POTATO GERMPLASM ENHANCEMENT THROUGH TRAIT DISCOVERY, GENETIC EVALUATION AND INCORPORATION
Location: Vegetable and Forage Crops Production Research
Title: Stability and broad-sense heritability of mineral content in potato: Iron
Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 15, 2010
Publication Date: June 15, 2010
Citation: Brown, C.R., Haynes, K.G., Moore, M., Pavek, M.J., Hane, D.C., Love, S.L., Novy, R.G., Miller, Jr, J.C. 2010. Stability and Broad-sense Heritability of Mineral Content in Potato: Iron. American Journal of Potato Research. 87: 390–396.
Interpretive Summary: Iron is an essential micronutrient in the human diet. Children and women of child-bearing age are particularly vulnerable to iron deficiency. About 6 % of the US population suffers from iron deficiency, while 40% of the world's poorest populations are iron deficient. The effects of iron deficiency include stunting of growth, lower cognitive capacity, and lifelong generally poor health. Potatoes are a modest contributor of iron to the human diet. A single serving may supply 6 % of the recommended daily requirment. Americans obtain 2 % of their dietary need from potato. This study shows that there is considerable range of iron content in modern advanced breeding lines. The heritability, or the ratio of variability that is explained by genes, is rather high. Thus it appears that selection among available experimental variability would lead to an increase. It is likely that iron content could be increased by two to three times if this were a high priority goal in the selection program. Iron is subject to inhibitors of absorption into the gastrointestinal tract. Common ingredients of food legumes and small grains, polyphenols and phytic acid, respectively, are strong inhibitors of iron absorption. Potato, in contrast has little of these two classes, and a high content of the the best booster of iron absorption, vitamin C. A high iron potato would be most likely be a good source of highly available iron in the diet. Furthermore, potato is the vegetable with the highest level of consumption in the US. It is a popular and efficient means to add iron to the diet.
Iron deficiency in humans occurs in all regions of the world. Potatoes are a modest source of iron. The purpose of this study was to determine if genetic variation for potato tuber iron content exists.
Iron content in potato was measured in 33 clones, including varieties and advanced breeding selections, in three trials (Tri-State, Western Regional, Western Specialty/Red, ) which in total were grown in twelve environments. In two trials significant clone x environment interaction occurred. Thirteen clones contributed significantly to this clone x environment interaction, making them unstable across environments, including the variety Russet Burbank. Broad-sense heritabilities and their 95% confidence intervals in the Tri-State, Western Regional and Western Specialty/Red Trials were 0.00 (0.00, 0.38), 0.64 (0.17, 0.87), and 0.73 (0.25, 0.90), respectively. Overall the range of mean iron content on a clonal basis was 17 to 62 ug per gram dry weight. The upper limit is three times higher than generally reported values of potato.. The five highest values were found in the Western Specialty/Red trial and were red-skinned, white-fleshed clones. These results suggest that genetic variation for tuber iron content exists and that breeding for enhanced iron content would be feasible.