Effect of growth regulators on micropropagation of different olive cultivars ( Olea europaea L.)

Olive (oleaeuropaea L.) is considered as the most extensively cultivated fruit crop due to its economic importance and nutritional values. Before the introduction of biotechnological techniques it was propagated by traditional methods which are sustained and laborious, having limited growth efficiency. Most of the work has been carried on plant regeneration by using different explants and different combinations of growth regulators. Keeping in view the importance of olive, attention should be paid to improve the technology to achieve 100% success in the micro propagation. Growth regulators and carbohydrate source have major role in micro propagation. Under particular conditions, olive cultivars display a high competence to propagate. Internal carbohydrates might interact with hormones and play a stimulatory effect on propagation. Various exogenously applied auxins primarily indolebutyric acid, Naphthaleneacetic acid and indoleacetic acid help promoting in vitro rooting of shoots. When used in combination with other hormones, they promote root initiation. For in vitro shoot initiation cytokinins have been suggested, most common form is zeatin, which induces satisfactory growth. Gibberellins have been suggested to increase fruit size and to control fruit drop. In this review, Olive micro propagation, with special focus on the effect of growth regulators on different olive cultivars has been reviewed..