species grow. WPBR can kill up to 95% of tree stands in regions with serious infection
This has detrimental ecosystem impacts
- The widespread tree mortality across Canada caused by WPBR is leading to the collapse of high elevation mountain ecosystems
- No other tree species can replace whitebark and limber pines at these elevations
- Infected forests are struggling to regenerate, and newly planted trees are facing high infection rates, making restoration efforts ever more challenging
The importance of genomics research for tree-breeding
- Genomics uses genetic information to identify desirable characteristics, such as disease resistance, in natural populations.
- Genomics differs from genetic engineering and does not involve modifying an organism's genetic material
- Scientists are working to identify genetic markers of disease resistance that can be used to select resistant trees for breeding and planting programs
- Newly planted trees containing identified resistance genes will be better adapted to survive fungal threats
- Without human led restoration and advanced programs such as this, these pine species face a high risk of extinction in the future
In closing:
“Research of these forest species drives innovation and societal progress. It informs policy decisions, advances technology, and improves our understanding of how to keep our forests sustainable.” — Jun-Jun Liu
For more information on this research, contact NRCan’s Science communications team.
Discover more:
More about Jun-Jun’s research on ResearchGate