جستجوی مقالات مرتبط با کلیدواژه "total flavonoid" در نشریات گروه "کشاورزی"

AbstractNitrate accumulation is a common problem in most leafy vegetables and it happens when the amount of nitrate absorption exceeds the amount consumed by the plant. This study was conducted as a factorial experiment in the form of a completely randomized design and in three replications. The first factor included adding nitrate (calcium nitrate) to Hoagland's standard solution at three levels of 0, 10 and 20%, and the second factor was adding different concentrations of molybdenum from sodium molybdate salt at four levels of 0, 0.5, 1.5 and 3 µM. The measured traits included traits of some growth characteristics, total phenol and flavonoids, ascorbic acid, spinach leaf nitrate. According to the obtained results, fresh and dry weight of leaf, dry weight of root and percentage of dry matter increased by increasing calcium nitrate concentration up to 20% and molybdenum application up to 3 µM in nutrient solution. The simultaneous application of molybdenum and nitrogen had no significant effect on total phenolic, total flavonoid and ascorbic acid traits, and the highest amount of these traits was observed in 3 µM molybdenum. The highest amount of leaf nitrate (3247.4 mg kg-1 FW) was observed in the treatment of 20% additional nitrate along with molybdenum. Based on the results, the use of molybdenum in nutrient solution had a reducing effect on nitrate accumulation in spinach leaf, therefore adding 3 µM sodium molybdate to Hoagland nutrient solution in hydroponic system for spinach production is recommended to obtain the maximum amount of antioxidant compounds and the minimum amount of nitrate accumulation.IntroductionPlants take nitrogen (N) either as nitrate (NO3−) or ammonium (NH4+) form for various growth and developmental processes; however, NO3− is more important for such processes. For most of the crop plants, the nitrate form is mobile, less toxic, and can be stored in vacuoles. However, Nitrate must be reduced to NH4+ before it can be utilized for the synthesis of amino acids, proteins, and other nitrogenous compounds in plant cells. Nitrate reductase (NR) and nitrite reductase (NiR), the key nitrate assimilatory enzymes, are located in cytosol and chloroplasts and catalyze nitrate reduction to NO2− followed by NO2− to NH4+, respectively, in the leaf tissues. However, NH4+ is directly assimilated to produce different amino acids by the mutual actions of glutamine synthetase (GS) and glutamate synthase (GOGAT) enzymes in a cyclic manner within the plant cells. Nitrate accumulation is a common problem in most leafy vegetables and it happens when the amount of nitrate absorption exceeds the amount consumed by the plant. Molybdenum (Mo) is an essential microelement for higher plants and also a metal component of the Mo-cofactor, (Moco) biosynthesis. Moco binds to Mo-requiring enzymes and optimizes their activities for normal functioning of plant growth and developmental processes. Molybdenum plays a significant role in N metabolism, which includes nitrate reduction, assimilation, and fixation, by regulating the NR and GS enzymes activities and expressions. During symbiotic N fixation, Mo acts as a cofactor for nitrogenase enzymes to catalyze the redox reaction to convert elemental N into ammonium ions.Materials and methodsThis study was conducted as a factorial experiment in the form of a completely randomized design and in three replications. The first factor included adding nitrate (calcium nitrate) to Hoagland's standard solution at three levels of 0, 10 and 20%, and the second factor was adding different concentrations of molybdenum from sodium molybdate salt at four levels of 0, 0.5, 1.5 and 3 µM. This research was conducted in the research greenhouse of Campus of Agriculture and Natural Resources Razi University. Senator spinach seeds were obtained from Fardin Kasht Alborz Institute. Spinach seeds were disinfected with 1% sodium hypochlorite for 5 minutes and then planted in seedling trays containing cocopeat and perlite with a volume ratio of 1:1. The measured traits included traits of some growth characteristics, total phenol and flavonoids, ascorbic acid, spinach leaf nitrate.Results and discussion According to the obtained results, fresh and dry weight of leaf, dry weight of root and percentage of dry matter increased by increasing calcium nitrate concentration up to 20% and molybdenum application up to 3 µM in nutrient solution. The simultaneous application of molybdenum and nitrogen had no significant effect on total phenolic, total flavonoid and ascorbic acid traits, and the highest amount of these traits was observed in 3 µM molybdenum. The highest amount of leaf nitrate (3247.4 mg kg-1 FW) was observed in the treatment of 20% additional nitrate along with molybdenum. The most important point in this research was the use of molybdenum to control nitrate accumulation, and the use of molybdenum in concentrations of 1.5 and 3 µM was able to reduce the amount of nitrate accumulation in the aerial parts to some extent, thus neutralizing the toxicity of excess nitrate. The use of sodium molybdate can be one of the recommended ways to reduce the accumulation of nitrates and at the same time enrich molybdenum in spinach and increase the nutritional value of this plant.ConclusionNitrate and ammonium are the major forms of N that plants use for different growth and developmental processes. The present study revealed that Mo fertilizer plays a key role in N metabolism through regulating the activities and expressions of N-assimilating enzymes. In general, the results of this research showed that the increase in molybdenum concentration in hydroponic culture affected the growth and biochemical characteristics of spinach. Based on the results, the use of molybdenum in nutrient solution had a reducing effect on nitrate accumulation in spinach leaf, therefore adding 3 µM sodium molybdate to Hoagland nutrient solution in hydroponic system for spinach production is recommended to obtain the maximum amount of antioxidant compounds and the minimum amount of nitrate accumulation.

Due to the limitations of water resources and poor soil quality, the use of modern and high-quality solutions is necessary to produce agricultural products with better quality. One of the effective methods for achieving this goal is the production and cultivation of plants by hydroponic methods. This study was conducted as a factorial in a completely randomized design with the aim of investigating the effect of hydroponic cultivation systems [drip system and deep flow technology (DFT)] as the first factor on the quality and yield of two strawberry cultivars (Albion, Sabrina) as the second factor with four replications. The results showed that Sabrina had the highest fruit length and width in the drip system. Also, the highest fruit weight and yield were observed in the Sabrina cultivar under the drip irrigation system. The highest titratable acidity content was observed in Sabrina cultivar under the drip system and the highest contents of total soluble solids, total phenol and total flavonoid were recorded in the DFT system. Besides, the highest total anthocyanin content was revealed in the Albion cultivar under the drip system. In general, the results of the present study showed that most of the qualitative and quantitative characteristics of strawberry fruits were affected by the cultivation system type and the yield and fruit quality of strawberries were higher in the drip system compared to the DFT system. It can be also concluded that Sabrina had the highest biochemical properties under the drip system.

Roselle belongs to the Malvaceae family, it is an important source of vitamins, minerals, and the pharmacological effects of Roselle are related to its components such as flavonoids, anthocyanins, organic acids, phytosterols, polyphenols, and polysaccharides, some of which have antioxidant activities. In the present study, the storage life of fresh Roselle calyces was evaluated in terms of changes in terms of biochemical properties such as total phenol, flavonoid, anthocyanin contents and antioxidant activity for 5 to 30 days at 0, 4, 10 and ambient temperature (23) degrees Celsius. The results showed that the lower temperature (0 and 4 °C) preserves the appearance of the calyces during storage in the refrigerator. The shelf life based on the appearance of the product was higher at 0 and 4 °C than at 10 and 23 °C. In addition, fresh calyces exposed to 4°C accumulated higher amounts of phenolics, flavonoids, anthocyanins, and antioxidant activity than those exposed to 0°C to overcome severe cold stress. Consequently, for short-term storage or immediate consumption, it is desirable to store fresh calyces at 4°C to obtain high antioxidant content. However, if the goal is to extend the cold storage period, storage at 0°C is recommended.

To investigate the effect of salt stress on the growth and phytochemical characteristics in the in vitro cultivation of Nitraria schoberi, an experiment was conducted in the form of a factorial design with a completely random basis. The treatments included different concentrations of sodium chloride (0, 50 and 100 mM) and sodium sulfate (0, 10 and 20 mM). First, the seeds were germinated in vitro and then the cotyledon leaves with the hypocotyl of germinated seeds were placed as explants in MS cultivation environment with 2 mg/L BAP, 0.5 mg/L IBA, and the mentioned treatments. The explants were placed in the growth room under the conditions of 16 hours of light and 8 hours of darkness at a temperature of 25±2. After 4 weeks, stem length, number of leaves, and total phenol and flavonoids were measured. The results of variance analysis showed that different levels of salt have a significant effect (at the 99% level) on the growth indices of seedlings such as the length of the stem and the number of leaves, as well as on the total amount of phenol and flavonoid in the tissue of leaves. Based on comparisons, the maximum length of the stem (4.3 cm) and the number of leaves (5.5) related to the cultivation environment without salt and the highest amount of total phenol (35.37 mg/g) and flavonoid (24.6 mg/g) g/g) related to the cultivation environment containing 50 mM sodium chloride with 10 mM sodium sulfate.

Taking advantage of the symbiotic relationship between plants and Trichoderma fungi is one of the ways to reduce water stress in plants. The present study was conducted in order to investigate the effect of Trichoderma fungus on the antioxidant properties of the basil medicinal plant (Ocimum basilicum L.) under water stress conditions.

This experiment was carried out in the greenhouse of the Department of Horticulture Sciences of Ahar Faculty of Agriculture and Natural Resources and laboratory studies in the basic and general laboratories of Ahar Faculty of Agriculture and Natural Resources (University of Tabriz) in 2019 in a factorial manner based on a randomized complete block design with three repetitions. The treatments included different levels of water deficit stress, including severe stress (25% of field capacity), moderate stress (50% of field capacity), mild stress (75% of field capacity), and no stress (100% of field capacity). Each pot contained a commercial mushroom species Trichoderma harzianum Na-lac with concentrations of 109 and 106 spores per milliliter as the inoculum.

The results showed that the amount of malondialdehyde, catalase and peroxidase, antioxidant activity and total flavonoid increased with the application of dehydration stress. The concentration of 106 spores per milliliter had a better impact on improving the mentioned indicators. Based on this, Trichoderma fungus proves effective when improving the antioxidant status of plants under drought stress and can prevent the effects of oxidative stress in plants by reducing the oxygen free radicals produced.

The results indicated that the use of Trichoderma mushroom in comparison with the control (without inoculation with the mushroom) can be a suitable tool to improve the physiological traits and antioxidant activities in the conditions drought stress.

In the present study, the effect of drying methods on the bioactive compounds of the two salvia spieces,Salviaofficinalis  andsalvia nemorosa,was investigated. The experiment was performed as a factorial experiment with two factors in a randomized complete block design with three replications. The first factor was two species of salvia and the second factor was drying method in 4 levels of shade drying for 144 hours, drying under the sun irradiation for 78 hours and drying in oven at 40 and 70°C for 37 and 6 hours, respectively. With concidering two levels for the first factor and four levels for the second factor, 8 treatments were studied in the experiment. The results showed that the highest extract yield (11%) was obtained from samples which dried in the oven with 70°C and in both species with a higher rate inS.nemorosa. The percentage of weight loss was not affected by drying methods but it affected by species andS.officinalis had the highest weight loss compared to another specie. High value of total phenolic compounds, total flavonoids, total tannin and antioxidant properties of two speiceswere found in samples dried in shade, and the lowest value of these traits were recorded in plants which dried in the oven at 70°C. High contents of phenolic acids including chlorogenic acid, caffeic acid, rosmarinic acid and salvainolic acidwere recorded  in both species which dried at shade condition and the lowest amount were found in samples dried in oven at 70°C. Also, salvainolicacid and rosmarinic acid was recorded at high level of phenolic acids in samples dried at shad condition.By comparing breeded (S. officinalis) and native species (S. nemorosa), it was found that the native species can have outstanding features for domestication, improvement and further research.

 Persimmon (Diospyros kaki Thunb.) is an important fruit that is consumed due to high nutritional, desirable taste and flavor. Unfortunately, most persimmon fruit producers do not use the suitable technology to preserve the fruit quality, consequently, marketing their product at lower prices. The fruit of Karaj cultivar is one of the best and highest quality cultivars in Iran but this fruit is sensitive to chilling injury and shows drastic softening and reduced nutritional value as chilling damage. Appliacation of effective treatments for reducing chilling symptoms and preserve quality can lead to the increase of shelf life in this fruit. Ascorbic acid is an important nutrient that it is required for the functioning of several enzymes and is important for immune system function. It also functions as an antioxidant. Recently this treatment has gained much attention for use as an environmentally friendly technology for the maintenance of postharvest quality of many horticultural crops. In this regard, the aim of the present study was to assess the effect of ascorbic acid and storage time on the postharvest life of persimmon fruit.

 Persimmon fruit (cv.‘Karaj’) was first harvested at physiological maturity stage from a commercial orchard in Karaj city, then immediately transported to the postharvest laboratory at University of Zanjan. Fruit selected for uniformity of size, shape, color and free from disease or mechanical damage. The treatments included ascorbic acid at three levels (15, 30 and distilled water as a control mmol.L-1) and storage time at three levels (15, 30 and 45 day). Fruit was dipped in solution of Ascorbic acid 15 and 30 mmol.L-1 and distilled water (control) for 10 min. After treatment, the fruits were stored at +4°C and 85-90% relative humidity for 45 days. Fruits were sampled during storage after (15, 30 and 45 days) and 24 hours maintaining at room temperature and fruit firmness, weight loss, TSS, TA, vitamin C, total flavonoids, total phenol, soluble tannins, total carotenoids, antioxidant capacity and MDA were measured at the end of each period. Persimmon fruit samples were weighed before and after the storage to calculate weight loss (%) during storage by using the formula of [(weight of fruits before the storage − weight of fruits after the storage)/weight of fruits before storage] × 100. Fruit firmness was determined using OSK 1618 penetrometer equipped with an 8 mm tip at 3 equatorial points, and the results were expressed as kg/cm2, Soluble tannin was measured by using the method of Tiara (1996). Total carotenoid was measured based on wang et al (2006), Total soluble solid (TSS) was measured by using refractometer, Ascorbic acid content was determined by using the method of Jalilimarandi (2000) and Antioxidant activity was evaluated by measuring the scavenging activity of the examined extracts on the 2,2-diphenylhydrazil (DPPH) radical as described by Dehghan and Khoshkam (2012). Statistical analysis was performed using SAS V9 software and the treatment means were separated by Duncan’s multiple range tests.

 Results showed that all treatments showed significant effect on evaluated traits. All treatments preserved vitamin C and antioxidant activity of fruit compared with control. Ascorbic acid 30 mmol.L-1 significantly preserved firmness, soluble tannin, total phenol, flavonoid, antioxidant capacity. Based on current results that ascorbic acid 15 and 30 mmol.L-1 treatments were the most effective in delaying decrease weight loss by reduced metabolic activity, delayed senescence, and maintained better cellular integrity thereby worked in an integrated manner to reduce fresh weight loss of persimmon fruit. Increasing Ascorbic acid suppressed oxidative damage possibly by quenching hydrogen peroxide and superoxide anion. Therefore, positively correlated with higher membrane integrity and less MDA of persimmon fruit. Ascorbic acid is not only an important nutraceutical compound but also a critical antioxidant that positively eliminates certain reactive oxygen species and preserve antioxidant compounds such as phenol, flavonoid, carotenoid and vitamin C in post-harvest. Ascorbic acid 15 and 30 mmol.L-1 treatments used in this experiment had no effect in changes TSS and total carotenoid. So ascorbic acid can improve effectively the quality and increase shelf life of fresh persimmon fruit in post-harvest.

 In conclusion, our research indicates that ascorbic acid could prolong postharvest life of persimmon fruit by maintaining fruit quality attributes. Ascorbic acid treatment significantly is effective in preserving, firmness antioxidant compounds, quality properties and increasing the storage time of persimmon fruit of Karaj cultivar without harmful for human health. Hence, ascorbic acid treatment is a safe and applicable method of increasing the shelf life and preserving the quality in persimmon during cold storage.

One of the valuable and rich sources of antioxidant compounds and vitamins is grape fruit. Nowadays, the production of high quality grapes with strong texture and high shelf life of fruits is very important. Therefore, the use of organic acids to improve the quality and quantity of crops and orchards is becoming more common. Humic acid, as an organic acid derived from humus and other natural sources, can work without damaging the environmental effects to enhance the quality of grapes. This study was conducted in a randomized complete block design with 4 replications. The experiment treatment consisted of four concentrations of humic acid (0, 0.5, 1 and 2 g L-1). Attributes such as weight, length and width of berry and grape panicle, as well as acidity, organic acids, soluble solids as well as some phytochemical traits such as total phenol and flavonoid, anthocyanin and antioxidant activity were evaluated by DPPH method. According to the results of analysis of variance, traits such as weight and width of berry and panicle, total phenol and antioxidant activity, acidity and soluble solids at 1% probability level were statistically significant between treated and control samples. But traits such as total flavonoid content and anthocyanin content of samples had significantly different at 5% probability level. In general, most of the traits had the highest values in the 2 g L-1 humic acid treatment. The highest total phenol content and antioxidant activity were observed in 2 and 1 g L-1 humic acid treatments with 1.667 mg ml-1 juice and 33.84%, respectively. In general, the results showed that application of humic acid can be improved many of the physical and biochemical properties of grape fruit.

Lavender is widely cultivated worldwide with its economic and ornamental potential and its high use in the cosmetic and pharmaceutical industries. Drought is one of the most important factors limiting plant growth worldwide and the most common environmental stress. In general, drought is considered to be the major environmental factor causing disturbance in water status and having a key impact on physiological and biochemical processes such as increased plant osmolality. In response to environmental stresses, abscisic acid plays an important role in initiating and coordinating many physiological and biochemical processes in reducing oxidative stress. Due to the fact that drought and water deficit in Iran is always one of the most important agricultural problems and due to the unique medicinal properties of lavender, the present study was conducted to evaluate the yield, physiological and biochemical properties of Lavandula angustifolia cv. Organic Munstead in irrigation regimes and application of abscisic acid was performed in order to understand how to induce drought tolerance.

In order to study the effects of drought and abscisic acid on physiological and biochemical characteristics of Lavandula angustifolia cv. Organic Munstead, a pot experiment was conducted as factorial based on randomized complete block design with three replications at Plant Production faculty of Gorgan University of Agricultural Sciences and Natural Resources, during growing season of 2017-18. The first factor was irrigation regimes in four levels (30-40, 50-60, 70-80 and 90-100% field capacity) and the second factor was abscisic acid spry including three levels (0, 15 and 30 µM/L). Traits evaluated were wet and dry weight and leaf area index, total phenol, total flavonoid, DPPH antioxidant activity, proline, carotenoid, RWC and soluble carbohydrate.

The results showed that drought increase phenol (151.42 mg/g) and carotenoid (46.32 mg/g) compared to control. Abscisic acid had significant effect on all traits except of phenol and carotenoid. Also interaction effect of drought and abscisic acid was significant for all traits except of phenol and carotenoid content that were the highest in abscisic acid 30 µM/L and drought 30-40 and 50-60 percent field capacity increase antioxidant activity 47.56 and 53.93 percent and 55.20 and 65.72 percent soluble carbohydrate, respectively. abscisic acid 30 µM/L spray and drought 30-40 increase proline 120.17 percent. Also, the highest RWC amount (78.74 percent) from interaction abscisic acid 30 µM/L and drought 90-100 percent field capacity.

Generally, abscisic acid 30 µM/L application and drought 30-40 and 50-60% field capacity Introduces the best treatment, due to the lower consumption of water and the use of abscisic acid in stress conditions, higher levels of abscisic acid can be achieved in inducing drought tolerance.

Greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), is a serious pest of a wide range of plants, such as common bean, cucumber, tomato, pepper, lettuce, etc, in both field and greenhouse production. It typically feeds on the underside of leaves, sucking phloem sap from the plant, which causes both direct damage, by overall weakening the plant and reducing yield, and indirect damage, by excreting honeydew, on which sooty mold grows, as well as transmission of several plant viruses. The widespread use of insecticides to control T. vaporariorum has resulted in developing resistance to the insecticides and affected human’s health and safety. The utilization of plant extract and elicitors is an environmentally safe method that is used in the control recently. Therefore, alternative control strategies are required to minimize the harmful effects of insecticides. In order to control this pest, environmentally friendly methods, especially of plant origin are recently considered by researchers. For this regard, the effect of some organic compounds including methanolic and n-hexanic extract of walnut’s husk or dill’s seeds and salicylic acid, individually and in combination with spirotetramat on population density of greenhouse whitefly’s nymphs and some secondary compounds of bean plant were investigated.
Seeds of common bean, Phaseolus vulgaris L. (Berloty cultivar) were sown and grown in 15-cm-plastic pots in a greenhouse at 25 ± 3°C, 50 ± 10% RH, and a natural photoperiod. For the experiments, potted bean plants at 6-8 leaf stage, highly infested with T. vaporariorum nymphs, were sprayed with 12 different treatments, including: (1) spirotetramat (SP), (2) methanolic extract of walnut husk (MW), (3) n-hexanic extract of walnut husk (NW), (4) methanolic extract of dill seed (MD), (5) n-hexanic extract of dill seed (ND, (6) salicylic acid (SA), (7) spirotetramat in combination with salicylic acid (SP+SA), (8) spirotetramat in combination with methanolic extract of dill seed (SP+MD), (9) spirotetramat in combination with methanolic extract of walnut husk (SP+MW), (10) spirotetramat in combination with n-hexanic extract of dill seed (SP+ND), (11) spirotetramat in combination with n-hexanic extract of walnut husk (SP+NW), and (12) water as a control (CO). After five days, the population density of T. vaporariorum nymphs on bean plants leaves was recorded. Furthermore, the effects of tested treatments on the total phenol and flavonoid contents of bean plants were evaluated. For this reason, dried leaves (5 g) from each treatment were used for the preparation of extracts. The total phenolic of the extracts were determined using the Folin - Ciocalteu reagent. Sample and standard readings were made using a spectrophotometer (Lambda 45-UV/Visible) at 765 nm against the reagent blank. Furthermore, the aluminum chloride colorimetric method was used for determination of the total flavonoid content of treatments. For total flavonoid determination, quercetin was used to make the standard calibration curve. The absorbance was read using a spectrophotometer (Lambda 45-UV/Visible) in the wavelengths of 415 nm. Data were analyzed by one-way ANOVA using SPSS 23.0 software. Comparison of means for nymph density using SNK (Student-Newman-Keuls) multi-range test and comparison of means for secondary chemical compositions using Tukey's test at probability level five Percentage occurred.
Results showed that the population density of greenhouse whitefly and the secondary metabolites of plant were significantly affected by the tested treatments. The lowest number of whitefly’s nymphs was on spirotetramat and spirotetramat in combination with methanolic extract of dill seed and the highest number was on control. Total phenolic contents ranged from 58.96 to 114.07 mg g-1 dry weight on different treatments, which the highest and lowest amount of it was obtained in spirotetramat in combination with methanolic extract of dill seed and spirotetramat in combination with n-hexanic extract of walnut husk, respectively. The highest amount of total flavonoid content of bean plants was in spirotetramat in combination with salicylic acid. The results of the present study showed that the density of greenhouse whitefly population in spirotetramate treatment was lower than other treatments but there was no significant difference with the combined treatments and methanolic extract of walnut husk. Also, all the treatments compared to the control significantly changed the population density of this pest and increased the amount of total phenolic compound in bean plant. Therefore, these compounds, especially the methanolic extract of walnut husk, can be used in integrated management programs of this pest.
This research could provide valuable information for control of T. vaporariorum in other plants like ornamental plants in the field and greenhouse and thus can be useful for the production of healthy and organic crops. So it can be used in the IPM programs of this pest.

In order to study the effect of foliar application of humic acid on the yield, yield components, and some physiological and phytochemical properties of Stevia rebaudiana under different irrigation regimes, a factorial experiment was conducted based on a randomized complete block design with three replications in the research campus of University of Agricultural Sciences and Natural Resources, Gorgan, Iran. The treatments included four levels of irrigation regimes (70, 85, 100 (control), and 115% of field capacity) and humic acid foliar application at four concentrations (zero, 250, 500, and 750 mg/L). Irrigation regimes and humic acid treatments started from the 10-leaf stage and continued until the flowering stage. At full flowering stage, data collected for shoot and root length, root diameter, shoot and biomass fresh and dry weights, number of sub branches, flowers number, internodes number, leaves number, leaf area, root antioxidant activities, total phenol, total flavonoid, proline, ion linkage, and leaf relative water content. According to the results, the effect of different irrigation regimes on shoot height, shoot and biomass fresh and dry weights, sub-branches number, internodes number, was significant (p<0.01). By flooding, the plant height, shoot and biomass fresh and dry weights were increased. The interaction effect of drought stress by humic acid was significant for plant height, root antioxidant activity, and proline. Low irrigation stress had negative effect on the growth traits but humic acid foliar application had moderated the negative effects caused by low irrigation stress. Therefore, based on the findings, it was concluded that stevia is a resistant plant to both flooding and drought stress and its resistance mechanisms to drought stress for maintaining vegetative yield components, are to increase osmolytes and phenolic compounds.

Stevia is a valuable medicinal plant. However, after the introduction of this plant as a natural sweetener without calories, rose to fame in the world. Recent years with the increasing number of patients with diabetes and obesity problems in Iran as well as favorable conditions for growing this plant in the country, demand for use of the plant has been increased. Important step after medicinal plant cultivation is proper planning for its processing and packaging. The aim of this study was to evaluate the effect of growing region and type of packaging on the biochemical compounds is Stevia plant.

A research was designed concerning the effect of growing region and the type of packaging, on the stevia dried leaves quality, based on the completely randomized factorial design with four replications. For this purpose, leaf samples collected from both Gorgan and Aghghala, two wet and semiarid lands, respectively. The harvested leaves were dried under shad conditions. Dried leaves were kept for three months in different packages including glass, plastic, paper and foam materials. Finally, the visual quality of samples and the variation of chemical compounds were investigated and the measured traits including total phenol (Folin Ciocalteau), total flavonoids the colorimetric method using aluminum chloride, antioxidant activity (DPPH), total sugar and reduced sugar (Fehling).

Analysis of variance showed that the highest antioxidant activity as well as the highest total sugar content was observed in the leaves of Aghghala area. This difference was statistically significant compared to Gorgan. Total phenols, flavonoids and reduced sugar were not affected by growing region. The highest antioxidant activity was observed in the samples stored in glass. The highest reducing sugar accumulation was observed in the samples which were stored in paper and plastic bags. The amount of reducing sugar in the paper and plastic packages was in the in its highest value. The investigated packages did not show significant difference in the total phenol and flavonoid contents as well as total sugar. The interaction effect between growing region and packaging type on the antioxidant activity, total sugar and reduced sugar showed a significant difference. As the plant samples collected from Aghghala region in which packaged in glass showed the highest antioxidant activity.

According to the results, stevia which gathered from Aghghala region biochemically was more potent than the plants which were cultivated in Gorgan. It has been showed that dried leaves of stevia which were stored in glass had the highest antioxidant activity. Thus it recommended that, for long term storage especially for home usage, the dried leaves of stevia stored in glass containers.

The aim of this study is to determine the total phenol and flavonoid content and antioxidant activity of hydroalcoholic extracts from different parts of pumpkin (skin, seed and flesh). The maximum extract production was obtained for flesh (27.83 g extract/100 g powder) while the lowest yield obtained from the seed extract (6.30 g extract/100 g powder). For seed extract, the highest amount of total phenol (25.80 ± 0.69 mg (GAE)/g extract) and flavonoid content (7.24 ± 0.28 mg(QE)/g extract) obtained respectively through the assay of Folin Ciocalteu and aluminum calorimetric and the best antioxidant activity was gained through antioxidant  assays of DPPH (IC50=794.32µg/ml) and β-carotene bleaching (at a dose of 2000 µg/ml it was equivalent to synthetic antioxidant BHA in the concentration of 200 µg/ml). Based on the results of oxidative stability index (OSI) for extracts, the skin extract showed the highest stability (8.58 ± 0.55 h) and no significant difference was observed between the seed and fruit extracts (7.13 ± 0.168 h and 7.33 ± 0.08 h, respectively). The results suggested that hydroalcoholic extracts of various parts of the pumpkin’s fruit, especially its seeds, may serve as a potential source of natural antioxidant for food and pharmaceutical products.

number of sub leaves (leaves on sub-branches), number of internodes on main stems, number of lateral stems, spike length on the main panicle, number of spikes, number of flowers per panicle, fresh and dry weight of aerial parts, fresh and dry weight of roots, root length, leaf area, internode length, total phenol content, total flavonoids content, antioxidant activity, total sugar content and chlorophyll quality were measured. The results of the analysis of variance showed that the studied treatments had a significant effect on all traits except the number of main leaves, the number of internodes on main stems, and root length. The means comparison showed that with increasing the concentration and period of colchicine application, height of aerial parts, internode length, the number of flowers per panicle, and total sugar content decreased and spike length on the main panicle and total phenol content increased. Based on the results of flow cytometric analysis, the mean genome size was 0.73 pg in plants treated with colchicine at a concentration of 0.4% for 48 hours, while the mean genome size in the control plants was 0.55 pg. Plants in other treatments showed a mean genome size of 0.57. In general, the results of this experiment showed a positive response of L. stricta to colchicine for the induction of polyploidy and the possibility of using this method in the future breeding of this plant.

Mullein (Verbascum L.) is a biennial herbaceous medicinal plant belonging to the Scrophulariaceae family. The flowers of this plant are used to treat respiratory disorders. In this study, the genetic diversity of different mullein species from different regions of West Azerbaijan province was investigated based on some phytochemical markers to domesticate this valuable plant. Phytochemical diversity among different species of mullein was evaluated based on the content of carotenoid, beta-carotene, total phenol, total flavonoid, and antioxidant activity (by FRAP and DPPH methods), and identification of phenolic compounds (gallic acid, caffeic acid, chlorogenic acid, rutin, coumaric acid, quercetin, cinnamic acid, and apigenin) by HPLC in leaf. The results showed that all phytochemical characteristics studied were significantly different among species (P<0.01). The highest content of carotenoid (76.27 mg g-1 DW), beta-carotene (5.88 mg 100g-1 DW), total phenol (32.83 mg GAE g-1 DW), total flavonoid (7.13 mg QE g-1 DW) and antioxidant activity by DPPH method (34.66 µg AA mL-1) was observed in V. sinuatum. The results showed that V. erianthum leaves had the highest content of chlorogenic acid, quercetin, cinnamic acid, and apigenin, while the highest content of gallic acid and caffeic acid was observed in V. saccatum. In general, the findings of this research showed that there was a wide variation of mullein species in West Azerbaijan province. Species V. erianthum and V. saccatum had unique phytochemical properties that can be used to design breeding programs and use them in the pharmaceutical industry.

In this study, loquat leaf from Gilan province was analyzed in terms of fatty acids profile, total phenol content, total flavonoids, total tannin, antioxidant activity, type and amount of polyphenol content. Results showed the maximum amounts of unsaturated fatty acids of loquat leaf belonged to linolenic acid (25.3 ± 0.15%), oleic acid (18 ± 0.01%) and linolenic acid (9.7 ± 0.15%), respectively. Total phenol content and total tannin of leaf extract of loquat were, respectively, obtained 171.45 ± 0.55, 3.41 ± 0.22 mg gallic acid/ g dry matter. Total flavonoid content was obtained 790.4 ± 0.86 mg quercetin per g dry matter and antioxidant activity was 92.11 ± 1.10%. According to high-pressure liquid chromatography (HPLC), caffeic acid had the highest amount of polyphenol compound detected in loquat leaf. Loquat leaf can be consumed as a rich source of antioxidant (such as herbal drink).

Coltsfoot (Tussilago farfara L.) from Asteraceae family is a perennial plant. T. farfara is native and widespread from Europe to Western and Northern Asia and North Africa. Coltsfoot distributed in wet mountainous regions of Iran, such as Azerbaijan, Tehran and Northern provinces. Its flowers and leaves have been used traditionally for the treatment of cough, bronchitis and phlegm disorders. T. farfara leaves and flowers have expectorant activity and are used for chronic dry cough and various pulmonary diseases. The extracts of T. farfara were shown to exhibit various activities, such as antioxidant and antimicrobial activity. Biologically active agents of T. farfara have been studied due to their antimicrobial and antioxidant characteristics.

For morphological study, the rhizomes of seven Iranian coltsfoot populations were collected in August 2016 from different regions of Iran including Pol-e zangholeh, Damavand, Firoozkooh, Nur, Deylaman, Kaleybar and Namin. The collected samples were planted in the same condition during 2016-2017 in research field of Tarbiat Modares University in Tehran (51º10ʹ23ʺ N, 35º44ʹ17ʺ E), with a randomized complete block design experiment and three replications. The average annual rainfall and temperature of cultivating place is about 220 mm and 16.4 ºC. In order to study the morphological characteristics between different samples, traits such as the number of flowers per plant, stem height, flower length, flower diameter, flower dry weight, root length, root dry weight, leaf area and leaf dry weight had been measured. Morphological traits were measured under the same conditions and for this research, were used ruler, caliper and balance. The leaves and flowers were prepared for phytochemical studies. DPPH method has been used to evaluate the antioxidant activity, and the IC50 was used to compare the antioxidant properties. The absorbance of the samples was measured at 517 nm with ELISA reader. The radical scavenging capacity (RSC) was calculated by the following formula: % In=[(Ab-As)/Ab]×100, where In is DPPH inhibition, Ab is the absorbance of the blank, As is the absorbance of samples including extracts and BHT as a positive control. The phenolic contents of different extracts were determined by Folin-Ciocalteu method and the aluminum chloride method was used to measure total flavonoid.

Analysis of variance showed that there is a significant difference between all evaluated traits in studied populations (p ≤0.01). Pol-e zangholeh population of T. farfara, has shown the best performance for all morphological traits. The results of the flowers per plant showed that the Pol-e zangholeh population was the highest and the Deylaman population had the lowest number of flowers. The maximum length of the stem was related to the Pol-e zangholeh population while the population of Namin had the smallest amount. Comparison of flower diameter showed that the Pol-e zangholeh population had the largest diameter and Nur population of all the smaller. The results of the flower length showed that the maximum flower length was related to the Pol-e zangholeh population and Deylaman population had the smallest amount of flower length. Comparison of mean of flower dry weight showed that the Pol-e zangholeh population of T. farfara had the highest value while the population of Nur had the smallest amount. Pol-e zangholeh population of T. farfara, considered as superior populations and its flowering time were earlier than the others. It was found that there is a significant difference (p ≤0.01) between different populations. This variation may be due to Population differences of People, either due to differences in environmental conditions or sometimes due to the interaction of the population and the environment. Our results also indicate the presence of comparable genetic potentials of T. farfara in these population for any further cultivar development. Analysis variance showed that there was significant difference between populations for total phenol, flavonoid and antioxidant activity (p ≤0.01) and the Nur population had the highest total phenolic content and highest antioxidant activity. Comparison of antioxidant activity of different extracts from leaves and flowers of T. farfara showed that the most antioxidant activity was related to leaf extract of Nur population with IC50 271 µg/ml closer to BHT (33 µg/ml) as a synthetic and industrial antioxidant. The least amount of this activity was related to Kaleybar leaf extract with IC50 888 µg/ml. Nur population showed the highest total phenol content with 242 mg GAE/g dried weight. Damavand population showed the highest total flavonoid content with 40 mg QE/g DW extract.

Our results indicate the presence of comparable potentials of T. farfara in these populations for any further cultivar development. Study of antioxidant activity in different habitats shows that Nur habitat is a suitable place for the cultivation of T. farfara to increase the amount of phenolic compounds and antioxidant activity.

Plums are highly perishable and deteriorate quickly during storage and shelf life. On the other hand the use of chemicals in postharvest technology of horticultural products is highly limited and it is necessary to introduce natural and safe methods to maintain the safety of food products. In this experiment, the effect of postharvest treatment with gamma aminobutyric acid (GABA) (at 0, 10 and 20 mM) and salicylic acid (at 0, 1 and 2 mM) during 16 and 34 days of storage at 1 ± 0.5 °C with 85 to 95% RH on some biochemical indices of plum fruit was studied. The study was carried out as a factorial completely randomized design with four replications. Biochemical indices including catalase enzyme activity, phenylalanine ammonia-lyase (PAL) enzymes activity, total phenolics and total flavonoid content were measured after 16 and 34 days of cold storage plus 24 H at 25 0C. Combination of GABA and salicylic acid significantly maintained fruit total phenolic and total flavonoid contents and enhanced PAL enzyme activity, and treatment with salicylic acid at 2 mM increased catalase enzyme activity in comparison to the control and other treatments. Overall, results revealed that the use of GABA and salicylic acid treatments can maintain the quality of "Shablon" plum fruit during cold storage.

To evaluate dry matter yield and phytochemical properties of two years old purple coneflower [Echinacea purpurea (L.) Moench] flower in intercropping with green beans and different summer time planting dates, a randomized complete block design in split plot arrangement with three replications was conducted in Research Farm of Genetics and Agricultural Biotechnology Institute of Tabarestan in 2012-2013. Treatments included planting arrangements [coneflower and green bean monoculture, replacement intercropping planting with patterns of 1:1 and 2:2 ratio of coneflower: green beans], planting dates (June 30, July 30 and August 29), and cultivation of green beans in the spring of 2012 coincided with the emergence of coneflower.Results of the experiment showed that planting date of June 30 increased dry matter, caffeic acid derivates, total phenol and flavonoid contents of flower. Among the intercropping planting arrangements, patterns of 2:2 ratio of coneflower: green beans, increased flower dry matter. While the highest amount of cichoric acid, chlorogenic acid and echinacoside (29.3, 2.4 and 2.3 mg/g dry matter, respectively) were obtained in coneflower plants cultivated as sole crop. The maximum amount of total phenol and flavonoid contents of flower were detected in coneflower plants cultivated in June 30 and sole cropping pattern. Overall, it can be concluded that if the aim of cultivation of this plant is increasing production of caffeic acid derivatives, sole cropping is better than mixed cropping. However, for dry matter improvement, mixed cropping has more advantages. In addition, early cultivation of the crop is more suitable for caffeic acid derivatives and dry matter production than delayed planting.

In order to evaluate the effect of Benzyl Adenine (BA) on qualitative characteristics and shelf life of plum fruits CV “Gold Drops”, an experiment was conducted as a factorial based on randomized complete block design with three replications. In this experiment different concentrations of BA (0, 50, 75, 100 and 125 mg L-1) were applied as a foliar application. After harvesting, fruits were stored at 0.5-1 °C and 90% relative humidity for 6 weeks. Fruit characteristics including weight loss, firmness, titratable acidity, soluble solids, pH, ascorbic acid, antioxidant capacity, phenolic and total flavonoid content, were measured once a week at Tabriz University, Tabriz, Iran. The results showed that effects of BA treatments and storage time were significant in all traits. The lowest percentage of weight loss was found at 125 mg L-1 BA in the first week of storage. The highest and lowest content of TSS were obtained at 125 mg L-1 BA during the six weeks of storage and control treatment in the first week, respectively. The amount of ascorbic acid gradually reduced during storage and the lowest content was found at the end of storage. The highest phenol content of fruit was occurred in 125 mg L-1 BA in the 2nd week and the lowest one in control at the 6th week of storage. According to these findings, BA spraying can bear positive effects on postharvest quality sustainment and shelf life of plum fruit.