IN-VITRO REINVIGORATION OF MATURE OLIVE TREES (OLEA-EUROPAEA L) THROUGH MICROGRAFTING

Portions (1.0-1.5 cm long) of terminal shoots from selected mature tre es Olea europaea L. cv. Arbequina, micrografted in one phase onto in v itro juvenile shoots, resulted in the restoration of shoot-bud prolife ration and rooting competence. Although higher in vitro survival rates were obtained after a second repeated micrografting, the reinvigorati on ratio of the regenerated shoots, indicated by proliferation and roo ting ability, was not improved after two phases of micrografting. Thus , one-phase micrograft allows for a successful micropropagation system for olive trees. The cuttings obtained from successive pruning of pla nts produced through micrografting and growth in soil showed complete restoration of rooting competence, with rooting percentages similar to those of juvenile microshoots.