2025 Forest Genetics Conference
The PA/NJ chapter of The American Chestnut Foundation was thrilled to be involved with this year’s Forest Genetics Conference. Our own Lake Graboski (TACF North Central Regional Science Coordinator) gave an engaging tour of the American chestnut orchard at Penn Nursery where he discussed previous and ongoing work in the restoration of the American chestnut tree.
The older trees in the orchard, planted beginning in 2012, were intended as a restoration seed orchard of disease-resistant American chestnuts. They represent the “B3F3” generation from The American Chestnut Foundation (TACF) and include diverse genetic backgrounds from across Pennsylvania. In partnership with DCNR, TACF will cull trees for both form and blight resistance, ensuring only the best remain. Progeny from the site may then be planted on state forest lands as directed by PA DCNR.
The younger trees, planted last fall, are part of a replicated “All vs. All” experiment designed to directly compare different known blight-resistance mechanisms. These include resistance from: (1) large surviving American chestnut trees (LSAs); (2) Chinese/American backcross hybrids; and (3) genetically modified OxO (Darling 54) trees, which express the oxalate oxidase gene—though these have not yet been planted due to permitting delays. A separate replicate of these families has already been evaluated in greenhouse conditions using small stem assays (SSAs) to assess their blight response.
There was also a visit to Pennsylvania DCNR’s Mira Lloyd Dock Resource Conservation Center with an overview of the site’s century-long history of tree production. The nursery grows seedlings for reforestation and regeneration projects on state forests, as well as special projects on other DCNR lands. The tour included the Seed & Seedling Processing Building, where seeds collected from across Pennsylvania are cleaned, assessed, and prepared. Nursery Operations Manager Annetta Ayers and Forester Chris Neufer (both DCNR, BOF) provided an overview of the workflow and shared insights from their extensive experience producing high-quality seedlings for Pennsylvania’s forests. All bare-root seedlings are counted, packaged, and stored for spring planting in this nearly 100-year-old building.
The nursery also hosts a variety of smaller projects, including support for native plant landscaping, tree breeding for pest and disease resistance, and provenance trials to guide seed transfer and assisted migration for future forest resilience. Forest Health Geneticist Amanda Penn (DCNR BOF) introduced several of these current projects and set the stage for the project-specific stops on the tour.
