Location: Temperate Tree Fruit and Vegetable Research
2019 Annual Report
Accomplishments
1. New methods to increase phytonutrients in potatoes. Potatoes with increased phytonutrient concentrations are needed to ensure producers have products that appeal to changing markets and consumer preferences that prioritize nutritional value. A limitation of breeding even more nutritious potatoes is the lack of knowledge of the mechanisms that control amounts of phytonutrients like phenylpropanoids, which are highly desirable in the diet, but low in most white potatoes. ARS researchers in Prosser, Washington, and scientists at Washington State University, identified genes and a microRNA that control the amount of health-promoting phenylpropanoids in potatoes. These discoveries reveal new opportunities to breed potatoes with increased phytonutrients that not only appeal to health-conscious consumers, but improve plant stress resistance, appearance, and flavor.
2. Impact of ‘Candidatus Liberibacter solanacearum’ haplotypes A and B on plant emergence from infected potato. Zebra chip is an economically devastating disease of potato in the U.S., where two Lso haplotypes (A and B) cause vascular darkening and necrotic flecking that render the potatoes unmarketable. ARS researchers in Prosser and Wapato, Washington, identified differences in plant emergence and daughter tuber yield produced from seed potato tubers infected with either Lso A or B and healthy control seed. Plant emergence from Lso A and B infected seed potato were slower to emerge, had lower overall rates of emergence, and produced reduced tuber numbers and yield compared to the healthy seed. Seed potato infected with Lso B generally had lower plant emergence and daughter tuber production compared to seed potato infected with Lso A, confirming earlier analyses that identified Lso B as a more severe haplotype. The results from this study indicate that potato tuber seed infected with either Lso A or B should not be a significant concern to growers, as poor emergence allows plants emerging from healthy seed to outgrow and outproduce plants emerging from infected seed of either Lso haplotype.
3. Cause of mysterious disease-like symptoms in Columbia Basin potatoes is not caused by a pathogen. Some potatoes grown in the Columbia Basin in the last few years have shown unusual symptoms of unknown origin, raising alarm in the industry that this may be due to a new, emerging disease. ARS researchers in Prosser, Washington, collected potato foliar tissue from commercial and research plots throughout the Columbia Basin of Washington and Oregon that showed leaf purpling, leaf deformity and necrotic stem lesions. Molecular diagnostic analyses to detect known pathogens and greenhouse grafting analyses to determine if infected tissue could transmit symptoms to the healthy plants was performed. Two years of molecular diagnostics did not identify a known pathogen associated with all symptomatic plants, and grafting analyses did not show transmission of the disease symptoms to healthy plants. These results suggest that the cause of the mysterious disease-like symptoms in the Columbia Basin is not pathogenic in nature, suggesting that an insect pest or environmental stimuli is likely responsible, providing critical answers to potato growers worried about a spreading disease.
Review Publications
Shock, C., Brown, C., Sathuvalli, V., Charlton, B., Yilma, S., Hane, D., Quick, R.A., Rykbost, K., James, S., Mosley, A., Feibert, E., Whitworth, J.L., Novy, R.G., Stark, J., Pavek, M., Knowles, R., Navarre, D.A., Miller, J., Holm, D., Jayanty, S., Debons, J., Vales, I., Wang, X., Hamlin, L. 2018. TerraRossa: A mid-season specialty potato with red flesh and skin and resistance to common scab and golden cyst nematode. American Journal of Potato Research. 95(5):597-605. https://doi.org/10.1007/s12230-018-9667-8.
Navarre, D.A., Sathuvalli, V., Brown, C. 2019. Potato vitamins, minerals and phytonutrients from a plant biology perspective. American Journal of Potato Research. 96(2):111-126. https://doi.org/10.1007/s12230-018-09703-6.
Bali, S., Patel, G., Novy, R.G., Vining, K., Thompson, A., Brown, C., Holm, D., Porter, G., Endleman, J., Sathuvalli, V. 2018. Evaluation of genetic diversity among Russet potato clones and varieties from breeding programs across the United States. PLoS One. 13(8): e0201415. https://doi.org/10.1371/journal.pone.0201415.
Si, M., Navarre, D.A. 2018. Optimization of hairy root induction in solanum tuberosum. American Journal of Potato Research. 95(6):650-658. https://doi.org/10.1007/s12230-018-9671-z.
Sun, X., Du, M., Navarre, D.A., Zhu, M. 2018. Purple potato extract promotes intestinal epithelial differentiation and barrier function by activating AMP-activated protein kinase. Molecular Nutrition and Food Research. 62(4):1700536. https://doi.org/10.1002/mnfr.201700536.
