Micropropagation of the Mediterranean tree Ceratonia siliqua

An in vitro propagation protocol based on axillary bud proliferation has been developed for mature female trees of Ceratonia siliqua L. `Galhosa' and `Mulata'. Browning and contaminants were the major obstacles for culture establishment. Shoot culture initiation was greatly influenced by explanting season, with the highest survival percentage observed in spring. The cultivar, cytokinin type and concentration were the most important factors affecting shoot multiplication. The best multiple-shoot response was obtained with `Mulata' on Murashige and Skoog medium supplemented with 4.44 μM 6-benzyladenine or 4.56 μM zeatin. Rooting was achieved on growth-regulator-free medium after basal dipping of shoots in indole-3-butyric acid (4.9 mM). Plantlets were successfully acclimatized (80–85%) under high relative humidity and then moved to the glasshouse. A field trial was established to follow their agronomic behaviour.