Seasonal Variation in Rooting ‘Nabali’ and ‘Raseei’ Olive Cuttings in Relation to Shoot Content of Endogenous Plant Hormones

This research was conducted to study the rooting ability of semi-hardwood stem cuttings in relation to seasonal changes in endogenous plant hormones of ‘Nabali’ and ‘Raseei’ olive shoots. This study was carried out at seven sampling dates. At each sampling date, cuttings were prepared and rooted in a greenhouse under intermittent mist. Thin layer chromatography was used for purification and identification of endogenous plant hormones (Indole-3-Acetic Acid (IAA), Abscisic Acid (ABA), Gibberellins (GAs) and Cytokinins) and high performance liquid chromatography was used for quantification of these hormones. Results indicated that ‘Raseei’ olive cuttings gave significantly higher rooting percentage and higher average number of roots per cutting than ‘Nabali’ at all sampling dates. IAA concentration in ‘Nabali’ buds was significantly higher than that of ‘Raseei’ during January, September and November. ABA concentration in ‘Nabali’ buds was significantly higher than that of ‘Raseei’ buds during January, September, November and December and lower during March. The high GAs concentration in ‘Nabali’ buds and leaves coincides with the low rooting percentage of the cuttings. No consistent relationship was established between cytokinins concentration in ‘Nabali’ and ‘Raseei’ buds and leaves and the rooting percentage of the cuttings