Around 1904, with the introduction of the Chinese Chestnut Blight (Cryphonectria parasitica) the American Chestnut (Castanea dentata (Marsh.)Borkh.) populations were decimated. In this study our goal is to provide new insights into mechanisms that may enhance blight resistance in the American Chestnut tree through the understanding of the interaction between the trees and their surrounding soil microbiome.
For this we 1) used oral history and maps generated by the American Chestnut Society to document/confirm the location of individual plants in our vicinity; 2) among individuals found, documented healthy versus blight infected individuals; 3) characterized putative differences in the soil microbiome with distance to infected and non-infected individuals, as well as between chestnut plants and hardwood neighbors.
We collected soil samples 1 m north of the base of each chestnut tree and 1 m from the base of one hardwood tree within 5 m of the chestnut and aligned to one cardinal direction. DNA was extracted from soil samples using commercially available DNA extraction kits and outsourced for analysis. DNA analysis is organized by genus in order to identify the species of fungi and other microbes that are present in each sample.
Results/Conclusions
Thirty-two individual wild American Chestnut trees have been identified using this method, with a yet undetermined number of additional unverified trees also available for study. Given the rarity of this species, this sample size of thirty-two is significant to the ongoing restoration efforts of the species. The majority of the thirty-two confirmed trees are previously unknown individuals that greatly aid in efforts to research and restore the species. Of the thirty-two known trees, one is currently known to be infected with the Chinese Chestnut Blight.