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ARS Home » Midwest Area » Madison, Wisconsin » Vegetable Crops Research » Research » Publications at this Location » Publication #352983
Research Project: Maximizing the Impact of Potato Genebank Resources: Development and Evaluation of a Wild Species Genotype Diversity Panel

Location: Vegetable Crops Research

Title: Considerations for Selecting Disease Resistant Wild Germplasm (Solanum spp.): Lessons From a Case Study of Resistance to Bacterial Soft Rot and Colorado Potato Beetle

Author
item CHUNG, YONG SUK - Jeju National University
item Jansky, Shelley

Submitted to: Genetic Resources and Crop Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/7/2018
Publication Date: 8/28/2018
Citation: Chung, Y., Jansky, S.H. 2018. Considerations for Selecting Disease Resistant Wild Germplasm (Solanum spp.): Lessons From a Case Study of Resistance to Bacterial Soft Rot and Colorado Potato Beetle. Genetic Resources and Crop Evolution. (2018) 65:2287–2292. https://doi.org/10.1007/s10722-018-0682-x.
DOI: https://doi.org/10.1007/s10722-018-0682-x

Interpretive Summary: Because large numbers of samples are present in genebanks, it would be helpful to have a strategy to systematically search for traits of interest. Previous studies have not been able to predict resistant accessions based on biogeographic or taxonomic data. In this paper, we discuss a reason for our inability to predict the presence of a resistance trait. In natural environments, a plant population is simultaneously exposed to multiple stresses. Interactions among pests and pathogens may influence the array of resistance traits in a plant population. We found that accessions susceptible to a foliar feeding insect were resistant to a bacterial pathogen. We propose that insect damage causes wounds that allow the pathogen to penetrate. Consequently, resistance to the pathogen is important for survival. This research will benefit users of genebank germplasm by providing insights into strategies for identifying resistant accessions.

Technical Abstract: Predictions of distributions of resistance phenotypes have been attempted for major diseases in wild potato germplasm. Interestingly, no consistent taxonomic or biogeographic predictors have been identified. However, an important lesson learned was that there are interactions among host plants, environmental factors, and characters of the pathogens. A logical extension of the predictivity project is to examine the dynamics of resistances when multiple biotic stresses are involved. In this study, we found that populations susceptible to a foliar feeding pest (Colorado potato beetle, Leptinotarsa decemlineata) are resistant to a bacterial pathogen (Pectobacterium subsp. carotovorum). We propose that wounds caused by the insect pest allow the bacterial pathogen to gain entry and cause disease. This would lead to strong selection pressure for resistance to the bacterial pathogen. Consequently, when searching for traits of interest in germplasm collections, it is important to consider the complex environments in which the source populations evolved.