Effect of gibberellic acid on the vase life and oxidative activities in senescing cut gladiolus flowers

Cut flowers face the problem of short display life and lose their aesthetic value rapidly. In order to enhance the vase life of gladiolus, its cut spikes were subjected to different levels of gibberellic acid (GA₃), viz., 0, 25, 50, 100 and 200 mg L^?1 in vase solution, during two consecutive years 2010 and 2011. The GA₃ treatment significantly influenced the vase quality attributes and antioxidants capacity of gladiolus cut flowers. Gibberellic acid at 25 mg L^?1 caused the longest time taken to open the floret and increased the floret opening, vase life duration and fresh weight. The highest antioxidative activities of superoxide dismutase and free radicals scavenging were also recorded with GA₃ at 25 mg L^?1. The highest peroxidase, catalase activity and the lowest membrane leakage were recorded with GA₃ at 50 mg L^?1. Present study concludes that GA₃ applied at lower concentrations (25 mg L^?1) renders greater beneficial effects on vase life quality, membrane stability and antioxidant activities in gladiolus cut spike, and further higher application rates cause no improvement in the flower longevity.     

Chemical composition,antibacterial and antifungal activities of flowerhead and root essential oils of Santolina chamaecyparissus L., growing wild in Tunisia

The antimicrobial properties of essential oil from various Santolina species have not been investigated enough in the previous studies dealing with the biological activities of medicinal plants. In Tunisia, Santolina chamaecyparissus L. (Asteraceae) is the only Santolina species recorded and is used as vermifuge and emmenagogue. The chemical composition, antibacterial and antifungal properties of essential oils from the flowerheads and roots of spontaneous S. chamaecyparissus growing in Tunisia and the chemical composition which leads to the Tunisian chemotype are investigated here for the first time. Essential oils isolated by hydro distillation from flowerheads and roots of S. chamaecyparissus were analyzed by GC and GC/MS. Two methods served for antimicrobial assays of the essential oils: diffusion in a solid medium and micro-well dilution assay. Antifungal tests were carried out by the agar incorporation method. Sixty-seven constituents were identified from the essential oil of the flowerhead. The major constituents were: 1,8-cineole and β-eudesmol. Two non identified compounds were present at the highest concentration in root oil. Flowerhead oil was characterized by high contents in monoterpenes and sesquiterpenes oxygenated compounds. The flowerhead essential oil demonstrated potent of antibacterial properties against Pseudomonas aeruginosa ATCC and Enterococcus faecalis ATCC, with MIC of 0.625 μg/ml. These findings demonstrate that the flowerhead essential oils of S. chamaecyparissus have excellent antibacterial properties and for this reason they could contribute to decrease the problem of microbial resistance to antibiotics.     

Ocimum gratissimum Linn. (Lamiaceae) essential oil for the management of Exorista sorbillans Wiedemann (Diptera: Tachinidae) menace of silkworm in seriecosystem

Although they act as biocontrol agents, Tachinid parasitoids attack economically beneficial insects, inviting the adoption of control measures against them. The uzi fly, Exorista sorbillans, infests silkworms incurring heavy loss. It is difficult to control such parasitoids as the larval stage is endoparasitic, and insecticides cannot reach them without subjecting the silkworms to potential risks. We selected the leaves of Ocimum gratissimum L. for testing their toxicity potential against E. sorboillans because of its low selective toxicity to Antheraea assamensis Helfer larvae. Assay for adulticidal efficacy of the leaf extracts showed the petroleum ether extract to be the most effective. But the essential oil (LC50 of 0.42%) was even more effective. GC–MS analysis of the oil revealed the presence of twenty-seven compounds with a high percentage of thymol (26.17%), indicating the plant oil as thymol rich chemotype. Thymol was the dominant constituent in the active fraction. The oil and constituents caused rapid death on topical application, indicating a higher penetration rate. We propose the exploration of the essential oil and its constituents as a sustainable solution for controlling E. sorbillans infestation of silkworms in the future.     

Effects of 1-MCP on the vase life and ethylene response of cut flowers

Pretreatment for 6 h with low concentrations of 1-MCP (1-Methylcyclopropene, formerly designated as SIS-X), a cyclic ethylene analog, inhibits the normal wilting response of cut carnations exposed continuously to 0.4 l·l^–1 ethylene. The response to 1-MCP was a function of treatment concentration and time. Treatment with 1-MCP was as effective in inhibiting ethylene effects as treatment with the anionic silver thiosulfate complex (STS), the standard commercial treatment. Other ethylene-sensitive cut flowers responded similarly to carnations. In the presence of 1 l·l^–1 ethylene, the vase life of 1-MCP-treated flowers was up to 4 times that of the controls.Abbreviations 1-MCP 1-Methylcyclopropene - STS silver thiosulfate     

Effects of 1-MCP on the vase life and ethylene response of cut flowers

Pretreatment for 6 h with low concentrations of 1-MCP (1-Methylcyclopropene, formerly designated as SIS-X), a cyclic ethylene analog, inhibits the normal wilting response of cut carnations exposed continuously to 0.4 μl·l^?1 ethylene. The response to 1-MCP was a function of treatment concentration and time. Treatment with 1-MCP was as effective in inhibiting ethylene effects as treatment with the anionic silver thiosulfate complex (STS), the standard commercial treatment. Other ethylene-sensitive cut flowers responded similarly to carnations. In the presence of 1 μl·l^?1 ethylene, the vase life of 1-MCP-treated flowers was up to 4 times that of the controls.     

Effects of ethylene and cytokinins on vase life of cut Eucalyptus parvifolia Cambage branches

The role of ethylene and cytokinins was investigated during postharvestsenescence of cut Eucalyptus parvifolia Cambage branches.The effect of endogenous and exogenous ethylene on the vase life of the cutbranches was studied using 2 mM 1-aminocyclopropane-1-carboxylicacid (ACC) as a continuous treatment or pulse treatment for 48h with 20, 40 and 80 l l^–1ethylene. Both endogenous and exogenous ethylene reduced the vase life of thebranches; however, the effect of the endogenous hormone was stronger than theexogenous applications. Ethylene biosynthesis was inhibited by pulse treatmentfor 24 h using 1 mM AOA or 2 mMCoCl₂. The latter treatment significantly extended the vase life ofthe branches by delaying senescence. The effect of cytokinins was evaluated onthe vase life of cut E. parvifolia branches by pulsetreatment for 24 h with 10, 50 and 100 mM thidiazuron(TDZ) or 85, 130 and 260 mM N6-benzyladenine (BA). The resultsobtained showed that no response was observed following pulse treatment with BAwhile, although TDZ had little effect on vase life, it was a good inhibitor ofchlorophyll degradation.     

Production of essential oils by flowers of Hyacinthus orientalis L. regenerated in vitro

Essential oils were produced by flowers of Hyacinthus orientalis L. that had been regenerated in vitro. The production of these oils was affected by the concentration of gibberellic acid and sucrose in the medium and by temperature. The highest concentration of essential oils was obtained when regenerated flowers were cultured in vitro for 3 weeks at 20 °C on Murashige and Skoog's medium that contained 30 g/l sucrose plus 1 mg/l gibberellic acid, whereas the highest amount of essential oils was obtained after a culture period of 3 weeks at 25 °C. The composition of essential oils from flowers that had been regenerated in vitro was compared with that from flowers grown in the field. Essential oils detected by gas-liquid chromatography included nine components in the case of the regenerated flowers and six and ten components in the case of stage 3 and stage 4 flowers grown in the field, respectively. There were four common components, namely, 1-hepten-3-ol, benzyl alcohol, phenethyl alcohol and cinnamyl alcohol. In the regenerated flowers, a single component, phenethyl alcohol, was a major constituent (75%), whereas two compounds, phenethyl alcohol (stage 3, 55%; stage 4, 48%) and cinnamyl alcohol (stage 3, 23%; stage 4, 29%) were the major constituents in the case of flowers grown in the field. Four and five other components were specific to flowers regenerated in vitro and field-grown flowers, respectively.Abbreviations BA 6-benzylaminopurine - 2,4-D 2,4-dichlorophenoxyacetic acid - IAA indole-3-acetic acid - NAA 1-naphthaleneacetic acid - ABA abscisic acid - GA₃ gibberellic acid - ACC 1-aminocyclopropane-1-carboxylic acid - ethephon (2-chloroethyl)phosphonic acid - MS medium Murashige and Skoog's medium - GLC gas-liquid chromatography - GC-MS gas chromatography-mass spectrometry - FW fresh weight     

Antimicrobial,antibiofilm and antitumor activities of essential oil of Agastache rugosa from Xinjiang,China

In the study, we evaluated chemical composition and antimicrobial, antibiofilm, and antitumor activities of essential oils from dried leaf essential oil of leaf and flower of Agastache rugosa for the first time. Essential oil of leaf and flower was evaluated with GC and GC–MS methods, and the essential oil of flower revealed the presence of 21 components, whose major compounds were pulegone (34.1%), estragole (29.5%), and p-Menthan-3-one (19.2%). 26 components from essential oil of leaf were identified, the major compounds were p-Menthan-3-one (48.8%) and estragole (20.8%). At the same time, essential oil of leaf, there is a very effective antimicrobial activity with MIC ranging from 9.4 to 42 μg ml⁻¹ and potential antibiofilm, antitumor activities for essential oils of flower and leaf essential oil of leaf. The study highlighted the diversity in two different parts of A. rugosa grown in Xinjiang region and other places, which have different active constituents. Our results showed that this native plant may be a good candidate for further biological and pharmacological investigations.     

Chemical composition and antibacterial activities of seven Eucalyptus species essential oils leaves

Background

In this paper, we have studied the essential oils chemical composition of the leaves of seven Eucalyptus species developed in Tunisia. Eucalyptus leaves were picked from trees growing in different arboretums in Tunisia. Choucha and Mrifeg arboretums located in Sedjnene, region of Bizerte (Choucha: E. maideni, E. astrengens et E. cinerea; Mrifeg : E. leucoxylon), Korbous arboretums located in the region of Nabeul, North East Tunisia with sub-humid bioclimate, (E. lehmani), Souiniet-Ain Drahem arboretum located in region of Jendouba (E. sideroxylon, E. bicostata). Essential oils were individually tested against a large panel of microorganisms including Staphylococcus aureus (ATCC 6539), Escherichia coli (ATCC 25922), Enterococcus faecalis (ATCC29212), Listeria ivanovii (RBL 30), Bacillus cereus (ATCC11778).

Results

The yield of essential oils ranged from 1.2% to 3% (w/w) for the different Eucalyptus species. All essential oils contain α-pinene, 1,8-cineol and pinocarveol-trans for all Eucalyptus species studied. The 1,8-cineol was the major compound in all species (49.07 to 83.59%). Diameter of inhibition zone of essential oils of Eucalyptus species varied from 10 to 29 mm. The largest zone of inhibition was obtained for Bacillus cereus (E. astrengens) and the lowest for Staphylococcus aureus (E. cinerea). The essential oils from E. maideni, E. astrengens, E. cinerea (arboretum of Bizerte), E. bicostata (arboretum of Aindraham) showed the highest antibacterial activity against Listeria ivanovii and Bacillus cereus.

Conclusion

The major constituents of Eucalyptus leaves essential oils are 1,8-cineol (49.07 to 83.59%) and α-pinene (1.27 to 26.35%). The essential oils from E. maideni, E. astrengens, E. cinerea, E. bicostata showed the highest antibacterial activity against Listeria ivanovii and Bacillus cereus, they may have potential applications in food and pharmaceutical products.     

Effect of 5-sulfosalicylic acid on antioxidant activity in relation to vase life of <Emphasis Type="Italic">Gladiolus</Emphasis> cut flowers

An experiment was conducted to study the effect of 5-sulfosalicylic acid (5-SSA) on the vase life of cut flowers of Gladiolus grandiflora variety ‘Green Willow’. The vase solution having 5-SSA significantly increased cumulative uptake of vase solution, vase life, number of opened florets and decreased the number of unopened florets compared to the controls. Spikes kept in vase solution containing 5-SSA also exhibited lower respiration rates, lipid peroxidation and lipoxygenase (LOX) activity, and higher membrane stability, soluble protein concentration, and activity of superoxide dismutase (SOD) and catalase. Results suggest that 5-SSA increases vase life by increasing the reactive oxygen species (ROS) scavenging activity of the Gladiolus cut flowers.     

Mosquitocidal and repellent activities of essential oils against Culex pipiens L.

Plants are a prospective source of novel natural insect repellents and botanical insecticides. This study was conducted to investigate the chemical composition of the essential oils of three plants growing in Saudi Arabia, namely Ducrosia anethifolia, Achillea fragrantissima, and Teucrium polium; and to evaluate their potential mosquitocidal and repellent activities against adult female Culex pipiens L. The main components of the three oils were found to be decanal (28.9%) and chrysanthenyl acetate (10.04%), (D. anethifolia); sabinyl acetate (35.79) and artemesia ketone (18.28%) (A. fragrantissima); α‐cadinol (49.53%) and δ‐cadinene (10.23%) (T. polium). The oil of A. fragrantissima was the most toxic (LC₅₀ = 0.11 μL/L air) followed by D. anethifolia and T. polium with LC₅₀ values of 5.22 and 25.98 μL/L air, respectively. T. polium oil was the most repellent (292 min at 2 μL/cm²), followed by D. anethifolia and A. fragrantissima. The results indicate that the essential oils have a potential fumigant insecticidal and repellent activities for mosquito control.     

Composition and biological activities of essential oils from Limnophila geoffrayi Bonati

Essential oils from the dried aerial parts of Limnophila geoffrayi Bonati were obtained by water-distillation. d-Pulegone (27.14%), perillaldehyde (19.13%) and limonene (9.00%) were characterized as the major constituents using gas chromatography-mass spectrometry analysis. The antimicrobial activities of the essential oils and their major components were evaluated against microorganisms encountered normally in contaminated cosmetic products, using the agar- and broth-dilution methods. Their insecticidal activities against the Oriental fruit fly Bactrocera dorsalis (Hendel) were tested using a bioassay with impregnated filter paper. The results showed that the essential oils possessed high antimicrobial activity, with minimum inhibitory concentrations ranging from 0.03 to 0.2% per unit volume (v/v). Strong insecticidal activity as a fumigant was also observed at an oil dose of 5 μl/disc, with a 94% mortality. Perillaldehyde was the most active compound among the main components of these essential oils.     

Antimicrobial and antioxidative activity of extracts and essential oils of Myrtus communis L.

Since synthetic antimicrobial agents and food additives can cause a number of adverse effects, there is a growing interest from consumers in ingredients from natural sources. Medicinal plants, such as Myrtus communis L. are a source of new compounds which can be used in both the food industry and for medical purposes, primarily as antimicrobial agents. In this review, the characteristics of myrtle essential oils and extracts are summarized, with particular attention to their chemical composition, biological activities and potential applications.     

几种典型植物精油的化学成分与其抗菌活性

【目的】植物精油萃取自天然植物, 因具有抗菌活性, 近年来受到广泛关注。论文的目的是分析植物精油的化学成分, 测试其抗菌活性, 并研究其化学成分与抗菌活性之间的联系。【方法】实验选取了肉桂、山苍子、丁香、香茅、迷迭香和大蒜精油等6种典型植物精油, 通过气质联用分析方法研究了其化学组分, 并通过污染食物技术研究了其对黑曲霉和绳状青霉的抗真菌活性, 以及对大肠杆菌和金黄色葡萄球菌的抗细菌活性。【结果】气质联用分析结果表明, 肉桂、山苍子、香茅和迷迭香等4种植物精油的化学成分主要是醛类和醇类, 丁香精油的主要化学成分是丁香油酚, 大蒜精油化学成分基本上都是含硫的醚类, 其中二烯丙基三硫醚(大蒜素)含量最高。抗菌活性结果显示, 不同植物精油的抗菌活性不同, 6种植物精油的抗真菌活性由强到弱依次为: 肉桂>大蒜>丁香>山苍子=香茅>迷迭香, 抗细菌活性由强到弱依次为: 肉桂>山苍子>丁香>香茅=迷迭香>大蒜。【结论】植物精油的抗真菌、细菌活性与其化学组分密切相关, 肉桂、山苍子、香茅和迷迭香等4种精油的抗菌活性可能主要与其化学成分中的醛类和醇类有关, 丁香精油较高的抗菌活性可能主要源于丁香油酚; 大蒜精油具有高效的抗真菌活性主要源于其化学成分中的含硫醚。不同植物精油化学成分不同, 抗真菌、细菌活性也不同, 表明其可能有不同的抗真菌与抗细菌机制。     

Effects of plant growth regulators and sucrose on post harvest physiology,membrane stability and vase life of cut spikes of gladiolus

Effects of post-harvest application of two plant growth regulators viz., gibberellic acid (GA₃) and benzyl adenine (BA) with sucrose in the vase solution on cell membrane stability and vase life of gladiolus were investigated. The vase solution treatment combinations of GA₃ and BA with sucrose significantly increased the membrane stability index and enhanced the vase life as compared to the sucrose alone treatments or the controls. Vase solution treatment of GA₃ (50 mg l⁻¹), followed by BA (50 mg l⁻¹) with sucrose (50 g l⁻¹) significantly increased solution uptake, fresh weight and dry weight of cut spikes. The same treatments also enhanced the concentration of reducing and non-reducing sugars in gladioli petals 4 days after treatment (DAT). Cut spikes in vase solution enriched with 50 mg l⁻¹ GA₃ + 50 g l⁻¹ sucrose showed higher antioxidative enzyme activities of superoxide dismutase (SOD) and glutathione reductase (GR), lower lipoxygenase (LOX) activity and lipid peroxidation (measured as TBARS). Petal membrane stability index was also highest in cut spikes 6 DAT with 50 mg l⁻¹ GA₃ + 50 g l⁻¹ sucrose vase solution. Treatment of gladiolus cut spikes with 50 mg l⁻¹ GA₃ + 50 g l⁻¹ sucrose vase solution showed two fold increase in vase life and improved flower quality with a higher number of open flower per spike at any one time. These results suggest that post-harvest application of GA₃ (50 mg l⁻¹) with sucrose (50 g l⁻¹) maintains higher spike fresh and dry weight, improves anti-oxidative defence, stabilizes membrane integrity leading to a delay in petal cell death.     

Effects of essential oils on in vitro ruminal fermentation and ammonia release

Ruminal inoculum enriched with particle-associated microorganisms was collected from two lactating dairy cows fed an alfalfa hay/cereal silage/concentrate diet 1 h before feeding and used to evaluate effects of essential oils (EO) on ruminal fermentation in short-term in vitro incubations. Ruminal ammonia N was labeled with ¹⁵N and native and hydrolyzed casein were provided as sources of amino acids. Forty EO were tested at 10 and 100 mg/l final medium concentration. Monensin-Na, and sodium laurate were also incubated at 5 and 2000 mg/l, respectively. Compared with blanks (i.e., no addition of EO), sodium laurate increased medium pH and a number of EO reduced medium pH. Both sodium laurate and monensin reduced ammonia concentrations compared to the blank. Only one of the tested EO (i.e., Caraway) slightly reduced ammonia concentration, by 8%, compared with the blank. Monensin and sodium laurate resulted in higher (i.e., 9–34%, monensin, and 29–47%, sodium laurate) ¹⁵N enrichment of ammonia N, an indication of reduced deamination of amino acids in these treatments versus the blank. Several EO (i.e., FrankMyrrh, Gardenia, Hibiscus, Eucaliptus, and Peppermint) had similar effects, but of a smaller magnitude (i.e., 5–12%). Some EO increased medium total VFA concentration, primarily through an increase in acetate concentration. Overall, effects of EO on fermentation were subtle, and it is unlikely that these moderate in vitro effects would correspond to any substantive impact on ruminal fermentation in vivo.     

Effects of the time of sucrose treatment on vase life, soluble carbohydrate concentrations and ethylene production in cut sweet pea flowers

Cut sweet pea flowers were put in vase water containing 200 mg l^–1 8-hydroxyquinoline sulfate (HQS), and 100 g l^–1 sucrose was added to the solution during the first 24 h (initial treatment), from the 24th h on (late treatment) or throughout the experimental period (continuous treatment). The vase life of the florets in the control (with no sucrose added), initial-, late-, and continuous-treatment groups were 2.8, 6.0, 5.0 and 8.0 days, respectively. Climacteric ethylene production of the florets was the earliest in the control group followed by the late-, initial- and continuous-treatment groups, in this order. The concentrations of glucose, fructose and s ucrose at the 2nd day and later were the highest in the continuous-treatment group followed by the initial-treatment, late-treatment and control group, in this order. Thus, the correlation between sugar concentrations in petals and vase life was positive, whereas that between the sugar concentrations and ethylene production was negative. These results suggest that sugar concentration in petals affects the vase life of cut sweet pea flowers through ethylene production.     

Screening of chemical composition, antimicrobial and antioxidant activities of Artemisia essential oils

The chemical composition of essential oils isolated from aerial parts of seven wild sages from Western Canada – Artemisia absinthium L., Artemisia biennis Willd., Artemisia cana Pursh, Artemisia dracunculus L., Artemisia frigida Willd., Artemisia longifolia Nutt. and Artemisia ludoviciana Nutt., was investigated by GC–MS. A total of 110 components were identified accounting for 71.0–98.8% of the oil composition. High contents of 1,8-cineole (21.5–27.6%) and camphor (15.9–37.3%) were found in Artemisia cana, A. frigida, A. longifolia and A. ludoviciana oils. The oil of A. ludoviciana was also characterized by a high content of oxygenated sesquiterpenes with a 5-ethenyltetrahydro-5-methyl-2-furanyl moiety, of which davanone (11.5%) was the main component identified. A. absinthium oil was characterized by high amounts of myrcene (10.8%), trans-thujone (10.1%) and trans-sabinyl acetate (26.4%). A. biennis yielded an oil rich in (Z)-beta-ocimene (34.7%), (E)-beta-farnesene (40.0%) and the acetylenes (11.0%) (Z)- and (E)-en-yn-dicycloethers. A. dracunculus oil contained predominantly phenylpropanoids such as methyl chavicol (16.2%) and methyl eugenol (35.8%). Artemisia oils had inhibitory effects on the growth of bacteria (Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis), yeasts (Candida albicans, Cryptococcus neoformans), dermatophytes (Trichophyton rubrum, Microsporum canis, and Microsporum gypseum), Fonsecaea pedrosoi and Aspergillus niger. A. biennis oil was the most active against dermatophytes, Cryptococcus neoformans, Fonsecaea pedrosoi and Aspergillus niger, and A. absinthium oil the most active against Staphylococcus strains. In addition, antioxidant (beta-carotene/linoleate model) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities were determined, and weak activities were found for these oils.     

Screening the essential oil composition of wild Sicilian oregano

The qualitative and quantitative composition of the essential oils obtained from wild Sicilian oregano plants has been investigated. Samples were collected from three areas of Sicily namely Val Mazara (M), Val di Noto (N) and Val Demona (D). These areas are based on historical territorial subdivision. The essential oils were obtained by hydrodistillation and analyzed by GC-FID-MS. Seventy eight compounds were identified representing more than 98% of the compounds in the oils. All samples are thymol-chemotype with variable percentage of γ-terpinene, p-cymene, trans-sabinene hydrate, terpinen-4-ol and carvacrol. Statistical analyses were performed in order to evaluate the variability of the essential oils. Six groups were formed reflecting the compositional differences of the essential oil profiles of the wild Sicilian oregano samples.     

Agrobacterium-mediated transformation of Artemisia absinthium L. (wormwood) and production of secondary metabolites

Hairy roots were obtained after infection of Artemisia absinthium shoots with Agrobacterium rhizogenes strains 1855 and LBA 9402. The susceptibility to hairy root transformation varied between plant genotypes and bacterial strains. Hairy roots showed macroscopic differences from control root cultures. Southern blot hybridization confirmed the integration of T-DNA from both p1855 and pBin19, while polymerase chain reaction analysis indicated the presence of the neomycin phosphotransferase gene in the hairy root genome. Subcultured transformed root lines grew well in selective B5 agar-solidified medium containing kanamycin or rifampicin and without hormones. Shake-flask experiments with fast-growing root lines showed that 40 g l^–1 was the best sucrose concentration for biomass production, yielding a 463-fold increase in dry weight after 28 days of culture. Great differences were found in the profiles of the essential oils isolated from normal and hairy roots. Gas chromatography/mass spectrometry analysis showed the oil produced by transformed cultures to be a mixture of 50 compounds with only one major component representing 37% of the oil content. Received: 19 March 1996 / Revision received: 15 July 1996 / Accepted: 13 December 1996