Abstract Rhododendron tomentosum Harmaja (formerly Ledum palustre L.) is a medicinal peat bog plant native to northern Europe, Asia and North America. This plant has a distinctive aroma thanks to the presence of essential oil, to which it also owes its anti-inflammatory, analgesic, antimicrobial and insecticidal properties. However, in Europe R. tomentosum is classified as an endangered species, mainly due to degradation of peatlands. In the present work, the micropropagation protocol for R. tomentosum was established for the first time, providing both an ex situ conservation tool and a means of continuous production of in vivo and in vitro plant material for further studies. R. tomentosum microshoots were initiated from leaf explants and further multiplied using Schenk-Hildebrandt (SH) medium supplemented with 9.84 μM 2iP and 1.00 μM TDZ. The shoots were elongated on the SH medium supplemented with 24.6 μM 2iP and subsequently rooted using the perlite substrate saturated with half-strength Woody Plant medium supplemented with 1.0% sucrose and 4.92 μM IBA. The regenerated plants were hardened on the phytohormone-free SH medium and acclimatized using 3:1:1 deacidified peat:perlite:gravel substrate. The identity of the mother plant was confirmed at morphological and molecular levels and Random Amplified Polymorphic DNA (RAPD) method was implemented to assess the genetic fidelity of the regenerants. The essential oil content of the maternal plant, in vitro shoots and the regenerants was determined by steam-distillation, and the obtained volatile fractions were analyzed by GC/MS.

Abstract This study deals with populations of the European-South-Siberian geoelement Adenophora liliifolia (L.) A. DC. in the Czech Republic, Slovakia, Hungary, Romania, and Poland, where this species has its European periphery distribution. We studied the population size, genetic variability, site conditions, and vegetation units in which A. liliifolia grows. Recent and historical localities of A. liliifolia were ranked into six vegetation units of both forest and non-forest character. A phytosociological survey showed differences in the species composition among localities. Only a weak pattern of population structure was observed (only 22% of total genetic variation present at the interpopulation level, AMOVA analysis), with moderate values for gene diversity (Hj = 0.141) and polymorphism (P = 27.6%). Neighbor-joining and Bayesian clusterings suggest a similar genetic background for most of the populations from Slovakia, the Czech Republic, and Poland, contrary to the populations from Hungary, Romania, as well as two populations from Central and South Slovakia. This might be explained by a relatively recent fragmentation of the A. liliifolia populations in Central Europe. Nevertheless, it seems that several populations in Romania, South Hungary, and Slovakia were isolated for a longer period of time and their genetic differentiation is more evident.