Phytochemical and molecular characterization of centaury (Centaurium erythraea Rafn) populations from the Balkan Peninsula

Kičica (Centaurium erythraea Rafn) je farmakološki atraktivna biljna vrsta koja pokazuje čitav spektar bioloških aktivnosti, a čiji je biodiverzitet nedovoljno istražen. Osnovni cilj predstavljenog istraživanja jeste analiza genetičkog i fitohemijskog diverziteta kičice na teritoriji Balkanskog poluostrva. U tom smislu, formirana je kolekcija semena kičice poreklom iz prirodnih populacija, koja oslikava diverzitet vrste na ovom području. Istraživanja su uključila 43 populacije ove vrste, od kojih je 41 poreklom sa Balkanskog poluostrva. Za procenu genetičkog diverziteta optimizovane su tehnike RAPD (Random Amplified Polymorphic DNA) i TRAP (Target Region Amplification Polymorphism) molekularnih marker sistema. DNK upotrebljena u ovim analizama je izolovana iz biljaka gajenih u uslovima in vitro, kako bi se obezbedila autentičnost DNK kičice i eliminisala mogućnost kontaminanacije stranom DNK. Za potrebe dobijanja što većeg broja informativnih jedinica, upotrebljeno je 16 desetomernih prajmera u slučaju RAPD markera, pri čemu je dobijeno ukupno 408 različitih PCR produkata, dok su za TRAP markere upotrebljene kombinacije tri specifična i tri arbitrarna prajmera i dobijeno je 767 fragmenata DNK. Specifični prajmeri korišćeni u TRAP analizama, konstruisani su na osnovu sekvenci RNK kičice sa visokim stepenom homologije sa DNK sekvencama za sledeće enzime: geraniol 10-hidroksilaza, citohrom P450 reduktaza i sekologanin sintaza, objavljenih u elektronskim bazama podataka. Primenom molekularnih markera dobijen je visok procenat polimorfizma, a informativnost odabranih prajmera ili kombinacija prajmera je potvrđena pomoću više parametara. Ustanovljena je vrlo niska unutarpopulaciona genetička varijabilnost kičice, što može da se objasni velikim udelom samooplodnje i geitonogamije u nastanku Rezime/Summary semena kod prirodnih populacija, kao i snažnim genetičkim driftom. S obzirom da se kičica javlja u malim i fragmentisanim populacijama, između kojih verovatno ne postoji protok gena, očekivana je i visoka genetička diferenciranost analiziranih populacija, što je potvrđeno i metodama molekularnih markera. Osim toga, molekularnim markerima vrlo uspešno su razdvojene diploidne od tetraploidnih populacija kičice. Tetraploidne populacije se prilično jasno diferenciraju u posebne grupe koje su povezane sa njihovim geografskim poreklom, naročito kada su primenjeni RAPD markeri. Značajna korelacija pokazana je između genetičkih sličnosti populacija kičice sa Balkanskog poluostrva, dobijenih pomoću dva tipa molekularnih markera i geografskih distanci lokaliteta sa kojih ove populacije potiču. Određivanje i kvantifikacija osnovnih jedinjenja sekundarnog metabolizma kičice, sekoiridoidnih glikozida, dalo je značajan doprinos proceni varijabilnosti analiziranih populacija kičice. Sadržaj svercijamarina, dominantnog sekoiridoidnog glikozida u nadzemnim delovima biljaka gajenih u uslovima staklare, pokazao se kao najznačajniji faktor međupopulacione varijabilnosti kičice. Uz to, pokazana je značajna korelacija između sadržaja sekoiridoidnih glikozida i genetičke sličnosti populacija, korišćenjem oba tipa molekularnih markera, s tim što je snažnija korelacija primećena u slučaju TRAP markera. Predstavljena procena genetičkog i fitohemijskog diverziteta kičice daju osnovu za eventualnu zaštitu ukupnog biodiverziteta ove vrste na Balkanskom poluostrvu, kao i za odabir genotipova za zasnivanje i unapređenje njene plantažne proizvodnje.Centaury (Centaurium erythraea Rafn) is a medicinal and pharmacologically attractive plant species which has a wide range of biological activity. The main objective of presented study was to estimate genetic and phytochemical diversity of centaury within the Balkan Peninsula. With that purpose, seed collection of natural centaury populations was established. The study included 43 populations of C. erythraea, among which 41 originated from the Balkan Peninsula. Molecular marker techniques, such as RAPD (Random Amplification Polymorphic DNA) and TRAP (Target Region Amplification Polymorphism) were optimized to investigate the genetic diversity among these populations. DNA used in these analyses originated from in vitro grown plants to ensure the authenticity of centaury DNA by eliminating the possibility of its contamination by extraneous DNA. To acquire sufficient informational characters, 16 decameric primers were applied in RAPD assays, which produced 408 different PCR products, while TRAP assays included the combinations of 3 specific and 3 arbitrary primers, resulting in 767 fragments of DNA. Specific primers used for TRAP analyses were constructed according to the RNA sequences, showing high homology with DNA sequences published in electronic data bases for following enzymes: geraniol 10-hydroxylase, cytochrome P450 reductase and secologanin synthase. Molecular markers provided a high percentage of polymorphism. The informativeness of single primers (RAPD) of primer combinations (TRAP) was confirmed by various parameters. Low within-population genetic variability of natural populations of centaury could be explained by the high levels of selfing or geitonogamy in the process of fertilization and by strong genetic drift. Due to the fact that centaury grows in small, fragmented populations and that gene flow between them probably does not exist, a high genetic differentiation of analyzed populations was expected and this was confirmed by molecular markers. Moreover, molecular markers Резиме/Summary efficiently differentiated diploid populations from tetraploids. Tetraploid populations were clearly clustered into groups related to their geographic origin, especially when RAPD markers were analyzed. Genetic similarity data between the Balkan Peninsula populations, obtained with either RAPD or TRAP markers, significantly correlated with the geographic distances between localities of their origin. Identification and quantification of secondary metabolite compounds, secoiridoid glycosides, highly contributed to the estimation of diversity of centaury populations in the analyzed region. A dominant secoiridoid glycoside in aerial parts of plants grown under greenhouse conditions was swertiamarin, which pointed to the interpopulation variability of centaury. Furthermore, a significant correlation between the secoiridoid glycosides content and genetic similarity of populations has been obtained, though a higher correlation was recorded for TRAP markers. The genetic and phytochemical diversity estimation of centaury from the Balkan Peninsula provides a basis for future biodiversity conservation efforts and also for high-productive genotype selection and field production improvement

Optical sorting and detection of sub-micron objects in a motional standing wave

An extended interference pattern close to surface may result in both a transmissive or evanescent surface fields for large area manipulation of trapped particles. The affinity of differing particle sizes to a moving standing wave light pattern allows us to hold and deliver them in a bi-directional manner and importantly demonstrate experimentally particle sorting in the sub-micron region. This is performed without the need of fluid flow (static sorting). Theoretical calculations experimentally confirm that certain sizes of colloidal particles thermally hop more easily between neighboring traps. A new generic method is also presented for particle position detection in an extended periodic light pattern and applied to characterization of optical traps and particle behaviorComment: 5 pages, 6 figures, Optical Trapping pape

Directed assembly of optically bound matter

We present a study of optically bound matter formation in a counter-propagating evanescent field, exploiting total internal reflection on a prism surface. Small ensembles of silica microspheres are assembled in a controlled manner using optical tweezers. The structures and dynamics of the resulting optically bound chains are interpreted using a simulation implementing generalized Lorentz-Mie theory. In particular, we observe enhancement of the scattering force along the propagation direction of the optically bound colloidal chains leading to a microscopic analogue of a driven pendulum which, at least superficially, resembles Newton’s cradle

Growth curves of highly inbred lines of fowl and their F1 hybrids

International audienc

Observations of a PT-like phase transition and limit cycle oscillations in non-reciprocally coupled optomechanical oscillators levitated in vacuum

We explore the collective non-Hermitian dynamics of a pair of non-conservatively coupled optomechanical oscillators. The oscillators consist of silica nanoparticles optically levitated in vacuum in two parallel pairs of interfering counter-propagating laser beams. By adjusting the relative phase, polarization, and separation of the trapping laser beams, we set the optical interaction between the particles to be purely non-reciprocal. Continuously varying the relative power of the trapping beams over a predefined range takes the system through transition, analogous to a parity-time (PT) phase transition. Decreasing the dissipation rate within the non-equilibrium phase induces a Hopf bifurcation resulting in the formation of collective limit cycle oscillations similar to those observed in phonon lasers. Such systems provide a novel platform for exceptional point optomechanical sensing and due to their wide flexibility and tunability of the interactions can be extended to multi-particle systems, paving the way for the development of topological optomechanical media

Experimental amplification and squeezing of a motional state of an optically levitated nanoparticle

A contactless control of fluctuations of phase space variables of a nanoobject belongs among the key methods needed for ultra-precise nanotechnology and the upcoming quantum technology of macroscopic systems. Here we utilize the experimental platform of a single levitating nanoparticle (NP) to demonstrate essential protocols providing linear amplification of the mechanical phase space variables together with squeezing of phase space probability distribution. The protocol combines a controlled fast switching between the parabolic trapping potential and either weak parabolic or inverted parabolic amplifying potential leading to amplification of mean value and variance (fluctuations) along an arbitrary phase space variable and squeezing along the complementary one. The protocol is completed with cold damping scheme to control the initial fluctuations of the NP phase space variables. We reached the amplification gain $|G|>2$, the squeezing coefficient above 4 dB, and the second-order energy correlation function approaching 3 which corresponds to a maximum for a stochastic non-equilibrium classical state. These experimental results will already allow pre-amplification and manipulation of nanomechanical NP motion for all quantum protocols if the NP cooling towards the ground state is applied