关键词: 溶解性有机质, 提取方法, 来源, 组成, 生物有效性, 环境意义

Abstract: A hydroponic experiment was conducted to investigate the cadmium (Cd) tolerance of and the Cd transportation and accumulation in Salix matsudana. S. matsudana showed a relatively higher tolerance to Cd. Its growth was promoted by Cd when Cd concentration in the medium was 0.2 mg·L^-1. Phloem played an important role in the long distance Cd transportation from root to shoot. The top tissues of the plant had significantly higher Cd concentration (P<0.05) than the bottom tissues, and phloem had 14 times higher Cd concentration than xylem. Shoot had strong sustainable capability in accumulating Cd. The accumulated Cd in aboveground part, especially in leaves, accounted for 52%-62% of the total. Consequently, through cleaning out the fallen leaves of S. matsudana during its defoliation stage, soil Cd could be removed. S. matsudana would be a suitable plant for the phytoremediation of Cd-polluted soil.

Key words: Dissolved organic matter, Extraction method, Origin, Composition, Bioavailability, Environmental significance