THE INTERFERENCE OF BUD DORMANCY IN THE MORPHOGENSIS OF TREES AND SHRUBS

Dormancy gradients between buds along the one-year-old shoot are the basis for the differentiation of woody plants into trees and shrubs. An autumnal basitonic gradient, i.e. an increasing outgrowth capability downwards along the shoot, makes the shrubs sprout out of a stump every year. Tree buds show the same evolution in dormancy but are prevented from growing out basally by correlative effects between buds and stem tissues: The varying sensitivity of the buds to cytokinins and gibberellins, depending on time or level of insertion on the shoot, might further explain the reported facts.