Clonal In Vitro Propagation as a Tool for Production of High Quality Planting Material of Helichrysum italicum (Asteraceae)

Abstract

Helichrysum italicum (immortelle), Asteraceae, is a perennial plant species with increasing market demand for its essential oil possessing anti-inflammatory, antibacterial, and antioxidant properties. The present study deals with clonal in vitro propagation of high-productive immortelle individuals. In vitro culture was initiated from stem tips on basal MS medium and sub-cultured several times on the same medium or on media supplemented with activated charcoal or with different plant growth regulators. Plants differed by their height, ramification, in vitro rooting, and callus formation. The highest propagation rate of 13.5±4.2 new shoots per explant, along with spontaneous rooting, was noticed in spring on the control MS medium. About 180 plants were successfully ex vitro adapted first in a phytotron, then in a greenhouse, and 14 were transferred outdoor in the ex situ collection where they acclimatized and bloomed in the first season. The nuclear DNA amount in 65 individuals was measured by flow cytometry, and no deviations in the ploidy level were detected. The results suggest the genome of the in vitro obtained plants is stable. Essential oil was extracted by water distillation from two pooled samples, one for the mother plants and another one for the ex vitro adapted plants. The main components identified by GC/MS in both samples were α-pinene, nerol acetate, and γ-curcumene. The results proved that the method of the in vitro clonal propagation is reliable for obtaining of numerous true-to-type plants in a short time, by direct organogenesis of high-productive individuals of H. italicum.