Location: Vegetable Crops ResearchTitle: Plant resistance to Colorado potato beetle (Coleoptera: Chrysomelidae) in diploid F2 families derived from crosses between cultivated and wild potato Author
|Crossley, Michael - University Of Wisconsin|
|Schoville, Sean - University Of Wisconsin|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/2018
Publication Date: 4/24/2018
Citation: Crossley, M.S., Schoville, S., Haagenson, D., Jansky, S.H. 2018. Plant resistance to Colorado potato beetle (Coleoptera: Chrysomelidae) in diploid F2 families derived from crosses between cultivated and wild potato. Journal of Economic Entomology. https://doi.org/10.1093/jee/toy120.
DOI: https://doi.org/10.1093/jee/toy120 Interpretive Summary: The Colorado potato beetle continues to be a serious pest of potato. It is typically controlled with pesticides, but host plant resistance is present in some wild potato germplasm. The breeding of resistant potato varieties offers a long term, environmentally friendly management strategy. This paper reports on the identification of resistance in two populations of cultivated x wild potatoes. It also documents the need for breeders to account for differences in insect populations when developing resistant germplasm.
Technical Abstract: Colorado potato beetle, Leptinotarsa decemlineata Say, is a serious pest of potato, Solanum tuberosum L., worldwide. Management of L. decemlineata has relied heavily on insecticides, but rapid and repeated evolution of insecticide resistance has motivated the exploration and development of alternative strategies, such as host plant resistance. The recent development of two diploid potato families derived from crosses between cultivated and wild potato (S. chacoense and S. berthaultii) has provided a unique opportunity to re-visit opportunities and challenges for resistance breeding. In this two-year study, we surveyed select F2 clones for the induction of L. decemlineata mortality and a reduction in defoliation in no-choice feeding assays when challenged with adults and larvae from three sites in Wisconsin. We also tested for an association with glandular trichome density and foliar levels of the glycoalkaloids chacocine and solanine. We found several potato clones with apparent resistance in specific feeding assays, but none that excelled consistently across assays. Mortality and defoliation generally differed significantly among L. decemlineata populations, which could be indicative of heritable variation in beetle responses to plant defenses or variation in the physiological status of the beetle populations tested. Contrary to expectations, higher trichome density increased mortality or decreased defoliation only in a few cases, and levels of mortality and defoliation were unrelated to foliar glycoalkaloid content, warranting further investigation of the defense mechanisms of resistant clones. In addition to identifying several potential L. decemlineata resistance sources, this study underscores the need to include multiple insect populations in surveys of host plant resistance to this diverse pest species.