盐分和水分胁迫对盐地碱蓬幼苗渗透调节效应的研究

EFFECTS OF SALT AND WATER STRESSES ON OSMOTIC ADJUSTMENT OF SUAEDA SALSA SEEDLINGS

利用不同浓度ＮａＣｌ和等渗ＰＥＧ处理４０ｄ龄的盐地碱蓬（Ｓｕａｅｄａｓａｌｓａ（Ｌ．）Ｐａｌ．）幼苗，１０ｄ后测定植株中主要有机溶质和无机离子的含量及叶片渗透势和渗透调节能力。结果表明，ＮａＣｌ处理的无机离子总含量急剧增加，其中Ｎａ＋、Ｃｌ－增加最多，占总计算渗透势（ＣＯＰ）的７１％～８８％，总无机离子占ＣＯＰ的９５％～９７％。而有机溶质总含量则稍有降低，约占ＣＯＰ的２％～５％。ＰＥＧ处理使有机溶质（氨基酸、糖、有机酸）含量明显增加，特别是氨基酸占ＣＯＰ的９％。不同处理的实测渗透势（ＭＯＰ）均小于ＣＯＰ，说明在这些条件下，还有其它的渗透剂参与盐地碱蓬幼苗的渗透调节。结果还表明，盐地碱蓬幼苗的渗透调节能力随外界盐浓度的增大而增加。

Fortyday old Suaeda salsa (L.) Pall. seedlings were treated with different concentrations of NaCl and isoosmotic PEG solutions. The content of the main organic solutes and inorganic ions,the osmotic potential and osmotic adjustment ability of leaves were determined 10 days after treatment. The results showed that under NaCl stress,the sum of inorganic ions had a significant increase and their contribution to the calculated osmotic potential (COP) was up to 95% to 98%.The great increase of Na+ and Cl- content accounted for 71% to 98% of COP, whereas the total content of organic solutes decreased slightly and thier contribution to COP was only 2% to 5%. Under water stress the organic solutes (amino acid,sugar and organic acid) were markedly increased,especially amino acid,which accounted for more than 9% of COP. The measured osmotic potential (MOP) from each treatment was always lower than the COP,which indicated that the other osmotic solutes were involved in the osmotic adjustment in S. salsa seedlings under these circumstances. The results also suggested that osmotic adjustment ability of S. salsa seedlings increased with the external salinity.