Fig. 1. Light dependencies of PS I delayed fluorescence (1) and rate of chlorophyll bleaching (2) in the membranes of  S. elongatus (A) and relationship between them (B) obtained at various irradiances (I): 0.1 (1); 0.3 (2); 1.2 (3); 3 (4); 5.5 (5); 8 (6); 14 (7) and 20 (8) W m^-2. Temperature was 78^oC.