Showing 41 results for Gc
Volume 0, Issue 0 (1-2024)
Abstract
Ganoderma boninense Pat. is a persistent soil-borne pathogen that causes significant losses in oil palm (Elaeis guineensis Pat.) productivity. In this study, we evaluated the antifungal activity of volatile organic compounds (VOCs) produced by a fungal isolate, later identified as Paraconiothyrium archidendri F10, against G. boninense. The isolate was identified based on ITS-rDNA sequence analysis and BLASTn results. VOCs produced by P. archidendri F10 were found to inhibit G. boninense mycelium growth by up to 55.8% in four days, with the mycelium exhibiting wavy, non-smooth, and wrinkled morphology, abnormal branching, fused, defective hyphae, and lysis from within. The major VOC components were esters, with 7,9-ditert-butyl-1-oxaspiro[4.5]deca-6,9-diene-2,8-dione being the most abundant (16.72%). The other top-ranking components were 2-O-(6-ethyloctan-3-yl) 1-O-hexyl oxalate (8.71%), methyl heptadecanoate (8.66%), and butyl acetate (5.66%), with minor components comprising less than 5% of the total VOCs. Our findings suggest that P. archidendri F10 has potential as a biofungicide for controlling G. boninense in the field.
Volume 0, Issue 0 (1-2024)
Abstract
The incidence of allelochemical substances on the oviposition behaviour of Ectomyelois ceratoniae Zeller (Lepidoptera: Pyralidae), to select appropriate site for oviposition and food sources for his future offspring, on three Algerian date varieties (Ghars, Deglet-Nour, and Degla-Beidha) was investigated. The use of Headspace collection via Solid Phase Micro-Extraction followed by Gas Chromatography-Mass Spectrometry method allowed the detection of 68 compounds of which only 22 were identified in all date varieties studied. The behavioural test with wind tunnel explored the response of E. ceratoniae adult females to the various sources of odours, coming from different combinations of synthetic substances identified in the three date varieties. The pure substances (mono-compounds) presented the highest rates of laid eggs compared to those in the mixture. Ketones stimuli were the most attractive with about 41% of the total eggs laid rate, followed by the alcohols (15%) and terpene (7.44%). The esters and phenols showed 6.38% and 5.58% eggs laid, respectively. These results could open up other research paths to manage this pest and their impact on it host plants.
Volume 1, Issue 4 (12-2012)
Abstract
Essential oil extracted from the leaves of Lemon verbena, Lippia citriodora Kunth (Verbenaceae) was tested for fumigant toxicity in the laboratory against two stored-product insects Tribolium confusum Jacquelin du Val and Callosobruchus maculatus (F.). The chemical composition of the isolated oil was examined by GC-MS. The major compounds were citral (11.3%), limonene (10.6%), neral (7.9%), 4-phenyl undecan-4-ol (7.7%), α-curcumene (6.5%), α-cedrol (4.5%) and caryophyllene oxide (4.5%). Furthermore, lesser amounts of the other components include carveol (3.7%), linalool (3.5%), α-pinene (3.2%), caryophyllene (2.8%) and geranyl acetat (1.8%) were existed in the essential oil. In the fumigant toxicity set at 27 ± 1 °C and 65 ± 5% R. H., darkness condition and 24 h exposure time, considerable differences in mortality of insect to essential oil vapor were observed. C. maculatus (LC50 = 10.2 µl/l air) was significantly more susceptible than T. confusum (LC50 = 497.8 µl/l air). These results suggested that essential oil of L. citriodora could be used as a potential control agent against stored-product insects.
Volume 2, Issue 4 (12-2013)
Abstract
Mulberry pyralid, Glyphodes pyloalis Walker is an important pest on mulberry. The essential oil of Rosemary Rosemarinus officinalis L. (Lamiales: Lamiaceae) has been investigated on toxicity and physiological characteristics of this moth under controlled conditions. The major compounds of the oil were analyzed as 1, 8 Cineol (20.021%), Borneol (7.17%), Camphor (6.541%), Geraniol (6.281%), Camphene (5.623%), Linalool (4.993%) Alpha fenchyl acetate (4.222%) and Verbenone (4.147%). Lethal and sublethal concentrations (LC10, LC30 and LC50) were estimated 0.77%, 1.18% and 1.59% (v/v) respectively. The essential oil affected the nutritional indices of fourth instar larvae of G. pyloalis. efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), relative consumption rate (RCR) and relative growth rate (RGR) were reduced in larvae treated with R. officinalis essential oil while approximate digestibility (AD) in treated larvae was significantly increased compared with the control. The essential oil affected the insect’s some key metabolic compounds like; lipid, protein and carbohydrates. Similarly this effect was also significant in the activities of certain key enzymes like; alpha- amylase, lipase, protease, glutathione-s-transferase and esterases.
Volume 3, Issue 1 (3-2015)
Abstract
Prediction of climatic variables on a local scale by General Circulation Models of the atmosphere is impossible because the models have large-scale network of resolution. Therefore, downscaling methods are used to solve this problem. Since the climate change phenomenon can affect different systems such as, water resources, agriculture, environment, industry and economy as well, Selection of the most suitable downscaling method is very important. This study aims to evaluate performance of Change-Factor (CF) and LARS-WG downscaling methods in prediction of future climate variability of the Azam River Watershed, located in Yazd Province, Iran, for the period of 2010-2039. For this purpose, the CGCM3-AR4 model under the A2 emission scenario and also two methods of downscaling including statistical (LARS-WG) and proportional (CF) approaches were applied. The results showed increasing of temperature by both downscaling methods in the Azam River watershed in the future. Average temperature difference obtained from the two methods is about 3 to 4 percent. On the other hand, based on the climate condition, the amount of rainfall varied in the whole watershed, in a way that the future maximum precipitation difference calculated by two downscaling methods is about 30 percent.
Volume 3, Issue 2 (6-2014)
Abstract
Essential oils are volatile mixtures of hydrocarbons with diverse functional groups. In the current study the effect of essential oils from five medicinal plants including Zataria multiflora and Nepeta cataria (Lamiaceae), Tagetes minuta and Artemisia sieberi (Asteraceae), and Trachyspermum ammi (Apiaceae) were analyzed using GC-mass spectrometry. The toxicity of these plant essential oils against the adult stage of the cabbage aphid, Brevicoryne brassicae L. (Hemiptera: Aphididae) was studied using a fumigant assay.GC/Mass analysis revealed that the main essential oils varied between species. The most abundant components in N. cataria, Z. multiflora, T. ammi, T. minuta and A. sieberi were 4a-α, 7-β, 7a-α-nepetalactone (76.8%), carvacrol (62.1%), γ-terpinene (27.1%), limonene (13.0%) and artemisia ketone (48.0%) respectively. The fumigant assays showed that all of these essential oils were toxic to B.brassicae in a dose-dependent manner. The essential oils of N. cataria at 126, 63, 31, 16, 8, and 3 μl L-1 air caused 94, 76, 52, 46, 36, and 24% mortality within 24 hours, respectively. The same trend was seen when essential oils of the other plants were tested against B. brassicae. These plant essential oils have great potential to be used in integrated pest management especially in greenhouses or other closed systems.
Volume 3, Issue 8 (4-2006)
Abstract
Regarding the increasing usage of pesticides to a broad variety of crops in Iran, and the importance of public concerns about possible health risks from pesticide residues, chlorinated pesticide residues in vegetables were determined in National Nutrition & Food Technology Research Institute in 2005. Thirty samples (melon, maskmelon, watermelon) were evaluated by an descriptive method. Sample extraction was carried out with ethyl acetate, and the extracts were cleaned up by high performance gel permeation chromatography. Pesticide residues were identified and quantified using gas chromatography ion trap mass spectrometry detector. Recoveries of chlorinated pesticides were within a range from 95-178%. Detection limit of pesticide residues were from 0.01 to 0.05 mgkg-1. The data demonstrated that the samples analysed did not contain residues of the monitored pesticides above the accepted maximum residue limit (MRL) as adapted by the FAO/WHO Codex Alimentarius Commission.This method proves to be successful in analyzing pesticides in vegetables and provides reliable and accurate results.
Volume 5, Issue 2 (6-2017)
Abstract
Background: Global warming and climate change are widely indicated as important phenomena in the 21st century that cause serious impacts on the global water resources. Changes in temperature, precipitation and evaporation are occurring in regions throughout the world, resulting in changes including, runoff, streamflow and groundwater regimes, reduced water quantity and quality.
Materials and Methods: Relying upon thirty years of base data (1965–1994), three global circulation models (GCM), namely GISS, GFDM and CCC, are utilized to assess impact of climate change to groundwater recharge rates between years 2010 to 2050 for the Guelph region of the Grand River Basin in Canada. The resulting groundwater recharge rates for alternative soil layers are used to assess water balance conditions, and ultimately, the percolation rate to the groundwater using the Visual-HELP model.
Results: While the climate change impact assessment indicates that evaporation will increase and percolation will decrease during summer, increased percolation is indicated in winter due to additional freeze/thaw dimensions of climate change. The net effect is that the impact of climate change, based upon use of GCM models, is expected to increase groundwater recharge rate by 10% on average (7% for CCC, 10.6% for GISS and 12% for GFDM) in future.
Discussion and Conclusions: According to the results of this research in the Guelph region, the monthly average percolation rate is higher with climate change; (i) the percolation rate is increased during winter due to freeze/thaw effects, while (ii) it is decreased during summer due to higher evaporation rate.
Volume 5, Issue 4 (12-2016)
Abstract
In this study, anti Alternaria solani effects of essential oils of 11 medicinal and aromatic plant species belonging to four families collected from the west of Iran were investigated based on agar dilution method with five replications at concentration of 1.0 µl/ml. The results showed that the highest inhibitory effect belonged to Oliveria decumbens, Cinnamomum zeylanicum, Carum copticum and Thymus kotschyanus which completely inhibited the mycelial growth of the fungus. Therefore, their activity was examined in lower concentrations, too. The essential oil of O. decumbens at concentration of 0.50 and 0.25 µl/ml completely suppressed the mycelial growth of the fungus. The major constituents of its essential oil were carvacrol (46.53%), thymol (23.75%), p-Cymene (13.70%), γ-terpinene (7.66%) and myristicin (3.65%), respectively. Thus, the essential oil of this species with the highest anti-Alternaria activity could be selected for further studies on in vivo application as natural fungicide.
Volume 7, Issue 1 (1-2019)
Abstract
Aims: The use of plants for treatment and food returns to ancient times. This study was conducted to examine the essential oil composition and antioxidant activity of the essential oil of
Artemisia sieberi Besser at 3 phenological stages and effect of grazing livestock on these properties.
Materials & Methods: For this purpose, 5 shrubs from two sites (under grazing site and enclosure site) were selected randomly at 3 phenological stages. In laboratory operations, essential oil of the species was extracted in by SDE method.
Findings: The results of GC/MS analysis indicated 45 compounds for grazed site with essential oil content 98.73%, and 42 compounds for enclosure site with essential oil content 98.54%. Also, α-tujune (21.63%), α-Pinene (19.53%), and Camphene (10.34%) were the main compounds in the enclosure site and α-tujune (23.70%), α-Pinene (20.33%), and Camphene (12.60%) were the main compounds in the grazed site. The results of screening antioxidant activity using two assays (DPPH and β-carotene-linoleic acid) showed that the free radical scavenging activity of essential oil (IC
50 µg ml
-1) in the first phenological stage (vegetative stage) was more than other phenological stages in two sites. Also, the inhibition of essential oil in the grazed sites had a significant difference with essential oil's inhibition in the enclosure site.
Conclusions: Effect of grazing on the composition and properties of the essential oil of this species can be considered in the planning of livestock grazing management. We wish our future research on this plant leads to the finding of new natural antioxidant compounds.
Volume 7, Issue 2 (7-2018)
Abstract
Habrobracon hebetor Say is an idiobiont and gregarious larval ectoparasitoid of many moths. In this study, lethal and sublethal effects of Eucalyptus camaldulensis, Carum carvi and Heracleum persicum essential oils on the demographic parameters of H. hebetor were assessed at 26 ± 2 °C, 60 ± 5% RH, and a photoperiod of 16:8 (L: D) h. Essential oils were obtained from these plants by hydro-distillation method using a Clevenger apparatus. The chemical constituents of essential oils were detected by Gas Chromatography-Mass spectrometry (GC-MS). 250ml Glass vials were used for the fumigant toxicity experiments. In order to assess the sublethal effects, adult wasps were exposed to an LC25 of each essential oil and then the demographic parameters of live parasitoid wasps were studied. Fumigant toxicity with adults indicated that the lethal concentration (LC50) values of the above essential oils against H. hebetor females were 1.116, 0.34 and 3.416μl/l air, respectively. Chemical analysis by GC-MS displayed o-Cymene (15.11%), Carvone (55.8%) and Hexyl butyrate (41.78%) were main constituents of the essential oils of E. camaldulensis, C. carvi and H. persicum, respectively. The results showed that the intrinsic rate of increase (r), finite rate of increase (λ), net reproductive rate (R0) and gross reproductive rate (GRR) were significantly affected by the essential oils. The highest and the lowest r values were 0.226 and 0.130 day-1 in control and C. carvi-treated insects, respectively. According to these results, essential oils have suitable potential for the integrated management of stored product pests.
Volume 7, Issue 3 (7-2019)
Abstract
Aims: One of the herbal indices that effects on the livestock grazing behavior is the herbal compounds including the essential oils, so the aim of the present study is the comparison of three Artemisia species in terms of the composition of essential oils coincident and the relationship between livestock grazing time from these three plant species.
Materials and Methods: Three Artemisia species (
Artemisia sieberi Bess.,
Artemisia kermanensis Podl
., and
Artemisia khorassanica podl.) in the natural from habitats with similar conditions were studied. Five plant stands were selected randomly from each species and the essential oils were obtained by SDE of air-dried samples and the essential oil were analyzed by GC-MS.
Findings: About 88% of essential oil compounds in these three Artemisia species were common and
Artemisia kermanensis Podl. had more essential oil percentage (98.47%) and
Artemisia sieberi had the lowest essential oil percentage (73.21%) while the rate of grazing on the
Artemisia sieberi Bess. was higher compared to two other species in the same vegetative stage. Also, 6% of the compounds were observed only in the
Artemisia kermanensis species, which is probably the presence of these compounds are the reason for the lack of feeding by the livestock of this species.
Conclusion: The selection of livestock for grazing of these three species to be highly relevant to their essential oil compounds, although the amount of these compounds has decreased in the third phenological stage, preventing livestock feeding on these species in the first and second stage of vegetation. Livestock grazing planning based on essential oil combinations can be a new horizontal in rangeland management. It seems the biochemical defense in the plants with essential oil is a way to combat animal grazing.
Pouria Gholami Tilko, Zahra Hajihassan, Navid Nazari, Hamid Moghimi,
Volume 8, Issue 2 (10-2017)
Abstract
Production of recombinant proteins in Escherichia coli has been very common in recent decades. Many studies and experiments have been done in order to optimize the production and expression of recombinant proteins in E.coli. One strategy is using high cell density to increase recombinant protein production such as β-NGF in the cell. Therefore, in this study for the first time bacterial cell culture in high cell density was done using glycerol and yeast extract as carbon and nitrogen sources and MgCl2 as a growth effective factor. Also the effects of overnight culture conditions on bacterial growth were evaluated. Meanwhile culture conditions were optimized using response surface methodology (RSM) and the optimum conditions were as follows: 18/23 g/lit glycerol, 14.44 g/lit yeast extract and 10mM MgCl2. Also the obtained results indicated that the 14 hours incubation at 37 °C and 180 rpm were optimum conditions for the overnight culture. Our results showed that the rate of cell growth and recombinant β-NGF production in optimized condition is significantly higher than in basic medium.
Volume 10, Issue 4 (11-2021)
Abstract
The carob moth, Ectomyelois ceratoniae (Zeller, 1839), is the most critical pest of pomegranate in Iran. The sex pheromone components emitted by the virgin females were characterized by headspace solid-phase
microextraction (HS-SPME) and subsequently analyzed by gas chromatography/mass spectrometry (GC-MS). In this research, the level of individual variation in the female sex pheromone composition of the pest was studied. By extracting pheromone glands of females from different locations, the primary component, (
Z, E)-9, 11, 13-tetradecatrienal, and minor components, (
Z, E)-9, 11-tetradecadienal and (
Z)-9-tetradecenal, were identified. The following ratios were 10: 2.5: 2.1 (trienal: dienal: monoenal) in Kuhdasht,
10: 1.3: 0.7 in Tarom, 10: 1.3: 0.5 in Bajestan, 10: 1.2: 1 in Sorkheh, 10: 1.1: 0.9 in Ferdows, 10: 0.9: 1 in Neyriz, 10: 0.9: 0.9 in Khash and Meybod, 10: 0.9: 1.4 in Saveh, 10: 0.5: 1 in Behshahr, and 10: 0.45: 0.43 in Shahrreza. There was also a significant variation among the populations in response to wind tunnels and field tests. The discrepancies in these ratios show a possibility of a conspecific relationship among carob moth species in Iran. Findings led to a conclusion of
the monomorphic variation in sexual communication of the species.
Nasrin Fazelian, Morteza Yousefzadi, Ahmad Ahmadi,
Volume 11, Issue 2 (6-2020)
Abstract
Objectives: In this study, the effect of different concentrations (1-50 mg/L) of colloidal Ag-NPs investigated on the growth, fatty acids profile and biodiesel indices of N. oculata, after estimating EC50 (20.88 mg/L).
Materials and methods: In this research, N. oculata was selected owing to fast growth and its ability to synthesize lipids for biodiesel production. This microalga exposed to colloidal silver nanoparticles under marine conditions for 72 h. The optical density (OD) and fatty acid profiles were investigated using spectrophotometric analysis and gas chromatography, respectively. Statistical analysis growth data was performed using ANOVA and Duncan's multiple test at 2% probability level.
Results: The algal growth significantly decreased in N. oculata cells treated with the 5-50 mg/L of Ag-NPs. The increase of saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs) as well as the decrease of monounsaturated fatty acids (MUFAs) contents were also observed in response to 25 mg/L of Ag-NPs in compared to the control. The important indicators of biodiesel oxidative stability containing LCSF, CFPP and CP increased in N. oculata exposed to Ag-NPs, while the level of DU decreased. The results of this study showed that despite the toxicity of silver nanoparticles, this nanoparticle can increase the biodiesel stability produced from N. oculata.
Volume 14, Issue 2 (5-2014)
Abstract
The purpose of this paper is to investigate the effect of unsteady trailing edge flapping on lift generation for fixed airfoils at low angles of attack. To do this, a 2D unsteady compressible flow around a fixed airfoil is analyzed at different angles of incidence by means of Coarse Grid CFD (CGCFD) method with spring dynamic network. In this method Euler system of equation is solved with coarse Grid and no slip boundary condition using vorticity confinement technique. At first for code validation, the results of fixed airfoil at different angles of attack and also pitching airfoil are compared with experiments. Further, the CGCFD consequences are compared with the results of RANS with SA turbulent model in the quasi steady case. Then trailing edge flapping (TEF) is added to the fixed airfoil at low angles of attack. The effects of unsteady parameters such as the amplitude and the frequency of TEF are investigated at different low angles of attack. The results show that in a specific low angle of attack, adding TEF results in increasing the lift coefficient comparing with the fixed airfoil without TEF.
Volume 14, Issue 68 (0-0)
Abstract
Volume 14, Issue 69 (0-0)
Abstract
Volume 14, Issue 70 (0-0)
Abstract
Volume 15, Issue 1 (1-2013)
Abstract
The diallel cross design is frequently utilized to obtain information on genetic effects, estimates of General and Specific Combining Ability (GCA and SCA) and to identify promising heterotic combinations as well as heterotic patterns. In the present study, heterotic crosses were identified for specific alkaloids in opium poppy (Papaver somniferum L.) following Yan’s GGE Biplot model by use of 5×5 full diallel data. The results obtained through biplot analysis were compared with those obtained through Griffing’s to check and confirm the accuracy of Yan’s GGE biplot model. Parents A (papline), B (NB5KR40-7/2-3), and E (58/1) were identified as good general combiners. The crosses B×C, B×E and E×B for morphine, C×D and C×E for narcotine, and A×B, A×C and A×E were identified as heterotic combinations. None of the crosses were found heterotic for codeine and thebaine.
