ARS | Publication request: Variation in Solanum species’ tuber potassium accumulation and its implications for human nutrition

Submitted to: American Journal of Potato Research
Publication Type: Abstract Only
Publication Acceptance Date: April 1, 2007
Publication Date: February 1, 2008
Citation: Bamberg, J.B., Martin, M., Palta, J. 2008. Variation in Solanum species’ tuber potassium accumulation and its implications for human nutrition [abstract]. American Journal of Potato Research. 85:2.

Technical Abstract: High blood pressure (HBP) is the primary or contributing cause of about ¼ of all US deaths. HBP triples risk of heart disease and increases risk of congestive heart failure by six-fold. Estimated cost of HBP in 2005 = $60 billion. Most experts find link with Na highly conclusive. Potassium is regarded as the “sodium antidote” since it stimulates Na excretion. We consume 2-3 times the recommended daily Na and about half the 4,700 mg recommended daily K. Potato is a food uniquely positioned to mitigate HBP, since it is naturally high in K, consumed widely and regularly at high levels, and inexpensive. Current per capita consumption of potato = 700 mg K per day, about 1/3 of total. So even small gains in genetic potential for high tuber K could have great health impacts, with no consumer action needed except to maintain current potato consumption. We did preliminary screening of the US Potato Genebank mini-core collection (3 populations of each of 25 species) by tuberizing them in the greenhouse watered with either 90 ppm (low) or 460 ppm (high) K as potassium sulfate. Highly significant differences were found among species for tuber K. The highest species were acaule, chacoense, okadae and pinnatisectum at both doses. At low dose, okadae PI 458368 had higher tuber K than the average of cultivated accessions grown at high dose. If exotic genetic resources can be used to breed acceptable potato cultivars with higher tuber K, this could have an important impact on health, healthcare costs, and the demand for potato as compared to it’s food competitors.