Gibberellin-like substances in embryonic shoots of Scots pine in relation to generative differentiation

Investigations were carried out on embryonic shoots of lateral and terminal buds of Scots pine (<em>Pinus silvestris</em> L.) of different age. at various stages of seasonal devclopment. The results show that there is a correlation between gibberellins content and apical dominance in pine. More are found in terminal buds than in lateral ones. The transition from a juvenile phase into a mature one in Scots pine is accompanied by a lowering of the gibberellin content. The formation of male inflorescences is accompanied by an increased amount of endogenous gibberellins and the appearence of a new group of non-polar gibberellin-like substances. The formation of female cones is connected with the lowering of endogenous gibberellin content.