Postdoctoral Fellowship: PRFB: American Beech Tree Diversity, Disease Resistance, and Outreach

This action funds an NSF Plant Genome Postdoctoral Research Fellowship in Biology for FY 2024. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Michelle Neitzey is “American Beech Tree Diversity, Disease Resistance, and Outreach” The host institution for the fellowship is the University of Connecticut and the sponsoring scientist is Dr. Jill Wegrzyn.

U.S. forests, valued for their carbon sequestration, wildlife habitat, and human recreation, are widely threatened by climate change and pests. Scientists and conservation managers are working together to improve both climate and pest resistance in trees. Knowledge of a species genetic diversity, in association with climate and resistance variables, can expedite the future-proofing process.

American Beech is a dominant forest species that spans most of the eastern US. For decades beech trees have been threatened by Beech Bark Disease (BBD); they are now facing an even greater threat–Beech Leaf Disease (BLD)–which arrived in 2012 and is leading to massive die-offs. This project will assess the genetic diversity of beech and potential disease resistance genetic mechanisms in conjunction with conservation managers.

Broader impacts include the generation of public digital resources, including expansion of the TreeSap mobile application (https://treesap.info/) to assist in collecting materials and education about tree diseases. Training objectives include acquiring skills in plant pathology, population and landscape genomes as well as in public engagement through citizen science and networking with conservation managers.

American beech (Fagus grandifolia Ehrh.), a native forest tree of North America, is facing significant threats from invasive pathogens. BBD and the emergent BLD are threatening major portions of the species range. This project will provide the first genomic estimates of F. grandifolia range-wide genetic diversity, population structure, signatures of local adaptation, and estimates of genetic offset, as well as look for the first genetic signs of BLD resistance candidate loci and further investigate BBD resistance.

This will be achieved through two aims. The first involves a landscape-level assessment of neutral and adaptive variation utilizing the recently assembled F. grandifolia genome and connections with field-based organizations to collect and sequence range-wide samples guided by the U.S. Environmental Protection Agency’s (EPA) Level III Ecoregions (https://www.epa.gov/eco-research/level-iii-and-iv-ecoregions-continental-united-states).

This aim will facilitate analyses of the genetic diversity, population structure, and demographic history of individual trees that will be used to identify signatures of local adaptation and estimates of genetic offset. The second aim involves a pangenome-level assessment of BBD and BLD disease resistant and susceptible individuals. Leveraging existing gardens and recently established BLD inoculation experiments hosted by the Holden Arboretum, the project will generate a pangenome from F. grandifolia trees that display signatures of strong resistance and susceptibility to BLD and BBD.

These genomes will be interrogated for structural and presence-absence variation that may contribute to signatures of resistance. Metadata from sample collections will be available on CartograPlant (https://treegenesdb.org/ct/), and all genomic sequencing data and derived products will be shared freely on NCBI.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.