Effects of Cadmium Stress on Growth and Cadmium Accumulation Characteristics of Brassica napus L. Seedlings

Cadmium（Cd） is a heavy metal element with strong biotoxin, which is easy to be enriched and transferred between soil, animals and plants, and human body, and ultimately endangers human health. In order to screen Brassica napus L. varieties with high concentration/cadmium（Cd） tolerance, six B. napus varieties were selected for studying the effects of cadmium stress on seedling growth, Cd accumulation, glutathione（GSH） content etc. The results showed that Cd stress inhibited leaf dry weight of different varieties seedlings, with the largest inhibition on Meiyou 88 and the smallest on Nanyou 868. There was certain difference in the seedling root dry weight of different rape varieties. Under stress conditions, Nanyou 868 had the largest root dry weight. Cadmium stress had the largest inhibition on root weight of Zaoshu 100 Days and Fengyou 9 seedlings, and the smallest inhibition on Meiyou 88. The Root-shoot ratio of the six tested varieties increased under Cd stress, with the highest increase of Meiyou 88 and the smallest increase of Nanyou 868. There was certain difference in the biomass of different varieties. Under normal and stress conditions, Nanyou 868 was significantly higher than the others. Cd stress had the greatest inhibitory effect on the biomass of Meiyou 88 seedlings and the least on Nanyou 868 seedlings. There were significant differences in heavy metal contents among different varieties. Meiyou 88 had low Cd concentration, Nanyou 868 had high Cd concentration. But the results showed that glutathione content of different varieties significantly increased under the Cd stress, with the highest increase rate of Meiyou 88, followed by Nanyou 868. This study provides guidance for food safety or repairing Cd contaminated soil in B. napus L.