Improving the Adventitious Rooting Ability of Hard-to-Root Olive (Olea europaea L.) Cultivar Cuttings Through Inhibiting Strigolactone Biosynthesis

Strigolactones (SLs) are synthesized in roots and control plant development. As phytohormones, SLs regulate plant architecture, including roots. Recently, the inhibiting effects of SLs on the adventitious rooting have been identified. Olive (Olea europaea L.) is consumed for oil and table in Mediterranean countries and is an economically important crop. Turkey is one of the countries with the highest olive production. Olive is mostly propagated asexually via cuttings, however the rooting capacities of some agriculturally important olive cultivars is very low. Indole Butyric Acid (IBA) is commonly used to promote rooting of the olive cuttings, however it can be inadequate. Ayvalık is an easy-to-root cultivar and one of the most common cultivars grown for oil production and Domat is a hard-to-root cultivar which IBA is insufficient for inducing rooting. In our study, the effects of synthetic SLs rac-GR24 and SLs biosynthesis inhibitor TIS108 on the rooting ability of olive cuttings were investigated. As a result, the adventitious rooting ability was increased when a hard to root cultivar was treated with TIS108, indicating a promising future for olive cutting rooting. Therefore, our study will provide potentially new tools for propagation strategies using SLs in fruit trees.