Tuber calcium accumulation in the wild potato Solanum microdontum

Authors: Bamberg, John; PALTA, JIWAN - University Of Wisconsin; ATUCHA, AMAYA - University Of Wisconsin; DEL RIO, ALFONSO - University Of Wisconsin

Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/9/2024
Publication Date: 9/23/2024
Citation: Bamberg, J.B., Palta, J., Atucha, A., Del Rio, A. 2024. Tuber calcium accumulation in the wild potato Solanum microdontum. American Journal of Potato Research. Potato Res. (2024)6-10. https://doi.org/10.1007/s12230-024-09970-6.
DOI: https://doi.org/10.1007/s12230-024-09970-6

Interpretive Summary: The US potato crop produces a remarkable yield of nutritious food every year. But USDA and state partners are working on making it even better. A key way to do that is to breed better varieties. The US Potato Genebank (USPG) at Sturgeon Bay, Wisconsin has about 6,500 samples of wild and cultivated potato for use for raw materials to support that breeding effort. This includes samples of the wild species Solanum microdontum (mcd). Previous reports suggested that some mcd accumulate very high levels of calcium in their tubers when plants are grown in a high-calcium soil. Such levels of calcium are trivial for human nutrition, but make a big improvement in a potato's ability to resist rotting diseases and avoid defects like discolored or hollow tubers due to heat and drought stress. When we tested a set of plants crafted to be a comprehensive representation of the mcd species, several extremely-high-calcium individuals were identified. Since mcd is relatively closely-related to the potato of commerce, breeding this valuable trait into new varieties should be relatively simple and rapid. These elite individuals will also be valuable standards for basic studies aimed at better understanding the trait.

Technical Abstract: Solanum microdontum (mcd) is a tuber-bearing relative of commercial potato. Although wild, it has many attractive traits for breeding. Previous research has shown it has exceptional ability to sequester calcium in its tubers, a trait associated with tuber disease resistance and tuber quality. We used a set of mcd from 50 populations in the US Potato Genebank (USPG) shown to encompass most of the genetic diversity in the species, two individuals from each population. Tubers were produced in pots in the USPG greenhouse in two years, and freeze dried samples tested for calcium content. Some exceptionally high Ca accumulators were identified (especially clone mcd40B1 from PI 473166). Because other minerals were measured in the same tests, the highest accumulators for K, Mg, Zn in mcd were also identified. All the stocks tested are available in vitro from USPG for additional research and breeding.