Improving the adventitious rooting ability of hard-to-root olive (Olea europaea L.) cultivar cuttings through inhibiting strigolactone biosynthesis

Abstract

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 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 has mostly propagated asexually via cuttings, however, the rooting capacities of some agriculturally important olive cultivars are very low. Indole Butyric Acid (IBA) is commonly used to promote the rooting of 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 in 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.