Effect of biocontrol agent Bacillus amyloliquefaciens and 1-methyl cyclopropene on the control of postharvest diseases and maintenance of fruit quality

Efficacy of biocontrol agent Bacillus amyloliquefaciens PPCB004 was evaluated on the control of anthracnose and phomopsis rot in ‘Solo’ papaya pre-treated with 1-methyl cyclopropene (100 μl) (1-MCP) during storage. This treatment was compared to the untreated control, commercial treatment (washing in chlorinated water), stand alone 1-MCP and PPCB004 treatment. Although fruit pre-treated with 1-MCP delayed the ripening (100% yellow) after cold storage by 9-10 d, it showed higher incidence and severity of anthracnose and phomopsis rot than the fruit subjected to commercial treatment. Application of PPCB004 after 1-MCP pre-treatment (1-MCP + PPCB004) reduced the anthracnose and phomopsis incidence and severity after cold storage (10 °C, 85% RH for 14 d) and ripening at 25 °C. The 1-MCP + PPCB004 treatment helped to retain the fruit firmness, overall quality and uniform yellow skin (100%) and flesh colour after ripening. The PPCB004 was effectively recovered from stand alone PPCB004 and 1-MCP + PPCB004 treated fruit after cold storage and ripening. The PPCB004 population showed an increase by 1 log units after ripening in 1-MCP + PPCB004 treated fruit. After ripening the recovery of PPCB004 population was higher (0.7 log units) in 1-MCP + PPCB004. The total recovery of fungal population on the fruit surface after ripening was lower in 1-MCP + PPCB004 and stand alone PPCB004 treated fruit. It can be concluded that application of B. amyloliquefaciens PPCB004 with 1-MCP pre-treated papaya (at 25-30% skin yellow stage) can significantly reduce disease incidence associated with 1-MCP treatment. This treatment has the potential for commercial application in the ‘organic’ papaya industry.     

Mosquitocidal activity of two Bacillus bacterial endotoxins combined with plant oils and conventional insecticides

The full whole culture (FWC), containing parasporal protein toxins of Bacillus thuringiensis israelinsis (Bti) and Bacillus sphaericus 2362 (Bs), either singly or in combination with plant oils and commercial insecticides, was tested against larval and adult stages of Culex pipiens mosquitoes under controlled laboratory conditions. In terms of LC₅₀ values recorded after 24, 48, 72 and 96 h, the bacterial toxins showed high potency towards both larvae and adults of mosquitoes in a dose-dependent manner. Generally, the Bti toxin seemed to be more potent than the Bs toxin. For example, the Bti toxin showed a 24 h LC₅₀ of 8.2 ppm against mosquito larvae compared to 13.6 ppm for the Bs toxin. In the adult bioassay, the obtained 24 h LC₅₀ values were 0.064 and 0.085 mg/cm², respectively for the two bacterial toxins. The bacterial toxins mixed with plant oils or insecticides at equitoxic doses (e.g., LC₂₅ values) mostly showed potentiation effects, either against larvae or adults of the tested insect. Among a total of 14 paired mixtures, only the joint action estimated for the mixture of malathion + Bti or Bs was accounted as additively. Combining Bti or Bs endotoxins at LC₀ with different plant oils and insecticides at LC₅₀ concentration levels each, has resulted in considerable synergism against either larvae or adults. In the case of larval bioassays, the maximum synergistic factor (SF) obtained (ca. 2.0) was entitled to the mixture of Bti + spinosad. In the adult bioassays, the mixtures containing Curcuma longa or Melia azedarach oil extracts with Bti or Bs toxins achieved a SF accounted to 2.0. The results of the present study may be considered as an additional contribution to the area of joint toxicity of biocidal agents combining bacterial toxins, plant oils and traditional insecticides. The reached findings may encourage future research to elucidate its performance under practical field conditions.     

Repellent effects of five monoterpenoid odours against Tribolium castaneum (Herbst) and Rhyzopertha dominica (F.) in Calabar, Nigeria

Secondary plant compounds are recognised as important components of plant defence system against herbivores and pathogens. Five monoterpenoids, (R)-linalool, 1,8-cineole, (S)-2-heptyl acetate, (S)-2-heptanol and citral, which are natural components of the essential oils of Aframomum melegueta (K. Schum) and Zingiber officinale (Roscoe), were tested at the ratios in which they occur naturally for repellent activity against Tribolium castaneum (Herbst.) and Rhyzopertha dominica (F.) in a 4-way olfactometer. The results showed the repellent properties of the compounds as both beetles spent less time in the olfactometer arm containing the test stimuli. (R)-linalool and (S)-2-heptanol were stronger repellent compounds than the others. Linalool showed good repellent activity against T. castaneum (P = 0.001) as the insect spent 1.22 min in the test arm compared to the control arms (2.78 min), and R. dominica (P = 0.001) with 0.89 min in the test arm compared to 2.87 min in the control arms. With (S)-2-heptanol, T. castaneum spent 1.23 min in the test arm compared to 2.83 min in the control arms. R. dominica spent 1.61 min in the test arm and 2.69 min in the control arms. For the number of entries or visits made, while both insects were significantly repelled (P < 0.05) by the linalool-treated arm than the control, only R. dominica was repelled by the (S)-2-heptanol-treated arm (P = 0.038) compared to the control arms. The results indicate that A. melegueta and Z. officinale essential oils and their components could be suitable as safer repellents or fumigants against T. castaneum and R. dominica.     

Activities of essential oils from Asarum heterotropoides var. mandshuricum against five phytopathogens

Some secondary metabolites of plants function as antimicrobial products against phytopathogens and constitute an increasingly important class of pesticides. In the present study, the essential oil of Asarum heterotropoides var. mandshuricum was analyzed by GC/MS and its antimicrobial activity was evaluated against five phytopathogenic fungi. Major components of the oil were methyleugenol (59.42%), eucarvone (24.10%), 5-allyl-1,2,3-trimethoxybenzene (5.72%), and 3,7,7-trimethylbicyclo(4.1.0)hept-3-ene (4.93%). The essential oil and the most abundant component, methyleugenol, were separately assayed for inhibition of 5 pathogens: Alternaria humicola, Colletotrichum gloeosporioides, Rhizoctonia solani, Phytophthora cactorum and Fusarium solani. Both the oil and methyleugenol strongly inhibited the growth of the test pathogens (IC₅₀ values <0.42 μg ml⁻¹) except F. solani, with the best activity against P. cactorum (IC₅₀ values = 0.073 and 0.052 μg ml⁻¹, respectively). It is concluded that the essential oil of A. heterotropoides var. mandshuricum has a broad antiphytopathogenic spectrum, and that methyleugenol is largely responsible for the bioactivity of the oil. The mode of action of methyleugenol against P. cactorum is discussed based on changes in the mycelial ultrastructure.     

Insecticidal and repellent activity of selected essential oils against of the pollen beetle, Meligethes aeneus (Fabricius) adults

The essential oils from 9 aromatic plants were tested on repellency and mortality of Meligethes aeneus adults. All the tested essential oils caused high mortality of M. aeneus adults in the tarsal tests. The lethal doses after 6 h exposure were ranged between 197 and 1508 μg cm⁻². Essential oils obtained from Carum carvi and Thymus vulgaris were most efficient where LD₅₀ was estimated as 197 and 250 μg cm⁻², respectively.Repellency declined in all the essential oils as a function of time. The longest persistence time was determined for essences obtained from C. carvi and T. vulgaris where significantly the highest repellent index of 65.6% and 63.8%, respectively, was determined. Repellent index lower than 15% was determined for the remaining essential oils.     

Carbohydrate degrading enzyme production by plant pathogenic mycelia and microsclerotia isolates of Macrophomina phaseolina through koji fermentation

The ability of hydrolytic enzyme production by two different isolates of Macrophomina phaseolina was studied on apple pomace as a substrate for solid state fermentation (SSF). Initial moisture level, temperature and fermentation period was optimized so as to achieve higher output. Among the two different isolates, microsclerotial (MphP) and mycelial (MphM), MphP was observed as a potential source of different hydrolytic enzymes as compared to MphM. MphP gave higher enzyme activities (IU/gram dry substrate (gds): filter paper cellulase (FPase) activity 196.21 ± 16.3 (120 h), carboxymethyl cellulase (CMCase) 279.34 ± 28.25 (72 h), β-glucosidase (BGL) 129.82 ± 12.41 (96 h), xylanase 2527.88 ± 46.15 (120 h), and amylase 2780.72 ± 38.13 (96 h), respectively at 70% (v/w) IML. The incubation temperature was also found to have impact on the enzyme production ability of Macrophomina strains. The higher enzyme activities were achieved (IU/gds) as follows FPase 276.13 ± 25.02 (40 °C, 120 h), CMCase 278.11 ± 24.47 (35 °C, 144 h), BGL 189.47 ± 15.05 (30 °C, 144 h), xylanase 3845.77 ± 43.38 (35 °C, 144 h) and amylase activity of 3309.45 ± 29.22 (35 °C, 120 h), respectively using MphP at 70% (v/w) IML. This study reports for the first time the potential of carbohydrate degrading enzyme bioproduction by different isolates of M. phaseolina.     

Temperature-induced structural and chemical changes in cork from Quercus cerris

The effects of temperature on anatomical and chemical characteristics of Quercus cerris cork were examined. Cork samples were subjected to isothermal air heating between 150 °C and 400 °C and analyzed for mass loss, cellular structure and chemical composition.The thermal decomposition of Q. cerris cork is similar to that of Q. suber cork. Cork is thermally stable below 200 °C and after that degradation depended on temperature and heating time with increasing mass loss, i.e. 3% at 200 °C 10 min and 46% at 350 °C 60 min. With temperature and starting at 200 °C, cells expanded, cell wall thickness was reduced and corrugations were lost.Extractives degraded at lower temperatures, although aliphatic extractives were found to be more stable. Suberin from Q. cerris was more heat resistant than Q. suber suberin, while lignin showed similar resistance.These results provide a basis for studies on the production of Q. cerris bark expanded cork agglomerates for insulation purposes.     

In vitro activity of eighteen essential oils and some major components against common postharvest fungal pathogens of fruit

The development of natural crop protective products as alternatives to synthetic fungicides is currently in the spotlight. In vitro experiments are valuable precursors to more costly in vivo trials, allowing the identification of effective essential oils and establishing the concentrations required for inhibition of a specific, or spectrum of decay pathogens. In this study, the antifungal properties of eighteen essential oils were evaluated in vitro by addition to the fungal growth medium of five pathogens (Lasiodiplodia theobromae, Colletotrichum gloeosporioides, Alternaria citrii, Botrytis cinerea and Penicillium digitatum) isolated from mango, avocado, citrus, grapes and cactus pear. The inhibitory properties of some of the major compounds of the oils, identified and quantified by gas chromatography-mass spectroscopy and gas chromatography-flame ionization detection were also determined. Most of the oils were selected on the basis of commercial availability and for containing a predominant compound. Visual inspection of fungal growth was done and the lowest concentration where fungal growth was completely inhibited on all replicates was recorded. Thyme oil proved to be the most effective inhibitor, totally inhibiting all of the pathogens tested at concentrations of 1000 μl/l and lower, with the exception of a resistant Penicillium strain. Cinnamon oil, rich in eugenol (81.2%), demonstrated good fungicide potential, while the carvone-rich oils displayed promising activity against the citrus pathogens. Oils characterized by high concentrations of S-carvone were less effective than those containing the R-enantiomer. Essential oil of Lippia citriodora was active against all of the pathogens, excluding L. theobromae from avocado. These essential oils, applied alone or in combination, are good candidates for further in vivo testing and for investigations concerning their modes of action.     

Thermal tolerance of propagative anthurium stem cuttings to disinfestation by heat treatment for burrowing nematodes and bacterial blight

Hot water and hot air treatments were evaluated for disinfesting anthurium, Anthurium andraeanum Lind., stem cuttings of the bacterial blight pathogen, Xanthomonas axonopodis pathovar dieffenbachiae (Xa pv. dieffenbachiae), and burrowing nematodes, Radopholus similis, and their effect on viability of the cuttings. Xa pv. dieffenbachiae suspended in distilled water in 1.5 ml microcentrifuge tubes, lost at least 6 logs of viability when exposed to hot water at 50 °C for 12 min or hot air at 50 °C, 60% RH for 35 min administered in commercial-sized heat treatment facilities. Stem cuttings exposed to hot air at 50 °C, 60% RH were disinfested of R. similis when their core temperatures attained 50 °C. Plant response to heat treatments varied among cultivars; however, all evaluated cultivars exhibited high tolerance to hot water at 50 °C for up to 24 min with equal or enhanced sprouting rates as compared to untreated checks. Sprouting rates of three of the four cultivars treated with hot air at 50 °C, 60% RH for up to 125 min were equal to or higher than untreated checks, while cuttings from the less tolerant cultivar ‘Tropic Fire’ registered lower sprouting rates for all hot air treatment durations as compared to untreated checks, Flower quality parameters, including average spathe size, stem diameter and number of flowers harvested from plants heat-treated as cuttings, were comparable to or higher than untreated checks for all treatments and cultivars. Disinfestation of anthurium stem cuttings for bacterial blight and the burrowing nematode can be achieved in hot water at 50 °C for 24 min without loss of sprouting rate or flower quality.     

Characteristics, composition and thermal stability of Acacia senegal (L.) Willd. seed oil

The chemical composition, main physicochemical properties and thermal stability of oil extracted from Acacia senegal seeds were evaluated. The oil, moisture and the ash contents of the seeds were 9.80%, 6.92% and 3.82%, respectively. Physicochemical properties of the oil were iodine value, 106.56 g/100 g of oil; saponification value, 190.23 mg KOH/g of oil; refractive index (25 °C), 1.471; unsaponifiable matter, 0.93%; acidity, 6.41% and peroxide value, 5.43 meq. O₂/kg of oil. The main fatty acids in the oil were oleic acid (43.62%) followed by linoleic acid (30.66%) and palmitic acid (11.04%). The triacylglycerols (TAGs) with equivalent carbon number ECN 44 (34.90%) were dominant, followed by TAGs ECN 46 (28.19%), TAGs ECN 42 (16.48%) and TAGs ECN 48 (11.23%). The thermal stability analysed in a normal oxidizing atmosphere showed that the oil decomposition began at 268.6 °C and ended at 618.5 °C, with two stages of decomposition at 401.5 °C and 576.3 °C. According to these results, A. senegal seed oil has physicochemical properties, fatty acids composition and thermal characteristics that may become interesting for specific applications in several segments of food and non-food industries.     

Effects of fungicide seed treatments on germination, population, and yield of maize grown from seed infected with fungal pathogens

Seedborne fungi can reduce survival, growth, and yield of maize (Zea mays L.). Laboratory, field, and growth chamber experiments were conducted to determine the effects of the seed treatment fungicides fludioxonil, mefenoxam, and azoxystrobin on germination, plant population, and grain yield of maize grown from low-quality hybrid seed infected with seedborne fungal pathogens. Study I used seed of four hybrids infected at 0-54% incidence with Fusarium spp., Stenocarpella maydis, Penicillium spp., Rhizopus spp., and/or Aspergillus spp. Study II used three seed lots for each of two hybrids infected at 7-37% incidence with S. maydis. Warm and cold germination for untreated seed varied among hybrids in both studies. Warm germination of the seed lot with the highest incidence of S. maydis in study II treated with azoxystrobin and fludioxonil was significantly greater (+7%) than the nontreated control. Plant population in study I was significantly affected by seed treatment, hybrid, and their interactions. Populations were greater (≥9%) for fludioxonil, fludioxonil + mefenoxam, and fludioxonil + mefenoxam + azoxystrobin treatments compared to controls. In growth chamber experiments with pasteurized soil, emergence (≥5%) and plant dry weight (≥14%) were both greater than controls only with the triple seed treatment. Plant populations in study II for all seed treatments except mefenoxam and azoxystrobin alone were greater (≥4%) than controls. Yield in study I was significantly affected by hybrid and seed treatment. Yield for one hybrid was higher (≥20%) than the control with all seed treatments except fludioxonil, whereas yield with another hybrid was consistently greater (≥26%) only with the triple seed treatment. Yield in study II was significantly affected by hybrid, seed treatment, and their interactions. Yield was greater (≥8%) than the controls for all seed treatments with one hybrid and with all (≥5%) except azoxystrobin for the other hybrid. Highest yields occurred with the triple seed treatment. Results indicate that fludioxonil and azoxystrobin can increase germination, population, and yield of maize grown from seed infected by S. maydis and other fungi.     

Control of Penicillium expansum with potassium phosphite and heat treatment

Potassium phosphite (Phi) was evaluated for its in vitro activity against Penicillium expansum and for its potential long-term efficacy against postharvest blue mold infections on apple fruit. Phi amended to malt extract agar medium at 2 and 4 mg/ml completely inhibited mycelial growth and conidial germination, respectively. Conidia of P. expansum suspended for 3 min in a solution of 2 mg/ml Phi at 20 °C or heated to 50 °C germinated at 53 and 0%, respectively. Disease incidence of P. expansum on Elstar apples wounded and inoculated with a thiabendazole-resistant isolate was reduced significantly (P = 0.01) following a curative treatment with Phi at 2 mg/ml. When applied on freshly harvested unwounded Elstar apples, Phi (2 mg/ml) reduced blue mold incidence about three-fold compared to the control and was found to be as effective as thiabendazole against natural blue mold infections after six months of storage at 2 °C. Our results suggest that potassium phosphite has a potential to be part of the general management program implemented for the control of postharvest blue mold infections on pome fruits.     

Identification and antimicrobial activity of two alkaloids from traditional Chinese medicinal plant Tinospora capillipes

Two antimicrobial alkaloids, palmatine and jatrorrhizine, were isolated from tubers of traditional Chinese medicinal plant Tinospora capillipes using activity-guided isolation method and chromatography. Their antimicrobial activity was determined in vitro. The results showed that palmatine and jatrorrhizine had inhibitory activity against plant pathogens Colletotrichum gloeosporioides, Fusarium oxysporum f. sp. niveum, Mycosphaerella sentina, Pestalotia mangiferae, Cercospora kaki, Gymnosporangium haraeanum, Rhizoctonia solani and Colletotrichum graminicola, with the EC₅₀ values of 0.0348-0.8356 g L⁻¹ and 0.0240-0.8649 g L⁻¹, respectively. Palmatine and jatrorrhizine also exhibited inhibition against animal pathogens Bacillus cereus, Bacillus megaterium, Bacillus subtilis, Staphyloccocus aureus, Staphylococcus epidermidi, Micrococcus lysodeikticus, Proteus vulgaris, Salmonella typhi and Escherichia coli, with the MIC values of 0.1-0.8 g L⁻¹ and 0.1-0.6 g L⁻¹, respectively. These results suggested that palmatine and jatrorrhizine showed relatively broad spectrum antimicrobial activity against plant and animal pathogens.     

Impact of intercropping of medicinal and aromatic plants with organic farming approach on resource use efficiency in arecanut (Areca catechu L.) plantation in India

The present investigation was conducted at Vittal, Karnataka, India during 2004-2007 to study the feasibility of intercropping of medicinal and aromatic plants (MAPs) in arecanut plantation. The results revealed that MAPs can be successfully grown as intercrops in arecanut plantation with increased productivity and net income per unit area. Kernel equivalent yield of MAPs varied between 272 kg ha⁻¹ in case of Piper longum to 1218 kg ha⁻¹ in Cymbopogon flexuosus. Pooled data indicated that Asparagus racemosus produced fresh root yield of 10,666 kg ha⁻¹ of arecanut plantation and contributed to maximum kernel equivalent yield of 1524 kg ha⁻¹ among all medicinal and aromatic plants. Intercropping of MAPs in arecanut was found economical. The net return per rupee investment was highest in C. flexuosus (4.25) followed by Bacopa monnieri (3.64), Ocimum basilicum (3.46) and Artemisia pallens (3.12). The total system productivity of arecanut + MAPs intercropping system varied from 2990 to 4144 kg ha⁻¹. Arecanut + O. basilicum intercropping system registered significantly higher production efficiency 8.2 kg ha⁻¹ day⁻¹ than other systems. Intercropping of MAPs had more positive effect on soil pH in arecanut based cropping system. The soil pH was 5.6 in 2004 and it was 0.3-0.9 units higher in 2007. Soil organic carbon (SOC) content varied significantly due to intercropping of MAPs at the end of experiment. The SOC content increased in Aloe vera, A. pallens, P. longum and B. monnieri, while it depleted in grasses and rhizomatic MAPs. Based on demand and marketing opportunities for MAPs, farmers are advised to grow aromatic plants in large areas on a community basis to meet huge industrial demand and variety of medicinal crops in small areas to meet the requirement of traditional systems of medicine.     

Characteristics, chemical composition and utilisation of Albizia julibrissin seed oil

The physicochemical characteristics, fatty acid and triacylglycerol compositions, DSC profile and UV/vis spectrum of oil extracted from Albizia julibrissin seeds were determined in this study. The oil content and the moisture of the seeds were 10.50% and 1.56%. The free fatty acid, the peroxide value, the p-anisidine value, the saponification value, the iodine value were 2.54%, 6.61 mequiv. O₂/kg of oil, 1.98, 190.63 (mg KOH/g) and 111.33 (g/100 g of oil), respectively. The specific extinction coefficients K₂₃₂, K₂₆₈ were 7.55 and 0.96, respectively. Linoleic acid (C_18:2, 58.58%), palmitic acid (C₁₆, 13.86%) and oleic acid (C_18:1, 10.47%) were the dominant fatty acids in the A. julibrissin seed oil. LLL (36.87%), OLL (21.62%), PLL (16.69%) and PLO + SLL (8.59%) were the abundant triacylglycerol representing > 83% of the seed oil (L: linoleic, O: oleic, P: palmitic, S: stearic). The DSC melting curves reveal that: melting point = −14.70° C and melting enthalpy = 54.34 J/g. A. julibrissin seed oil showed some absorbance in the UV-B and UV-C ranges. The results of the present analytical study show that A. julibrissin is a promising oilseed crop, which can be used for making soap, hair shampoo and UV protectors. Furthermore, the high level of unsaturated fatty acids makes it desirable in terms of nutrition.     

Fatty acid composition and oxidation stability of hemp (Cannabis sativa L.) seed oil extracted by supercritical carbon dioxide

Supercritical carbon dioxide (SC-CO₂) was employed to extract oil from hemp (Cannabis sativa L.) seeds. For ground seeds, the supercritical extraction was carried out at temperatures of 40, 60 and 80 °C and pressures of 300 and 400 bar. Different solvent-ratios were applied. Supercritical CO₂ extractions were compared with a conventional technique, n-hexane in Soxhlet. The extraction yields, fatty acid composition of the oil and oxidation stability were determined. The seed samples used in this work contained 81% PUFAs, of which 59.6% was linoleic acid (ω-6), 3.4% γ-linolenic (ω-3), and 18% α-linolenic (ω-6). The highest oil yield from seeds was 22%, corresponding to 72% recovery, at 300 bar and 40 °C and at 400 bar and 80 °C. The highest oxidation stability corresponding to 2.16 mM Eq Vit E was obtained at 300 bar and 80 °C.     

Synthesis of withanolide A depends on carbon source and medium pH in hairy root cultures of Withania somnifera

Withania somnifera (L.) Dunal. (Indian ginseng) is an important medicinal plant which yields pharmaceutically active compounds called withanolides. The present work deals with optimization of parameters of hairy root culture of W. somnifera for the production of biomass and withanolide A. We also investigated the effects of carbon source [sucrose, glucose, fructose, maltose, glucose + fructose (1:1), fructose + sucrose (1:1) and sucrose + glucose (1:1)], sucrose concentration (1%, 2%, 3%, 4%, 6% and 8%) and the initial medium pH (4.0, 4.5, 5.0, 5.5, 5.8, 6.0 and 6.5) on growth and production of withanolide A in hairy root cultures of W. somnifera. We found that biomass accumulation and production of withanolide A was highest when sucrose was used as the carbon source (11.92 g l⁻¹ DW and 11.96 mg g⁻¹ DW of withanolide A). Further 3% sucrose concentration was found to be optimal for biomass accumulation (11.92 g l⁻¹ DW) and 4% sucrose favoured the production of withanolide A (13.28 mg g⁻¹ DW) in the tested range of concentrations (1-8%). The biomass of hairy roots was optimal when the initial medium pH was 5.8 (12.1 g l⁻¹ DW) and the withanolide A production was highest in the medium pH set at 6.0 (13.84 mg g⁻¹ DW).     

Supercritical carbon dioxide (SC-CO2) extraction of Nigella sativa L. oil using full factorial design

In this study, Nigella sativa L. oil was extracted using supercritical carbon dioxide with full factorial design to determine the best extraction condition (pressure, temperature and dynamic extraction time) for obtaining an extract with high yield, antioxidant activity and thymoquinone (TQ) quantity. The maximum thymoquinone content in the highest overall yield was achieved through SC-CO₂ extraction condition of 150 bar, 40 °C, 120 min with the value of 4.09 mg/ml. The highest SC-CO₂ extraction yield was 23.20% which obtained through extraction condition of 350 bar, 60 °C and 120 min. The extraction conducted at 350 bar, 50 °C, 60 min showed the lowest IC₅₀ value (highest antioxidant activity) of 2.59 mg/ml using DPPH radical scavenging activity method. Fatty acid composition of the extracted oil with highest radical scavenging activity was obtained by gas chromatographic analysis.     

NaCl plays a key role for in vitro micropropagation of Salicornia brachiata, an extreme halophyte

A simple and rapid method for micropropagation of succulent, salt accumulator and extreme halophyte Salicornia brachiata has been established for the first time using shoot tips and nodes. Individually, BA showed significant response compared to Kn and in combinations, improved shoot proliferation was observed with BA + NAA than BA + 2,4-D, however no significant response was observed with BA + IAA. Percentage of shoot response significantly increased with NaCl treatment in the combination of BA + NAA while BA + 2,4-D + NaCl combination showed reduced shoot proliferation followed by demises of most of cultures. Efficient shoot proliferation was observed with combinations BA (8.9 μM) + NAA (5.37 μM) + NaCl (500 mM) and BA (13.3 μM) + NAA (5.37 μM) + NaCl (250 mM) indicating that NaCl is required for the micropropagation. The developed method will facilitate functional analysis of novel salt responsive gene(s) isolated from S. brachiata and propagation of industrially important elite accessions.     

Lavender and hyssop productivity, oil content, and bioactivity as a function of harvest time and drying

Field and laboratory experiments were conducted to evaluate the productivity and essential oil composition of lavender (Lavandula angustifolia Mill.) and hyssop (Hyssopus officinalis L.) as functions of year, harvest time, and drying. Lavender essential oil content ranged from 0.71 to 1.3% (overall average of 0.89%) and hyssop oil content ranged from 0.13 to 0.26% (overall average of 0.19%). Lavender and hyssop essential oil yields increased with time. Hyssop oil yields varied from 7.3 kg ha⁻¹ to 19.6 kg ha⁻¹, and lavender oil yields varied from 7.8 kg ha⁻¹ to 55.5 kg ha⁻¹. The major constituents of lavender oil were linalool (23.3-43.4%) and linalylacetate (20.2-39.6%), while the major constituents of hyssop oil were pinocamphene + isopinocamphene (57-75%) and β-pinene (5-15%). Lavender oil extracted from dry material had higher concentrations of linalyl acetate and caryophyllene but lower concentrations of myrcene than the oil from the fresh material. Delayed harvest of hyssop increased the concentrations of β-pinene, myrcene, and limonene + cineole but reduced pinocamphone + isopinocamphone. The chemical composition of the lavender and hyssop oil produced in Mississippi was similar to commercial oils from Bulgaria, Canada, France, and US. Lavender and hyssop can be established as essential oil crops in areas of the southeastern United States. Lavender and hyssop essential oils did not show significant antimicrobial, antileishmanial, antimalarial activity, and did not alter ruminal fermentation. However, commercial oil from L. latifolia reduced methane production in an in vitro digestibility study. The antioxidant activity of hyssop essential oil was 2039 μmol of TE L⁻¹, whereas the antioxidant activity of lavender essential oil was 328 μmol of TE L⁻¹.