Stress responses of Canna indica to Cd and its accumulation of Cd
美人蕉对镉的胁迫反应及积累特性

Aims The valuable ornamental plant Canna indica is widely distributed in city gardens and on roadsides in China. Our objective was to study the stress responses of C. indica to cadmium (Cd) and its accumulation of Cd. Methods With pot culture experiments, C. indica was cultured with different Cd concentrations. Morphological, ecological, physiological indexes were observed during the growth of C. indica. The distribution of Cd in C. indica plants was determined after harvest. Important findings The Cd treatment of <1 mg·kg–1 had no obvious effect on growth of C. indica; however, Cd concentration of >5 mg·kg–1 inhibited growth. The flowering period was prolonged with <5 mg·kg–1 Cd concentration. With increasing Cd concentration, root activity, chlorophyll and water content all decreased, soluble sugar content initially increased and then decreased, and free proline content and permeability of cell membrane increased gradually. The distribution of Cd in C. indica was root > shoot. With increasing Cd concentration of the medium, Cd concentration in shoots and roots increased; however, the accumulator and translocation factors decreased gradually. The maximum accumulation of Cd in C. indica was 5.89 mg·plant–1 with the treatment of 20 mg·kg–1 . It is concluded that C. indica is suitable for landscaping use when the Cd concentration in soil is <1 mg·kg–1 .