Analysis of the relationship between allozyme heterozygosity and fitness in the rare Gentiana pneumonanthe L.

Especially for rare species occurring in small populations, which are prone to loss of genetic variation and inbreeding, detailed knowledge of the relationship between heterozygosity and fitness is generally lacking. After reporting on allozyme variation and fitness in relation to population size in the rare plant Gentiana pneumonanthe, we present a more detailed analysis of the association between heterozygosity and individual fitness. The aim of this study was to test whether increased fitness of more heterozygous individuals is explained best by the ‘inbreeding’ hypothesis or by the ‘overdominance’ hypothesis. Individual fitness was measured during 8 months of growth in the greenhouse as the performance for six life-history parameters. PCA reduced these parameters to four main Fitness Components. Individual heterozygosity was scored for seven polymorphic allozyme loci. For some of these loci (e.g. Aat3, Pgm1 and 6Pgdh2) heterozygotes showed a significantly higher relative fitness than homozygotes. To test the inbreeding model, regression analyses were performed between each Fitness Component and the number of heterozygous loci per individual. Multiple regressions with the adaptive distance of five loci as independent variables were used to test the overdominance model. Only the inbreeding model was a statistically significant explanation for the relationship between heterozygosity and fitness in G. pneumonanthe. The number of heterozygous loci was significantly negatively correlated with the coefficients of variation of three of the six initially measured fitness parameters. This suggests a lower developmental stability among more homozygous plants and may explain the higher phenotypic variation in small populations of the species observed earlier. The importance of the results for conservation biology is discussed.     

Inter‐ and Intra‐Regional Variability of Leaf Litter Breakdown in Reference Headwater Streams of Northern Spain: Atlantic versus Mediterranean Streams

The main goal of this study was to examine the natural variability of alder (Alnus glutinosa (L.) Gaertn.) leaf processing and explore its potentiality as a functional indicator to assess the ecological status of Spanish headwater streams. Breakdown of leaf litter was studied during autumn‐winter in reference headwater streams of two regions of northern Spain: the Basque Country (on the Atlantic) and Catalonia (on the Mediterranean). Spring experiments were also carried out in the Atlantic region in order to study seasonal changes. Leaf mass loss rates were slightly higher in Catalonian streams. Temperature was not the main factor for explaining differences between the two regions. In the Atlantic one, however, water temperature determined the spatial and seasonal variability of leaf litter processing. Because of the high natural variability in breakdown rates, our results highlight the difficulty in detecting moderate impairments on stream functioning through the analysis of leaf litter decomposition if this process is not accompanied by the study of other factors affecting it. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Genetic Variability in Stress Tolerance and Fitness among Natural Populations of Steinernema carpocapsae

Genetic variability in stress tolerance (heat, desiccation, and hypoxia) and fitness (virulence and reproduction potential) among natural populations of Steinernema carpocapsae was assessed by estimating phenotypic differences. Significant differences were observed in stress tolerance among populations. Populations isolated from North Carolina showed significantly more stress tolerance than those isolated from Ohio. Significant differences were also observed in populations isolated from the same locality. Survival of infective juveniles after exposure to 40°C for 2 h ranged from 37 to 82%. A threefold difference was observed in infective juvenile survival following exposure to osmotic desiccation or hypoxic condition. Several populations tested were superior to the most widely used strain (‘All’ strain) in stress tolerance traits, with one population KMD33, being superior to the ‘All’ strain in all traits. Fitness as expressed by virulence and reproductive potential differed significantly among populations but showed less variability than the stress tolerance traits. All populations tested had a reproductive potential greater than or similar to that of the ‘All’ strain and most of them caused >60% insect mortality of the wax moth larvae, Galleria mellonella. The high genetic variability in stress tolerance among natural populations suggests the feasibility of using selection for genetic improvement of these traits.     

Chemical Composition of Juniperus communis L. Cone Essential Oil and Its Variability among Wild Populations in Kosovo

Ripe cones of Juniperus communis L. (Cupressaceae) were collected from five wild populations in Kosovo, with the aim of investigating the chemical composition and natural variation of essential oils between and within wild populations. Ripe cones were collected, air dried, crushed, and the essential oils obtained by hydrodistillation. The essential‐oil constituents were identified by GC‐FID and GC/MS analyses. The yield of essential oil differed depending on the population origins and ranged from 0.4 to 3.8% (v/w, based on the dry weight). In total, 42 compounds were identified in the essential oils of all populations. The principal components of the cone‐essential oils were α‐pinene, followed by β‐myrcene, sabinene, and D ‐limonene. Taking into consideration the yield and chemical composition, the essential oil originating from various collection sites in Kosovo fulfilled the minimum requirements for J. communis essential oils of the European Pharmacopoeia. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used to determine the influence of the geographical variations on the essential‐oil composition. These statistical analyses suggested that the clustering of populations was not related to their geographic location, but rather appeared to be linked to local selective forces acting on the chemotype diversity.     

Natural Multi‐Target Inhibitors of Cholinesterases and Monoamine Oxidase Enzymes with Antioxidant Potential from Skin Extracts of Hypsiboas cordobae and Pseudis minuta (Anura: Hylidae)

Alzheimer's disease (AD) is the most common cause of dementia, characterized by loss of selective neuronal and normal brain functions. Every year, ten million new cases are diagnosed worldwide. AD is a complex disease associated with all kind of different pathways, making their simultaneous modulation necessary. Nowadays anti‐AD treatments are focused on enzymatic inhibitors. The study of the amphibians’ skin had acquired great importance in the fields of biology and human health and represents an attractive and novel source for natural compounds with high potential in the development of new drugs. The present work exhibits the power of amphibian skins as a source of bioactive compounds. Herein we report the activity of extracts of two species from Hylidae family (H. cordobae and P. minuta) as reversible inhibitors of acetylcholinesterase and butyrylcholinesterase enzymes. Furthermore, the extracts inhibit MAO?B enzyme and showed antioxidant activities, acting on four important pathways of AD.     

Essential Oil Variability in Natural Populations of Artemisia campestris (L.) and Artemisia herba‐alba (Asso) and Incidence on Antiacetylcholinesterase and Antioxidant Activities

The intraspecific variability of Artemisia herba‐alba and A. campestris essential oils and the evaluation of their antioxidant and antiacetylcholinesterase activities were determined. Artemisia herba‐alba essential oil was found rich in camphor (19.61%), α‐thujone (19.40%), β‐thujone (9.44%), chrysanthenone (9.26%), and trans‐sabinyl acetate (8.43%). The major compounds of A. campestris essential oil were germacrene D (16.38%), β‐pinene (16.33%), and limonene (9.17%). Significant variation in the essential oil composition was observed among populations of each species. The divergence between populations was attributed to the variation of some climatic factors such as altitude, annual rainfall, winter cold stress, summer precipitation, summer drought stress, evapotranspiration, and humidity. Artemisia herba‐alba and A. campestris essential oils exhibited promising antioxidant and antiacetylcholinesterase activities. The level of activity varied significantly according to the species and the essential oil. The highest scavenging activity (IC₅₀ = 0.14 mg/ml) and the uppermost capacity to prevent β‐carotene bleaching (IC₅₀ = 0.10 mg/ml) characterized A. campestris from population 6. A. campestris population 3 possessed the uppermost ability to reduce ferric ions (450.7 μmol Fe²⁺/g EO). The population 2 of A. campestris showed the strongest antiacetylcholinesterase activity (IC₅₀ = 0.02 mg/ml). The variation of these activities between the essential oils was explained by their composition differences.     

Natural selection and gynodioecy in Thymus vulgaris L.

Thymus vulgaris L. is a gynodioecious species with hermaphrodites (mF) and females (mS) widely distributed in southern France and in which reproduction of which is exclusively sexual. Numerous samples have been collected in the French Mediterranean region and the percentage of mS varies from 5 to 95% in different populations. By studying environmental conditions—the area covered at ground level by vegetation, stones and rocks—high percentages of mS are found to be related to a high vegetation cover and an absence or a scarcity of stones. Grasslands and old fields favour mS, while rocky sites favour mF. This relationship, which has been found both on the plains and on a mountain, is related to the most important reproductive characteristics of T. vulgaris —genetic control of male sterility, mode of pollination, percentage of selling and seed production. These relationships agree with the assumption that unstable environmental conditions such as grasslands or old fields in southern France favour maximum seed production and outcrossing. The greater stability of uncultivated areas such as rocky sites allows for the maintenance of autogamy. Consequently, it is natural selection which adjusts the percentage of male sterility in natural populations of Thymus vulgaris.     

Structure and Dynamics of Natural Populations of Polyploid Trilliums. V. Predominant Self-pollination in Trillium apetalon-T. smallii Association

Abstract Predominant self-pollination was confirmed in mixed populations of Trillium apetalon (4x = 20, SSUU) and T. smallii (6x = 30, K₁K₁SSUU). In pollination tests conducted on both species from the Muroran (Mr) population, many good seeds were obtained from bagged flowers as well as open-pollinated intact flowers. In striking contrast, fruits from castrated open-pollinated flowers failed to give any good seeds. In T. smallii in the Usu (Us) population, the same results were obtained for bagged and open-pollinated intact flowers. On the other hand, fruits from castrated open-pollinated flowers yielded only a few good seeds. Although both species were experimentally cross-compatible in both directions, no interspecific hybrids have so far been found in nature. It may be possible that both species are isolated by predominant self-pollinatioin even though their flowering seasons coincide.     

Composition,Chemical Variability and Biological Activity of Cymbopogon schoenanthus Essential Oil from Central Algeria

Cymbopogon schoenanthus (L.) Spreng . (Poaceae) is an aromatic plant whose aerial parts and rhizome produced an essential oil with pleasant odor. A chemical variability has been observed depending of the countries where the plant grows wild, including Algeria. The chemical compositions of 24 oil samples isolated from plants harvested in Central Algeria have been investigated, to evidence homogeneity or chemical variability within a given area of harvest. Twenty of these were dominated by cis‐ and trans‐p‐menth‐2‐en‐1‐ols (22.6 %±3.6 and 14.3 %±1.7, resp.) beside four atypical compositions. Otherwise, aerial parts and rhizomes produced similar essential oils. Lastly, a fair antimicrobial activity was measured against Staphylococcus aureus strain, while the antioxidant potential was low.     

Variability in Chemical Composition and Antimicrobial Activity of Mentha pulegium L. Essential Oil,Cultivated under Different Plant Growth Promoting Rhizobacteria

The aim of present work was to study the essential oil chemical composition and antimicrobial activity of cultivated Mentha pulegium L. under different plant growth promoting rhizobacteria (Pseudomonas fluorescens, Bradyrhizobium sp. and Sinorhizobium meliloti) individually and in consortium. Yield, in plants inoculated with Bradyrhizobium sp. and S. meliloti in consortium, increase significantly relative to control plants. GC and GC/MS analyses pointed to a qualitative and quantitative variability of components. The investigated essential oils were clustered into three chemotypes: piperitenone/1,8-cineol (40.9/29.4 %) chemotype in plants inoculated with Bradyrhizobium sp. individually, S. meliloti individually, and Bradyrhizobium sp. and S. meliloti in consortium, piperitone/menthone (41.8/33.8 %) chemotype in plants inoculated with P. fluorescens individually, P. fluorescens and Bradyrhizobium sp. in consortium, and P. fluorescens and S. meliloti in consortium and pulegone/menthol (47.9/31.5 %) chemotype in control plants. The antimicrobial activity, carried out by the disc diffusion method and the determination of the Minimum Inhibitory Concentration (MIC) against ten microorganisms, varied significantly according to the tested microorganism and the rhizobacterial species used individually or in consortium (inhibition zone: 8.5–33.5 mm; MIC: 0.25–2.5 μL/mL). Our findings provided useful indications to select interesting chemotype within M. pulegium, especially in perspective of its cultivation.     

Variability of n‐Alkanes and Nonacosan‐10‐ol in Natural Populations of Picea omorika

This is the first report of population variability of the contents of n‐alkanes and nonacosan‐10‐ol in the needle epicuticular waxes of Serbian spruce (Picea omorika). The hexane extracts of needle samples originated from three natural populations in Serbia (Vranjak, Zmajeva?ki potok, and Mile?evka Canyon) were investigated by GC and GC/MS analyses. The amount of nonacosan‐10‐ol varied individually from 50.05 to 74.42% (65.74% in average), but the differences between the three investigated populations were not statistically confirmed. The results exhibited variability of the composition of n‐alkanes in the epicuticular waxes with their size ranging from C₁₈ to C₃₅. The most abundant n‐alkanes were C₂₉, C₃₁, and C₂₇ (35.22, 13.77, and 12.28% in average, resp.). The carbon preference index of all the n‐alkanes (CPI_total) of the P. omorika populations (average of populations I–III) ranged from 3.3 to 11.5 (mean of 5.9), while the average chain length (ACL) ranged from 26.6 to 29.2. The principal component and cluster analyses of the contents of nine n‐alkanes showed the greatest difference for the population growing in the Mile?evka Canyon. The obtained results were compared with previous literature data given for other Picea species, and this comparison was briefly discussed.     

Achillea filipendulina Lam.: Chemical Constituents and Antimicrobial Activities of Essential Oil of Stem,Leaf, and Flower

In this study, we extracted the essential oils of the stem, leaf, and flower of Achillea filipendulina, analyzed them, and studied their antibacterial properties. Of 16, 53, and 35 compounds identified in the stem, leaf, and flowers, respectively, only five are present in all three segments of the plant. The essential oil of the stem was mainly composed of neryl acetate, spathulenol, carvacrol, santolina alcohol, and trans‐caryophyllene oxide. However, the main identified components of leaf were 1,8‐cineole, camphor, ascaridole, trans‐isoascaridole, and piperitone oxide and the main components of the flower oil were ascaridole, trans‐isoascaridole, 1,8‐cineole, p‐cymene, and camphor. The extracted oil from different segments demonstrated varying antibacterial properties against both Gram‐positive and Gram‐negative bacteria, demonstrated by disk, minimum inhibitory concentration, and minimum bactericidal concentration methods. These suggest that the application of all segments of aerial parts of A. filipendulina may have a better therapeutic effect in fighting pathogenic systems.     

Essential‐Oil Composition and Chemical Variability of Senecio vulgaris L. from Corsica

The chemical composition of the essential oils isolated from the aerial parts of Senecio vulgaris plants collected in 30 Corsican localities was characterized using GC‐FID and GC/MS analyses. Altogether, 54 components, which accounted for 95.2% of the total oil composition, were identified in the 30 essential‐oil samples. The main compounds were α‐humulene ( 1 ; 57.3%), (E)‐β‐caryophyllene ( 2 ; 5.6%), terpinolene ( 3 ; 5.3%), ar‐curcumene ( 4 ; 4.3%), and geranyl linalool ( 5 ; 3.4%). The chemical composition of the essential oils obtained from separate organs and during the complete vegetative cycle of the plants were also studied, to gain more knowledge about the plant ecology. The production of monoterpene hydrocarbons, especially terpinolene, seems to be implicated in the plant‐flowering process and, indirectly, in the dispersal of this weed species. Comparison of the present results with the literature highlighted the originality of the Corsican S. vulgaris essential oils and indicated that α‐humulene might be used as taxonomical marker for the future classification of the Senecio genus. A study of the chemical variability of the 30 S. vulgaris essential oils using statistical analysis allowed the discrimination of two main clusters according to the soil nature of the sample locations. These results confirmed that there is a relation between the soil nature, the chemical composition of the essential oils, and morphological plant characteristics. Moreover, they are of interest for commercial producers of essential oil in selecting the most appropriate plants.     

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.     

Variability in the Phytochemical Contents and Free Radical‐Scavenging Capacity of Capsicum annuum var. glabriusculum (Wild Piquin Chili)

The variability in the phytochemical concentrations of Capsicum annuum var. glabriusculum has not been extensively analyzed among wild populations and ecologic niches in its phylogeographic area. This study aimed to determine the variations in the phytochemical and antioxidant contents of the wild Piquin chili. The total flavonoid content of hydroalcoholic extracts (0.06 to 0.70 mg equivalent of quercetin per gram of dry weight (mg QE/g DW)), free radical‐scavenging capacity for 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH^.) radicals (0.55 to 8.55 mm TE/g DW), amount of 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS⁺) in aqueous extracts (18.13 to 107.6 mm TE/g DW) and pungency (21,760 to 88,476 Scoville heat units) were highly variable. By analyzing the spatial distribution using the first three principal components, correlations between the phytochemical content and the free radical‐scavenging capacity (in both extracts) and flavonoid and phenolic contents (in the hydroalcoholic extract) were observed. Consistent with the statistical analysis, the spatial analysis showed intraregional differences in composition patterns, with an emphasis on central and coastal areas. Flavonoid contents, polyphenol contents and free radical‐scavenging activity were the phytochemical components that mainly contributed to the diversity of the population.     

Synthesis and Biological Evaluation of New Natural Phenolic (2E,4E,6E)‐Octa‐2,4,6‐trienoic Esters

In the present study the esterification of the OH groups of resveratrol, caffeic acid, ferulic acid, and β‐sitosterol with an antioxidant polyconjugated fatty acid, (2E,4E,6E)‐octa‐2,4,6‐trienoic acid, was achieved. As the selective esterification of OH groups of natural compounds can affect their biological activity, a selective esterification of resveratrol and caffeic acid was performed by an enzymatic approach. The new resulting compounds were characterized spectroscopically (FT‐IR, NMR mono, and bidimensional techniques); when necessary the experimental data were integrated by quantum chemical calculations. The antioxidant, anti‐inflammatory and proliferative activity was evaluated. The good results encourage the use of these molecules as antioxidant and/or anti‐inflammatory agents in dermocosmetic application.     

Variation of the Chemical Composition and Antimicrobial Activity of the Essential Oils of Natural Populations of Tunisian Daucus carota L. (Apiaceae)

The essential oils of Daucus carota L. (Apiaceae) seeds sampled from ten wild populations spread over northern Tunisia were characterized by GC‐FID and GC/MS analyses. In total, 36 compounds were identified in the D. carota seed essential oils, with a predominance of sesquiterpene hydrocarbons in most samples (22.63–89.93% of the total oil composition). The main volatile compounds identified were β‐bisabolene (mean content of 39.33%), sabinene (8.53%), geranyl acetate (7.12%), and elemicin (6.26%). The volatile composition varied significantly across the populations, even for oils of populations harvested in similar areas. The chemometric principal component analysis and the hierarchical clustering identified four groups, each corresponding to a composition‐specific chemotype. The in vitro antimicrobial activity of the isolated essential oils was preliminarily evaluated, using the disk‐diffusion method, against one Gram‐positive (Staphylococcus aureus) and two Gram‐negative bacteria (Escherichia coli and Salmonella typhimurium), as well as against a pathogenic yeast (Candida albicans). All tested essential oils exhibited interesting antibacterial and antifungal activities against the assayed microorganisms.     

Evaluation of Antibacterial Activity of Lavandulapedunculata subsp. atlantica (Braun‐Blanq.) Romo Essential Oil and Selected Terpenoids against Resistant Bacteria Strains–Structure–Activity Relationships

The genus Lavandula is known for its different uses in traditional medicine. This study is interested in the chemical composition of Lavandulapedunculata subsp.atlantica (Braun‐Blanq. ) Romo as well as evaluating its antibacterial potential against multi‐resistant strains. The analysis of Lavandulaatlantica essential oil (LAEO) allows the identification of 47 components representing 93.6 % of all identified. The main constituent of LAEO was camphor (50.4 %), followed by fenchone (14.1 %) and camphene (5.6 %). The antibacterial assays revealed that LAEO was active against all the studied bacteria. A preliminary study of the relationship between certain terpenoids and antibacterial activity was also carried out in order to note the compound(s) that are responsible for LAEO's antibacterial activity. This study showed that the activity of the essential oil may be due to the presence of certain minor compounds such as carvone, considering the presence of the synergistic effect between the essential oil.     

Somatic embryogenesis of <Emphasis Type="Italic">Gentiana cruciata</Emphasis> (L.): Histological and ultrastructural changes in seedling hypocotyl explant

Summary Structure and ultrastructure changes that occurred during tissue culture of upper explants of hypocotyl (adjacent to cotyledons) of 10-d-old seedlings of Gentiana cruciata were studied. The explants were cultured on Murashige and Skoog induction medium supplemented with 1.0 mg l⁻¹ dicamba +0.1 mg l⁻¹ naphthaleneacetic acid +2.0 mg l⁻¹ benzyladenine +80.0 mg l⁻¹ adenine sulfate. The initial response of the explant and callus formation were ultrastructurally analyzed during the first 11 d of culture. After 6–8 wk, various methods were employed to collect evidence of indirect somatic embryogenesis. After 48 h of culture, the earliest cell response was cell division of epidermis and primary cortex. There were numerous disturbances of karyo- and cytokinesis, leading to formation of multinuclear cells. With time, the divisions ceased, and cortex cells underwent strong expansion, vacuolization and degradation. About the 6th day of culture, callus tissue proliferated and the initial divisions of vascular cylinder cells were observed. Their division appeared normal. Cells originating from that tissue were small, weakly vacuolated, with dense cytoplasm containing active-looking cell organelles. Numerous divisions occurred in the vascular cylinder, which led to its expansion and the formation of embryogenic callus tissue. During the 6–8th wk of culture, in the proximal end of the explant, masses of somatic embryos were formed from outer parts of intensively proliferating tissue.