Gibberellins in Picea sitchensis carriere: Seasonal variation and partial characterization.

The gibberellin content of needles of Picea sitchensis was investigated during a whole vegetative cycle. During the period of active growth the major gibberellin activity was present in a less polar fraction (Fraction B) whilst during the winter a more polar fraction (Fraction A) was predominant. A similar pattern of activity was observed in buds of the same species. The pattern of change of these fractions is discussed and Fraction B is partially characterized as a gibberellin isomeric with GA9.