NaCl胁迫下高羊茅生长及K+、Na+吸收与运输的动态变化

通过室内水培试验研究探讨了NaCl胁迫对高羊茅苗期生长及K 、Na 吸收与运输的影响及其随时间的变化.结果表明,高羊茅苗期的干物质重和分蘖数随盐分水平的升高而降低,且与NaCl浓度存在极显著的负相关关系(r=-0.990 2**);NaCl胁迫对高羊茅苗期茎叶生长的抑制作用大于对根系的影响;NaCl盐浓度的增加使高羊茅地上部干物质重、K 的相对含量、K / Na 、S K / Na 吸收降低,Na 的相对含量增高;胁迫时间对K 、Na 含量的影响显著.高羊茅根系对K 的吸收具有较高的选择性,吸收选择性系数S K / Na 吸收主要受环境盐分浓度的影响,但运输选择性系数S K / Na 运输却主要受胁迫时间的影响,且盐分阈值随胁迫和生长时间的增加而呈下降趋势.

Dynamic effect of NaCl on absorption and transportation of K+ and Na+ in Festuca arundinacea

This study ai med to elucidate the effects of salinity on the growth of tall Fescue (Festuca arundina-cea) . Seedlings were cultured for 5 weeks under hydroponic conditions with nutrient solutions containing 0(CK) ,50 ,100 ,150 ,200 ,250 ,300 and,350 mmol/L NaCl . At several intervals over the study period the tillernumber ,dry matter and, K+and Na+content in top and root , were determined. Results showed that the tillernumber ,dry matter weight , K+content , K+/Na+and the transport selectivity of K+(SK+/Na+-transport) de-clined under high NaCl concentration, while Na+content wasincreasedin both shoots and roots .It was shownthat the depressive effect of NaCl stress on growth was more pronouncedin shoots thanin roots . The absorp-tion selectivity of K+was reduced mainly by NaCl concentrationin the nutrient solution. The transport selec-tivity of K+and Na+decreased significantly as the treat ment duration progressed.