Coconut water and BAP successfully replaced zeatin in olive (Olea europaea L.) micropropagation

Abstract

The data presented report on trials conducted during 24 months using the Portuguese olive cultivar ‘Galega vulgar’. The effectiveness of coconut water, BAP, or kinetin, as possible zeatin substitutes in olive micropropagation protocols, was investigated. In all stages of the micropropagation process, the mineral and vitamin formulation of Olive Medium (OM) was used. Regarding culture establishment the best results were achieved when 50 ml l-1 coconut water and 2.22 µM BAP were used as medium supplements. For the in vitro multiplication stage, the highest proliferation rates with an average of 3.4 new explants on each thirty days were achieved maintaining the coconut water concentration at 50 ml l-1 and increasing BAP up to 8.87 µM. The effects of IBA and activated charcoal on the in vitro root induction were also studied. Rooting rates of over 85 percent were obtained by basal immersion of the explants in IBA solution at 3 g l-1 for 10 seconds, followed by inoculation in the OM culture medium, added with 2 g l-1 of activated charcoal and without growth regulators. All in vitro rooted plants were transferred into jiffy-pots filled with vermiculite-perlite 3/1 (v/v) substrate. Those were subsequently wetted with the OM mineral solution, placed into polystyrene plates each one with 100 jiffy-pots capacity, which were transferred to traditional rooting mist benches, on a water-cooling equipped greenhouse. Such a simple acclimatization procedure allowed for 95 percent of plants survival.