Stability and Broad-Sense Heritability of Mineral Content in Potato: Copper and Sulfur

Sulfur and copper are important for human health. Sulfur deficiency is rare, but may occur in the elderly. However, a large percentage of the U.S. population is deficient in copper. The purpose of this study was to determine the range of values for sulfur and copper available in advanced potato germplasm and varieties and estimate how much genetic variation exists for these two elements. Potato breeding lines and varieties in three multisite trials were evaluated for copper and sulfur content by wet ashing and Inductively Coupled Argon Plasma Emission Spectrophotometer analysis. Stability and broad-sense heritability were determined. Among genotypes, copper content ranged from 2.0 to 4.5 ug-g⁻¹ DW. This was a 2.25-fold difference. In these three trials, environment was never significant, while genotype by environment interactions were always significant. Genotype was significant in two of the regional trials. Broad-sense heritabilities were estimated to be 0.0, 0.93 and 0.51 for the Tri-State, Western Regional Russet and Western Regional Red/Specialty trials, respectively. Among genotypes, sulfur content ranged from 991 to 1488 ug-g⁻¹ DW. The highest value was 50 % higher than the lowest. In these three trials, environment was never significant, while genotype x environment interactions were always significant. Genotype was significant in two of the regional trials. Broad-sense heritabilities were estimated to be 0.53, 0.68 and 0.88, for Tri-State, Western Regional Russet, and Western Regional Red/Specialty trials, respectively. For both sulfur and copper, selection in the Western Regional Russet and Western Regional Red/Specialty trials is likely to lead to an increase in content. Selection for sulfur in the Tri-State would result in a gain as well. These results suggest that genetic improvements could be made to potato to enhance the concentrations of these minerals.