Effects of Ca~(2+) on Cold-resistance Related Physiological Indexes in Cassava under Chilling Stress

SC8,a cultivar of cassava,was used as the experiment material in this research.The cassava seedlings,which were at the same growth status,irrigated with six different concentrations of 0,10,20,30,40,50 mmol/L Ca2+,were treated under 4 ℃ chilling stress.Cold-resistance related physiological indices were determined.The results showed that,cold-resistance related physiological indices of cassava seedlings treated with 20 mmol/L extraneous Ca2+ were better than others.It could significantly reduce conductivity increase amplitude and malondialdehyde(MDA)content,while significantly enhance the activities of protective enzyme,superoxide dismutase(SOD)and peroxidase(POD),increase the content of soluble sugar,soluble protein and free proline.However,there would be a negative effect to the hardiness of cassava seedlings when the concentration of Ca2+ was too high.