Stability and Broad-sense Heritability of Mineral Content in Potato: Zinc

The mineral content of potato is an important consideration in the evaluation of its role in the human diet. Zinc content is vital due to its crucial role as a micronutrient. Zinc deficiency occurs among the poorest of the world's populations. In this study, 36 breeding lines and varieties (genotypes) were divided among three trials (Tri-State, Western Regional Russet and Western Specialty/Red) which were grown in 11 locations. Zinc content was measured in harvested tubers by wet ashing and passage through an Inductively Coupled Argon Plasma Emission Spectrophotometer Genotype mean zinc content ranged from 12 to 18 mu g g(-1) dry weight over all trials. In two of the three trials there were no significant differences among genotypes for zinc. Broad sense heritabilities for zinc content were small in these two trials. In the Western Regional Russet Trial there were significant differences among genotypes and the heritability was 0.61, suggesting that genotypes with higher zinc content could be selected. However, the largest zinc value was only 50% above the lowest value. Furthermore, a 100 g serving of the highest zinc genotype would only provide 4% of the adult Estimated Average Requirement From these results, potato from this breeding pool would not appear to be a good candidate for biofortification of zinc through traditional breeding. Higher values from other studies suggest that zinc biofortification through breeding may be warranted in potato for populations with high potato consumption and high risk for zinc deficiency in the Andes of South America.