Impact of Plant Growth Regulators on Greek oregano Micropropagation and Antioxidant Activity

Abstract

This study highlights the development and achievements made for the micropropagation of Greek oregano (Origanum heracleoticum L. ) using stem tip explants. The shoots were cultured on Murashige and Skoog (MS) medium followed different concentrations of plant growth regulators (PGR) - 6-benzyl aminopurine, thidiazuron and zeatin at concentrations (0.5 or 1.0 mg L-1). The induction of multiple shoots from stem tip segments was the highest in MS medium supplemented with 1.0 mg L-1 zeatin. It was the most effective medium for shoot formation, which produced multiple shoots (2.7) with an average height of 3.5 cm. These shoots were transferred on half strength MS medium containing three different auxins: indole-3-butyric acid, α-naphthalene acetic acid or indole-3-acetic acid (0, 0.1 and 0.5 mg L-1) for rooting, Multiple shoots were the most efficiently rooted on ½ MS medium supplemented with 0.5 mg L-1indole-3-butyric acid. Rooted plants showed the best adaptation on pots containing peat: perlite (2: 1 v/v). The higher rates of shoots number and height per plant have a positive relationship with the production of metabolites with antioxidant potential as phenols and flavonoids as well as with ferric reducing antioxidant potential.