Correlation between dissipative fluorescence quenching at photosystem II and 50 μs recombination luminescence

Charge recombination luminescence in the 50 μs time range was measured in isolated chloroplasts under identical conditions as modulated chlorophyll fluorescence. In this way the relationship between fluorescence quenching, as analysed by the saturation pulse method, and charge recombination was investigated. Various treatments known to slow down the donation rate of water splitting, were found to induce correlated increases in 50 μs recombination luminescence and fluorescence quenching, with both photochemical and non‐photochemical quenching components being enhanced. It is concluded that charge recombination at photosystem II provides a mechanism for rapid dissipation of excitation energy.