Saving the Butternut
- Science Theme:
- Sustaining Forests
- Science Topic
- Understanding the ecological roles of natural disturbance
The butternut tree (Juglans cinerea), a member of the walnut family, has been prized over centuries for its beautiful, easily carved wood and its delicious nuts. It is a source of traditional medicines, fabric dye, syrup and oil for people, and food and shelter for wildlife. Although it is not a common tree, it is found in most of the eastern United States and southeastern Canada.
The butternut is being attacked throughout its range by the fungus Ophiognomonia clavigignenti-juglandacearum, which causes dead spots on the bark known as cankers. Over time, the cankers multiply and kill the tree. The fungus is thought to be non-native to North America and may have been introduced on imported walnut trees from Asia. It is spread over short distances by rain splashes and over longer distances by insects.
Butternut canker has been known to kill every butternut tree in a forest, but occasionally individual trees survive for long periods of time. These surviving trees show some natural resistance to the fungus and are the focus of our research program.
Northern Research Station scientists have done extensive research on the biology of the butternut canker fungus, how trees respond to the fungus, and what might make individual trees able to resist the fungus successfully.
- We breed and grow butternut trees that have natural resistance to the canker fungus. We evaluate the inherited disease resistance of seedlings grown from these parents.
- Through resistance screening and field evaluations of healthy trees, we have identified traits such as bark texture and color that are linked to high levels of disease resistance. We are also investigating bark chemistry and genetic markers that may be linked to resistance in order to help identify disease-resistant trees.
- Butternut naturally hybridizes (cross-breeds) with the Japanese walnut (J. ailantifolia) and the resulting trees appear to be more resistant to the disease. We are using genetic tests to identify hybrid trees and evaluate them for use in breeding.
- Various forest management strategies are being tested to save and grow butternut. We have found that site differences are important – for example, trees on drier upland sites may be less prone to disease.
- We have studied the survival of butternut canker fungal spores in forests and investigated the possible role of insects in the dispersal of the disease.
The goal of our research is to identify butternut trees with canker resistance, understand how the butternut canker fungus spreads, evaluate breeding populations of butternut trees, and develop healthy butternut trees so that we can restore the species in forests over time.
Morin, Randall S.; Gottschalk, Kurt W.; Ostry, Michael E.; Liebhold, Andrew M. 2018. Regional patterns of declining butternut (Juglans cinerea L.) suggest site characteristics for restoration. Ecology and Evolution. 8(1): 546-559. https://doi.org/10.1002/ece3.3641
Crystal, Philip A.; Lichti, Nathanael I.; Woeste, Keith E.; Jacobs, Douglass F. 2016. Vegetative and adaptive traits predict different outcomes for restoration using hybrids. Frontiers in Plant Science. 7: 1741. 11 p. http://dx.doi.org/10.3389/fpls.2016.01741
LaBonte, N. R.; Ostry, M. E.; Ross-Davis, A.; Woeste, K. E. 2015. Estimating heritability of disease resistance and factors that contribute to long-term survival in butternut (Juglans cinerea L.). Tree Genetics & Genomes 11(3): 63.
Moore, M. J.; Ostry, M. E. 2015. Influence of temperature and humidity on the viability of Ophiognomonia clavigignenti-juglandacearum conidia. Plant Disease 99:1841-1846.
Moore, M. J.; Ostry, M. E.; Hegeman, A. D.; Martin, A. C. 2014. Inhibition of Ophiognomonia clavigignenti-juglandacearum by Juglans species bark extracts." Plant Disease 99: 401-408.
McKenna, J. R.; Ostry, M. E.; Woeste, K. 2011. Screening butternut and butternut hybrids for resistance to butternut canker. 17th Central Hardwood Tree Improvement Conf., Lexington, KY, GTR-NRS-P-78 U.S. Dep. Agric. For. Serv. NRS, Newtown Square, PA.
Zhao, P.; Woeste, K. E. 2010. DNA markers identify hybrids between butternut (Juglans cinerea L.) and Japanese walnut (Juglans ailantifolia Carr.). Tree Genetics & Genomes 7(3): 511-533.
- Melanie Moore, US Forest Service -- Northern Research Station, Biological Technician
- Michael E. Ostry, US Forest Service -- Northern Research Station, Research Plant Pathologist (retired)
- Jim McKenna, US Forest Service -- Northern Research Station, Biologist
- Keith Woeste, US Forest Service -- Northern Research Station, Research Plant Molecular Geneticist
- Paul Berrang, US Forest Service -- Eastern Region , Geneticist
- John Lampereur, US Forest Service -- Eastern Region, Silviculturist
- James Jacobs, US Forest Service -- Forest Health Protection, Plant Pathologist
- Last modified: May 6, 2019