Review - The formation of adventitious roots: New concepts, new possibilities

Considerable progress has recently been made in understanding adventitious root formation using physiological studies. It is recognized that rooting i s a process consisting of distinct phases, each with its own requirements. In this review the successive phases in the rooting process are described a nd the possible roles of wounding-related compounds, auxin, ethylene and ph enolic compounds during these specific phases are discussed, Recent results are assisting the development of advanced routing treatments. Molecular st udies on rooting are underway and will be essential in revealing the mechan isms underlying adventitious root formation.