海滨锦葵光合作用对盐胁迫的响应

分别用含有0、100、200和300mmol／LNaCl的Hoagland培养液处理海滨锦葵（Kosteletzkya virginica L.Presl），在处理的第0、1、3、5、7、9、11天分别测定其光合作用参数，同时对海滨锦葵的CO2补偿点进行测定．结果发现，盐处理下海滨锦蓥叶片的光合速率在处理的初期均下降，而且盐浓度越高下降越明显，当其下降至最低点后又会有一定程度的回升。而后随着处理时间的延长，又会出现持续的下降，处理盐度越高光合速率下降得越明显．在处理的初期使光合降低的主要因素是气孔限制因素，在后期非气孔限制因素逐渐开始起作用；实验同时发现盐处理能明显提高海滨锦葵的CO2补偿点，且盐度越高上升的幅度越大．

PHOTOSYNTHETIC RESPONSE OF KOSTELETZLYA VIRGINICA L. PRESL TO SALT STRESS

Seedlings of Kosteletzkya virginica L.presl were treated with Hoagland solutions containing 0,100,200 and 300 rnmol/L NaCl respectively. After 0,1,3,5,7,9 and 11 days, Pn, Gs, Ci and CO2 compensation point were measured. The results show an initial decrease of Pn under all NaCl concentrations, and the higher the concentration, the lower the Pn. After the initial drop phase, the Pn then rises to some extent with the time course, and at last dropps again successively, with the seedings under 300 mmol/L NaCl declined most. The results also indicate that in the early period of salt stress, the limitation factor to photosynthesis is stomatal limitation one. With the elapse of time non - stomatal limitation factor prevails and affects photosynthesis. Moreover, CO2 compensation point was remarkably affected by NaCl treatment, which is increased obviously with the concentration of NaCl.