Anaesthetic stimulation of Amaranthus albus seed germination: Interaction with phytochrome

Abstract

Exposure to solutions of acetaldehyde, ethanol and n‐propanol ranging from 0.06 to 0.6 M for about 5 h induced photosensitivity in imbibed Amaranthus albus L. seeds which normally would be insensitive. When the seeds were made dormant by pre‐treattnent with continuous incandescent light for 24 h, n‐propanol promoted germination np to 80% provided the active form of phytochrome was present. Pre‐treatment of seeds with continuous incandescent light terminated by far‐red reduced the n‐propanol‐stimulated germination to about 33% which could again be increased by a red irradiation. Red light and n‐propanol also interacted in seeds made insensitive to red treatment by 20°C in darkness. Loss of the n‐propanol stimulation resulted from treatment in continuous far‐red for 2 or more days, even when a red irradiance and n‐propanol treatment were combined. It is suggested that n‐propanol may act at a membrane level.