Physiological predetermination of germination responses in Arabidopsis thaliana (L.) HEYNH.

Seed of Arabidopsis thaliana (L.) HEYNH., race Estland, produced under temperature controlled axenic conditions and continuous exposure to white light containing markedly different proportions of red and far-red radiant energy, were tested for photoinduced and dark-germination patterns. Dark germination percentages for after-ripened seed grown under cool white fluorescent lamps averaged 45%, under cool white plus incandescent lamps 12%, and under incandescent lamps alone 0%. Since incandescent lamps provide a larger proportion of energy of wavelengths greater than 700 nm, it is concluded that subsequent dark germination is altered by the spectral quality to which the parent plant is exposed. The sensitivity of light germinating seed for photoinduction by red energy also was altered by changing the spectral quality under which they were grown. Light energy rich in wavelengths greater than 700 nm produced seed most sensitive to subsequent red induction. This sensitivity changed during storage and is probably related to changes in after-ripening time.