Genetic Variances and Selection Potential for Selenium Accumulation in a Rapid-cycling Brassica oleracea Population

Beneficial effects of selenium (Se) can be delivered to humans through enriched plant foods. Plants in the Brassicaceae are good sources of sulfur (S) and can be enriched with Se. Breeding plants to be more efficient at Se accumulation may complement enrichment efforts. Because Se and S are chemically similar and can compete in plant metabolic pathways, S levels must be considered when attempting to manipulate Se, and vice versa. The objectives of this study were to establish genetic variances for S and Se accumulation, and to determine if simple recurrent selection could be used to manipulate Se accumulation in a rapid-cycling (Brassica oleracea L.) population. Progeny from a North Carolina Design II mating scheme were grown in two seleniferous environments and expressed variability for Se and S accumulation. Narrow sense heritability estimates for Se and S accumulation were moderate (0.55 to 0.75), which suggested progress was possible. However, standard errors were large and may influence expected progress during improvement efforts. Plants of a rapid-cycling B. oleracea were also subjected to two cycles of divergent selection for Se accumulation in leaf tissues. Realized heritabilities were high during selection for both high and low Se accumulation. Simultaneous evaluation of all populations revealed actual gains from selection to be 4.8% and 4.0% per selection cycle for high and low Se accumulation, respectively. Predicted gains for Se accumulation in the plants were 6.8%. Selection for Se accumulation was successful and indicates population improvements for such traits are possible within the B. oleracea analyzed. Breeding plants that are more efficient at accumulating Se could be a useful tool towards Se enrichment.