摘要：本文采用室内砂培试验，探讨白萝卜对汞离子胁迫的生理响应。方法：采用沙培法研究不同浓度的汞离子胁迫下，白萝卜幼苗干鲜重、根系活力、叶绿素的含量、MAD、SOD和POD抗氧化酶活性的变化。结果表明：随着汞离子浓度的增加，鲜重和干重皆呈下降趋势。当萝卜幼苗在低浓度胁迫下,植株的根系活力大于对照组，但是随着浓度的继续增加，根系活力则呈下降趋势。幼苗叶绿素含量随着Hg2+胁迫的加强而降低。丙二醛含量则随Hg2+胁迫浓度的怎加而增加，白萝卜的细胞质膜遭到破坏程度逐渐加重。SOD和POD活性均随着Hg2+浓度的增加呈先上升后下降的趋势。

关键词：白萝卜；汞离子；抗氧化酶；叶绿素

Abstract: This article uses the sand culture test, to investigate the physiological responses of turnip Hg2+. Methods: Used the sand culture method study of different concentrations of Hg2+ stress, white radish seedling fresh weight and dry weight, root activity, chlorophyll content, MAD, SOD and POD changes of antioxidant enzyme activities. The results showed that: with the increase of the  concentration of the mercury ion, fresh weight and dry weight were decreased. When the radish seedlings in low concentration under stress, the root activities greater than in the control group, but with the concentration continued to increase, root activity decreased. The chlorophyll content of seedling with Hg2+ stress and the strengthening of the lower Malondialdehyde content with Hg2+ stress concentration increases how plus, white radish cytoplasmic membrane destroyed gradually increased. SOD and POD activity significantly with the increase of Hg2+ concentration and then decreased.

Keywords：White radish；Hg2+；Antioxidant enzymes；Chlorophyll