ARS | Publication request: A test of taxonomic and biogeographic predictivity: Resistance to soft rot in wild relatives of cultivated potato

Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 12, 2010
Publication Date: January 21, 2011
Citation: Chung, Y.S., Jansky, S.H., Spooner, D.M. 2011. A test of taxonomic and biogeographic predictivity: Resistance to soft rot in wild relatives of cultivated potato. Phytopathology. 101(2):205-212.

Interpretive Summary: Taxonomy is the theory and practice of describing, naming, and classifying organisms into related groups. Taxonomy has many uses, but perhaps one of the most useful is to serve as a predictive tool. That is, it is assumed that related organisms share traits, and breeders interested in choosing potential sources of disease resistant plants use taxonomy as a guide. This study was designed to test this prediction idea by associating disease resistance of wild potatoes to a bacterial pathogen that causes potato tuber soft rot. We also tested associations of potato taxonomy to biogeography, with the potential that closely spaced populations or populations sharing habitats shared disease resistances. No consistent association was observed between soft rot resistance and taxonomy or biogeography. However, species distributed across a wide range of habitats were more resistant than other species.

Technical Abstract: The concept that traits should be associated with related organisms and that nearby populations of the same species is likely to be more similar to each other than to populations spread far apart has long been accepted. Consequently, taxonomic relationships and sometimes geographical data are commonly believed to have the power to predict the distribution of disease resistance genes among plant species. We here test claims of such predictivity in a group of widely distributed wild potato species and suggest that there is no clear association of either factor. Instead, high levels of phenotypic plasticity among species may be related to resistance.