EFFECTS OF BLUE AND RED-LIGHT OF LOW-INTENSITY ON CHLOROPHYLL-A AND CHLOROPHYLL-B CONTENTS IN BARLEY LEAVES AND LIGHT CURVES OF PHOTOSYNTHESIS

Effects of blue and red light at intensities ranging from 0.3 to 12.0 mu mol/(m(2) s) on the contents of a and b chlorophylls and light curv es of photosynthesis in the primary leaves of barley (Hordeum vulgare L,, cv. Zarya) were studied. Lowering the light intensity produced an increase in the chlorophyll a : b ratio, which was more pronounced in blue than in red light. Chlorophyll b was accumulated better in red li ght, even when plants grown in blue light were additionally irradiated with red light. It is concluded that phytochrome specifically activat es accumulation in leaves of the light-harvesting complex associated w ith photosystem II. This manifests itself in a markedly steeper slope of light curve of CO2 exchange in leaves of barley seedlings grown in low-intensity red light, as compared to that in seedlings grown in low -intensity blue light.