Download (PDF 203 KB): https://research.fs.usda.gov/download/treesearch/54004.pdf
Abstract
A strong focus on tree germplasm that can resist threats such as non-native insects and pathogens, or a changing climate, is fundamental for successful conservation efforts. This project is predicated on the fact that genetic resistance is the cornerstone for protecting plants against pathogens and insects in environments conducive to the attacking organisms, a principle we have extensively applied to the study of coast live oak (CLO –
Quercus agrifolia) interactions with
Phytophthora ramorum in California wildlands. The largest obstacle to the implementation of host resistance as a tree health management tactic in forest environments, as well as for germplasm conservation, is the lack of tools for the rapid phenotyping of tree disease resistance in the field. Previously, in work conducted in Briones Regional Park, East Bay Regional Park District (EBRPD), Alameda County, California, we have demonstrated that the levels of soluble phenolics extracted from CLO trunk phloem can predict resistance to
P. ramorum by way of a logistic regression model that included total phenolics and four individual phenolic compounds: ellagic acid, a partially characterized ellagic acid derivative, and two chromatographic peaks representing two uncharacterized phenolic compounds (McPherson and others 2014a).
In vitro tests subsequently showed that ellagic acid was fungistatic against
P. ramorum and total phenolics were fungicidal at physiologically relevant concentrations.
Parent Publication
Citation
Bonello, Pierluigi (Enrico); Conrad, Anna O.; Saona, Luis Rodriguez; McPherson, Brice A.; Wood, David L. 2017. Vibrational spectroscopy-based chemometrics to map host resistance to sudden oak death. In: Frankel, Susan J.; Harrell, Katharine M., tech. coords. Proceedings of the sudden oak death sixth science symposium. Gen. Tech. Rep. GTR-PSW-255. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 29-30.
