低浓度镉对小白菜生长及营养元素吸收积累的影响

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

用水培模拟轻度重金属污染土壤,研究低浓度Cd(5μmol/L)对10个品种小白菜生长及营养元素吸收积累的影响。结果表明,低浓度Cd对耐性强的品种的生长有促进作用,对耐性差的品种的生长有抑制作用。5μmol/L Cd促进小白菜根系对Ca、Mg的吸收,但抑制Ca、Mg向地上部转运;小白菜地上部Ca、Mg、Mn、Zn、Cu含量受到Cd的抑制,且抑制程度存在品种差异。小白菜根部Fe、Zn含量受到不同程度的抑制。不同品种小白菜地上部和根部的镉含量存在差异,其中日本华冠火青菜地上部镉含量较低,耐性指数较高;大头.沪王青、抗热605两个品种地上部镉含量也较低,但地上部生长量受到抑制较大,不利于生产。

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.