| Abstract: | The kinetics of photochemical (qQ) and nonphotochemical (qE) fluorescence quenching during induction was studied in terms of the earlier developed theoretical model of photosynthesis. Photochemical and nonphotochemical quenching was calculated from the parameters of fluorescence induction upon simultaneous excitation with continuous light and by high-intensity light pulses by the method used in a PAM fluorometer. It is shown that the fraction of closed reaction centers during the pulse can change in the course of induction. In consequence, even when none of supposed mechanisms of photochemical quenching is taken into account, the value of qE during induction varies and is not equal to zero. |
