NaCl胁迫对骆驼蓬属植物渗透调节作用的影响

Effect of NaCl stress on osmotic adjustment of Peganum L.seedlings

研究NaCl处理对骆驼蓬属植物幼苗生物量、植株中主要无机离子和有机溶质的含量及渗透调节能力的影响。结果表明，骆驼蓬在NaCl浓度小于200mmol／L，骆驼蒿和多裂骆驼蓬小于100mmol／L时促进根系和地上部干重的增加，超过相应浓度时，幼苗生物量明显下降。3种植物根系和叶片的Na^＋和Cl^-含量随NaCl浓度升高而增加，NO3^-含量及K^＋／Na^＋比则下降，K^＋对Na^＋的选择性吸收和运输SK．Na增大，但多裂骆驼蓬叶片的离子运输SK,Na则降低，Ca2^＋、Mg2^＋含量有升有降。无机离子占总计算渗透势（COP）的68．37％～83．82％，但随NaCl浓度增大而降低；可溶性糖和氨基酸含量随NaCl浓度增大明显增加，有机酸和脯氨酸变化不明显。有机物质约占COP的16．18％～31．63％，且随NaCl浓度提高而增大。骆驼蓬、骆驼蒿和多裂骆驼蓬的渗透调节能力随NaCl浓度增加而增强，其中叶片的渗透调节能力大干根系，渗透调节能力骆驼蓬〉骆驼蒿〉多裂骆驼蓬，表明骆驼蓬比骆驼蒿和多裂骆驼蓬具有更强适应盐渍生境的能力。

Three species of Peganum seedlings were treated with different concentrations of NaCl. The content of main inorganic ions and organic solutes, the osmotic potential and the osmotic adjustment ability of roots and leaves were determined in 28 days after being treated. The results showed that dry weight of shoot and root of P. harmala L. , P. nigellastrum Bge and P. multisectum Bobr were markedly increased under the treatment of 200, 100, 100 mmol/L NaCl concentration, respectively, whereas over those concentration of NaCl, the biomass displayed an apparent reduction. With the increase of NaCl concentration, the content of Na^- and Cl^- in leaves and roots of these three species of Peganum were obviously increased, the content of NO3^- and the ratio of K^＋/Na^＋ were decreased, the selectivity of K^＋ over Na^＋ （SK.Na） were increased except for that in leaves of P. multisectum Bobr which was decreased, and the content of Ca^2＋ and Mg^2＋ were either increased or decreased under different NaCl concentration. The content of inorganic ions accounted for 68.37 % - 83.82 % of the calculated osmotic potential （COP）, and tended to decrease with the increase of NaCl concentration. With NaCl concentration increasing, the content of soluble sugar and amino acid was clearly increased, whereas the content of organic acids and proline showed little change. The total content of organic solutes accounted for 16.18%-31.63% of COP, and showed a remarkable increase with the increase of NaCl concentration. The ability of osmotic adjustment of Peganum was increased with NaCl concentration increasing, and it was higher in leaves than that in roots. The ability of osmotic adjustment presented a tendency of P. harmala L. 〉 P. nigellastrum Bge 〉 P. multisectum Bobr, indicating that P. harrnala L. had a strong adaptability to salt environment.