Patterns of cadmium uptake and accumulation by exclusion and inclusion soybean cultivars

Abstract

In the areas where the soils are polluted by cadmium (Cd), farmers cannot afford to use their lands for remediation due to high demand for soybean (Glycine max L.) production. In order to provide information for safe soybean production and achieve the phytoremediation using the root at the meantime, four soybean cultivars (mentioned as Cd excluder and Cd includer) differing in seed Cd accumulation were grown in a mixed growing media treated with different Cd concentrations (0 and 0.35 mg kg −1 ) in a growth cabinet. The biomass and Cd concentration in roots, stems, leaves, pods, and seeds were measured at the beginning of seed development (R5) and maturity (R8) stages; accumulation coefficient and translocation coefficient of Cd in different organs were calculated. Cadmium concentration in seeds was positively correlated with the Cd concentration in stem, leaf, and pod. Cadmium concentration in the roots of the Cd excluder was significantly higher than that in the Cd includer at the R5 and R8 stages; however, the Cd concentration in the seeds of the Cd includer was higher than that in the Cd excluder. Compared with the Cd excluder, more Cd was transported from the root to the aboveground organs of Cd includer. This suggests that Cd excluder with high cadmium accumulation in the root and low accumulation in the seed could provide a possible way to develop Cd-safe cultivars with high phytoremediation capacity when grown on Cd-polluted lands.