APS Homepage

Poster: Biology & Disease Mgmt: Genetics of Resistance


Evaluating chemical fingerprinting as a tool to rapidly screen hybrid chestnut for resistance to pathogens
A. CONRAD (1), J. Westbrook (2), T. Zhebentyayeva (3), L. Rodriguez-Saona (4), P. Bonello (4), C. Nelson (5), A. Abbott (1) (1) University of Kentucky, U.S.A.; (2) The American Chestnut Foundation, U.S.A.; (3) Clemson University, U.S.A.; (4) The Ohio Stat

Chestnut blight, caused by the introduced pathogen Cryphonectria parasitica, continues to plague American chestnut (Castanea dentata) in the eastern US. Restoration is focused on breeding hybrids that morphologically resemble American chestnut but contain blight resistance from Chinese chestnut (C. mollissima). Compounding the problem for restoration efforts, Phytophthora cinnamomi, an agent of root rot, has emerged as a major pathogen in chestnut’s southern range. Time and resource intensive inoculation-based screening methods are used currently to identify chestnuts resistant to these pathogens. Therefore, we evaluated if chemical fingerprinting (CF), a potentially less resource-intensive tool for phenotyping resistant/susceptible trees, can be used to screen chestnut for disease resistance. A Varian 3100 Fourier-transform infrared (FT-IR) spectrometer equipped with an attenuated total reflectance accessory was used to fingerprint methanol extracts from 0-1 year old chestnut stem tissue that differed in susceptibility to chestnut blight. Using Soft Independent Modeling of Class Analogy, chemical differences among disease rating classes were identified and used to develop class discriminating models. Early results suggest that CF may be a useful tool for screening seedlings for blight resistance; however, we are currently testing additional samples to refine, optimize, and validate models for both diseases.