Abstract: Pot experiments were carried out to study the effects of NaCl stress on the growth， quality， ion distribution and chlorophyll fluorescence in Portulaca oleracea L． Eight different concentrations of NaCl were applied: 0，25， 50， 75， 100， 150， 200， 250 mmol /L． The results showed as follows: The germination rate， plant fresh weights andheights of seedlings had no difference with the control when the concentration of NaCl was 25 － 50 mmol /L， but decreased when the NaCl concentration was above 50 mmol /L． When the concentration of NaCl was 0 － 75 mmol /L，the Vc content of Portulaca oleracea L． increased． Increased treatment of NaCl induces increased of Na ⁺ and decreased of K ⁺ ， Mg²⁺ and Ca²⁺ ． Minimal fluorescence ( Fo) ， maximum fluorescence ( Fm) ， PSⅡ potential fluorescence efficiency ( Fv /Fo) and PSⅡ actual fluorescence efficiency( Ф PSⅡ ) all decreased when stressed by NaCl．And at low concentrations NaCl (0 － 50 mmol /L) stress， the fluorescence parameters changed slightly． So Portulacaoleracea L． was injured by photo-inhibition on NaCl stress， and at low concentrations， plant applied more light energyto photochemical reaction to maintain a high net photosynthetic rate， the degree of photo-inhibition was lower， therefor， NaCl stress had little effect on growth．

Key words: Portulaca oleracea L． , NaCl stress, Chlorophyll fluorescence, Ion distribution, Salty-soil agriculture

CLC Number: 

• S636.9