Researching the controls of adventitious rooting

Cloning is crucial in horticulture and forestry for commercial production of plants and in genetic improvement programs. However, inability to induce adventitious root formation (rooting) often limits cloning of woody plants by cuttage or tissue culture. To improve cloning, past physiological and biochemical studies of rooting have largely been aimed at understanding controls by researching post‐translational processes. Still, the sought‐for controls of rooting remain obscure. However, those controls may be discovered by searching for and studying direct genetic effects, using current molecular genetic technologies and new plant materials (e.g., non‐rooting mutants, normally rootless plants). In particular, applying molecular genetic technologies in studies at the transcriptional and translational levels may soon reveal the controls of rooting. We review strategies for achieving that goal.