The Gibberellin-like Substances and Growth Inhibitors in Developing Strawberry Leaves

Abstract

Gibberellin-like substances and inhibitors present in extracts of runner buds, and unfolding and mature leaves of strawberry have been fractionated and compared. The runner-bud water-soluble residue was more strongly inhibitory than that from unfolding and mature leaves. The crude acid fraction from unfolding and mature leaves contained appreciable amounts of an inhibitor, probably abscisic acid, which was not detected in the buds. The unfolding leaves had a higher concentration of acidic gibberellin-like substances than either buds or mature leaves; they also contained a number of neutral gibberellin-like substances. Mature leaves had a low concentration of gibberellin-like substances, all of which were acidic. A number of these were highly non-polar types, not found in the buds or unfolding leaves.