Effect of Calcium on Physiological Property of Brassica chinensis L. Under Cadmium Stress

In this research,Brassica chinensis L.was cultivated in mixed culture medium(vermiculite and perlite 2∶1) with improved Hoagland nutrient solution(substitute ammonium nitrate with calcium nitrate).The research mainly studied the effects of Ca with various concentrations(0,200,400,800 mg/L)on physiological property of Brassica chinensis L.under Cd stress.The physiological indexes included root activity,NR activity,NO3-N content and chlorophyll content.The results showed that:1) Under Cd stress,the NR activity and root activity declined,the synthesis of chlorophyll was inhibited obviously,but the content of NO3-N rised gradually.2) The root activity of plant got significantly increased under the treatment with Ca(p0.05),the activity of NR also improved.The contents of chlorophyll in Brassica chinensis L.with Ca supply were higher than the treatment without Ca,but they were lower than the blank treatment.3) The contents of chlorophyll under low Ca treatment were higher than the treatment without Ca apparently,but they decreased gradually.The content of NO3-N first decreased then increased,and there was a significant negative correlation between NO3-N content and NR activity.The treatment of higher Ca concentration inhibited the activity of root and NR.In conclusion,appropriate concentration(200~400 mg/L)of exogenous Ca could relieve the stress of Cd to the Brassica chinensis L..