Title: Stability and broad-sense heritability of mineral content in potato: potassium and phosphorus Authors
|Moore, Martin -|
|Hane, Dan -|
|Pavek, Mark -|
|Lowe, Steven -|
Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 1, 2013
Publication Date: June 27, 2013
Citation: Brown, C.R., Haynes, K.G., Moore, M., Hane, D., Pavek, M., Lowe, S., Novy, R.G. 2013. Stability and broad-sense heritability of mineral content in potato: potassium and phosphorus. American Journal of Potato Research. DOI: 10.1007/s12230-013-9323-2. Interpretive Summary: Potatoes are a good source of many nutrients not least of which are minerals. In general consumption of fruits and vegetables is good means to obtain minerals. But potatoes are overachievers when it comes to potassium. The adult human body needs 4500 mg of potassium per day to achieve its recommended dietary allowance. Potassium is a co-factor in many enzymatic reactions. The body maintains a fairly narrow range of potassium in the blood stream, with the kidneys providing the gatekeeper to retain or eliminate. Deficiency in potassium can be the cause of irregular heart activity. A potato weighing 100 grams provides 500 mg or one-ninth of the RDA. A common mode of potato consumption provides one fourth of the RDA. Phosphorus is needed at one fifth the amount that potassium is needed and the amount provided by the potato is minor, but phosphorus is the second most common in the human body due to its being a major structural constituent of the bones. This study showed that it is possible to increase both phosphorus and potassium in potato by selection within certain breeding populations. This could be important especially for potassium which is needed in high amounts and can be provided by potato which is the most potassium dense vegetable. An increase in potato would make satisfying the potassium RDA with potato even more efficient.
Technical Abstract: In the study of nutritional variability in potato it is desirable to know the present range of expression and genetic potential for increase. Potato breeding lines and varieties in two separate trials were evaluated for potassium and phosphorus content by wet ashing and Inductively Coupled Argon Plasma Emission Spectrophotometer analysis. Stability and broad-sense heritability were determined. Among genotypes, potassium content ranged from 1.85 and 2.49 percent DW while phosphorus content ranged from 0.16 to 0.34 percent DW over both trials. Genotype by environment interactions were significant in the Tri-State and Western Regional Red/Specialty (WR-R/SP) trials for both potassium and phosphorus, while environments were not. Genotype was a significant source of variation for both minerals in the WR- R/SP trial only. In the Tri-State trials, 7 and 4 of ten clones were unstable before and after removal of environmental heterogeneity, respectively, for potassium content, and 5 and 4 genotypes were unstable before and after removal of environmental heterogeneity, respectively, for phosphorus. In the WR-R/SP Trials, 7 and 3 of 13 clones were unstable before and after removal of environmental heterogeneity, respectively, for potassium content, and 3 and 4 genotypes were unstable before and after removal of environmental heterogeneity, respectively, for phosphorus. Broad sense heritability was low for both potassium and phosphorus in the Tri-State Russeted-Skin Trials but high for both potassium and phosphorus in the WR-R/SP Trials. Although potato is a minor contributor of phosphorus to the human diet, it is an important source of potassium. Adult males and females receive 12 % of the Recommended Dietary Allowance of potassium from 100 g of potato. Estimates of broad-sense heritability from these two trials suggest that genotypes with higher levels of both potassium and phosphorus can be selected from within the Red/Specialty market class, but not from within the Tri-State russet class. An increase in potassium content in the potato, for which the daily need in the human body is so high, could be a boon to human health.