Adventitious root formation in Eucalyptus: the role of phytohormones

Abstract

Successful adventitious root induction from macro-, mini- and micro-cuttings is critical for Eucalyptus forestry establishments. As for all the aspects of plant development, adventitious rooting is controlled by plant growth regulators (PGRs), primarily the auxins and their interaction with the cytokinins. Nevertheless, the approach to eucalyptus root induction from vegetative tissues remains empirical, with protocols that are often only clone-specific. Recent advancements have allowed for a more guided approach with respect to exogenous PGR supply for root induction. This review explores the genetic and phytohormone control of root development as it relates to woody plants and commercially-important Eucalyptus clones, and offers some suggestions with respect to the selection of PGRs for enhanced root induction and subsequent development.