Effect of Low Concentration Cadmium on the Growth and Accumulation of Nutrient Elements in Pakchoi

A hydroponic experiment was conducted to investigate the effect of low level Cd on the growth and accumulation of nutrient elements in pakchoi cultivars with different Cd tolerance.The results indicated that low concentration Cd stimulated the growth of high-tolerant cultivars but inhibited that of low-tolerant ones.5μmol/L Cd enhanced the accumulation of Ca and Mg in the roots,but inhibited the transport of them to the shoots.Cd inhibited the accumulation of Ca,Mg,Mn,Zn and Cu in the shoots,and the inhibition degree differed among different cultivars.The contents of Fe and Zn were subject to inhibition in different degrees in the roots.The cadmium content of pakcho varied in different cultivars,among them Huaguanhuoqingcai had a lower Cd content in the shoots and showed a higher Cd tolerance index.The two cultivars Datou·huwangqing and Kangre 605 had lower cadmium content in the shoots,but the growth of the shoots was inhibited greatly,which was detrimental to production.