Gymnosperms are a very old and small group of plants compared to angiosperms. Contemporary science recognizes about 650 extant conifers worldwide. This review focuses on species of the Pinaceae ...family found in Europe. There are 23 species from the genera Abies, Larix, Picea, and Pinus. Some of them are widespread in Europe, but others have fragmented and limited distribution and are classified as relic, endemic, or endangered. The aim of this review is providing cumulative information about the variability of needle morpho-anatomy, terpenes, and n-alkanes, as well as the genetics of the Pinaceae species, native to Europe. The first morpho-anatomical examinations of needles were conducted in the 19th century. A lot of species have been investigated up to now, but the population variability of many conifer species is still not known. The composition and abundance of terpenes differ between genera and families but also within the same genus, pointing to their taxonomic importance. n-Alkanes on the needle wax surfaces of conifers are sometimes very useful markers of species and population variability. The most abundant n-alkanes in Abies species are nonacosane (C29), hentriacontane (C31), or heptacosane (C27), whereas in Larix decidua and the majority of Picea species, C31 is predominant. C31 and C29 are the dominant n-alkanes in the genus Pinus. The most extensive population-genetic studies of European representatives of the Pinaceae family have focused on Abies alba, Picea abies, Pinus nigra, and Pinus sylvestris, but also examined endemic species such as Abies borisii-regis, A. cephalonica, A. nebrodensis, and Picea omorika. These studies hold significant practical value in assessing species’ evolutionary potential, devising strategies for long-term species conservation, identifying centers of diversity, detecting relict and ancestral populations, unveiling cryptic species and hybrids, and elucidating the taxonomic significance of species. These investigations are of great value not only on the biodiversity level, but also on the levels of ecology, physiology, taxonomy, and evolution.
Essential oils (EOs) derived from evergreen conifer trees are recognized as complex sources of agents with various biological activities. In this study, the biological activities of the EOs derived ...from Chamaecyparis lawsoniana (A.Murray bis) Parl. (CLEO) and Thuja plicata Donn ex D.Don (TPEO) were investigated. The third instar larvae of the fruit fly Drosophila melanogaster were used as a model organism to determine the in vivo toxicity, genotoxicity, and antigenotoxicity of five different concentrations of CLEO and TPEO, ranging from 0.19% to 3%. Artemia salina was used for acute toxicity assessment and determination of LC50 after 24 h and 48 h. The antimicrobial activity of the CLEO and TPEO was tested against fourteen bacterial and two fungal strains using the microdilution method. The larvicidal activity and developmental time of D. melanogaster increased as the concentrations of the EOs rose. CLEO and TPEO produced a dose-dependent increase in DNA damage compared with the negative control. Both oils, at concentrations up to 1.5%, demonstrated the ability to reduce the genotoxic effect induced by ethyl methanesulfonate, with a reduction rate exceeding 60%. CLEO and TPEO were highly toxic against Artemia salina nauplii. The results indicate that the tested EOs act as antimicrobial agents against some pathogenic bacteria and fungi. CLEO and TPEO show promising potential as a source of antimicrobial and antigenotoxic agents and as potential biocides against pest insects and arthropods.
Key message
This study identified 10 fir populations that may be hybridogenous. The immediate activities on conservation of these polymorphic fir populations should be supported as hybrids may be ...ecologically and economically superior to the parent species.
This is the first report on morpho-anatomical differentiation of both lower-rank and upper-rank needles in
Abies alba
,
A.
x
borisii-regis,
and
A. cephalonica
, using 18 native populations from almost the entire assumed hybrid zone in the Balkan Peninsula. The 35 morpho-anatomical characteristics were analyzed biometrically, and 18 with the application of multivariate statistical analysis. Clinal pattern in distribution of morpho-anatomical variation over the broader transition zone between the putative parent species was observed. Furthermore, the results of the biometric analyses justify the validity of this method for differentiating between the eastern
A. alba
lineage and
A. cephalonica
, for both needle types. Thus, the results of this study show clear differences between
A. alba
and
A. cephalonica
, but unstable characteristics of
A.
x
borisii-regis
. This finding supports the hypothesis that
A.
x
borisii-regis
is an unstabilized taxon produced by recent hybridization and introgression between
A. alba
and
A. cephalonica
. Based on the multivariate statistical analysis, 10 of the studied fir populations may be hybridogenous within a wider geographical area (southwestern and southern Bulgaria, southernmost North Macedonia and almost the entire Greece). The obtained results did not indicate a hybrid status for two fir populations from Peloponnese and one from the Cephalonia Island (pure
A. cephalonica
populations), which partly agrees with the recent molecular data.
This is the first report on morpho-anatomical and phytochemical differentiation of 19 native populations representing different Pinus nigra J.F.Arnold subspecies (banatica (Borbás) Novák, dalmatica ...(Vis.) Franco, nigra, and pallasiana (Lamb.) Holmboe) in the Balkans and Southern Carpathians. The 9 morpho-anatomical characteristics and 10 headspace volatiles of needles were analyzed with multivariate statistical analyses. The combination of results from all multivariate analyses with both types of markers revealed that P. nigra is differentiated into three groups within the studied area (the Dalmatian coast, Greece, and the rest of the Balkans with the Southern Carpathians). The first group included the population from an island in Dalmatia that corresponds to P. nigra subsp. dalmatica. The third group consisted of populations from continental Croatia, Bosnia and Herzegovina, Serbia, Romania, and Bulgaria, which corresponds to P. nigra subsp. nigra. In light of the recent molecular data that indicated that the Greek populations (the second group) represent a distinct genetic lineage of P. nigra placed between the populations from the principal area (P. nigra subsp. nigra) and Turkey (P. nigra subsp. pallasiana), one can speculate that there is one more subspecies of P. nigra in this region that corresponds to populations from Greece. Extending our analyses to Asia Minor and Crimea could bring additional results that would be valuable for clarifying the intriguing issue of the diversification of P. nigra in the eastern part of its range.
This study focused on the essential oils (EOs) isolated from needles with twigs of three indigenous Balkan Abies species (A. alba, A. × borisii‐regis and A. cephalonica) regarding their chemical ...composition, antimicrobial activity and toxicity toward crustaceans and insects. Even though distinct phytochemical profiles of dominant volatiles were revealed for each species, β‐pinene and α‐pinene represented the first two major volatiles in all three EOs. Antimicrobial activity of EOs has shown inhibitory effect against all 17 studied strains (ATCC and respiratory isolates) in the range of 0.62–20.00 mg/mL (MICs). Further, all three EOs exhibited strong toxicity (LC50<100 μg/mL) in Artemia salina lethality bioassay, but with significant differences that depended on the EO type. Additionally, tested EOs have shown a certain level of toxicity against Drosophila melanogaster, mostly at the highest tested concentration (3 %) which caused significant prolongation of developmental time, larvicidal effect and pupal mortality. In the three biological assays performed, there was no observed inhibitory effect or weakest activity for A. alba EO. Further, A. cephalonica EO has shown the highest levels of antimicrobial activity and toxicity toward A. salina, while in relation to the insecticidal potential, A. cephalonica and A. × borisii‐regis EOs exhibited similar level of toxicity against D. melanogaster.
•The essential oils of two Mediterranean pines were analyzed.•The total number of identified volatile constituents was 64.•Diterpene alcohol thunbergol might be an important antibacterial ...agent.•Total content of pinenes is positively correlated to the larvicidal activity.
Pines (Pinus spp.) are a potentially viable source of bioactive molecules. The present paper investigates the chemical composition as well as biological activity of the needle essential oils (EOs) of the two Mediterranean pines (Pinus halepensis and P. heldreichii). The EOs were tested against respiratory pathogenic bacterial strains isolated from human swabs. Furthermore, a subchronic test on Drosophila melanogaster was conducted to assess insecticidal potential of the investigated EOs against dipteran insects. Regarding the composition of the studied EOs, significant differences in relation to the major components as well as the content of the different terpene classes was observed. Sesquiterpenes and diterpenes were most present classes in the oil of P. halepensis, where (E)-caryophyllene and thunbergol were dominant compounds (32.2% and 29.2%, resp.). Oil of P. heldreichii was rich in monoterpenes, among which limonene (34.4%) followed by α-pinene (23.8%) make up more than 50%. Tested EOs showed inhibitory action against respiratory pathogenic bacterial strains in the range of 0.19–12.00 mg/mL (MICs) and bactericidal effect (MBCs) at concentrations from 0.50 to 12.00 mg/mL. Among two presently and four previously tested pine EOs, P. halepensis demonstrated the highest potential, which might be contributed to relatively unusual composition. Namely, the results suggested that diterpene alcohol thunbergol might be an important antimicrobial agent either alone or in combination with other compounds, which should be the subject of the future studies. On the other hand, toxicity of P. heldreichii oil towards developing Drosophila melanogaster larvae was low, while oil of P. halepensis did not show any signs of toxicity at concentrations up to 3%. The data indicated that total content of pinenes in the EO of the Pinus species is positively correlated to the inhibition of development and larvicidal activity in a fruit fly model.
The survival of marginal/peripheral silver fir (
Mill.) populations in the broader region of Southeast Europe is endangered due to climate change and population decline. This study aimed to determine ...the level and pattern of variability for the anatomical traits of needles and the possibility of linking the pattern of phenotypic variability with environmental factors. In most of the analyzed needle traits, the statistically significant variability between populations was determined. According to the results of the multivariate principal component analysis, it is evident that the populations are distinct from each other, in three groups. The climatic factors Hargreaves reference evaporation, mean annual temperature, and growing degree-days, were statistically significantly correlated. The altitude and heating degree-days are statistically significantly correlated with the following three environmental factors: Hargreaves reference evaporation, mean annual temperature and growing degree-days, but negatively with others. The paper's findings indicate significant moderate and high correlations between the anatomical traits of the needles' central bundle diameter with the resin duct diameter, the distance between the vascular bundle and the resin duct and the epidermis thickness with cuticle, the resin duct diameter with the distance between the vascular bundle and the resin duct and the epidermis thickness with cuticle, as well as the distance between the vascular bundle and the resin duct with the hypodermis height and the epidermis thickness with cuticle. The results of agglomerative hierarchical clustering analysis, performed for anatomical and climatic traits, confirmed the existence of three groups of tested populations according to the altitude gradient. Research results provide knowledge on the diversity and structure of
populations of Southeast Europe, important for further research and guidelines for the species' conservation and genetic variability preservation in the southern marginal distribution area and keeping in line with climate change projections.
This study provides information on plants used for medicinal purposes in Pirot District (southeastern Serbia). The population of 157 villages in four municipalities of Pirot District (631 informants) ...completed questionnaires about the knowledge and use of medicinal herbs; the questionnaires included information about respondents and specific issues related to the applications of medicinal herbs. There were 4817 URs (use reports) on plants used for different ailments classified in various categories. The informant consensus factor (ICF) for the most frequently reported taxa and a comparison of nationality and gender in the use of plants for most frequent medical indications were calculated by ICF analysis. The overlap of plant taxa and URs recorded for three ethnic groups (Serbian, Bulgarian, and Roma) in the study area is also presented. Multivariate correspondence analysis was performed. A total of 182 medicinal plant taxa belonging to 68 families were recorded, of which 53 are included in European Pharmacopoeia 10.2. The most frequently mentioned families were Lamiaceae (1322 URs), and Compositae (899 URs).
Hypericum perforatum
and
Matricaria chamomilla
were the most used plant species. Aerial parts and leaves were the most frequently used plant parts. Infusion and oil extracts were the most reported preparations of medicinal herbs. Among 14 categories, respiratory (1235 URs), and digestive (911 URs) groups of diseases were the most frequently reported. Data on the knowledge and use of medicinal plants in Pirot District could be a good starting point for further ethnopharmacological investigations.
This is the first study on cuticular wax variability of Abies alba, A.×borisii‐regis and A. cephalonica, using 18 native populations from the assumed hybrid zone in the Balkan Peninsula. Presence of ...13 n‐alkanes with chain‐lengths ranging from C21 to C33, one primary alcohol, two diterpenes, one triterpene and one sterol was determined in hexane extracts of 269 needle samples. The multivariate statistical analyses at the population level entirely failed in supporting circumscription of Balkan Abies taxa and therefore, in identifying hybrid populations. However, performed at the species level, these analyses revealed a certain tendency of differentiation between A. alba and A. cephalonica, while individuals of A.×borisii‐regis were largely overlapped by the clouds of both parent species. Finally, the correlation analysis suggested that the observed variation of wax compounds was probably genetically conditioned and that it does not represent an adaptive response to various environmental factors.
Chemical compositions of needle essential oils of 27 taxa from the section Pinus, including 20 and 7 taxa of the subsections Pinus and Pinaster, respectively, were compared in order to determine ...chemotaxonomic significance of terpenes at infrageneric level. According to analysis of variance, six out of 31 studied terpene characters were characterized by a high level of significance, indicating statistically significant difference between the examined subsections. Agglomerative hierarchical cluster analysis has shown separation of eight groups, where representatives of subsect. Pinaster were distributed within the first seven groups on the dendrogram together with P. nigra subsp. laricio and P. merkusii from the subsect. Pinus. On the other hand, the eighth group included the majority of the members of subsect. Pinus. Our findings, based on terpene characters, complement those obtained from morphological, biochemical, and molecular parameters studied over the past two decades. In addition, results presented in this article confirmed that terpenes are good markers at infrageneric level.
