Comparison in Chemical Compositions of the Essential Oil from Leaves of Lippia citriodora H.B.K. Plantlets Produced from Micro-propagation and Stem Cutting

Lemon verbena (Lippia citriodora H.B.K.) is an aromatic and medicinal plant of family Verbenaceae, which cultivated in the North region of Iran. This comparative study was carried out on essential oil content and composition of Lippia citriodora H.B.K. from micro-propagated and rooted apical stem cutting plantlets. The micro-propagated plantlets were obtained by use of synthetic medium condition containing basal MS medium supplemented with 1 mg.l-1 BAP, 0.5 mg.l-1 IBA, 1 g.l-1 activated charcoal, 30 g.l-1 sucrose, and 7 g.l-1 agars. Pre-acclimated plantlets were transferred to the research greenhouse. To determine the essential oil content and its components in two types of plantlets, leaves of L. citriodora were collected in August 2013 before flowering stage. The essential oils were extracted by Clevenger apparatus and their constituents were determined by GC-MS. The results indicated that thirty-two components were determined in the stem cutting derived plantlets. The main components of stem cutting plantlets were geranial (13.81%), limonene (11.41%), spathulenol (11.22%), and neral (11.21%). Thirty-five components were also obtained in the micro-propagated plantlets. The main components of micro-propagated plantlets were consisted of geranial (17.26%), neral (14.48%), 6-methyl-5-hepten-2-one (10.75%), and limonene (8.93%). In general, the essential oil content of stem cutting plantlets was higher than micro-propagated plantlets, while the number of compounds and amount of geranial and neral in stem cutting plantlets was lower than micro-propagated plantlets.