Abstract
Girdling (a ring of bark approximately 5 mm wide) was applied on olive mother plants to investigate its effect on the rooting ability of cuttings. Treatment was applied in autumn and in spring. The cuttings were then immersed for 5 s into 2000 mg L−1 indole-3-butyric acid (IBA) in a 45% v/v ethanolic solution. Thirty days after girdling, cuttings were taken from girdled and control shoots from the part just above the girdle zone (basal), as well as from the part right above (middle). The base of the cuttings was collected, and the concentration of polyamines, phenolic compounds and soluble carbohydrates was determined. Girdling enhanced the rooting performance of the cuttings, while autumn proved to be a better season for rooting compared to spring. Girdling positively affected the concentration of all the measured parameters. The main characteristics of autumn cuttings were the high levels of glucose, mannitol, free and total polyamines, hydroxytyrosol, tyrosol, verbascoside, oleuropein, quercetin and luteolin. The cuttings taken from the middle part of the girdled shoot exhibited high sucrose, glucose, mannitol, free polyamines, hydroxytyrosol, luteolin-7-glucoside, total phenols and flavanol concentrations. Nonetheless, further research is needed in order to draw conclusions on the overall efficiency of girdling on inducing rooting of olive cuttings.
Highlights
The olive is one of the most ancient fruit tree species, and is traditionally cultivated in the Mediterranean basin with great socioeconomic impact for the countries in the region.Since 2000, there has been a remarkable rapid expansion of olive cultivation in countries such as Australia, China, Argentina, Chile and New Zealand
The differences in genotypes, the kind of hormone applied and its concentration, the rooting medium, the nutritional status of mother plants, and the phenological stage are some of the possible factors that affect the rooting ability in olive cuttings [4,5,6,7]
The experiments were carried out at the orchard of the Agricultural University of Athens on 30-year-old olive trees (Olea europaea L.) cv Kalamata grown in the field
Summary
The olive is one of the most ancient fruit tree species, and is traditionally cultivated in the Mediterranean basin with great socioeconomic impact for the countries in the region.Since 2000, there has been a remarkable rapid expansion of olive cultivation in countries such as Australia, China, Argentina, Chile and New Zealand. The differences in genotypes, the kind of hormone applied and its concentration, the rooting medium, the nutritional status of mother plants, and the phenological stage are some of the possible factors that affect the rooting ability in olive cuttings [4,5,6,7]. Endogenous factors such as polyamines and phenolic compounds, as well as the interactions between them, may influence the primary triggers for root initiation [8]. Cristofori et al [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
