Location: Vegetable Crops Research Unit
Title: A Test of Taxonomic Predictivity: Resistance to the Colorado Potato Beetle in Wild Relatives of Cultivated Potato Authors
Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 20, 2008
Publication Date: April 30, 2008
Citation: Jansky, S.H., Simon, R., Spooner, D.M. 2008. A test of taxonomic predictivity: resistance to the colorado potato beetle in wild relatives of cultivated potato. Phytopathology. 98:680-687. Interpretive Summary: The Colorado potato beetle is a serious insect pest in potato. It is currently controlled using pesticides. This study was carried out to identify resistance to the Colorado potato beetle in wild relatives of potato. In addition, we were interested in determining whether we could use information about species relationships or geographic distribution to predict where additional sources of resistance are likely to be found. High levels of resistance were identified in some species in which resistance has been previously reported and also in species in which resistance has not been previously found. These new sources of resistance are being used to create breeding clones with resistance to the Colorado potato beetle.
Technical Abstract: Wild relatives of potato offer a tremendous germplasm resource for breeders. Because the germplasm base of potato is so broad and diverse, we have undertaken a series of studies to determine whether we can predict the distribution of valuable genes in wild Solanum species based on taxonomic or biogeographic data. This is the third study in the series. Resistance to defoliation by Colorado potato beetle larvae was evaluated in 156 accessions of 41 wild Solanum species. The highest frequencies of resistant accessions were found in diploid species with an endosperm balance number of one. In contrast to previous studies on resistance to foliar fungal pathogens, there was little variability among plants within an accession and accessions within a species, at least for the most resistant species. Resistance was confirmed in species previously characterized by high levels of glycoalkaloids or dense glandular trichomes. However, we identified additional species with resistance to the Colorado potato beetle. Mechanisms of resistance are being studied in these species and attempts will be made to introgress them into the cultivated potato.