盐胁迫对白萝卜幼苗的生理的影响.doc

摘要：本文采用室内砂培试验，研究不同盐浓度下对白萝卜幼苗生长发育（干重、鲜重）、生理生化（叶绿素含量，根系活力）、抗氧化系统中酶活性（MDA，SOD,POD)和脯氨酸含量的变化规律。结果表明：随着盐浓度的增加，鲜重和干重皆呈下降趋势，干重相比于鲜重减少的速度较慢，在200mg/L时，鲜重与干重分别为对照组的58%和80%,随着浓度增加，叶绿素含量呈下降趋势，在200mg/L时为对照组24%;当萝卜幼苗在低浓度胁迫下,植株的根系活力和酶活性（SOD,POD)大于对照组,在盐浓度为20mg/L时达到最高点，而高浓度则抑制萝卜幼苗的生长，表现出对低浓度Na+有较强的抗性作用，随着Na+的增加，萝卜幼苗体内脯氨酸含量持续增加，在200mg/L时脯氨酸含量为对照组的186%；当MDA含量随着盐浓度增加时，在盐浓度120mg/L时含量最明显。

关键词：Na+； 萝卜幼苗； 生理特性

Abstract:In this article it used indoor soil culture experiment to study he different salt concentrations of  radish seedlings grows (Fresh weight, Dry weight),physiological and biochemical (Chlorophyll content, Root activity Proline)and antioxidant enzyme activity in the system(MDA,SOD,POD) and the change rule of Proline content. The results show that dry and fresh weight with the salt concentration increases to drop, However, dry weight was reducing slower salt concentration of 200mg/L was 58% and 80% of the control group. When salt concentration of 200mg/L is 24% in control group. In the ways of low salt Concentra, the root and enzyme activity all are higher than the control group, and salt concentration in 20mg/L reached a peak. Radish seedlings showed low concentrations of Na+ have a strong resistance to the role of, When the Proline content with the salt concentration increases, salt concentration of 200mg/L was 186% of the control group. When the MDA content with the salt concentration increases and increases, and salt concentration 120mg/L MDA content increased when more obvious.

Key words：Na+; radish seedlings; adverse circumstance physical