Butternut is a medium-sized tree native to the eastern U.S. that produces a large, tasty nut; unfortunately butternut is threatened by an exotic fungal disease called butternut canker.
Through collaboration with local and regional public and private landowners we have identified and propagated over one-hundred butternuts that appear to have improved resistance to butternut canker disease, and we are preparing to characterize their resistance in replicated trials. We are also using DNA-based analysis of the nuclear and chloroplast genomes of butternut to understand the genetic diversity and regional genetic structure of butternut. We have found that some of the apparently canker-resistant butternut trees are in fact hybrids between butternut and Japanese walnut, an exotic species that was introduced into the U.S. in the 1860s. These hybrid trees may represent the vanguard of a hybrid invasion that threatens butternut conservation efforts.
We expect ultimately to determine if true (non-hybrid) butternuts have sufficient resistance to butternut canker to initiate a breeding program for resistance to butternut canker. Our goal is the reintroduction of regionally adapted, resistant butternut to the eastern North American forest.
Ostry, M. E.; Moore, M. 2007. Natural and experimental host range of Sirococcus clavigignenti-juglandacearum. Plant Disease 91(5):581-584.
Michler, C.H., Pijut, P.M., Jacobs, D.F., Meilan, R., Woeste, K.E. and Ostry, M.E. 2006. Improving disease resistance of butternut (Juglans cinera), a threatened fine hardwood: a case for single-tree selection through genetic improvement and deployment. Tree Physiology 26:121-128.
- Keith Woeste, USDA-Forest Service- NRS Research Plant Molecular Geneticist
- Mike Ostry, USDA-Forest Service- NRS Participating Scientist
- Jim McKenna, USDA-Forest Service- NRS Participating Professional Biologist
- The Nature Conservancy
- Canadian Forest Service
- Paul Berrang, USDA-Forest Service, Region 9 Geneticist
- Purdue University
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