Breeding Beech Bark Disease Resistant American Beech

Research Issue

[photo:] Michigan Parks and Recreation Department staff and Friends of Ludington State Park Volunteers sorting beech bark disease resistant seedlings prior to planting at the Ludington State Park Beechwood Campground, to replace the hundreds of beech trees that succumbed to the disease. Photo by Elissa Buck, Michigan DNR, used with permission.The American beech tree is an easily recognized species with smooth, silver-gray bark that provides a tempting surface for lovers to carve their initials on. Since the late 1890s, beech bark disease caused by the scale insect Cryptococcus fagisuga has been attacking trees in North America, decreasing the productivity, health and biodiversity of our forests. The disease eventually kills most beeches. Trees that survive are often stunted and deformed.

Beech is a particularly important species for wildlife, providing food and habitat for over 40 species of birds and mammals. Beech branches are a preferred nesting site for many birds and the hollowed-out trunks of large beeches provide a home for raccoons, squirrels and foxes. The high fat and protein content of beechnuts make them a critical part of the winter diet for ruffed grouse, wild turkey, wood ducks, northern bobwhite, black bear and many other species. This is especially true in northern hardwood forests where beech may be the only nut producing species.

Our Research

[photo:] Friends of Ludington State Park Volunteers planting a resistant American beech seedling at the Beechwood Campground. Photo by Elissa Buck, Michigan DNR, used with permission. We have made significant advances in breeding trees that are resistant to beech bark disease. We have developed protocols for testing resistance to the beech scale insect in potted grafts, seedlings, and beech trees in the field. Our ultimate goal is to help this critical species recover in our forests.
The feeding activity of the beech scale insect creates openings in the bark that allow infection by one of the Neonectria species of fungus, resulting in beech bark disease. Trees with resistance to the scale insect are therefore considered resistant to the disease. Genetic studies have shown that when two resistant parents are bred, at least half of the seedlings will be fully resistant. This is a substantial increase over the 1- 5 % of beech trees with natural resistance that are typically found in forests. We have also studied the genetic makeup of trees that are naturally resistant to beech bark disease.

Beech is a notoriously difficult species to breed and grow but we developed a hot-callus grafting technique that allows efficient, successful grafting of disease-resistant beeches. This method even works with cuttings from mature trees which are usually very difficult to graft. The development of these techniques along with results from the genetic studies provided the foundation for establishing regional beech seed orchards with genetically diverse, grafted, disease-resistant trees. 

We work collaboratively with many partners to survey forests infested with beech bark disease and identify surviving mature beeches. We field test these trees for resistance to the scale insect and harvest dormant branches for grafting at one of the regional seed orchards. As of 2018, there are beech orchards in Michigan, Ohio, West Virginia, Pennsylvania and Vermont. Once the orchard trees reach maturity, they will begin to produce seeds that can be planted in local forests. To speed up seed production, we are studying different methods of encouraging early flowering including introducing drought stress and providing light and hormone treatments.

Expected Outcomes

Regional seed orchards will capture and concentrate the natural genetic resistance to beech scale insect that is found in a small percentage of American beech trees. The seeds from these orchards will provide genetically diverse and regionally adapted seedlings for planting in forests where beech bark scale insects are present.

Research Results

Ćalić, Irina; Koch, Jennifer; Carey, David; Addo-Quaye, Charles; Carlson, John E.; Neale, David B. 2017. Genome-wide association study identifies a major gene for beech bark disease resistance in American beech (Fagus grandifolia Ehrh.). BMC Genomics. 18: 547. 14 p.

Koch, Jennifer L.; Carey, David W. 2014. A technique to screen American beech for resistance to the beech scale insect (Cryptococcus fagisuga Lind.). Journal of Visualized Experiments. e51515. 9 p.

Carey, David W.; Mason, Mary E.; Bloese, Paul; Koch, Jennifer L. 2013. Hot callusing for propagation of American beech by grafting. HortScience. 48(5): 620-624.

Koch, Jennifer L.; Heyd, Robert L. 2013. Battling beech bark disease: establishment of beech seed orchards in Michigan. Newsletter of the Michigan Entomological Society. 58 (1 & 2): 11-14.

Mason, Mary E.; Koch, Jennifer L.; Krasowski, Marek; Loo, Judy. 2013. Comparisons of protein profiles of beech bark disease resistant and susceptible American beech (Fagus grandifolia). Proteome Science. 11:2. doi:10.1186/1477-5956-11-2.

Koch, Jennifer L.; Mason, Mary E.; Carey, David W. 2012. Screening for resistance to beech bark disease: Improvements and results from seedlings and grafted field selections. In: Sniezko, Richard A.; Yanchuk, Alvin D.; Kliejunas, John T.; Palmieri, Katharine M.; Alexander, Janice M.; Frankel, Susan J., tech. coords. Proceedings of the fourth international workshop on the genetics of host-parasite interactions in forestry: Disease and insect resistance in forest trees. Gen. Tech. Rep. PSW-GTR-240. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture. pp. 196-208.

Koch, Jennifer L.; Carey, David W.; Mason, Mary E.; Nelson, C. Dana; Barakat, Abdelali; Carlson, John E.; Neale, David. 2011. Development of molecular tools for use in beech bark disease management. In: McManus, Katherine A; Gottschalk, Kurt W., eds. 2010. Proceedings. 21st U.S. Department of Agriculture interagency research forum on invasive species 2010; 2010 January 12-15; Annapolis, MD. Gen. Tech. Rep. NRS-P-75. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station: 38-40.

Koch, Jennifer L. 2010. Beech bark disease: the oldest "new" threat to American beech in the United States. Outlooks on Pest Management. April 2010: 64-68.

Koch, Jennifer L.; Carey, David W.; Mason, Mary E.; Nelson, C. Dana. 2010. Assessment of beech scale resistance in full- and half-sibling American beech families. Canadian Journal of Forest Research. 40: 265-272.

Koch, JL; Mason, ME; Carey, DW. 2007. Advances in breeding American beech for resistance to beech bark disease.  In: Proceedings of the 3rd Northern Forest Genetics Association Meeting: Tree Improvement in the 21st Century, Planning for the Future. A. David, comp., Univ of MN Dept. of For. Res. Staff Pap. Ser. No. 194: 22-28.

Research Participants

Principal Investigator

  • Jennifer Koch, Research Plant Pathologist, U.S. Forest Service, Northern Research Station

Research Partners

  • Last modified: September 11, 2018