Phosphorescence and delayed fluorescence of chlorophyll have been observed in frozen suspensions of green, blue-green and red alga, normal and mutant leaves of pea, kidney bean and maize at the temperature range from --196 to --70 degrees C. The phosphorescence maximum lies at 960--980 nm, excitation maximum--at 674+/-2 nm, lifetime is 1.5--2.5 msec, quantum yield vaires in the range of 0.03--3 x 10(-6), being much lower than that of chlorophyll phosphorescence in solutions. The weakest phosphorescence was found in normal leaves, the strongest one--in cells of Scendesmus and leaves of xi-carotene mutants of maize. The data suggest that phosphorescence belongs to antenna chlorophyll and phosphorescence quenching is due to energy migration from singlet and triplet states of antenna to non-phosphorescent forms of chlorophyll and carotenoids.
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