جستجوی مقالات مرتبط با کلیدواژه « آنتی اکسیدان » در نشریات گروه « آب و خاک »

Violet is an annual ornamental plant that is widely used in urban green spaces. The aim of this study was to investigate the role of melatonin in reducing salinity stress in violet. The factors included melatonin at three levels (0, 50 and 100 μM) and salinity stress at four levels (0, 60, 30 and 90 mM). According to the obtained results, The highest plant height was observed in the treatment of 100 μM melatonin with an increase of 16.07% compared to the control without salt stress.The highest number of flowers was recorded in plants treated with 100 µM melatonin under 0, 30 and 60 mM salinity which showed a 50% increase in the number of flowers.The maximum root volume was in 100 μM melatonin under 30 mM salinity. The lowest percentage of relative plant water content was obtained at 90 mM salinity without the use of melatonin. Ionic leakage in salinity increased with increasing salt concentration. The highest sodium ion concentration of the plant was observed in the 60 mM salinity treatment without the use of melatonin, and the lowest sodium accumulation was observed in the no salinity treatment. The highest concentration of potassium element in salinity was recorded at 50 μM melatonin under 30 mM salinity. According to the obtained results, the use of melatonin is suggested to reduce damage to the violet plant under salt stress conditions.

To evaluate the changes in essential oil and chemical compounds of ginger plant under the influence of irrigation interval and NPK macronutrients, an experiment was carried out using randomized complete blocks in the form of a split plot with 9 treatments and 3 replications in Pakdasht Region, in 2021. Treatments included irrigation internals at three levels: V1=4, V2=6, and V3=8 days, as the main factor, and NPK at three levels, F1= (N: 300, P: 100, K: 200), F2= (350, 150, 250), F3 :( 250, 50, 150) (kg.ha-1) as the sub-factor. Extraction of essential oil in this research was done by distillation with water using a Cloninger machine, and the analysis of essential oil compounds was done by gas chromatograph, and 34 chemical compounds were identified. The main components of essential oil in terms of percentage included (α-zingiberene=23.65), (geranial=11.09), (camphene=9.58), (β-sesquiphellandrene =8.43), (β-bisabolene=3.75) and (α-curcumene=2.6). These 6 compounds included 59.1% of the total ginger essential oil, and the other 28 compounds made up only 40.9% of the total essential oil. The results of analysis of variance showed that the interaction effect of irrigation and studied fertilizers on essential oil and main compounds of ginger essential oil were significant at the 1% probability level. The best treatments for essential oil and camphene traits were V1F3, geranial V3F2, α-zingiberene V1F2, and for three traits of α-curcumene, β-bisabolene, and β-sesquiphellandrene was V3F3. Some of the compounds in ginger essential oil were increased by optimal irrigation and supply of essential nutrients for the plant, but some compounds increased under water stress and insufficiency of NPK.

Water stress is the most important non-living factor in reducing plant growth and production. In order to investigate the effect of different levels of irrigation and manure on biochemical properties and nutrient uptake of chicory, a factorial experiment was conducted in a randomized complete block design with three replications. Experimental treatments included moisture levels (50, 70 and 90% of field capacity moisture) and doses of rotten cow manure (zero, 10, 20 and 30 tons per hectare of manure). The results of analysis of variance showed that the content of phosphorus and potassium, soluble sugars, proline, glycine betaine, glutathione and ascorbic acid of chicory were affected by different levels of irrigation and fertilizer consumption at a probability level of 1 %. Interaction of experimental treatments (moisture levels× amounts of manure consumption) on the uptake of trace nutrients (zinc, copper and manganese) and relative moisture content at a probability level of 1%, catalase enzyme activity at a probability level of 5%, glutathione reductase and ascorbate peroxidase and forage yield of chicory were also significant at the level of 1% probability. The results showed that with increasing water stress, the content of phosphorus, potassium, glutathione and ascorbic acid significantly decreases. While the highest amount of total soluble sugars, proline and glycine betaine was obtained under conditions of severe water stress. Consumption of 30 tons per hectare of manure the amount of phosphorus, potassium, total soluble sugars, glutathione and ascorbic acid increased by 44, 42, 27, 26 and 41%, respectively, compared to the control. Increasing the consumption of livestock manure played an effective role in the absorption of micronutrients (zinc, copper and manganese with values of 2.57, 0.74 and 1.72 mg/kg, respectively) and improving the relative moisture content (83.54%) and yield of chicory biomass (250/83 kg/ha) at each irrigation level. Therefore, in different stress treatments, the use of manure by reducing the oxidative damage caused by dehydration improves the absorption of nutrients and some biochemical characteristics of chicory plant for sustainable agriculture.

Soil salinity is a major abiotic constraint affecting crop yield and quality of ornamental plants. The current study aimed to investigate the melatonin and ascorbic acid regulator on the morphological and physiological characteristics of miniature roses under salinity stress, in the research greenhouse of Agriculture and Natural Resources Campus, University of Tehran, located in Karaj, on biennial cuttings of miniature roses, in plastic pots with a diameter of 14 cm containing cocopeat and perlite (1: 1), in the randomized complete block design with four replications, in the spring of 2018. The studied factors included foliar application of melatonin (at four concentrations of 0, 1, 10, and 100 μM) and ascorbic acid (at three concentrations of 0.5, 1.5, and 3 mM) and combined treatment containing two levels of melatonin 1 μM × ascorbic acid 0.5 mM and melatonin 1 μM × ascorbic acid 1.5 mM and salinity stress at three levels of zero, four and eight dS/m. The results showed that the salinity stress generally reduced morphological characteristics; in this study, the most effective treatment in the foliar application was observed with 3 mM ascorbic acid treatment, which increased the number of flowers and branch height by 36% and 86%, respectively, compared to the control. Foliar application of melatonin 100 μM showed the highest effect on the concentration of nitrogen and potassium equal to 43% and 11% as compared to the control, respectively. Accumulation of soluble sugars during salinity stress conserving osmotic potential and reducing dehydration, and the leaf soluble sugar increased by 11% as compared to the control and proline was observed in foliar application with 1 μM melatonin treatment. The results of this study showed that the ability of this antioxidant (Ascorbic acid 3 mM) can be used to improve the growth and development of miniature roses under salinity stress.

Due to the importance of useful elements such as silicon in improving plant resistance to environmental and biological stresses, a factorial experiment was conducted in a completely randomized design in Hashtgerd city, hydroponic greenhouse No. 256. Experimental factors included temperature at 4°C (stress temperature) and 25°C (optimum growth temperature) and application of silicon fertilizer from source of silicic acid at five levels; 0, 500, 1000, 1500 and 2000 mg/kg with three replications, in total 30 pots. The measured traits included the activity of superoxide dismutase (SOD), catalase (CAT), antioxidant enzymes and the qualitative characteristics of aloe vera consist of Mannose, Glucomannan and Aloin concentrations and the plant growth characteristics including aloe vera gel and leaf weight, which were tested at 4°C as cold stress temperature and 25°C as the optimum growth temperature of the plant. The obtained results after applying cold stress showed that the effect of silicon fertilizer levels applied on (SOD) and (CAT) and Glucomannan and Mannose activities were significant at 1% level. It was also observed that the interaction of different concentrations of silicon fertilizer and temperature stress is significant at 1% level on all compounds. For vegetative and biochemical traits, the highest interaction was observed in treatment of 2000 mg/kg silicic asid fertilizer at 25°C. For antioxidants, the highest interaction was found in treatment of 2000 mg/kg silicic acid and stress temperature of 4°C. Therefore, the application of 2000 mg/kg pure silicon could have positive effects on the activity of antioxidant enzymes and vegetative traits at normal temperature and a more favorable effect on biochemical traits under temperature stress. Consequently, the silicium fertilizer can be applied as a useful and suitable element in ncreasing the quantity and quality of aloe vera plant.

Drought is one of the major constraints on agricultural productivity worldwide. Selenium plays an important role in plants tolerance to environmental stresses by increasing the levels of antioxidant enzymes and compounds. In order to investigate the effect of selenium on some growth and physiological characteristics of the Dragons head (Lallemantia iberica), a factorial experiment was conducted in a completely randomized design with three replications in greenhouse conditions. Treatments included different levels of drought stress (100%, 75%, 50% and 25% field capacity) and different concentrations of selenium (0, 5 and 10 mg.L-1 sodium selenate). Foliar application of sodium selenate was performed in two stages. According to the results, drought stress had a negative effect on fresh and dry weight leaf and yield. But, under drought stress conditions, foliar selenium caused a significant increase in plant height (32.2 cm), proline (0.92 mg/g DW), and total phenol (0.82 mg/g DW) content. Increase in selenium concentration increased Dragons head physiological properties: relative leaf water content (65.10 %), total soluble sugar (2.55 mg/g DW), soluble protein (0.289 mg/g DW), and antioxidant activity (0.21 %). Concentration of 10 mg.L-1 sodium selenate had a positive effect on plant fresh weight and biological yield of Dragons head, which was probably associated with the antioxidant role of selenium. Under drought stress, selenium increased the amount of proline and total phenol, which increased these adaptation osmolytes and had an important role in the drought tolerance of Dragons head.

Synthetic sulphonated anthraquinones are the raw materials used for producing a large palette of synthetic dyes, and microorganisms have a limited ability to decompose them, hence they are one of the important environmental pollutants. In order to study the ability of plants to remove this pollutant from the environment, corn, as a plant not containing any natural anthraquinones and common sorrel, as a plant containing natural anthraquinones, were studied in hydroponic conditions. A factorial experiment was conducted in a completely randomized design. The first factor was the plant species (Corn, as plant without natural anthraquinones, and common sorrel, plants with natural anthraquinones) and the second factor was sulphonated anthraquinones pollutant concentration. To reduce number of data, they were first analyzed using principle component analysis (PCA) procedure. Parameters with the highest specific value and highest effect on total variance as well as characteristics with the highest coefficients were selected.Result of PCA showed that shoot characteristics were less affected by pollutant concentration than root, and antioxidative defense system, lipid peroxidation and production of hydrogen peroxide in root, shoot and root dry weight had the highest contribution in total variance. Data analysis of variance indicated that corn ability was less than common sorrel for removing sulphonated anthraquinones. Root and shoot dry weighs were reduced by sulphonated anthraquinones, while activity of some enzymes such as Superoxide Dismutase (SOD), Ascorbate Peroxidase (APX), Catalase (CAT) and malondialdehyde were increased. The highest activity of antioxidative enzymes was measured in common sorrel treated by 3 mM sulphonated anthraquinones.