Studies of nutritional components effect on the olive micropropagation

Although the olive tree (Olea europaea L.) is a species of great importance, the use of micropropagation for the species still faces obstacles mainly of economic order. The aim of this study was to analyze the effect of the nutritional components in the culture medium for the multiplication phase and their effectiveness in combination with growth regulators. Two trials were conducted: for the first we used three concentrations of the substrate called OM (OM, OM/2 and 2OM) combined with three concentrations of Zeatin (0, 2 and 4 mg L-1). For the second trial we tested the effect two concentrations of OM substrate (OM, OM/2) added with 10% coconut water along two concentrations of zeatin (2 and 4 mg L-1), and a control treatment only with coconut water. In both experiments uninodal explants of shoots obtained in vitro of olive variety ‘Moraiolo’ were employed and kept in a growth chamber at 21±2°C with a photoperiod of 16 hours light at an intensity of 40 µE m-2 sec-1 for 45 days. In order to evaluate the effect of the treatments we analyzed the percentage of survival, regeneration rate, number of shoots, shoot length, number of nodes, number of leaves, percentage of callus formation, average fresh weight, total dry weight and the vegetative activity index. It is concluded that the use of medium OM added 2 mg L-1 zeatin provides best results for in vitro regeneration of olive. Also, the use of coconut water added to the medium OM culture provided interesting results for in vitro regeneration of ‘Moraiolo’, and the use of lower concentration of zeatin could be considered from an economic point of view. In fact, it was also observed that the use of coconut water significantly increases the number of shoots produced, and this factor should be further studied with the aim to improve the micropropagation of olive.