Effect of NO_3~-/NH_4~+ Ratio on Cadmium Content and Physiological Index in Chinese Cabbage under Cadmium Stress
WANG Ling-mao(Huhhot Vegetables and Non-staple Food Product Bureau Saihan Area,Huhhot 010020,China)
The purpose was to discuss the effect of different NO3-/NH4+ ratio(10:0、7:3、5:5、3:7、0:10) on Cadmium content and physiological indexes of plant under Cadmium stress.[Method]With Chinese white cabbage as tested material,effect of NO3-/NH4+ ratio on the growth,Cadmium content and contents of total nitrogen,total carbon under Cadmium stress(1 mg/L) were studied on the basis of Hoagland nutrition.Under Cd stress(1 mg/L),hight of plant was the highest at a 5:5 ratio,and lower than the control;Above-and belowground biomass arrived at peak value at a 7:3 ratio,but root/shoot ratio was not significant difference among treatments.Pn and Te showed a trend of increasing firstly and reducing again with increasing of NH4+concentration,and there was the highest at NO3-/NH4+ratio of 7:3,while the changing pattern in Ci was contrary to Pn.With increasing of NH4+ concentration,content of total carbon aboveground elevated,and contents of total carbon belowground in each treatment were higher than that of the control.Contents of total nitrogen aboveground reduced with increasing of NH4+concentration,and contents of total nitrogen in each treatment were lower than that of the control.Content of Cd aboveground has a trend of increasing with adding of NH4+concentration,and there was the lowest content at NO3-/NH4+ ratio of 7:3,but content of Cd belowgroun was higher than that aboveground.Shoot of Chinese white Cabbage had less absorbed to Cd at NO3-/NH4+ ratio of 7:3 under Cadmium Stress(1mg/L);Shoot of Chinese white Cabbage absorbed more Cadmium at more NH4+ concentrations.
【CateGory Index】： S634.3