EN
An efficient in vitro plant propagation procedure was established from the shoot tips of Rehmannia elata. Shoot proliferation was performed on Murashige and Skoog (MS) agar medium containing 0.57 μM of indole-3- acetic acid (IAA) and different concentrations (2–8 μM) of 6-benzylaminopurine (BAP), kinetin, or 2-isopentenyladenine (2iP). The highest multiplication rate (nine shoots and buds per explant after 4 weeks) was achieved on MS medium with IAA and 2iP (6 μM). All shoots developed an average of 7.92 roots of 29.6 mm length after 4 weeks of culture on MS medium with half the macro- and micronutrient content (1/2 MS) with 0.57 μM of indole-3-butyric acid. The plantlets were successfully transferred into a greenhouse and then the plants were grown in a field. The iridoid and phenylethanoid contents in multiple shoots as well as shoots and roots of 4-month-old field-grown plants of R. elata derived in vitro (from shoot tips) or from seeds were determined using UHPLC. Quantitative differences in production of secondary metabolites were found depending on the type of analyzed plant material. Harpagide, verbascoside, and isoverbascoside were identified in shoot culture, whereas additionally catalpol was detected in the shoots and roots of intact plants. The highest yield of harpagide was revealed in multiple shoots in the presence of 2iP (4 μM). Higher levels of catalpol, verbascoside, and isoverbascoside were found in in vitro derived plants than in seed-raised plants. The obtained shoot cultures as well as regenerated R. elata plants may be an efficient source of biologically active iridoid (catalpol, harpagide) and phenylethanoid (verbascoside, isoverbascoside) glycosides.