[Different sensitivity of 23 common crop species to cadmium toxicity]

Cadmium toxicity to 23 kinds of commonly cultivated crops of 9 families was studied by solution culture with different cadmium concentrations. Most of the studied crop seedlings showed cadmium toxicity symptoms with 0.1-0.25 mg x L(-1). The toxic effects of cadmium on the crops were quite different. The effect of Cd on shoot biomass was more obvious and stable than the other parameters at low Cd concentrations (0.1-0.5 mg x L(-1)), Therefore, shoot fresh weight was selected to be the indicator of plant sensitivity to Cd. The EC20 (effective concentration causing a 20% inhibition of shoot biomass) values of Cd for the studied crops ranged from 0.03 to 24.67 mg x L(-1). The Cd sensitivity of the crops is classified according to the response endpoint of apparent symptoms and the EC20 values. Chinese cabbage, brassica napus, youmai lettuce, mustard and pakchoi are sensitive species to Cd toxicity that can be used as ecological receptors to determine the critical value of the toxicity of soil Cd to crops or as monitoring crop species of soil Cd pollution. Cucumber is most tolerant to Cd toxicity among the studies crops.