Rada Matić

Sand topography influences the distribution of xerohalophytic vegetation on a southern Adriatic beach in Montenegro

Abstract Totally, 26 xerohalophytic species belonging to the associations Cakilo-Xanthietum italici and Echinophoro-Elymetum farcti were registered at the Velika plaža beach (Montenegro); they were distributed following the spatial succession common in this type of habitat. Three transects of different terrain morphology (positioned perpendicularly to the shoreline) were surveyed to establish if there were any differences in the floristic composition and species distribution due to the configuration discrepancy. Moreover, each transect was divided into zones: The first zone from 0 to 30 m inland, the second zone from 30 m to 60 m inland, and the third zone from 60 m to the end of beach (75–115 m, depending on transect length). The floristic composition was relatively uniform in the different transects. However, the number of individuals per species differed significantly among these transects. An analysis of the qualitative composition of transects/zones showed high differences between zones within transects I and II, whereas species composition of zones within transect III was mostly similar. When analyzing the quantitative composition of species, a positive correlation between the distance from the shoreline and the number of individuals per species in transects I and II was registered for most analyzed species (Spearman correlation, p < 0.001). This indicates that terrain configuration affected the ability of present species to become established and propagate.

Significance of diarylheptanoids for chemotaxonomical distinguishing between Alnus glutinosa and Alnus incana

Abstract Diarylheptanoids are a group of secondary metabolites widely distributed in the Betulaceae family and characteristic for Alnus species. In this study, the chemotaxonomic power of diarylheptanoids, such as hirsutanonol-5-O-β-d-glucopyranoside, rubranoside A, oregonin, platyphylloside, alnuside A and hirsutanonol, has been investigated in combination with principal component analysis (PCA) for differentiation of Alnus species. Concentrations of six diarylheptanoids in the bark extracts of two natural populations of Alnus glutinosa (black alder) and Alnus incana (gray alder) were determined by ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). PCA clearly shows the separation of three groups. Populations I (A. glutinosa) and II (A. incana) both consisted of individuals of the corresponding species. Four individuals from both sampled populations formed a separate group (population III), which possibly represents a hybrid group. Accordingly, diarylheptanoids may serve in combination with PCA as chemotaxonomic markers at the species level, which may also reveal hybrid species.

Geographic variability of selected phenolic compounds in fresh berries of two Cornus species

Key messageThe contents of quercetin glycosides and neochlorogenic acid in fresh berries of Cornelian cherry and Common dogwood were assessed through LC–MS/MS analysis to determine chemical differentiation between two distant populations of each species.AbstractThe aim of this study was to investigate the chemical variability of Cornus mas and Cornus sanguinea on the basis of the content of six selected phenolic compounds in fruit extracts. Fruits were sampled at the time of full ripening, mid-September, from two localities that differed in terms of orographic and environmental conditions. Fresh fruit extracts were analyzed by LC–MS/MS to determine the presence and contents of neochlorogenic acid, quercitrin, isoquercetin, hyperoside, rutoside and querciturone. While all of the tested compounds were detected in both species, their content was several times higher in C. sanguinea. Locality-dependent differences were tested by appropriate statistical tests, which confirmed that the contents of all compounds significantly differed in C. mas, whereas the content of only one compound differed in C. sanguinea. Differences between populations were also revealed by PCA analyses. Both species showed clear separation of populations based on the analyzed phenolic compounds. The results showed that a specific environment can significantly affect the contents of certain secondary metabolites, as in the case of C. mas, and/or that the synthesis of these compounds can be to a lesser extent influenced by external factors, as in the case of C. sanguinea.

Chemical Composition and Interpopulation Variability of Essential Oils of Taxus baccata L. from Serbia

The composition of the essential oil of the twigs and needles of Taxus baccata L. from three natural populations in Serbia has been determined by GC/MS analysis. Of the 91 detected compounds, 87 were identified. The most abundant compound classes were aliphatic alcohols, terpenes, aliphatic hydrocarbons, and aliphatic aldehydes, which together comprised ca. 86.92% of the total oil composition. The dominant constituents were oct‐1‐en‐3‐ol (23.48%), (3Z)‐hex‐3‐en‐1‐ol (11.46%; aliphatic alcohols), and myrtenol (11.38%; oxygenated monoterpene). The PCA of 22 selected compounds revealed differentiations of populations based on geographic distribution. The CA showed that Populations I and II from the Dinaric Alps were similar, and that Population III from the Balkan mountain system was distinct. This was the first investigation of interpopulation variability of T. baccata populations based on essential oil composition. The results of this study were compared with those of previous studies concerning volatile compounds produced by Taxus species. The results indicate that the essential oil content of T. baccata populations from this study is unique, mostly resembling the population from southeast Serbia.

Essential-Oil Variability in Natural Populations of Pinus mugo Turra from the Julian Alps.

The composition and variability of the terpenes and their derivatives isolated from the needles of a representative pool of 114 adult trees originating from four natural populations of dwarf mountain pine (Pinus mugo Turra) from the Julian Alps were investigated by GC‐FID and GC/MS analyses. In total, 54 of the 57 detected essential‐oil components were identified. Among the different compound classes present in the essential oils, the chief constituents belonged to the monoterpenes, comprising an average content of 79.67% of the total oil composition (74.80% of monoterpene hydrocarbons and 4.87% of oxygenated monoterpenes). Sesquiterpenes were present in smaller amounts (average content of 19.02%), out of which 16.39% were sesquiterpene hydrocarbons and 2.62% oxygenated sesquiterpenes. The most abundant components in the needle essential oils were the monoterpenes δ‐car‐3‐ene, β‐phellandrene, α‐pinene, β‐myrcene, and β‐pinene and the sesquiterpene β‐caryophyllene. From the total data set of 57 detected compounds, 40 were selected for principal‐component analysis (PCA), discriminant analysis (DA), and cluster analysis (CA). The overlap tendency of the four populations suggested by PCA, was as well observed by DA. CA also demonstrated similarity among the populations, which was the highest between Populations I and II.

Comparative ecophysiology of seven spring geophytes from an oak-hornbeam forest

The ecophysiological traits of seven spring forest geophytes (Gagea lutea L., Scilla bifolia L., Ficaria verna L., Corydalis cava (L.) Koerte, Arum maculatum L., Dentaria bulbifera L. Crantz, and Ornithogalum pyrenaicum L.) were compared in terms of photosynthetic performance, chlorophyll content, specific leaf area, and relative water content from early spring to summer under field conditions. Light response curves were measured for each species throughout the continuum of its phenological phases to quantify the photosynthetic photon flux density at light saturation, light-saturated photosynthetic rate and light compensation point. All species showed similar seasonal dynamics of the assessed parameters, but the average seasonal values of photosynthesis, dark respiration and maximum efficiency of the photosystem II, as well as light saturation point and light compensation point, differed significantly. From the ecophysiological parameters that were determined it appears that the investigated species can be grouped in two categories: ‘early-flowering’ spring ephemerals (higher PN, Icomp, Isat, Rd, lower Fv/Fm, more shade-avoiding strategy): G. lutea, S. bifolia, F. verna, C. cava and ‘later-flowering’ spring ephemerals (lower PN, Icomp, Isat, Rd, higher Fv/Fm, more shade-tolerating strategy): A. maculatum, D. bulbifera, and O. pyrenaicum.

Inter- and intraspecific variability of selected diarylheptanoid compounds and leaf morphometric traits in Alnus glutinosa and Alnus incana

Abstract The reliability of diarylheptanoids as chemotaxonomic markers at inter- and intraspecific levels has been investigated. Six diarylheptanoids were quantified in bark ethanol extracts of four Alnus spp. populations by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The populations described here as locus classicus Alnus glutinosa (I) and locus classicus Alnus incana (III) are clearly differentiated. Compared to population I, individuals in population III have higher extract yields and hirsutanonol-5-O-β-D-glucopyranoside content and lower contents of hirsutanonol, rubranoside A and oregonin. Individuals from neighboring populations of A. glutinosa (II) and A. incana (IV) share similar contents of hirsutanonol. All the studied populations exhibit a high intrapopulation variability of the selected diarylheptanoids; they have a heterogeneous chemotype and they partially overlap. The geographical proximity of populations II and IV increases their chemical similarity. Principal component analysis (PCA) clearly shows that the biggest dispersion of individuals lies within population IV. The reason for its heterogeneity might be its physical proximity to population II, i.e. the appearance of hybrids. Also, geometric morphometrics of leaves was performed as a screening criterion for spontaneous hybrids.

First evidence and quantification of quercetin derivatives in dogberries (Cornus sanguinea L.)

Abstract Aim: C. sanguinea L. is a widespread European shrubby species. It is a potential source of biologically active compounds, especially antioxidants, as indicated by the dogberries’ black color. The aim of the present study was to determine the content of several quercetin derivatives in the dogberries and to evaluate phytogeographical variability of these compounds. Materials and methods: The dogberries were collected in the middle of September at two natural habitats of this species: Mt. Avala and Lake Zlatar, Serbia. The extract obtained from fresh fruits was subjected to LC-MS/MS analysis to identify and quantify the content of five quercetin derivatives: quercetin-3-O-glucuronide (Q-3-O-GlcA), quercetin-3-O-galactoside (Q-3-O-Gal), quercetin-3-O-rutinoside (Q-3-O-Rut), quercetin-3-O-glucoside (Q-3-O-Glc) and quercetin-3-O-rhamnoside (Q-3-O-Rha). Results: All of examined quercetin derivatives were detected in extract of fresh dogberries and their contents were in the following order: Q-3-O-GlcA>Q-3-O-Gal>Q-3-O-Rut>Q-3-O-Glc>Q-3-O-Rha. The average amount of Q-3-O- Rut varied significantly and depended on the geographic origin of the fruit sample. Conclusions: These results indicate that dogberries could be a potential source of natural antioxidants, and encourage further investigation of this species considering that it has not yet been exploited in either nutrition or as a source of important pharmacological compounds.

Exploration of sexual dimorphism of Taxus baccata L. needles in natural populations

Key messageMultivariate morphometric analyses were used for the first time to examine sexual dimorphism and shape variability of needles in natural populations of relict speciesTaxus baccataL.AbstractNeedle morphology and intraspecific variability of Taxus baccata L. were examined for the first time in Serbian natural populations (in the central Balkans). A geometric morphometric approach was used to assess size and shape variation of needles and to address questions of sexual dimorphism and phenotypic plasticity. Population-specific sexual size dimorphism was found. In the Tara population, females had larger needles than males and this was in accordance with earlier reports on T. baccata dimorphism. We found it unusual that in the other two populations, Kopaonik and Malinik, sexual size dimorphism was constrained and the sexes had needles of equal size. Multivariate analysis of needle shape revealed that the Tara population differed from the other two populations and was characterized by straighter, more symmetric needles. The absence of sexual size dimorphism and the less symmetrical shape of needles could be signs of a deviation from optimal conditions for yew in the Kopaonik and Malinik populations as regards mean annual temperature, precipitation, humidity and soil quality. There is also an indication that sexual size dimorphism in needles arises from a modification in female morphology and that female yews carry more information about climate. However, the conclusions presented in this study have certain limitations because of the small number of individuals in the Tara population (only 3 female and 4 male plants) that represent the quasi-total of adult yews at this site.

Assessing terpene content variability of whitebark pine in order to estimate representative sample size.

In studies of population variability, particular attention has to be paid to the selection of a representative sample. The aim of this study was to assess the size of the new representative sample on the basis of the variability of chemical content of the initial sample on the example of a whitebark pine population. Statistical analysis included the content of 19 characteristics (terpene hydrocarbons and their derivates) of the initial sample of 10 elements (trees). It was determined that the new sample should contain 20 trees so that the mean value calculated from it represents a basic set with a probability higher than 95 %. Determination of the lower limit of the representative sample size that guarantees a satisfactory reliability of generalization proved to be very important in order to achieve cost efficiency of the research. [Projekat Ministarstva nauke Republike Srbije, br. OI-173011, br. TR-37002 i br. III-43007]