13种小白菜基因型对Cd、Pb、A s累积特性比较

Differential accumulation of cadmium,lead and arsenic among 13 cabbage(Brassica chinensis) genotypes in hydroponics culture

13种小白菜基因型在温室以125μmol.L-1Cd、Pb、As等3种重金属离子胁迫培育8 d,比较茎叶和根系的金属累积能力.结果表明:①不同基因型茎叶和根系累积重金属离子能力的差异达极显著水平.②根系累积能力大于茎叶.茎叶对不同金属离子累积能力不同,13种基因型,茎叶Cd平均累积量为373.34 mg.kg-1,分别是Pb(62.20 mg.kg-1)和As(27.56mg.kg-1)的6.0和13.6倍,即小白菜茎叶食用部位是Cd累积和分配的主要部位,Cd对蔬菜可食部位卫生品质的影响很大.③在本试验条件下,小白菜基因型L、B茎叶、根系Cd含量交叉分列前两位,初步认为它们是Cd高累积基因型;而基因型D茎叶Cd含量次低和根系最低,则可能为Cd低累积基因型.

Thirteen cabbage （Brassica chinensis） genotypes were cultured in hydroponics with 125 μmol·L^-1 of Cd, Pb to differentiate their metal accumulating capacity in shoot and root. The results showed as follows. Firstly, there was a remarkable significance （P 〈 0.01 ） of metal accumulation in shoot and root among genotypes. Secondly, metal accumulation in root was higher than that in shoot in general, however, Cd was much easier to be accumulated than Pb and As in shoot, the averaged shoot Cd content was added up to 373.34 mg·kg^-1 which was 6.0 folds of Pb （62.20 mg· kg^-1 ） and 13.6 folds of As （27.56 mg·kg^-1） , respectively, indicating that cabbage shoot was the main part of Cd accumulation and distribution, thus Cd had more negative effect than Ph, As on the sanitary quality of cabbage for human dietary. Finally, genotype L and B were evaluated as high Cd accumulating genotype, while D as low Cd accumulating genotype according to shoot and root accumulating capacity.