جستجوی مقالات مرتبط با کلیدواژه « متابولیت های ثانویه » در نشریات گروه « باغبانی »

Climate changes have led to drought stress, which is a threat to the production of agricultural products, including pomegranate, which is one of the important horticultural products of Iran. This research aimed at to evaluate the effects of low water stress on the physiological and biochemical characteristics of pomegranate in a factorial experiment in the form of a completely randomized design with two factors including irrigation level (100, 75, 55 and 35% of field capacity) and five pomegranate cultivars (‘Rabab Niriz’, ‘Malas Momtaz Saveh’, ‘Malas Yusef Khani’, ‘Tabrizi’ and ‘Wonderful’). The results showed that low water stress decreased the relative water content (35% decrease), cell membrane stability (42.9% decrease), chlorophyll a and total chlorophyll, and increased carotenoid (19.5% increase), flavonoid (7.9% increase), total soluble carbohydrate (23.9 percent increase) and total phenol (21.4 percent increase), at the level of 35 percent of the field capacity compared to the control. Among the cultivars, ‘Wonderful’ had the highest relative content of water, chlorophyll a, b and total chlorophyll, carotenoid, membrane stability and total phenol based on ellagic acid, which has effective roles in activity of the non-enzymatic antioxidant and defense system of this cultivar, in comparison with cultivar ‘Tabrizi’ that showed less tolerance to stress compared with other pomegranate cultivars.

Hibiscus sabdariffa L., commonly known as Roselle, is a plant cultivated in many regions of the world regions. Roselle has been used as a medicinal herb in traditional medicine for controlling and treating different diseases and physical ailments. These therapeutic effects are attributed to active compounds such as carotenoids, fatty acids, and phenolic compounds, including phenolic acids and flavonoids. One common method to stimulate plants for increased production of active compounds is subjecting them to various types of stresses, such as drought or salinity, along with plant growth regulators. This study investigated salicylic acid's effect on the phytochemical content and various biological properties of Roselle plants under water scarcity conditions.

The experiment was conducted as a factorial experiment in a completely randomized design, including irrigation intervals at three levels: three days (D1), five days (D2), and seven days (D3), and foliar application of salicylic acid at three levels: 0 (SA0), 0.75 mM (SA1), and 1.25 mM (SA2), with three replicates in a research greenhouse at the International Imam Khomeini University. The required seeds for cultivation were obtained from Pakanbazr Company in Isfahan. The imposition of drought stress through irrigation intervals of 3, 5, and 7 days started at the 4-leaf stage of the plants, and the plant spraying with salicylic acid was performed at the 6-leaf stage, three days before the start of irrigation treatments. The measurement of electrolyte leakage and malondialdehyde content was carried out to determine membrane stability and lipid peroxidation level. Additionally, the measurement of proline content and the activity of three antioxidant enzymes, including peroxidase, catalase, and ascorbate peroxidase, was performed in different samples. Furthermore, the total phenolic, flavonoid, and anthocyanin contents, as the main secondary metabolites of Roselle plants, were measured. The biological and medicinal properties, including the free radical scavenging activity (DPPH) and α-glucosidase inhibitory activity, were also evaluated. The obtained data were analyzed using SAS statistical software version 9.4. Mean comparisons were conducted using Duncan's multiple range test at a significance level of 5%.

The results showed both electrolyte leakage and malondialdehyde content increased significantly with increasing levels of applied drought stress on Roselle plants. However, overall, applying salicylic acid treatments led to a decrease in both indicators. The measurement of proline content in Roselle samples showed that the highest amount of proline was observed in plants subjected to the highest drought stress and treated with the 1.5 mM salicylic acid solution. The activity of all three antioxidant enzymes increased with the intensity of the applied drought stress and the concentration of salicylic acid solutions. Roselle's highest levels of phenolic and anthocyanin content were observed in samples sprayed with 1.5 mM salicylic acid solution. The change in anthocyanin content of Roselle plants also demonstrated that increasing the severity of water scarcity resulted in higher levels of this compound. The highest DPPH free radical scavenging activity was observed in Roselle samples grown under the highest drought severity and sprayed with the highest concentration of salicylic acid (61.93%). The highest antioxidant activity was also observed in samples treated with the highest concentration of salicylic acid solution in all irrigation regimes. The highest α-glucosidase inhibitory activity (69.2% and 67.7%) was associated with Roselle samples grown under the highest applied drought severity, sprayed with 1.5 mM and 0.75 mM salicylic acid solutions, respectively.

It can be concluded that the use of salicylic acid as a growth regulator can contribute to the enhancement of phytochemical content, especially secondary metabolites such as phenolic and flavonoid compounds, anthocyanins, and the elevation of defensive parameters such as the activation of antioxidant enzymes, as well as an increase in osmolyte content like proline in Roselle plants. These effects assist the plants in exhibiting greater resistance to drought stress and mitigating the negative impacts of this type of stress on the plant.

Recent advances in biotechnology, especially tissue culture of plants under various light conditions, have provided a good platform for the production of secondary metabolites. The present study aims to investigate the effect of intensity and different light qualities on in vitro growth and production of secondary metabolites in Dracocephalum kotschyi plant. The evaluated morphological traits included the number of regenerated plantlets, plantlet height, leaf area, the number of roots and leaves. Also, the measured biochemical traits were total phenol and flavonoid contents, chlorophyll a and b, carotenoid, total protein and FRAP antioxidant. The results showed that the combination effect of red and blue light improves the growth and biochemical indices, so that the highest regeneration rate and number of leaves was attained in combined 80% Red + 20% blue light treatment. the highest amount of total protein (15.36 mg/g FW), total phenol (606.13 mg GA / g FW), chlorophyll a (7.73 mg / g FW) and carotenoids (2.78 mg / g FW) were obtained in combined light treatment of 60 % red + 40% blue. In general, the results obtained in the present study showed that the combination of red and blue light, compared to white light, has effectively improved the morphological and biochemical indices of Dracocephalum kotschyi plant.

Medicinal plants are a rich and valuable source of secondary metabolites that are strongly influenced by the environmental factors, especially drought stress. In this regard, a greenhouse experiment was conducted on Thymus vulgaris L. as split plots in a randomized complete block design with three replications. The main plot included three levels of moisture supply (40, 65, and 90% of potting soil field capacity (FC)) and the sub-plot was the elicitors levels including (1) control: without elicitor, (2) 150 µM cyclodextrin (CYC), (3) 75 nM coronatine (COR) + 150 µM CYC, (4) 150 nM COR + 150 µM CYC, (5) 150 µM methyl jasmonate (MJ) + 150 µM CYC, and (6) 300 µM MJ + 150 µM CYC. Except for the essential oil percentage, the other traits including the leaves proline content, electrolyte leakage, relative water content, plant height, canopy diameter, dry and fresh weight of shoots, dry weight of leaves and stems, and weight of essential oil had a very significant correlation with each other. The highest amount of leaves proline was obtained form the interaction of elicitors (levels 4 and 6) and the 40% FC level of moisture supply (3.88 and 3.94 μmol g-1 fresh leaf weight, respectively). The highest amount of plant height (28.3 cm), canopy diameter (17 cm), and relative water content (79%) was observed at the 90% FC level of moisture supply. The highest percentage of essential oil was obtained in the treatment of non-application of elicitor (2.67%) and the highest essential oil weight per plant (0.046 g plant-1) was observed in the treatment of non-application of elicitor at the 65% FC level of moisture supply. The mild stress increased the essential oil yield and the elicitor treatments decreased it.

To investigate the effects of different nitrogen sources including ammonium nitrate, asparagine, and glutamine in five concentrations of 0, 50, 100,150, and 200 mg l-1 on some physiological and biochemical characteristics of rosemary (Rosmarinus officinalis L.), an experiment was conducted in a completely randomized design with five repliacations. The indices including plant height, shooting rate, number of leaves, necrotic leaf size, chlorophylls a, b, and total chlorophyll content, and the content of carotenoids, phenols, and flavonoids were measured. The results showed that the nitrogen sources significantly (P≤0.01) affected the all measured indices except the necrotic leaf size. The results of means comparison showed that the highest shooting rate and number of leaves were obtained at 100 mg l-1 of glutamine and asparagine and the highest plant height was obtained at 200 mg l-1 of ammonium nitrate. Also, the highest amount of photosynthetic pigments was obtained at 50 mg l-1 of asparagine and the highest amount of phenols and flavonoids was related to 200 mg l-1 of glutamine. In general, the results showed that the various nitrogen sources studied could positively and significantly improve the morphological and physiological characteristics of rosemary under in vitro conditions.

Identification of the genes biosynthesizing medicinal plants-specific metabolites is now performed with great speed and accuracy using new transcriptome study technologies such as RNA sequencing. The present study was carried out to find the specific genes in the biosynthetic pathway of triterpenes and sesquiterpenes in the fruit tissue of colocynth (Citrullus colocynthis L.). After RNA extraction from the tissue of colocynth fruits harvested from Andimeshk region in Khuzestan province in 2017, RNA sequencing technique was performed using the Illumina HiSeq2500 platform. The bioinformatics steps including de novo assembly, using the Evidential-gene software, and functional annotation, using the KAAS database, were performed. In the KAAS database, 17359 unigenes were annotated in 134 plant pathways. Among the different and important secondary metabolites pathways in the fruit tissue of colocynth, 39 unigenes and 8 orthologous genes were assigned to the triterpenes and sesquiterpenes gene pathways. Transcriptome analysis of this medicinal plant with the aim of identifying the genes of secondary metabolites biosynthetic pathways underlies various research and practical aspects such as biosynthetic pathway engineering of herbal medicines.

Medicinal plant licorice (Glycyrrhiza glabra L.) has been used by the pharmaceutical industries for its important secondary metabolites. This study was carried out to determine the best harvest time for obtaining the highest content of extract, glycyrrhizin, total phenols, total flavonoids, and phenolic compounds of licorice rhizome of the Behbahan area in Khuzestan province in two seasons of autumn and spring. The results of this study showed that the extract content of rhizomes and also glycyrrhizin, total phenols, and flavonoids content in autumn were higher than those in spring. The results of the independent T-test for glycyrrhizin, as an important and valuable secondary metabolite of licorice, showed a significant difference between autumn and spring seasons. Among the phenolic compounds studied, the highest amount was given to ferulic and coumaric acids in autumn, and the lowest one to caffeic acid in spring. Considering the importance of these secondary metabolites in the pharmaceutical, health and food industries, as well as the widespread use of phenolics, glycyrrhizin, and flavonoids of licorice in herbal drugs, it is necessary to determine the best time for the highest production and accumulation of these metabolites in the licorice rhizomes to take an effective step to enrich the industries mentioned.

To investigate the effect of planting density on quantitative and qualitative characteristics of globe artichoke (Cynara cardunculus L. var. Scolymus (L.) Fiori) under weedy and weed-free conditions, a field experiment was conducted at Tarbiat Modares University, Tehran in 2016 growing season. A factorial arrangement of the experimental treatments was studied in a randomized complete block design with three replications. The factors included four crop planting densities (2, 4, 6 and 8 plants m-2) under two conditions of presence and absence of weeds. Different traits including leaf number per plant, leaf area index, total dry weight, chlorophylls a, b and total chlorophyll, caffeic acid, chlorogenic acid and total polyphenol contents were measured. The results showed that leaf number and dry weight were significantly affected by plant density and weed competition in artichoke, so that the weed competition reduced the artichoke dry weight by 22.4%. The highest leaf area index (2.29) and dry weight of artichoke (253.44 g m-2) were observed at 6 plants m-2, while the highest number of leaves per plant (16.33) belonged to the density of 2 plants m-2. Among qualitative traits chlorophylls a, b and total chlorophyll were only affected by weed presence while caffeic acid, chlorogenic acid and total polyphenol contents were only affected by plant density. The effect of crop plant density on weed leaf area and dry weight was also significant. Overall, the highest performance of the main secondary metabolites in artichoke including caffeic acid, chlorogenic acid and total polyphenol (5.99, 9.55 and 5.89 g m-2, respectively) were obtained at 6 plants m-2, completely affected by crop dry matter yield.

To study the effect of foliar application of proline and salicylic acid on growth, morphological and phytochemical traits of Stevia, an experiment based on completely randomized block design in a factorial arrangement was conducted with three replications in the University of Zanjan. Foliar applications of proline in three levels (0, 1, 2 mM) as well as salicylic acid (0, 0.3, 0.6 mM) were applied after establishment of transplants in the field three times with 10 days intervals. Factors including leaf area, leaf fresh and dry weight, total fresh and dry weight, chlorophyll a, b and total chlorophyll, carotenoid, total phenol, total flavonoid and antioxidant activity were studied. Results showed that salicylic acid and proline applications significantly influenced above mentioned traits. The highest average leaf area/ plant (5949.39 cm2), leaf fresh (787.17 g/m2) and dry leaf weight (228.5 g/m2), total fresh (1339.23 g/m2) and total dry weight (327.52 g/m2) were recorded in 1 mM proline in combination with 0.3 mM salicylic acid. Solely applications of proline at 2 mM and salicylic acid at 0.6 mM enhanced chlorophyll a, b, carotenoid and total flavonoid contents. The highest average total chlorophyll (5.23 mg/g fw) observed in 2 mM proline in combination with 0.3 mM salicylic acid and highest phenol (19.94 mg/g dw) recorded in 1 mM proline in combination with 0.6 mM salicylic acid. Collectively, results showed that application of proline and salicylic acid significantly improved vegetative growth and production of active substances in Stevia rebaudiana.

Hairy root cultures are an effective method for production of secondary metabolites, because hairy roots are genetically and biologically stable and they are able to produce metabolite within a short time without need to use hormones. Chicory (Cichorium intybus L.) is one of the important medicinal plants that contains a number of important medicinal compounds.In this research, hairy root induction was established through the mediation of the A4 strain of Agrobacterium rhizogenes. In first experiment, the effects of type and age of explant and co-culture times on the efficiency of hairy root induction were investigated. In the second experiment, the effect of three different media (Murashige and Skoog solid, liquid and liquid half strength) were investigated on growth rate and biomass accumulation hairy roots. In third experiment, effects of type and age of explant were investigated on the total phenolic content of hairy roots. In fourth experiment, the effect of various concentrations of NAA (0, 0.5, 1 and 1.5 mg/l) and sucrose (3, 4, 5 and 6%) were investigated on biomass accumulation. The obtained results showed maximum hairy root induction (60 percent) and number of roots (11.61 roots per explant) induced from 5-days-old cotyledons. The half strength medium of liquid Murashige and Skoog was the best medium for growth of hairy roots. Also, maximum total phenolic content in hairy roots was obtained by 28-days-old leaves. Medium supplemented with combination of 0.5 mg/l NAA and 3% sucrose showed the best effect on biomass accumulation.

Purslane (Portulaca oleracea L.) contains valuable ingredients such as dopamine, noradrinalin and omega-3. The increase of secondary metabolites by elicitors is widely used in tissue culture of medicinal plants. The aim of this study was to assess effect of plant growth regulators on callus induction and amount of dopamine in callus tissue of purslane under the influence of methyl jasmonate as an elicitor. For this purpose, in the first experiment the interaction effects of different concentrations of BAP (0, 1, and 2 mg L-1) and 2,4-D (0, 0.5, and 1.5 mg L-1) on two kinds of explants (leaf and meristem) was examined. The best callogenesis was obtained in the leaf explants with maximum callus induction (100%), fresh weight (121 mg), and callus diameter (5.1 mm) by combined application of 2 mg L-1 BAP and 0.5 mg L-1 2,4-D. In the second experiment the effects of methyl jasmonate application (0, 100, and 200 µM) on dopamine production of calluses during 2, 4, and 6 days of treatment were investigated. After extract preparation of different treatments, the amount of dopamine was determined by HPLC. The highest amount of dopamine (0.685 mg L-1) was obtained in concentrations of 200 µM after two days of treatment. Application of methyl jasmonate enhanced dopamine content in all treatments compared to the control. Therefore, methyl jasmonate which is an effective elicitor to increase secondary metabolite in purslane.

Nutrition management in growth season has a main effect on production and accumulation of secondary metabolites in grapevine berries. In this research the effects of foliar application of potassium sulfate (K; 0, 1.5, and 3%) and iron chelate (Fe; 0, 0.5, and 1%) on accumulation of resveratrol and viniferin and antioxidant capacity of ‘Bidaneh Sefid’ grape berries was evaluated. This study was carried out as a factorial experiment based on completely randomized block design in commercial vineyard located in Malayer city during 2016-2017. The fruits were harvested based on maturity index. Some characteristics of berries such as flavonoids, total phenols, anthocyanin, vitamin C, resveratrol, viniferin, antioxidant capacity, catalase, guaiacol peroxidase, and ascorbate peroxidase were measured. Based on the results, the highest berry total anthocyanin and vitamin C was related to sprayed vines with 1% Fe- EDDHA and 1.5% potassium sulfate in solely respectively. The highest total phenol observed in vines sprayed with 1.5% potassium sulfate in combination with 1% Fe- EDDHA. However, the lowest total phenol content was found in control vines. The highest berries resveratrol and viniferin concentration was observed in vines sprayed with moderate doses of both fertilizers. Moreover, berry antioxidant capacity of vines treated with moderate doses of both fertilizers was found to be highest. Nutrient -treated vines with both fertilizers at third level showed the higher guaiacol peroxidase in compared to others plants. The highest catalase activity of berries was related to vines treated with 3% potassium sulfate in combination with 0.5% Fe- EDDHA. However, the maximum ascorbate peroxidase was obtained with 1.5% potassium sulfate in combination with Fe-EDDHA at 0.5% concentrations. The lowest activity of all enzymes was obtained in control un-treated vines.

In order to study the effects of iron, zinc and manganese sulfate on essential oil percentage, yield and composition in hyssop (Hyssopus officinalis L.), an experiment was conducted as randomized complete block design with three replications during 2016.Experimental treatments consisted of control, foliar application of iron, zinc, manganese, iron츩, iron馩瞬, zinc馩瞬 and iron츩 manganese. Results showed that foliar application of microelements had significant effects on all traits studied except cis-pinocamphone. Foliar application of iron zinc manganese treatment produced the maximum essential oil percentage (0.6%) and essential oil yield (30.44 Kgha-1). Foliar application of iron zinc manganese treatment increased essential oil percentage up to 50% compared to the control treatment. β-pinene, trance-pinocamphone, pinocarvone and cis-pinocamphone formed 75 to 90% of the oil components. Foliar application of iron zinc manganese and control treatments produced the highest (89.4%) and the lowest (77.1%) values of total β-pinene, trance-pinocamphone, pinocarvone and cis-pinocamphone, respectively. Therefore, results showed that the foliar application of Zn Fe Mn could be used as a suitable management strategy to reach the optimum essential oil yield and composition in hyssop.

The hairy roots induced by Agrobacterium rhizogenes due to the stability and mass production in hormone free culture provide an appropriate tissue for secondary metabolite production, and the content of metabolites produced could be affected by bacterial strain. In the current study, the effect of different strains of A. rhizogenes including A4, A13 and 15834 on the percentage of hairy root induction of Echinacea purpurea (L.) moench. in the leaf and hypocotyl explants were studied. In another experiment, total phenolics and polysaccharides content of hairy roots were measured compared to the control (untransformed) roots. The results showed that the percentage of hairy root induction was significantly affected by bacterial strains, so that in E. purpurea leaves incubated by strains A13, 15834 and A4, the hairy root induction was 60%, 40% and 0, and in hypocotyl explants was 85%, 45% and 70%, respectively. Maximum total phenolic compounds were observed in A4 strain. As well, in comparison to control, the polysaccharide content in hairy root induced by strains 15834 and A13 increased and by A4 strain decreased significantly. Differences observed in this study about hairy root induction and secondary metabolites production could be due to different ability of A. rhizogenes strains in T-DNA transferring to plant cells.

There are 58 species belonging to sage genus as annual and perennial plant in different regions of Iran that 18 species of them are endemic to Iran and they have different medicinal properties such as antibiotic, sedative, carminative, antispasmodic and commonly used in treatment of respiratory problems: infections, cough, cold and sore throat and cosmetics industries. The present study has aimed to evaluate the composition of essential oils achieved by Solid Phase Micro-Extraction method from aerial parts of two Salvia species native to Iran: Salvia limbata and Salvia multicaulis.
The experiments were carried out at the Research Station of Agriculture College, TarbiatModares University in Tehran, Iran during the years 2011-2013. The seeds of Salvialimbata and Salvia multicauliswere collected in Ardabil and Isfahan provinces in 2009. The seeds were sown in planting trays(filled with soil and cocopeat 1:1) under controlled greenhouse condition (temperature: 26±1°C, light: 3000 lux, relative humidity: 65%) in the last week of February 2011. The soil of experimental pots (soil and coco peat 2:1) was a clay silt loam with pH of 7.4. After two months,seedlings with uniform height and stem diameter with two true leaves were transferred to a growth chamber adjusted to 30/20 °C, 50% relative humidity, light intensity of approximately 3000 Lux and 16 h photoperiod.Aerial parts of two cultivated plantsincludingSalvia limbata and Salvia multicaulisat flowering stage were harvested in June 2012 and kept at 80°C until further experiments. Volatile compounds were extracted by solid phase micro-extraction (SPME) method for the first time in Iran for these species. Before the SPME, the leaves lyophilized and then were used. The optimization of SPME extraction and desorption conditions were performed by analyzing dried leaves of Salvia officinalis L., used as the matrix. The sample preparation procedure was as: 15 mg of dried sage leaves mixed into a 20 ml screw-on cap HS vial to 5 ml of 5% Ethanol and 0.5 mg of Na2SO4. The vials were sealed after stirringwith a Teflon (PTFE) septum and an aluminum cap (Chromacol, Hertfordshire, UK) for the production of headspace and the successive analysis. The sample vial was put in the instrument dry block-heater and held at 40°C for 20 min to come into equilibrium. The extraction and injection processes were automatically performed using an auto sampler MPS 2 (Gerstel, Mülheim, Germany). The fiber was, then, automatically inserted into the vial’s septum for 10 min, to allow the volatile compounds absorption onto the SPME fiber surface. Each SPME fiber was conditioned before its first use, as recommended by the manufacturer. In order to desorb the volatile metabolites, the SPME fiber was introduced into the injector port of the gas chromatograph device, model GC 7890A, Agilent (Agilent Technologies, Santa Clara, USA) coupled with a mass spectrometer 5975 C (Agilent) wherein the metabolites were thermally desorbed and transferred directly to a capillary column HP-Innowax (30m×0.25 mm×0.5µm Agilent J&W) and analyzed. The identification of VOMs was accomplished by comparing the retention times of the chromatographic peaks with those, when available, of authentic standards run under the same conditions. For volatiles for which reference substances were not available, the identification was performed by matching their retention indices (RI) determined relative to the retention time of a series of n-alkanes (C8–C20) with linear interpolation, with those of authentic compounds or literature data (Van Den Dool&Kratz, 1963). Confirmation of metabolites identification was also conducted by searching mass spectra in the available database (NIST, version 2005; Wiley, version 2007).
66 volatile components were identified in Salvia limbata, which Sabinene (19.16%), β-Pinene (19%), α-Pinene (16.3%), α-Terpinolene (14.41%), 1,8-Cineole (10.86%) and Limonene (3.73%) were highest amounts. 58 volatile compounds were identified inSalvia multicaulis thatCamphene (28.85%), α-Pinene (12.33%), Camphor (10.73%), Limonene (9.01%), 1,8-Cineole (5.47%), β-Pinene (4.58%) and Bornyl Acetate (3.75%) had the maximum amounts, respectively. The main part of volatile constituents of Salvia limbata and Salvia multicaulisplantsbelonged to monoterpenes (91.57 and 84.28% respectively) and sesquiterpenes (5.12 % and 7.58 %, respectively).
The results obtained in Salvia limbataand Salvia multicaulisin respect to main components are similar to previous papers (3, 16). However, there is some compound such as α-Terpineol in Salvia limbatawhich has not been reported. According to the obtained results by solid phase micro-extraction is closer to plant compounds.

The Diamond back moth Plutella xylostella L. is one of the major pests of plants in Brassicaceae that has become resistant to many insecticides. In recent years، plant secondary metabolites play an important role in controlling pests because of their insecticidal and antifeedant properties. A laboratory experiment was conducted to investigate the effect of methanolic extracts of Matteuccia struthiopteris (L.) on diamondback moth third instar larvae. Findings showed significant increase in mortality as concentrations increased، so that، concentrations to cause 25% (LC25) and 50% (LC50) mortality in population were 12. 01% and 28. 58%، respectively. In this research، the effect of sublethal concentration of methanolic extract was studied on demography parameters such as life table، reproductive and population of P. xylostella. The obtained results showed that different concentration had a significant effect on the duration of different life stage، fecundity and adult longevity. Data analysis demonstrated that increased concentration decreased the net reproductive rate (R0)، intrinsic rate of natural increase (rm)، finite rate of increase (λ) but increased mean generation time (T) and doubling time (DT) significantly. These findings indicate that M. struthiopteris has the potential to be used as a reliable method in integrated management of this pest.

In medicinal plants، secondary metabolites are very important and factors influencing their quantity and quality are considered. Iranian borage (Echium amoenum Fisch. & C. A. Mey.) belonging to Boraginaceae family is a long-day، biennial، herbaceous plant، with a lot of rough trichomes، is found in northern Iran. In the present work، effects of silicon on some morphological، anatomical and physiological characteristics of this plant were investigated. For this purpose، borage plants، cultivated in hydroponic system in greenhouse، were treated with silicon (as sodium silicate) at 3 concentration levels (0، 0. 2 and 0. 7 mM). The experiment was carried out as completely randomized design. Some morphological and anatomical characteristics such as length of trichomes، number of trichomes، number of stomatal cells، cuticle thickness، stomatal index and palisade parenchyma cells density of treated plants and control were measured and anthocyanin and flavonoids content was also evaluated. Based on the results، in silicon-treated plants، compared to control، the stomatal index was decreased. The cuticle thickness، palisade parenchyma cells density، trichomes length، and anthocyanin and flavonoids content in silicon-treated plants were increased significantly. But، there was no significant difference in number of trichomes in the treated plants.