Enhanced production of valerenic acids and valepotriates by in vitro cultures of Valeriana officinalis L.

Valerian (valeriana officinalis l.) is an important medicinal plant that is widely exploited for itsroots and rhizomes which contain valepotriates and valerenic acids (with putative pharmacologicalactivities). thus root proliferation of valerian is very important. the aim of this study was to establisha practical tissue culture method for rapid and large-scale induction of v. officinalis l. roots with highcapacity for production of valerian phytomedicine. explants derived from leaves, petioles, and rootsegments (both basal and apical) of four months aged plantlets were cultured on ms basal mediumsupplemented with different concentrations (0.625-5 μm) of auxin and cytokinin hormones. thenaccumulation of valerenic acids and valepotriates in developed root cultures was studied to find thebest yielding conditions. maximum valerenic acids (0.84%) and valepotriates contents (7.41%) werequantified in roots developed on petiole explants and in roots formed on root basal segments inmedium supplemented with 1.25 μm and 0.625 μm indole-3-acetic acid, respectively. these valueswere significantly (p<0.05) higher than those in roots from basal and apical root segments withoutplant growth regulators as control. the highest average number (29.00) of directly formed rootsdeveloped on leaf explants in media supplemented with 5 μm α- naphthalene acetic acid. alsomaximum number of indirectly developed roots (30.05) was observed on root apical segments inmedia containing 2.5 μm α- naphthalene acetic acid. these results suggest that besides the appliedplant growth regulators, the type of primary explant is also relevant for biosynthetic capacity of thesemetabolites in root cultures.