Cadmium tolerance and enrichment characteristics of Viola prionantha

In order to study the physiological effects of cadmium (Cd) on Viola prionantha, the responses of growth and enrichment characteristics of V. prionantha to the Cd were evaluated. The results showed that the growth of plants was promoted under the low Cd concentration (≤10 mg·kg-1), and the biomass of root and shoot of the plants exposed to Cd significantly increased (P＜0.05) when compared to the controls which reached the peaks when the Cd concentration was 5 mg·kg-1. With the increase of Cd concentration, the chlorophyll content decreased, the activities of SOD, POD, CAT all increased firstly and then decreased, whereas, the MDA content decreased firstly and then increased. The activities of SOD, POD and CAT were higher than those of the control, while the contents of MDA and the chlorophyll did not change in the leaves compared to those in the control at concentration of 10 mg·kg-1 Cd treatments. On the other hand, the bioaccumulation and translocation of V. prionantha to Cd were more than 1.0, which confirmed the standard of Cd hyperaccumulator. Therefore V. prionantha can be classified into the Cd hyperaccumulator plants. The above results suggested that V. prionantha can be applied to purify contaminated environment which not only remedied contaminated environments but also bring landscape effects.