Studies on the Resistance to Cadmium in Different Cultivars of Brassica parachinensis
不同品种菜心对镉抗性的研究

The differences of translocation and accumulation of cadmium (Cd) in Brassica parachinensis of different Cd-resistant cultivars,Chixin-2 and Teqing-60,and their mechanisms were investigated with pot experiment in greenhouse under the different Cd treatment (0mg/kg,1.0mg/kg,3.0mg/kg,10.0mg/kg).The results showed that,at the same Cd treatment,the resistant cultivar Teqing-60 accumulated fewer Cd in shoots than Chixin-2.Under the higher Cd concentration (10.0mg/kg),dried weight of Teqing-60 was significantly increased,while that of Chixin-2 was remarkably decreased,compared to the control.In Chixin-2,dried weight of shoot and root were decreased by 52.54% and 68.85%,respectively.Furthermore,the translocation rate of Cd from root to shoots was lower in Teqing-60,especially under the 3.0mg/kg Cd treatment,lower by 5.62%,than that in Chixin-2.But the proportion of Cd in root cell wall in Teqing-60 was higher than that in Chixin-2.The total sulfur content in root were higher.Moreover,total sulfur in Teqing-60 were raised by 25.78% to 43.50%,but that in Chixin-2 were reduced by 1.0% to 32.60%,after adding Cd to soil.And pH value of root sap in Teqing-60 were higher than that in Chixin-2,higher by 1.02 pH unit,specially under 3.0mg/kg Cd treatment.Cd content in root sap was lower for Teqing-60,accordingly,the activity and translocation ability of Cd in Teqing-60 were lower than that in Chixin-2.And the Cd content in root sap were positively correlated with that in shoot (R 2=0.8151,n=8).The above results might be the reasons why the resistance of Teqing-60 to cadmium was higher than that of Chixin-2.