不同Cd水平对小白菜生长及其营养元素含量的影响

Effects of Different Cadmium Levels on the Growth and Nutrient Elements in Pakchoi

采用温室内液体培养方法,研究了不同Cd水平对2种小白菜(BrassicachinensisL.)沪青1号、杭州油冬儿的生长及营养元素含量影响。结果表明,培养液中添加Cd抑制了2种小白菜生长及叶绿素含量;2种小白菜地上部及根中的Cd含量随营养液中Cd浓度的增加而极显著增加,且植株从培养液中吸收的Cd大部分积累在根中。Cd影响小白菜对营养元素吸收和转运,但这种影响随着元素、植株部位的不同及Cd离子在介质中浓度的不同而不同,不同品种间也存在一定的差异。

A hydroponic experiment was carried out to determine the effects of different Cd levels （0, 1, 10 mg·L^-1 Cd） on the growth and nutrient elements in two pakchoi cuhivars, cv. Huqing No.1 and cv. Hangzhouyoudong. The results showed that Cd inhibited the growth and reduced chlorophyll contents of two cuhivars. The root dry weight （DW）, shoot dry weight, and chlorophyll content （SPAD value） decreased with increasing Cd concentrations in the culture solution. Cd was easily taken up by the plants and concentrations in shoots and roots in both of two cultivars increased with increasing Cd concentrations in the medium. Most of Cd absorbed by plants remained in the roots, and the shoot was more sensitive than the root to Cd stress. Cd affected the nutrient elements absorption and transport. The contents of K and Mg in shoots of both cultivars showed no significant differences in the three treatments, but contents of S in shoots of both cuhivars had a rise-fall tendency with increasing Cd concentrations. 1mg·L^-1 Cd had no significant effect on K contents, but 1.ng·L^-1 Cd significantly decreased K contents in roots of both cuhivars. Ca contents decreased, but S contents increased significantly in roots of both cuhivars under the two Cd treatments. Mn contents both in roots and shoots were decreased under the Cd treatment. The effects of Cd on the other nutrient elements were dependent on the elements, plant tissue, Cd concentrations and cultivars.