Effects of Cadmium on Physiological and Biochemical Characteristics and Bio-Accumulation of Pakchoi in Different Fertilizing

Pot experiments were conducted to study the effects of cadmium on physiological,biochemical characteristics and bio-accumulation of pakchoi under chemical or organic fertilizing.The experimental results showed that when cadmium was added to the soil with levels between 0 mg·kg-1 soil and 25 mg·kg-1 soil,biomass of pakchoi increased at Cd amounts≤ 5 mg·kg-1 soil,but decreased when Cd was≥10 mg·kg-1 soil.Chlorophyll content of pakchoi increased at Cd amounts≤10 mg·kg-1 soil,but decreased when Cd was≥25 mg·kg-1 soil.Vc content of pakchoi decreased as the amount of cadmium increased.MDA content and cadmium concentration in pakchoi were positively correlated with the amount of cadmium applied to soil and cadmium concentration was higher in roots than in aerial part of pakchoi.The result also indicated that the toxic effect of Cd on pakchoi and the biological availability of soil Cd both reduced in the presence of organic fertilizer compare to chemical fertilizer due to the uptake efficiency of Cd by pakchoi was lower under organic fertilizer than chemical fertilizer conditions.More research is needed to study the mechanisms of the reduction of toxicity effect and Cd accumulation in pakchoi with the application of organic fertilizer.