Differences In Uptake And Cumulation Of Cadmium In Different Vegetables

Effects of vegetable species, vegetable rape varieties and complex (EDTA or Cl~-) on cadmium uptake and translocation were studied in solution experiments of vegetables and rice. The results are summarized as follows:The Cd uptake was more in vegetable rape and Chinese cabbage than in others. A gradient of Cd concentrations was found in 6 vegetable species in the order of roots> stems> leaves. Large differences between vegetables were found in the Cd uptake of roots and transportation into shoots. Cd was mainly accumulated in cell wall fraction (62.1%-85.1%) in leaves, and a few in chloroplasts and protoplast fraction (excluding the chloroplasts).A gradient of Cd concentrations was found in 14 vegetable rape varieties in the order of roots> stems> leaves. Large differences between vegetable rapes were not found in the Cd concentration in the shoot dry matter, but found in the root dry matter, which means large differences between vegetable rapes in uptake of roots and transportation into shoots. Cd was mainly accumulated in cell wall fraction (69.5%-90.6%) in leaves of vegetable rapes, and a few in chloroplasts and protoplast fraction (excluding the chloroplasts).The effects of complex on cadmium uptake and translocation by rice and vegetable rape were studied in solution experiments added different levels Cl~- and EDTA. The results indicate: both of chloride and EDTA decreased cadmium content in shoots and roots of rice and vegetable rape; chloride decreased cadmium transport into shoots of rice; EDTA enhanced cadmium transport into shoots of vegetable rape.