烟草试管苗对盐胁迫的生理响应

The physiological responses of tobacco plantlets in vitro by salt stress

利用不同浓度的NaCl对烟草试管苗进行了20 d胁迫,结果发现:随着盐浓度的增加,烟草试管苗的生长明显受阻;根、茎、叶中K+的含量呈极显著的下降趋势,Na+的含量大幅度增加;叶片中叶绿素的含量下降,但丙二醛的含量增加,质膜透性增大,脯氨酸大量积累,且脯氨酸含量与丙二醛含量和质膜透性间呈极显著的正相关,表明盐胁迫下脯氨酸积累的多少可反映烟草试管苗的伤害程度。本研究认为离子伤害、膜透性增大和叶绿素含量下降是影响盐胁迫下烟草试管苗生长的原因。

The tobacco plantlets in Vitro were treated with different concentrations of NaCl in 20 days. The result indicated that the plant growth was retarded steadily with the increase of salt concentration; In this case, the content of K^＋ reduced and the content of Na^＋ increased in root, stem and leaf; In leaf, content of chlorophyll reduced, but the content of malonaldehyde（MDA）, membrane permeability and proline increased, moreover the content of proline showed significant positive correlation with the content of malonaldehyde（MDA） and membrane permeability. It showed that the accumulative content of praline could reflect the tobacco plantlets＇ hurt degree. The study indicated that either the hurt of ion, the increase of membrane permeability or the reduction of chlorophyll affected the growth of tobacco plantlets in vitro of salt treatment.