PHOTOSYNTHETIC PERFORMANCE AND PHOTOINHIBITION IN 2 SPECIES OF POTAMOGETON FROM LAKE BOHINJ (SLOVENIA)

Apparent photosynthesis, dark respiration, photochemical efficiency of photosystem II and potential respiration, estimated as terminal elect ron transport system (ETS) activity, were determined under experimenta l conditions to evaluate physiological differences in two competing sp ecies Potamogeton lucens L. and Potamogeton alpinus Balbis. The invest igations showed that there are no significant differences in photosynt hetic response and ETS activity. In P. lucens ETS capacity highly exce eds dark respiration measured as O-2 consumption. Photochemical effici ency of PS II in P. lucens was higher and the recovery after photoinhi bition was more effective.