PHYTOCHROME ACTION IN SEED-GERMINATION OF FRINGED SAGE (ARTEMISIA-FRIGIDA)

Seeds (achenes) of fringed sage were collected in central Saskatchewan in 1987, 1990, and 1991, and studies were conducted to determine the effects of imbibition time before brief or prolonged exposure to red ( R) and far-red (FR) light on germination. A majority of the seeds requ ired light for germination, but a substantial proportion germinated in darkness. Phytochrome controlled germination, and its activity was in fluenced by the duration of imbibition and by seed collections. At lea st 8 h of imbibition were required before phytochrome was activated by R light. The stimulation of germination could be reversed by FR light , and this suppression subsequently could be reversed by exposure to R light. Variable light requirements for germination of fringed sage ca n be met following large- or small-scale disturbances or in relatively undisturbed conditions.