NaCl胁迫下高羊茅生长及K^+、Na^+吸收与运输的动态变化

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

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=-0.9902**);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+、SK+/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SK+/Na+吸收主要受环境盐分浓度的影响,但运输选择性系数S++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。

This study aimed to elucidate the effects of salinity on the growth of tall Fescue （Festuca arundinacea）. 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 NaC1. At several intervals over the study period the tiller number,dry matter and, K＋ and Na＋ content in top and root, were determined. Results showed that the tiller number, dry matter weight, K＋ content, K＋/Na＋ and the transport selectivity of K^＋ （Sk^＋/Na^＋ -transport） declined under high NaCl concentration, while Na＋ content was increased in both shoots and roots.It was shown that the depressive effect of NaCl stress on growth was more pronounced in shoots than in roots. The absorption selectivity of K^＋ was reduced mainly by NaCl concentration in the nutrient solution. The transport selectivity of K^＋ and Na^＋ decreased significantly as the treatment duration progressed.