Abstract:

Tree architecture has been recognized to be the consequence of interactions between a tree's blue print or genotype,its environment and its developmental history.In tropical trees and many temperate zone trees,tree architecture includes two contrasting branching types,sylleptic and proleptic branches.Sylleptic branches develop from lateral buds of the main stem without an intervening period of dormancy,whereas proleptic branches develop from lateral buds of the main stem with an intervening period of dormancy.Although these two branch types can occur in the same tree,they normally display marked discrepancies in morphogensis and the extent to which they phenotypically respond to environmental changes.It has been recognized that the phenotypic plasticity of sylleptic branching plays an important role in determining tree growth, architecture and adaptation for many temperate zone woody plants.In this article,we further examine control mechanisms for the phenotypic plasticity of sylleptic branches at the environmental,developmental and genetic levels.

Key words: Phenotypic plasticity, Tree architecture, Branch, Development, Genetics