Dormancy Break in Seeds of Impatiens glandulifera Royle

When dormancy is broken by chilling in Impatiens glandulifera Royle anthocyanin appears in the cells of the root cap acting as a marker of the physiological condition of the seeds. This precedes growth of the embryo as indicated by increase in seed weight. Abscisic acid at some concentrations can inhibit dormancy break and anthocyanin synthesis in the root cap. All tissues of the embryo, when excised, responded independently to the cold stimulus. Grafting pieces of dormant and non-dormant seed showed the agent effective in breaking dormancy was not transmissible between a piece of chilled embryo placed in contact with a piece of dormant embryo.