Abstract:

In this article, we investigated effects of lead and cadmium on the biomass of ginkgo seedlings, and roles of the seedlings in accumulation characteristics of the heavy metals and remediation of the soil comtaminated by Cd²⁺ or Pb²⁺ as well as their combination. The results showed that both Cd²⁺ and Pb²⁺ significantly or very significantly reduced biomass increment of ginkgo seedlings, with Pb²⁺ more adverse than Cd²⁺. The Cd²⁺-Pb²⁺ combined pollution further reduced biomass increment of ginkgo seedlings. The mass fractions and enrichment coefficient of Pb²⁺ and Cd²⁺ in ginkgo seedlings were in an order of root>stem>leaf, which was in favor of transportation Pb²⁺ and Cd²⁺ from root to stem and leave. The Cd²⁺-Pb²⁺ compound pollution promoted ginkgo seedling absorbtion to Cd²⁺ and Pb²⁺. The capacityof the upward transport of Pb²⁺ was greater than that of Cd²⁺, which suggested an obvious dose-effect and synergistic effect. Cd²⁺ and Pb²⁺ accumulations in ginkgo seedlings were relatively large The accumulation in roots was higher than that in stems and leaves. The ability of the absorption, transportation and accumulation of ginkgo seedlings to Pb²⁺ was relatively greater under Cd²⁺-Pb²⁺ compound pollution. The phytoremediation efficiency of Cd²⁺ and Pb²⁺ was relatively high.

Key words: Ginkgo seedlings, heavy metals, Pb, Cd, accumulation characteristics, soil remediation