EFFECT OF CADMIUM,LEAD AND THEIR INTERACTIONSON THE PHYSIOLOGICAL AND ECOLOGICAL CHARA-CTERISTICS OF ROOT SYSTEM OF Brassica chinensis
镉、铅及其相互作用对小白菜根系生理生态效应的研究

The physiological and ecological effects on root system of Brassica chinensis grown in hydroponic culture under the stresses at different concentration of Cd and Pb were studied.The experimental results show that the Cd solution concentration of greater than 0.1 mg/L significantly inhibited the root growth, decreased the number of lateral roots,suppressed the root branching,lowered the root biomass and volume,hindered the development of root system,depressed the uptake of Mn,Zn by root,reduced the root activities,accelerated the decomposition of protein in root,made the free amino acid accumulation,led to a reduction in nitrate contents in Brassica chinensis,and caused nitrogen metabolism disorder.When Pb had added to the culture solution containing Cd, physiological and ecological effects(toxicity) of Cd on root system was strengthened.