Volatile‐Oils Composition,and Bioactivity of the Essential Oils of Plectranthus barbatus,P. neochilus,and P. ornatus Grown in Portugal

Volatile‐oils chemical composition and bioactivity of the essentail oils from Plectranthus barbatus, P. neochilus, and P. ornatus (Lamiaceae) were assessed. Aerial parts from these three related Plectranthus species were collected from cultivated plants grown in Portugal, during vegetative and flowering phases. Volatiles, isolated by distillation? extraction, were analyzed by GC and GC/MS. Monoterpene hydrocarbons (12–74%) and sesquiterpene hydrocarbons (4–45%) constituted the main fractions in all volatiles. α‐Pinene ( 3 ; 12–67%), oct‐1‐en‐3‐ol ( 6 ; traces–28%), β‐pinene ( 7 ; 0.1–22%), and β‐caryophyllene ( 50 ; 7–12%) dominated P. barbatus volatiles. P. neochilus major volatile components were α‐terpenyl acetate ( 41 ; traces–48%), α‐thujone ( 2 ; 2–28%), β‐caryophyllene ( 50 ; 2–28%), β‐pinene ( 7 ; 1–25%), and α‐pinene ( 3 ; 1–19%). Oct‐1‐en‐3‐ol ( 6 ; 13–31%), β‐pinene ( 7 ; 11–24%), α‐pinene ( 3 ; 11–19%), and β‐caryophyllene ( 50 ; traces–11%) were the main constituents from P. ornatus volatiles. These chemical compositions were rather different from those previously found for specimens harvested in Africa and Brazil. Moreover, the volatiles from the flowers are herewith reported for the first time. Essential oils, isolated by hydrodistillation from leaves and stems, showed a yellowish color and unpleasant odor, with yields ranging from 0.08% to 0.84% (v/dry weight). Antioxidant and antimicrobial activities of the essential oils were evaluated by DPPH^. and TBARS assays, and agar disc‐diffusion method, respectively. Results showed low or moderate antioxidant capacity and significant antimicrobial activity against Gram‐positive bacteria.     

Variability in the Essential‐Oil Composition of Sideritis scardica Griseb. from Native Bulgarian Populations

The essential‐oil composition of six native populations of Sideritis scardica from Bulgaria was studied by GC‐FID and GC/MS analyses. Altogether, 37 components, representing 73.1 to 79.2% of the total oil content were identified. Among them, α‐pinene (4.4–25.1%), β‐pinene (2.8–18.0%), oct‐1‐en‐3‐ol (2.3–8.0%), phenylacetaldehyde (0.5–9.5%), β‐bisabolene (1.3–11.0%), benzyl benzoate (1.1–14.3%), and m‐camphorene ( 1 ; 0.3–12.4%) were the main compounds. All samples were characterized by low contents of oxygenated mono‐ and sesquiterpenes (≤1.6 and 2.3%, resp.). Principal component analysis (PCA) and cluster analysis (CA) showed a significant variability in the chemical composition of the studied samples as well as a correlation between the oil profiles and the ecological conditions of the natural habitats of S. scardica.     

Chemical Composition of the Tuber Essential Oil from Helianthus tuberosus L. (Asteraceae)

Helianthus tuberosus L. (Jerusalem artichoke) is cultivated in Europe and other parts of the world as a food crop and ornamental plant. The volatile oils of the aerial parts of H. tuberosus were investigated more than 30 years ago, but no study could be found to date on the constituents of the tuber essential oil. Herein, the first characterization by GC‐FID, GC/MS, and ¹³C‐NMR analyses of a hydrodistilled essential oil of Jerusalem artichoke tubers was reported. Fresh plant material collected in Serbia (Sample A) and a commercial sample (Sample B) yielded only small amounts of oil (0.0014 and 0.0021% (w/w), resp.). In total, 195 constituents were identified, representing 88.2 and 93.6% of the oil compositions for Samples A and B, respectively. The main constituents identified were β‐bisabolene ( 1 ; 22.9–30.5%), undecanal (0–12.7%), α‐pinene (7.6–0.8%), kauran‐16‐ol ( 2 ; 6.9–9.8%), 2‐pentylfuran (0.0–5.7%), and (E)‐tetradec‐2‐enal (0.0–4.9%). Several rare compounds characteristic for Helianthus ssp. were also detected: helianthol A ( 6 ; 2.1–1.9%), dihydroeuparin ( 10 ; 0.0–2.3%), euparin ( 9 ; 0.0–0.4%), desmethoxyencecalin ( 7 ; traces – 0.2%), desmethylencecalin ( 8 ; 0.0–0.4%), and an isomer of desmethylencecalin (0.0%‐traces). The essential oils isolated from the tuber and the aerial parts share the common major component 1 .     

Composition and Chemical Variability of Ivoirian Polyalthia oliveri Leaf Oil

The chemical composition of 45 essential oil samples isolated from the leaves of Polyalthia oliveri harvested in three Ivoirian forests was investigated by GC‐FID (retention indices measured on two columns of different polarities), and by ¹³C‐NMR, following a method developed in our laboratory. In total, 41 components were identified. The content of the main components varied drastically from sample to sample: (E)‐β‐caryophyllene (1.2 – 50.8%), α‐humulene (0.6 – 47.7%), isoguaiene (0 – 27.9%), alloaromadendrene (0 – 24.7%), germacrene B (0 – 18.3%), δ‐cadinene (0.4 – 19.3%), and β‐selinene (0.2 – 18.5%). The analysis of six oil samples selected in function of their chromatographic profiles is reported in detail. The 45 oil compositions were submitted to hierarchical cluster and principal components analysis, which allowed the distinction of three groups within the oil samples. The compositions of the oils from group I (15 samples) and II (12 samples) were dominated by (E)‐β‐caryophyllene and α‐humulene, respectively. Oil samples of group III (18 samples) needed to be partitioned into four subgroups III.1–III.4 whose compositions were dominated by alloaromadenrene, isoguaiene, germacrene B, and δ‐cadinene, respectively.     

The Volatile Profiles of a Rare Apple (Malus domestica Borkh.) Honey: Shikimic Acid‐Pathway Derivatives,Terpenes, and Others

The volatile profiles of rare Malus domestica Borkh . honey were investigated for the first time. Two representative samples from Poland (sample I) and Spain (sample II) were selected by pollen analysis (44–45% of Malus spp. pollen) and investigated by GC/FID/MS after headspace solid‐phase microextraction (HS‐SPME) and ultrasonic solvent extraction (USE). The apple honey is characterized by high percentage of shikimic acid‐pathway derivatives, as well as terpenes, norisoprenoids, and some other compounds such as coumaran and methyl 1H‐indole‐3‐acetate. The main compounds of the honey headspace were (sample I; sample II): benzaldehyde (9.4%; 32.1%), benzyl alcohol (0.3%; 14.4%), hotrienol (26.0%, 6.2%), and lilac aldehyde isomers (26.3%; 1.7%), but only Spanish sample contained car‐2‐en‐4‐one (10.2%). CH₂Cl₂ and pentane/Et₂O 1 : 2 (v/v) were used for USE. The most relevant compounds identified in the extracts were: benzaldehyde (0.9–3.9%), benzoic acid (2.0–11.2%), terpendiol I (0.3–7.4%), coumaran (0.0–2.8%), 2‐phenylacetic acid (2.0–26.4%), methyl syringate (3.9–13.1%), vomifoliol (5.0–31.8%), and methyl 1H‐indole‐3‐acetate (1.9–10.2%). Apple honey contained also benzyl alcohol, 2‐phenylethanol, (E)‐cinnamaldehyde, (E)‐cinnamyl alcohol, eugenol, vanillin, and linalool that have been found previously in apple flowers, thus disclosing similarity of both volatile profiles.     

Formulation development of the biocontrol agent Bacillus subtilis strain CPA-8 by spray-drying

Aims: To prepare commercially acceptable formulations of Bacillus subtilis CPA‐8 by spray‐drying with long storage life and retained efficacy to control peach and nectarine brown rot caused by Monilinia spp. Methods and Results: CPA‐8 24‐h‐ and 72‐h‐old cultures were spray dried using 10% skimmed milk, 10% skimmed milk plus 10% MgSO₄, 10% MgSO₄ and 20% MgSO₄ as carriers/protectants. All carriers/protectants gave good percentages of powder recovery (28–38%) and moisture content (7–13%). CPA‐8 survival varied considerably among spray‐dried 24‐h‐ and 72‐h‐old cultures. Seventy‐two hours culture spray dried formulations showed the highest survival (28–32%) with final concentration products of 1·6–3·3 × 10⁹ CFU g^?1, while viability of 24‐h‐old formulations was lower than 1%. Spray‐dried 72‐h‐old formulations were selected to subsequent evaluation. Rehydration of cells with water provided a good recovery of CPA‐8 dried cells, similar to other complex rehydration media tested. Spray‐dried formulations stored at 4 ± 1 and 20 ± 1°C showed good shelf life during 6 months, and viability was maintained or slightly decreased by 0·2–0·3‐log. CPA‐8 formulations after 4‐ and 6 months storage were effective in controlling brown rot caused by Monilinia spp. on nectarines and peaches resulting in a 90–100% reduction in disease incidence. Conclusions: Stable and effective formulations of biocontrol agent B. subtilis CPA‐8 could be obtained by spray‐drying. Significance and Impact of the Study: New shelf‐stable and effective formulations of a biocontrol agent have been obtained by spray‐drying to control brown rot on peach.     

Phytochemical Diversity of Murraya koenigii (L.) Spreng. from Western Himalaya

Murraya koenigii (L.) Spreng. (Rutaceae), commonly known as ‘curry leaf tree’, is a popular spice and condiment of India. To explore the diversity of the essential‐oil yield and aroma profile of curry leaf, growing wild in foot and mid hills of north India, 58 populations were collected during spring season. M. koenigii populations were found to grow up to an altitude of 1487 m in north India. Comparative results showed considerable variations in the essential‐oil yield and composition. The essential‐oil yield varied from 0.14 to 0.80% in shade‐dried leaves of different populations of M. koenigii. Analysis of the essential oils by GC and GC/MS, and the subsequent classification by statistical analysis resulted in four clusters with significant variations in their terpenoid composition. Major components of the essential oils of investigated populations were α‐pinene ( 2 ; 4.5–71.5%), sabinene ( 3 ; <0.05–66.1%), (E)‐caryophyllene ( 11 ; 1.6–18.0%), β‐pinene ( 4 ; <0.05–13.6%), terpinen‐4‐ol ( 9 ; 0.0–8.4%), γ‐terpinene ( 8 ; 0.2–7.4%), limonene ( 7 ; 1.1–5.5%), α‐terpinene ( 6 ; 0.0–4.5%), (E)‐nerolidol ( 14 ; 0.0–4.1%), α‐humulene ( 12 ; 0.6–3.5%), α‐thujene ( 1 ; 0.0–2.5%), β‐elemene ( 10 ; 0.2–2.4%), β‐selinene ( 13 ; 0.2–2.3%), and myrcene ( 5 ; 0.5–2.1%). Comparison of the present results with those in earlier reports revealed new chemotypes of M. koenigii in investigated populations from Western Himalaya. The present study documents M. koenigii populations having higher amounts of sabinene ( 3 ; up to 66.1%) for the first time.     

Estimating the contribution of carnivorous waterbirds to nutrient loading in freshwater habitats

1. We estimated nitrogen (N) and phosphorus (P) loading into wetlands by carnivorous waterbirds with alternative physiological models using a food‐intake and an excreta‐production approach. The models were applied for non‐breeding and breeding Dutch inland carnivorous waterbird populations to quantify their contribution to nutrient loading on a landscape scale. 2. Model predictions based on food intake exceeded those based on excretion by 59–62% for N and by 2–36% for P, depending on dietary assumptions. Uncertainty analysis indicated that the intake model was most affected by errors in energy requirement, while the excretion model was dependent on faecal nutrient composition. 3. Per capita loading rate of non‐breeders increased with body mass from 0.3–0.8 g N day^?1 and 0.15 g P day^?1 in little gulls Larus minutus to 4.5–11.5 g N day^?1 and 2.1–3.2 g P day^?1 in great cormorants Phalacrocorax carbo. For breeding birds, the estimated nutrient loading by a family unit over the entire breeding period ranged between 17.6–443.0 g N and 8.6 g P for little tern Sterna albifrons to 619.6–1755.6 g N and 316.2–498.1 g P for great cormorants. 4. We distinguished between external (i.e. importing) and internal (i.e. recycling) nutrient loading by carnivorous waterbirds. For the Netherlands, average external‐loading estimates ranged between 38.1–91.5 tonnes N and 16.7–18.2 tonnes P per year, whilst internal‐loading estimates ranged between 53.1–140.5 tonnes N and 25.2–39.2 tonnes P and per year. The average contribution of breeding birds was estimated to be 17% and 32% for external and internal loading respectively. Most important species were black‐headed gull Larus ridibundus and mew gull Larus canus for external loading, and great cormorant and grey heron Ardea cinerea for internal loading. 5. On a landscape scale, loading by carnivorous waterbirds was of minor importance for freshwater habitats in the Netherlands with 0.26–0.65 kg N ha^?1 a^?1 and 0.12–0.16 kg P ha^?1 a^?1. However, on a local scale, breeding colonies may be responsible for significant P loading.     

Isolation of the major chiral compounds from Bubonium graveolens essential oil by HPLC and absolute configuration determination by VCD

The chirality issues in the essential oils (EOs) of leaves and flowers from Bubonium graveolens were addressed by chiral high‐performance liquid chromatography (HPLC) with polarimetric detection and vibrational circular dichroism (VCD). The chemical compositions of the crude oils of three samples were established by gas chromatography / mass spectrometry (GC/MS). The well‐known cis ‐chrysanthenyl acetate ( 1 ), oxocyclonerolidol ( 2 ), and the recently disclosed cis ‐acetyloxychrysanthenyl acetate ( 3 ), the three major chiral compounds, were isolated by preparative HPLC. The naturally occurring oxocycloneroledol ( 2 ), mostly found in the leaf oil (49.4–55.6%), presents a (+) sign in the mobile phase during HPLC on a chiral stationary phase (CSP) with a Jasco polarimetric detection. The naturally occurring cis ‐chrysanthenyl acetate ( 1 ) and cis ‐acetyloxychrysanthenyl acetate ( 3 ), mostly found in the flower EO (35.9–74.9% and 10.0–34.3%, respectively), both present a (−) sign. HPLC on a CSP with polarimetric detection is an unprecedented approach to readily differentiate the flower and leaf EOs according to their chiral signature. The comparison of the experimental and calculated VCD spectra of pure isolated 1 , 2, and 3 provided their absolute configuration as being (1S ,5R ,6S )‐(−)‐2,7,7‐trimethylbicyclo[3.1.1]hept‐2‐en‐6‐yl acetate 1 , (2R ,6R )‐(+)‐6‐ethenyl‐2,6‐dimethyl‐2‐(4‐methylpent‐3‐en‐1‐yl)dihydro‐2H‐pyran‐3(4H)‐one) 2 and (1S ,5R ,6R ,7S )‐(−)‐7‐(acetyloxy)‐2,6‐dimethylbicyclo[3.1.1]hept‐2‐en‐6‐yl]methyl acetate 3 . Compounds 1 , 2, and 3 were already known in B. graveolens but this is the first report of the absolute configuration of (+)‐ 2 and (−)‐ 3 . The VCD chiral signatures of the crude oils were also recorded.     

Chemical Variability and Antioxidant Activity of Limbarda crithmoides L. Essential Oil from Corsica

The chemical compositions of 25 Corsican Limbarda crithmoides ssp. longifolia essential oils were investigated for the first time using GC‐FID, GC/MS, and NMR analyses. Altogether, 65 compounds were identified, accounting for 90.0–99.3% of the total oil compositions. The main components were p‐cymene ( 1 ; 15.1–34.6%), 3‐methoxy‐p‐cymenene ( 4 ; 11.8–28.5%), 2,5‐dimethoxy‐p‐cymenene ( 5 ; 5.9–16.4%), thymol methyl ether ( 6 ; 1.3–14.9%), α‐phellandrene ( 2 ; 0.9–11.9%), and α‐pinene ( 3 ; 0.2–13.4%). The chemical variability of the Corsican oil samples was studied using multivariate statistical analysis, which allowed the discrimination of two main clusters. A direct correlation between the water salinities of the plant locations and the chemical compositions of the L. crithmoides essential oils was evidenced. Indeed, essential oils rich in 1 (30.4–34.6%) were found in samples growing in the wetlands of the southern oriental coast, which exhibit high salinity levels (24.4±0.2–33.9±0.2 ppt), and essential oils with lower contents of 1 (15.1–27.3%) were isolated form samples growing in the wetlands of northern Corsica, which exhibit lower salinity levels (10.90±0.20–15.47±0.15 ppt). The antioxidant potential of L. crithmoides essential oil was also investigated, by assessing the DPPH^.‐ and ABTS^.+‐scavenging activities and the reducing power of ferric ions, and was found to be interesting. Moreover, using bioassay‐guided fractionation of the essential oil, a higher antioxidant activity was obtained for the oxygenated fraction and both ester and alcohol subfractions.     

Intraspecific Variability of the Essential Oil of Ziziphora clinopodioides ssp. rigida from Iran

Hydrodistillated essential oils of Ziziphora clinopodioides ssp. rigida from nine populations of the Lashgardar protected region (Hamedan Province, Iran) were analyzed by using GC and GC/MS techniques to determine the intraspecific chemical variability. Altogether, 39 compounds were identified in the oils, and a relatively high variation in their contents was found. The main constituents of the essential oils were pulegone (0.7–44.5%), 1,8‐cineole (2.1–26.0%), neomenthol (2.5–22.5%), 4‐terpineol (0.0–9.9%), 1‐terpineol (0.0–13.2%), neomenthyl acetate (0.0–7.1%), and piperitenone (0.0–5.4%). For the determination of the chemotypes and the intraspecific chemical variability, the essential oil components were subjected to cluster analysis (CA). The five different chemotypes characterized were Chemotype I (pulegone/neomenthol), Chemotype II (pulegone), Chemotype III (pulegone/1,8‐cineole), Chemotype IV (neomenthol), and Chemotype V (1,8‐cineole/4‐terpineol).     

Hedge Mustard (Sisymbrium officinale): Chemical Diversity of Volatiles and Their Antimicrobial Activity

Volatile compounds of hedge mustard (Sysimbrium officinale) have been investigated for the first time. Forthy‐two compounds were identified after hydrodistillation (without or upon autolysis) after gas chromatography and gas chromatography/mass spectrometry analyses. In addition, after decoction and hydrolysis of O‐glycosides, 18 volatile O‐aglycones were identified. In general, the main volatiles found in hydrodistillates were: isopropyl isothiocyanate (27.6–48.9%), 2‐methylpropanenitrile (0.5–18.8%), (Z)‐hex‐3‐en‐1‐ol (0.5–18.0%), sec‐butyl isothiocyanate (4.9–9.4%), (E)‐hex‐2‐enal (3.5–8.6%), (Z)‐hex‐2‐en‐1‐ol (0.3–8.4%), octanoic (0.5–8.6%) and dodecanoic acid (0–5.0%), 2‐methylbutanenitrile (0–4.6%), dibutyl phthalate (0–4.5%), and ethyl linolenate (0–3.6%). The main volatile O‐aglycones were: 2‐phenylethyl alcohol (21.5%), 6,7‐dehydro‐7,8‐dihydro‐3‐oxo‐α‐ionol (9.3%), eugenol (8.3%), benzyl alcohol (7.0%), ethyl vanillate (5.2%), 6‐(tert‐butyl)‐5‐methylphenol (5.1%), vanillin acetone (4.7%), ethyl 4‐hydroxybenzoate (4.3%), and 2‐hydroxy‐β‐ionone (3.8%). All hydrodistillates exhibited great potential of antibacterial activity against five Gram‐positive bacteria, nine ampicillin‐resistant Gram‐negative bacteria, and four fungi at a concentration of 500 μg/ml using the disc diffusion method.     

Modulatory effect of methanolic extract of Vernonia amygdalina (MEVA) on tert‐butyl hydroperoxide–induced erythrocyte haemolysis

Reactive oxygen species (ROS) have been implicated in the aetiology of several pathological and degenerative diseases. The protective effect of natural products possessing antioxidant properties has played a crucial role in ameliorating these deleterious effects. This study investigated the chemoprotective properties of the methanolic extract of Vernonia amygdalina (MEVA) in an experimental model of tert‐butyl hydroperoxide (t‐BHP)–induced human erythrocyte lysis in vitro. Haemolysis was induced by incubating erythrocytes with t‐BHP (2 and 3 mM) in vitro. Samples of erythrocyte suspensions were removed at different intervals over a 6‐h period, and the degree of haemolysis was measured. The anti‐haemolytic effect of MEVA at 25–150 µg ml^–1 concentrations on the samples were assessed and compared with Triton X‐100. Administration of t‐BHP at 2‐ and 3‐mM concentrations significantly (p < 0.05) induced erythrocyte lysis by 37.5% and 31.4%, respectively. The addition of MEVA, however, reduced t‐BHP–induced erythrocyte lysis significantly (p < 0.05) by 39.3%, 48.4%, 67.3% and 73.4% at 25, 50, 100 and 150 µg ml^–1 concentrations, respectively. MEVA likewise protected against t‐BHP–induced lipid peroxidation significantly (p < 0.05) at 100 and 150 µg ml^–1 by the fourth hour and non‐significantly (p > 0.05) at all concentrations by the sixth hour. The reduced glutathione level was, however, increased with the administration of t‐BHP, while a delayed addition of MEVA had no protective effect on the t‐BHP–induced cell lysis. These findings therefore suggest that MEVA may have protective antioxidant properties, making it suitable for incorporation into food and drug products. Copyright © 2012 John Wiley & Sons, Ltd.     

Phylogeography of the freshwater red alga Sirodotia (Batrachospermales,Rhodophyta) in Brazil

Considering the lack of knowledge on genetic variation on members of the freshwater red algal of the order Batrachospermales in tropical regions, phylogeographic patterns in Sirodotia populations were investigated using two mitochondrial regions: the cox2‐3 spacer and partial cox1 gene (barcode). Individuals identified as Sirodotia delicatula were analyzed from 14 stream segments across its distribution in Brazil. Phylogenetic analyses based on the ribulose‐1,5‐bisphosphate carboxylase/oxygenase large sub‐unit gene showed three clades, one representing S. delicatula, from all locations in southeastern Brazil and other regions from Brazil. The remaining samples formed two clades, which were highly divergent and distantly positioned from those of S. delicatula: 2.5–2.7% and 3.4–3.7%. This level of variation would warrant the species split of these taxa from mid‐western Brazil. A total of eight cox2‐3 spacer and nine cox1 haplotypes were observed among the 122 individuals studied. One location had two cox2‐3 haplotypes and three locations had two cox1 haplotypes; all others had a single dominant haplotype each. The existence of high intraspecific genetic variation among individuals of distinct locations (several haplotypes), but little variation within a location seems to be a pattern for the Batrachospermales. Haplotype networks showed low variation among the haplotypes from southeastern Brazil (10 locations with divergence of 0.3–1.1% for cox2‐3, 0.1–0.3% for cox1) and high variation among the haplotypes from the mid‐west region (four locations, 4.0–9.3% for cox2‐3, 6.2–8.4% for cox1). Thus, the present data clearly suggest the existence of cryptic species in Sirodotia in Brazil.     

Chemical Variability,Antioxidant and Antifungal Activities of Essential Oils and Hydrosol Extract of Calendula arvensis L. from Western Algeria

The chemical composition of the essential oils and hydrosol extract from aerial parts of Calendula arvensis L. was investigated using GC‐FID and GC/MS. Intra‐species variations of the chemical compositions of essential oils from 18 Algerian sample locations were investigated using statistical analysis. Chemical analysis allowed the identification of 53 compounds amounting to 92.3 – 98.5% with yields varied of 0.09 – 0.36% and the main compounds were zingiberenol 1 (8.7 – 29.8%), eremoligenol (4.2 – 12.5%), β‐curcumene (2.1 – 12.5%), zingiberenol 2 (4.6 – 19.8%) and (E,Z)‐farnesol (3.5 – 23.4%). The study of the chemical variability of essential oils allowed the discrimination of two main clusters confirming that there is a relation between the essential oil compositions and the harvest locations. Different concentrations of essential oil and hydrosol extract were prepared and their antioxidant activity were assessed using three methods (2,2‐diphenyl‐1‐picrylhydrazyl, Ferric‐Reducing Antioxidant Power Assay and β‐carotene). The results showed that hydrosol extract presented an interesting antioxidant activity. The in vitro antifungal activity of hydrosol extract produced the best antifungal inhibition against Penicillium expansum and Aspergillus niger, while, essential oil was inhibitory at relatively higher concentrations. Results showed that the treatments of pear fruits with essential oil and hydrosol extract presented a very interesting protective activity on disease severity of pears caused by P. expansum.     

Responses of gas exchange and growth in Merkus pine seedlings to expected climatic changes in Thailand

Responses of gas exchange and growth in Merkus pine (Pinus merkusii Jungh. et de Vriese) seedlings to changing climate were analysed for high‐ and low‐altitude sites in Thailand. A gas exchange model, based on the optimality approach, derived the effect of drought from the probability of rains. A carbon‐and nitrogen‐balance growth model applied structural regularities of a tree and a modification of functional balance between foliage and fine roots as growth‐ guiding rules. Adaptation to local climates was incorporated in the models. The simulations yielded physiologically reasonable behaviour for annual photosynthesis (A) and transpiration (E) in relation to the distributions of precipitation over the course of a year. An annual temperature increase of 2 °C and a prolonged dry season (scenario 2) reduced A by 5–11% and E by 5–8% as compared to present climate (scenario 1). Doubled CO₂ concentration and the increased temperature (scenario 3) enhanced A by 56–59% and E by 14%. Simultaneously these changes (scenario 4) increased A by 41–53% and E by 1–5%. Simulated growth in scenario 1 fitted reasonably well to field data. By the age of five years, simulated total biomass (TB) and height (h) were reduced by 31–67% and 12–42%, respectively, in scenario 2 compared to scenario 1. In scenario 3, TB and h increased by 279–330% and 94–191%, and in scenario 4, by 83–241% and 55–69%, respectively. Large increases in TB and h are explained by the exponential growth phase of the young seedlings. These results suggest that climatic changes enhance growth and thus shorten the duration of the grass stage in these seedlings. However, the effects of climatic changes on growth depend strongly on how rainfall seasonality is altered in SE Asia because prolonged drought episodes may retard the fertilizing effects of the increasing CO₂ concentration.     

Volatile Composition and Biological Activities of the Leaf Essential Oil from Zanthoxylum limoncello Grown in Oaxaca,México

Zanthoxylum limoncello is a native plant from southern Mexico which is used as a timber source, condiment and as a traditional medicine. Herein, we report on the volatile content of the leaf essential oil and its biological activities. The annual essential oils (2015–2018) contained volatile organic compounds which exhibited a moderate growth inhibitory activity against H. pylori ATCC 53504 (MIC 121.4–139.7 μg mL^?1), 26695 (MIC 85.5–94.9 μg mL^?1) and J99 (MIC 94.7–110.4 μg mL^?1). These hydrodistillates contained 2‐undecanone (31.6–36.8 %; MIC 185.3–199.2 μg mL^?1) and 2‐undecenal (25.1–35.7 %; MIC 144.8–111.3 μg mL^?1) as the most abundant compounds which were partially involved in the anti‐H. pylori activity. The human ornithine decarboxylase enzyme (ODC1), which shows increased activity in several cancer types, was non‐competitively inhibited (V_max 2.7>0.8 K_cat s^?1) by the essential oil of Z. limoncello as well as by 2‐undecanone and 2‐undecenal in accordance to in vitro kinetic studies. In silico calculations strongly suggest that the carbonyl group of these oxygenated hydrocarbons interacts with both Asn319 and Ala39 at the subunit A of ODC1. Considering that Ala39 is located close to Asn44, a crucial amino acid of the ODC's allosteric site, the non‐competitive inhibition of the enzyme by 2‐undecanone and 2‐undecenal is endorsed. Finally, the essential oil of Z. limoncello and its main volatiles showed a significant (p<0.01) and prolonged repellent effect against Aedes aegypti.     

Molecular characterization of swine leucocyte antigen class II genes in outbred pig populations

The highly polymorphic swine leucocyte antigen (SLA) genes are among the most important determinants of swine immune responses to disease and vaccines. Accurate and effective SLA genotyping methods are required to understand how SLA gene polymorphisms affect immunity, especially in outbred pigs with diverse genetic backgrounds. In this study, we present a simple and rapid molecular‐based typing system for characterizing SLA class II alleles of the DRB1, DQB1 and DQA loci. This system utilizes a set of 47 sequence‐specific PCR primers developed to differentiate alleles by groups that share similar sequence motifs. We applied this typing method to investigate the SLA class II diversity in four populations of outbred pigs (n = 206) and characterized a total of 19 SLA class II haplotypes, six of which were shared by at least three of the sampled pig populations. We found that Lr‐0.1 (DRB1*01XX–DQB1*01XX–DQA*01XX) was the most prevalent haplotype with a combined frequency of 16.0%, followed by Lr‐0.2 (DRB1*02XX–DQB1*02XX–DQA*02XX) with 14.6% and Lr‐0.15b (DRB1*04XX–DQB1*0202–DQA*02XX) with 14.1%. Over 70% of the pigs (n = 147) had at least one copy of one of these three haplotypes. The PCR‐based typing system described in this study demonstrates a reliable and unambiguous detection method for SLA class II alleles. It will be a valuable tool for studying the influence of SLA diversity on various immunological, pathological and physiological traits in outbred pigs.     

Nuclear insertions and heteroplasmy of mitochondrial DNA as two sources of intra‐individual genomic variation in grasshoppers

We examined the level of intra‐individual variation in a region of the mitochondrial genome coding for cytochrome oxydase 1 (COI) in two grasshopper species using a clone‐and‐sequence analysis of hundreds of sequences. In both Locusta migratoria and Chortoicetes terminifera, we found that 60–65% of the clones were unique COI‐like sequences. Among these COI‐like sequences, 70–75% diverged by less than 1% from the real mitochondrial haplotypes, and were likely to represent microheteroplasmic molecules. About 20% of the COI‐like sequences diverged by more than 9% from the mitochondrial haplotypes, and generally included stop codons, suggesting that these sequences were nuclear mitochondrial pseudogenes (NUMTs). Only six sequences, diverging by 2–6% from the mitochondrial haplotypes, were identified as potentially misleading in phylogenetic studies. In addition, we found that five sequences from C. terminifera were associated with mobile elements or repetitive DNA families.     

Effects of potnetial trap crops and planting date on soil infestation with potato cyst nematodes and root-knot nematodes

In 1997 and 1998 the stimulation of hatch of potato cyst nematodes (PCN) by a trap crop was studied at various times during the growing season in a container and a field experiment. Solanum nigrum‘90‐4750‐188’was used as the trap crop in both experiments and was sown on 1 May, 16 June or 1 August in two successive years on different plots. Neither experiment revealed much seasonal variation in hatchability of PCN juveniles under a trap crop. In the container experiment, the hatch of the Globodera pallida Pa3 population was equally and strongly stimulated (89%) at all sowing dates in both years, except for the 1 August sowing in 1998 (when the hatch was 77% under extremely wet soil conditions). In the control treatment with non‐hosts (flax followed by barley) the total spontaneous hatch was 50% over 2 yr. In the field experiment, the hatch of PCN, averaged over the four populations, was also equally stimulated (71%) at all sowing dates in both years. In the control treatment with non‐hosts (flax‐barley) the total spontaneous hatch was 36% over 2 yr. Total hatch under the trap crop over 2 yr varied between the four PCN populations from 63% to 80%. In 1998 and 1999, control of potato cyst nematodes (PCN) by the potential trap crops Solanum sisymbriifolium and S. nigrum‘90‐4750‐188’was studied in the field. Potato was also included as a trap crop. In the 1998 experiment, potato, S. sisymbriifolium and S. nigrum strongly stimulated the hatch of PCN compared with the non‐host white mustard (Sinapis alba). Roots of potato and white mustard were mainly found in the top 10 cm of soil, whereas roots of S. sisymbriifolium and S. nigrum were also abundant at depths of 10–20 cm and 20–30 cm. In the 1999 experiment, soil infestation with PCN decreased markedly with potato and S. sisymbriifolium as trap crops. In plots moderately to severely infested with 2‐yr old cysts (2–29 juveniles ml^?1 air dried soil), potato reduced soil infestation by 87% and S. sisymbriifolium by 77%. In plots moderately to severely infested with 1‐yr old cysts the reductions were 74% and 60%, respectively. The reduction was least on plots very severely infested with PCN (110–242 juveniles ml^?1 soil): 69% and 52% for potato and S. sisymbriifolium, respectively. Soil infestations of plots that were initially slightly to severely infested with the root‐knot nematode Meloidogyne hapla were greatly reduced under fallow and S. sisymbriifolium but increased under potato. From these and previous experiments it was concluded that, for several reasons, S. sisymbriifolium is a promising trap crop.