盐分和水分胁迫对枸杞幼苗渗透调节效应的研究

Effects of salt and water stresses on osmotic adjustment of Lycium barbarum seedlings

利用不同浓度 Na Cl和等渗 PEG处理枸杞 (Lycium barbarum L.)幼苗 ,15 d后测定叶片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 ,Na Cl处理的无机离子总含量急剧增加 ,其中Na+ 和 Cl- 增加最多 ,占计算渗透势 (COP)的 5 3%～ 71% ,总无机离子占 COP的 90 %～ 93%。有机溶质总含量则稍有降低 ,约占 COP的 7%～ 10 %。 PEG处理使有机溶质 (甜菜碱 ,氨基酸 ,可溶性糖 ,有机酸 )含量明显增加 ,尤其是可溶性糖和有机酸 ,其渗透势分别占 COP的 8.18%和 6 .14 %。不同处理的实测渗透势 (MOP)均小于 COP,说明在这些条件下 ,还有其它渗透剂参与枸杞幼苗的渗透调节。同时 ,枸杞幼苗的渗透调节能力随外界盐浓度的增大而增加。

Lycium barbarum (L.) seedlings were treated with different concentrations of NaCl and iso osmotic PEG solutions. The content of the main inorganic ions and organic solutes, the osmotic potential and osmotic adjustment ability of leaves were determined in 15 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 90%~93%. The great increase of Na + and Cl - content accounted for 53%～71% of COP, whereas the total content of organic solutes decreased slightly and their contribution to COP was about 7%～10%. Under water stress, the organnic solutes (betaine, amino acid, soluble sugar and organic acid) were markedly increased, especially soluble sugar and organic acid, which accounted for 8.18% and 6.16% of COP, respectively. 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 Lycium barbarum seedlings under these conditions. The results also suggested that osmotic adjustment ability of Lycium barbarum seedlings increased with the external salinity.