盐胁迫对番茄种子萌发和幼苗生长的效应

Effects of Salt Stresses on Seed Germination and Growth of Tomato Seedlings

研究了不同浓度NaCl胁迫对番茄种子发芽、幼苗生长及其离子吸收、分布的效应。结果表明，25～100mmol／LNaCl胁迫对番茄的影响主要表现为推迟发芽，但最终并不影响发芽率，而随着NaCl浓度的进一步增加，番茄发芽率明显降低，250～300mmol／LNaCl处理，发芽率为0.25～300mmol／LNaCl处理均显著抑制幼苗生长，使干物质积累下降。Na^＋主要积累在茎秆、根部，叶片中较少，而Cl^-主要积累于茎秆。盐胁迫下叶片中K^＋含量显著增加，根系吸收SK,Na、叶片运输SK均显著上升，表明番茄在离子吸收和向叶片运输过程中，对K^＋具有较强的选择性。这是番茄具有一定耐盐性的主．要Na原因。

Effects of NaCl stress on seed germination, growth and ionic absorption and distribution of tomato seedlings were studied. Results showed that 25 - 100 mmol/L NaCl didn＇t decrease seed germination rate, but delayed the date of seed germination. 125 - 225 mmol/L NaCl obviously decreased seed germination rate and no seed germinated during 250 - 300 mmol/L. 25 - 300 mmol/L NaCl significantly inhibited seedling growth and decreased dry matter accumulation. Na^＋ was mainly accumulated in stem and root of the seedlings and with lower content in leaves; Cl^- was mainly distributed in stem. K ^＋ content in leaves exposed to salinity increased remarkabledly, and absorption of SK, Na in root and transportation of SK, Na in leaves were uniformly promoted obviously. It suggested that higher selectivity of tomato to K^＋ during ion absorption and transportion made tomato with salt-tolerance.