For maintaining the olive plants, we use various media enriched with hormones and vitamins that promote the development of new shoots. At the beginning of this process, a multiplication medium rich in auxins and gibberellins is used to stimulate the development of new shoots from the internode of a previous plant. After 6-8 weeks, these new shoots are sectioned by internodes for transfer to a new multiplication medium. Additionally, in this same step, the apical parts are sectioned for transfer to a rooting medium rich in auxins and myo-inositol to promote root development. To facilitate this growth, we keep the jars in darkness for the first two weeks, and then expose them to light for another two weeks. Once this process is completed, a maintenance medium with activated charcoal and without hormones is used. This medium serves two purposes: promoting the growth of the apical parts and eliminating the hormones from the previous media so they do not interfere with the results of subsequent tests. After 2-3 weeks, the material will be ready for bacterial inoculations.

For oleander plants, we use two different media. The first consists of a multiplication medium with a high content of auxin and gibberellin, as well as activated charcoal to promote the growth of the shoots. These new shoots should be sectioned similarly to the olive shoots, but unlike them, they need to be handled once a month. If a batch for in vitro inoculation is needed, a medium similar to the aforementioned one will be used, but in this case, in tubes and without growth regulators.

In vitro cultivation also allows us to obtain sufficient material to conduct ex vitro tests in chambers at 25ºC with a photoperiod of 16/8 hours. For this purpose, we use the plants located in the maintenance medium. These will be transplanted to jiffys, compressed peat discs surrounded by a porous mesh that provides adequate aeration to the younger roots. At the same time, these jiffys are placed in a tray covered with perlite to maintain humidity during the first weeks after transplantation, thus reducing the stress the plants undergo.

To control humidity, we also place a plastic film cover over the tray, which will gradually be opened until, after 2-3 weeks, the acclimatized plants can be transplanted to pots. Once acclimatized, they can also be placed in a greenhouse for tests that require a higher proportion of lignin.