PHOTOBIOLOGIE DU MESOCOTYLE D'AVOINE–IV. SPECTRES D'ACTION ET EFFICACITE QUANTIQUE DE LA LUMIERE

Abstract— The wavelengths most active in influencing the growth of segments of oat mesocotyl are 435 nm (blue), 665 nm (red) and 730 nm (far red). Using a high-energy source (1.5 × 10¹⁸ quanta/cm²), an inhibition in all areas of the spectrum except the far red was obtained. The efficiency of the different radiations was studied: blue light is the most active, red and far red have about the same efficiency; green is a thousand times less active. The effect induced by blue light cannot be directly attributed to phytochrome, because the wavelength of maximum effect does not correspond with that of maximum absorption of the pigment (there is 55 nm difference); also, blue light is more active than the red radiation.