Somatic embryogenesis in Olea spp.

Key Message In this review, progress in olive somatic embryogenesis is reported. Main factors influencing the different phases of this developmental pathway are analysed. Advances in olive biotechnology through somatic embryogenesis-based systems are revised as well. Olive is one of the most important oil tree crop worldwide and great attention is paid on its genetic improvement. Although different breeding programs have been developed, several issues limit their efficiency. In olive, somatic embryogenesis allows application of biotechnological tools, such as genetic transformation, somaclonal variation, in vitro selection or cryopreservation of valuable genotypes, which can be very useful for genetic improvement of this crop. In this review, progress in olive somatic embryogenesis is reported. All investigations carried out on this topic are examined and put together, clarifying possible confusing or misunderstanding details. Main factors influencing the different phases of this developmental pathway, i.e., induction and proliferation of embryogenic cultures, development and maturation of somatic embryos and their subsequent conversion into plants, are also analyzed and discussed. Advances thus far achieved in application of biotechnology to olive through somatic embryogenesis-based systems are revised as well.