The concept of the genus
L. has changed considerably since its first description. Most of the currently accepted species of the genus have traditionally been treated as separate genera in the group
...sensu lato:
L.,
sensu Miller or Moench, and
sensu Miller or Moench. This study aimed to gain a better insight into the species diversity of
L. from the Balkans by analyzing the taxa that have traditionally been placed in separate genera. The alkane profile and the micromorphological characteristics of the leaves are analyzed. The leaves are visualized using scanning electron microscopy, and alkanes are isolated using
-hexane as a solvent and analyzed using gas chromatography/mass spectrometry. The alkane profile showed the differentiation of the
-group from the other taxa based on the dominant
-C31, while most of the other taxa contained
-C33 as the dominant alkane. The micromorphological features also showed clear differences between the previously recognized genera, especially in the capitate trichomes. The results showed that micromorphological patterns are highly variable in certain groups of the genus
.
Groups of recent speciation are characterized by high levels of introgression and gene flow, which often confounds delimitation of species on a DNA basis. We analyzed nuclear DNA sequences (ETS ...spacer and the AGT1 gene) obtained from a large sample of the C. calocephala complex from the Balkan clade of Centaurea sect. Acrocentron (Compositae, Cardueae-Centaureinae) together with a wide representation of other species from the section. Our main goals were to verify the monophyly of the complex as currently defined and to examine the possible presence of introgression and gene flow. Within the complex, species are well-delimited from a morphological point of view and probably originated by allopatric speciation in the Balkan Peninsula. Our results confirm that the Balkan–Eurasian complex is a natural group, but the Centaurea calocephala complex shows a very complicated pattern and its phylogeny is not resolved. Our hypothesis suggests that altitudinal shifts in the transits from glacial to interglacial periods caused successive hybridization events, which are very evident from the DNA networks, between taxa not currently sympatric. As a result, confirmation of interspecific boundaries using molecular markers is extremely complicated.
Our research aimed to study high variability in Satureja montana L. (winter savory) essential oil composition indicated by the previous studies of this species. Winter savory is an aromatic and ...medicinal plant used in traditional medicine and flavoring due to its high essential oil content. Phytochemical investigations were done on individual plants from three S. montana subspecies (subsp. montana, subsp. variegata, and subsp. macedonica) collected from fourteen wild-growing populations in the western Balkans. Considering the number of sampels studied, the work reported here is the most extensive analysis of intra- and interpopulation variability of EOs in this species. The individual EOs were extracted using simultaneous distillation and extraction. The EO composition was dominated by monoterpenes (70.3–88.2%), followed by sesquiterpenes (8.1–25.0%). Almost one-half of the individuals had phenols (carvacrol and thymol) as dominant components, while others had aromatic, linear, or circular monoterpenes (p-cymene, linalool, geraniol, cis-sabinene hydrate). This led to the identification of five chemotypes, which showed geography-specific distribution. The dominant chemotypes in coastal populations (temperate climate with hot summers) were phenolic in S. montana subsp. variegata and subsp. montana, while p-cymene, linalool, cis-sabinene hydrate, and geraniol were more common in continental populations (colder climate with warm summers), irrespective of infraspecific taxonomy. This research confirmed strong genetic control of chemical composition. Additionally, these findings can contribute to domesticating specific chemotypes with desired EO profiles since the compounds mentioned above have distinct biological activities.
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•Evaluation of Satureja montana individual variability based on essential oils.•Five chemotypes are found in 14 populations, regardless of subspecies.•The most abundant are carvacrol and carvacrol–p-cymene type.•Phenolics are dominant in coastal while non-phenolics in continental climate.
In this work, the essential oil of black pine (Pinus nigra J. F. Arnold) was used for the first time as a natural, ecological, and sustainable corrosion inhibitor for the acid cleaning of carbon ...steel. The essential oil was extracted by hydrodistillation using a Clevenger-type apparatus, and the oil was analyzed by gas chromatography–flame–ionization detection (GC–FID) and gas chromatography–mass spectrometry (GC–MS). The most abundant components in the essential oil were α-pinene, germacrene D, (E)-cariophyllene, and β-pinene. The inhibition efficiency was determined by electrochemical methods (electrochemical impedance spectroscopy and potentiodynamic polarization measurements). The results showed that the inhibitory efficiency of the black pine essential oil increases with time, reaching the highest values after 4 h of immersion for all inhibitor concentrations. It was also shown that black pine essential oil is a mixed-type inhibitor. The contact angle measurements confirmed that the black pine essential oil, as a new natural, environmentally safe inhibitor, is able to protect carbon steel from corrosion in a 1 M HCl solution.
Lignocellulosic biomass is considered as a recalcitrant substrate for anaerobic digestion due to its complex nature that limits its biological degradation. Therefore, suitable preprocessing for the ...improvement of the performance of conventional anaerobic digestion remains a challenge in the development of anaerobic digestion technology. The physical and chemical characteristics of wheat straw (WS), as a representative lignocellulosic biomass, have a significant impact on the anaerobic digestion process in terms of quantity and quality of the produced biogas. This study aimed at investigating the enzymatic saccharification and detoxification of straw prior to anaerobic digestion with the final objective of enhancing the performance of conventional anaerobic systems of recalcitrant fractions of agricultural waste. The experimental activity was performed in lab and pilot scale treating WS. Alkaline delignification of straw using sodium hydroxide (NaOH) was studied prior to enzymatic hydrolysis for the production of easily biodegradable sugars. After defining the optimum conditions for the pretreatment scheme, the anaerobic digestability of the effluents produced was measured. Finally, the final liquid effluents were fed to a pilot scale anaerobic digester of 0.5 m
3
volume, applying an increasing organic loading rate (OLR) regime (in terms of chemical oxygen demand (COD) from 0.2 to 15 kg COD/m
3
/day). The optimum conditions for the delignification and enzymatic hydrolysis of WS were defined as 0.5 M NaOH at 50 °C for 3–5 h and 15 μL Cellic CTec2/g pretreated straw at 50 °C. It was proven that the resulting liquid effluents could be fed to an anaerobic digester in the ratio that they are produced with satisfactory COD removal efficiencies (over 70%) for OLRs up to 10 kg COD/m
3
/day. This value is correspondent to a hydraulic retention time of around 7.5 days, much lower than the respective one for untreated straw (over 12 days).
The cuticle is important in the interaction between the plant and its environment, especially in the dry areas. Four species of junipers from the section Sabina wild growing in the Balkans were ...selected to study leaf wax composition using GC/MS and GC‐FID and its surface morphology under SEM to understand the correlation between the distribution and/or habitat of these species and their cuticles. SEM micrographs showed continuous, smooth epicuticular layers with crusts in all species but with a species‐specific distribution of different 3D crystalloid types and different cuticle thickness. n‐C33 alkane was the most abundant compound, followed by n‐C29, n‐C31, and n‐C35, depending on the species and the site. The average chain length (N) was the lowest in J. phoenicea, but with the greatest dispersion around it. At the same time, the two most continental species (J. foetidissima and J. excelsa) show the N with the lowest dispersion around it. The statistical analyses confirmed the significance of climate on the evolution of the specific epicuticular wax composition in studied junipers.
Juniperus deltoides R.P.Adams is a prickly, evergreen shrub that grows in the East Mediterranean on dry hills and mountains. Needle-like leaves have a thick cuticular layer on the surface, which ...serves as the ultimate barrier for prevention of water loss. n-Alkanes comprise the biggest part of this hydrophobic wax mixture. These compounds are studied as chemophenetic characters due to their chemical and physiological stability, and strong genetic control. Six central Balkan populations were studied and compared to one eastern and one western. Fifteen n-alkanes were identified, with C33 being dominant in all samples. Univariate and multivariate statistical analyses separated western population from all central Balkan populations, while the eastern Balkan population showed high similarity with the central ones. Climatic, orographic and pedological characteristics of the studied localities were also taken into account.
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•Epicuticular alkanes of eight J. deltoides population were analysed.•n-Alkanes profiles varied between the studied populations.•Adriatic population separates strongly from central Balkan populations.•Populations growing in drier climate have dominant longer-chain alkanes.
In this work we analysed the essential oils (EO) obtained by hydrodistillation from the aerial parts of five Artemisia species (A. arborescens L., A. campestris L., A. lobelii All., A. annua L. and ...A. absinthium L.) originated from Serbia, Montenegro, and Libya, by gas chromatography coupled with mass spectrometry. In total, 126 compounds were detected, and 120 were identified. Even though a high number of compounds were detected, each individual sample had only 25 to 50, attesting to a great diversity of compounds between taxa. Depending on the species and the locality (geographical origin), EO was dominated by either monoterpenes or sesquiterpenes, with β-pinene, chamazulene, germacrene D, camphor, pinocarvone and thuja-2,4(10)-diene being the dominant compounds. The chemophenetic value of the EO compositions was discussed in relation to the results of the multivariate statistical test, including the detailed survey of the available literature data.
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•Essential oil of five Artemisia species was analysed.•Essential oil composition varied greatly between the studied taxa.•Depending on the taxon and locality different groups of terpenes dominated.•Results of chemophenetic analyses are in concordance with the molecular data.
In the present work, the leaf essential oil from 97 individuals of Juniperus phoenicea var. turbinata (Guss.) Parl. from the Balkan Peninsula was analyzed. The essential oil was dominated by ...monoterpene hydrocarbons (45.5 – 71.8%), of which α‐pinene was the most abundant in almost all of the samples (38.2 – 55.8%). Several other monoterpenes and sesquiterpenes were also present in relatively high abundances in samples such as myrcene, δ‐3‐carene, β‐phellandrene, α‐terpinyl acetate, (E)‐caryophyllene and germacrene D. Multivariate statistical analysis suggested the existence of three possible chemotypes based on the abundance of the four components. Even though the intrapopulation variability was high, discriminant analysis (DA) was able to separate populations. DA showed high separation between western and eastern populations but also grouped geographically closer populations along the west Balkan shoreline. The potential influence of the climate on the composition of the essential oil was also studied.
Satureja kitaibelii Wierzb. ex Heuff. is endemic species of central Balkan that lives along the Balkan mountains range. The aim of this research was to study the variability of n-alkane profiles of ...four S. kitaibelii populations growing wild in Serbia in regards to biogeography and chemotaxonomy. Using GC/MS and GC/FID, seventeen n-alkane homologues (C19–C35) were identified. n-Hentriacontane (C31) was dominant in all populations, except in population Djerdap and Rtanj were it was co-dominant with n-nonacosane (C29). Population Temšica and Poganovo also had high percentages of n-nonacosane and n-tritriacontane (C33). However, these two compounds had similar quantities in population Poganovo. Statistical analyses showed differences between studied populations based on n-alkane profiles. Moreover, geographically closer populations had a similar profile.
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•n-Alkane profile of endemic S. kitaibelii populations dominated by C31.•Based on C29and C33 northern populations separated from southern ones.•Profiles do not correlate significantly with climate, altitude and inclination.•Geographically closer populations show more similar n-alkane profiles.
