جستجوی مقالات مرتبط با کلیدواژه "آنتی اکسیدان" در نشریات گروه "منابع طبیعی"

The use of immune stimulants has become popular such as synbiotics and rare elements such as selenium in farmed fish to increase the activity of non-specific defense mechanisms and enhance the resistance against diseases. so; this research was conducted to determine the effect of diet supplemented with organic selenium (Selenomethionine) and synbiotic Dipro+ individually and combined on antioxidant capacity, liver metabolic enzymes and liver histology in Salmo caspius. 540 pieces of Caspian Sea salmon fry with an average weight of 66.34 ± 1.45 grams (reproduction of 2018) were prepared. After adapting to the experimental conditions, the fish was randomly distributed in 27 tanks. This experiment was conducted in the form of a completely randomized design under 8 experimental treatments and a control group (each with 3 repetitions) for 60 days. Experimental treatments include: 2 grams of synbiotics per kilogram of diet (treatment 1), 3 grams of synbiotics per kilogram of diet (treatment 2), 2 milligrams of organic selenium per kilogram of diet (treatment 3), 4 milligrams of synbiotics per kg of diet (treatment 4), 2 grams of synbiotic and 2 mg of organic selenium per kg of diet (treatment 5), 2 grams of synbiotic and 4 mg of organic selenium per kg of diet (treatment 6), 3 1 gram of synbiotic and 2 mg of organic selenium per kg of diet (treatment 7), 3 grams of synbiotic and 4 mg of organic selenium per kg of diet (treatment 8). At the end of the trial, in order to check the activity of liver enzymes (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase) and serum antioxidants (catalase, glutathione, total antioxidant capacity, glutathione peroxidase, superoxide desmutase, malondialdehyde) sampling was done from the artery or vein of the caudal region or by cutting the caudal stem. Also, in order to measure liver damage sampling was taken from liver. The results showed that there was a significant difference between the control group and the treatments fed with experimental diets in the amount of liver enzymes including: alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase (P < 0.05). So that the highest amount of these enzymes was observed in the control group. Based on the results, it was observed that the lowest amount of antioxidant enzymes including: superoxide dismutase, total antioxidant capacity, glutathione peroxidase, glutathione and catalase and the highest amount of malondialdehyde was significantly observed in the control group (P < 0.05). The histological study of the liver showed the organic selenium and synbiotic DPro+, separately or together, caused changes in the liver tissue, which in some cases caused damage. In general, the results showed that the combination of synbiotic Dpro+ and organic selenium could reduce liver damage and is recommended as a feed additive in the diet of Caspian salmon.

In order to investigate the effect of planting date on germination characteristics and biochemical activity of seed in different quinoa genotypes, an experiment was conducted in the Research Laboratory of Seed Physiology and Biotechnology of the Faculty of Agricultural Sciences at University of Guilan in 2019. The experiment was performed as a split plot in the form of a Randomized Complete Block Design in three replications. The seeds of three genotypes T, R and Q29 were planted on six planting dates: 15 January, 15 February, 15 March, 15 February, 15 May and 15 June in the research farm of Karaj Seedling and Seed Breeding Research Institute. The harvested seeds from the treatments available in the field were transferred to the laboratory in order to investigate seed germination characteristics and vigour, and were measured germination percentage and rate, length and weight of the seedling, length and weight index of the seed vigour, electrical conductivity of the seed solution, and biochemical characteristics of soluble protein content, malondialdehyde content, alpha amylase, catalase and peroxidase enzyme activity. The interaction of two factors was significant on germination percentage, germination rate, number of abnormal seedlings, activity of alpha-amylase, catalase, peroxidase and superoxide dismutase enzymes, soluble protein content, malondialdehyde content and electrical conductivity of seed solution. The three planting dates of 15 January, 15 February, 15 March in Q29 genotype showed the highest percentage, germination rate, alpha-amylase enzyme activity and the highest number of abnormal seedlings.

This study was performed to investigate the antimicrobial properties of Centella asiatica L. extract in the northern part of the country using the antimicrobial effects of hydroethanolic extract on Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Streptococcus Mutans and Aspergillus flavus and Candida albicans, as well as investigating free radical scavenging activities of DPPH, Total phenol and flavonoids were performed. The plant was collected from Shaft city in Gilan province and the extraction process was performed by Maceration method and distributed by solvent rotary apparatus and for the experiments, the antimicrobial and antioxidant activity in the extract increased with increasing concentration. Staphylococcus aureus and Aspergillus flavus had the most susceptible to plate water extract with minimum inhibitory and Bactericidal concentrations of 100 and 200 μg/ml. The average total phenol in the extract of this plant was equal to 1.469 mg GAE/g EXT and the average flavonoid was equal to 2.679 mg QE/g EXT of the medicinal plant dish water. In the study of free radical scavenging DPPH, concentrations of 400 μg / ml with an average of 94.89% and concentrations of 6.25 μg / ml with an average of 42.01% had the highest and lowest percentages of free radical scavenging, respectively.

The Calotropis procera Aiton plant is a valuable and effective medicinal species used to treat various diseases, including as an anti-carminative and for indigestion, as well as for anticancer and anticonvulsant treatments. This species naturally inhabits fragmented habitats in southern Iran, particularly near the coasts of the Persian Gulf and the Oman Sea, in the arid and semi-arid regions of Sistan and Baluchistan, Khuzestan, Bushehr, and Hormozgan. On the other hand, due to the discovery of adverse effects caused by chemical drugs, people have turned their attention towards using medicinal plants. The health of agricultural products, especially medicinal plants, has special importance. The symbiosis of plants with mycorrhiza can be lead to improve of the root development and will affect on the absorption of water and nutrients. Aim of this study was investigate the effects of symbiosis between C. procera Aiton. with three different species of mycorrhizal on some phytochemical and antioxidant activity, and content of potassium, phosphorus, and sodium in shoots of C. procera Aiton. This research was conducted in the greenhouse of the Horticultural Science Department, University of Zabol, Zabol, Iran. Transplants were cultured in the soil medium in pot condition. This experiment was carried out in a completely randomized design with four treatments include inoculation with three different mycorrhizal fungi (Glomus intraradicese, Glomus fasiculatum, and Glomus mosseae) and control (without inoculation) and three replicate.  Meusered indices were assessed 8 weeks after transplanting. Measured parameters include; growth indices such as fresh and dry weight of root and shoot, and phytochemical indices are chlorophyll a and b, Carotenoid, phenol, flavonoid, antioxidant activity, protein, and concentration of potassium, phosphorus, and sodium in shoots. Data were analyzed by ANOVA test using JMP, and means were compared using the LSD test at P˂0.01. The results of variance analysis were shown significant effects of mycorrhizal symbiosis on all investigated indices (P ≤ 0.01). Also, means comparison shows a significant difference between the effects of different mycorrhiza species. The highest content of chlorophyll a and carotenoid was obtained in symbiosis with G. mossae, and the highest content of chlorophyll b existed in symbiosis with G. fasiculatum and G. intraradicese. In this regard, it has been found that mycorrhizal symbiosis leads to an increase in water absorption, and an improvement in the absorption of nutrients by the plant, thereby leading to an increase in chlorophyll synthesis enzymes activity. symbiosis of G. fasiculatum had the highest effects on increasing phenol and antioxidant activity. increase in antioxidant activity leading to strong suppression of reactive oxygen species, which ultimately increases the remedial capability of C. procera Aiton. The highest amount of flavonoid was observed in the condition of symbiosis with G. intraradicese and G. fasiculatum, and the highest content of protein was observed in condition of symbiosis with G. fasiculatum and G. mossae. Symbiosis with the G. intraradicese significantly increased the concentration of potassium and phosphorus in shoots of C. procera Aiton, while symbiosis with G. mossae causes to a significant increase in sodium concentration. Generally, the results of the current study were shown that symbiosis with G. fasiculatum and G. intraradicese are more useful than symbiosis with G. mossae. The symbiosis of plants with mycorrhiza fungi increases the volume and length of their roots, as a result of which the roots have more contact with the soil, and the amount of water and nutrient absorption from the soil increases. results of the current study demonstrate that the phytochemical, antioxidant activity, and concentration of potassium and phosphorus and sodium have differed among extract and shoots related to symbiosis of C. procera Aiton and species of fungi. And symbiosis with G. fasiculatum had the greatest effect in increasing the production of secondary metabolites.

This research was conducted in order to investigate the effect of aqueous extract of different organs of Zygophyllum eurypterum on the growth and germination indices of Triticum aestivum and Acroptilon repens. The test treatments included aqueous extracts of Zygophyllum in concentrations of 5,10 and 15% of roots, aerial organs and control. The results showed that with increasing extract concentration, the growth traits and total chlorophyll of both investigated plants significantly decreased. In such a way that the highest and lowest inhibition rates were associated with 15%aerial organs extract and 5%root extract, respectively, but the antioxidant activity of Wheat and Acroptilon increased with increasing levels of root and stem extract of Zygophyllum. The highest level of aerial organs Zygophyllum in Wheat reduced the germination rate by 77.12% compared to the control. However, the germination of Acroptilon seeds completely stopped at the levels of 10 and 15% of aerial organs. By increasing the aerial organs extract concentration to 15%; root length decreased by 49.2% and 52.9% in Acroptilon and in Wheat respectively. The highest amount of antioxidant activity was observed at the level of 15% of aerial organs in both plants, and among this, Acroptilon had more antioxidant activity with 70.32%. Most of the traits including germination percentage, root length and stem length,in Acroptilon weed, were more sensitive to the allelopathic effects of Zygophyllum extract compared to Wheat Based on the results the aerial organs extract of Zygophyllum were more capable to dealing with germination and seedling growth than the root extract.

Using of postharvest treatments in citrus fruit is important due to maintaining of antioxidant compounds during cold storage. In this study, Thomson and Moro fruits after coating (Polyethylene, Shine, Storage and Britex Ti waxes, Polyethylene pack, Tecto 60 fungicide and Control) were stored for three months in cold storage (5°C, 85 RH). Antioxidant compounds changes were evaluated with sampling each 30 days interval. The results showed total phenolics increased during 30 days of storage and then decreased, significantly. Pulp phenolics in both cultivars increased using Polyethylene pack and Storage wax than other treatments. Peel tissues of Moro variety which treated by Polyethylene, Shine and Storage waxes had higher levels of total carotenoid in the second month of storage. Thomson fruits that covered with Shine and Storage waxes had the highest and the lowest ascorbic acid, respectively. The amount of ascorbic acid in Moro fruits covered with Britex Ti decreased during storage. In the end of storage, just fruits coated by Shine wax had higher total anthocyanin, significantly. Based on the total antioxidant capacity, it was found that fruits treated with Storage, Britex Ti waxes, and Polyethylene pack had higher inner quality and antiradical potential during storage.

Pomegranate or nature’s power fruit is one of the most important fruits of the tropical regions of Iran, which is mostly grown in marginal areas with hot and dry summers and cold winters, usually with relatively salty water and soil. Too much heat causes burns and too much cold causes it to burst and reduces the softness of the skin and the quality of the fruit. Good Agricultural Practice (GAP) is a good guide to have good quality pomegranate harvest. This operation is a set of agricultural methods that lead to the production of a safe and desirable product by maintaining environmental, economic and social stability. On the other hand, pomegranate fruit contains a group of chemicals called phytoestrogens, which are structurally similar to human estrogen and have similar effects. Nowadays, in addition to consuming pomegranate as a fruit, its medicinal properties and its use in the food industry are also of interest to many researchers. For example, pomegranate seed oil is important for providing essential fatty acids and is a natural source of phytoestrogens and strong antioxidants (substances that prevent oxidation). Now, one of the important indicators of pomegranate buyers is the amount of phytoestrogens in it. Because every year, a lot of money is spent on making and buying estrogen supplements, while in many cases, such as strengthening the health of the heart and blood vessels, and issues related to hormonal disorders, this substance can be obtained from natural food sources. Adhering to good agricultural practices such as pay attention to the pre-harvest subjects like soil kind and harvesting characteristics of pomegranates can be produced pomegranates with a good quality, including phytoestrogenic compounds, which this article deals with.

In order to investigate The effect of priming and aging on the growth indicators and activity of antioxidant enzymes in hybrid maize single cross 704 a factorial experiment was conducted based on a completely randomized design at the University of Mohaghegh Ardabili in 2021 with 3 replications. Treatments were aging (control, 7 and 14 days) and priming (control, hydro-priming, priming by gibberellin (20 mg / l) and salicylic acid (100 mg / l)). The results showed that aging decreased growth indicators including Radicle Length (RL), Plumule Length (PL), Seedling Length (SL), Radicle Dry Weight (RDW), Plumule Dry Weight (PDW), Radicle Fresh Weight (RFW), Plumule Fresh Weight (PFW) Seed Length Vigor Index (SLVI) and Seed Weight Vigor Index (SLWI), but types of priming, especially priming with gibberellin improved these traits. As compared to the control, the catalase, superoxide dismutase, and glutathione reductase activities increased respectively by 73%, 63%, and 21% after gibberellin treatment and 14 days of aging. The highest amount of peroxidase enzyme activity (1.797 units mg-1 protein) was related to gibberellin priming. In general, gibberellin pretreatment increased fragile corn seeds' growth indicators and antioxidant enzymes activities, and it can be used to enhance.aging compared to the control showed an increase respectively about 73%, 63% and 21%. The highest amount of peroxidase enzyme activity (1.797 units mg-1 protein) was related to gibberellin priming. In general, using gibberellin pretreatment strengthened weak corn seeds growth indicators and antioxidant enzymes and the treatment can be used to increase weak seed vigor.

This research was conducted with the aim of investigating the effect of edible coating (aloe vera gel) on the quantitative, qualitative, sensory and microbial properties of nectarine. The variables include the type of coating in 6 levels (the sample without coating as a negative control, the sample treated with the fungicide imazalil as a positive control, concentrations of 1, 2, 3 and 4 g/l of aloe vera gel) and storage time at 5 levels (zero, 6, 12, 18 and 24 days after harvest). Fruit coating was done by immersion method. During the storage period, chemical , physicaland antioxidant properties were measured. The sensory attributes (color, smell, texture and overall quality) and microbial contamination (total count and total number of mold and yeast) of different samples were evaluated at the end of the storage time. The results showed that during the cold storage time, the red-green color value, the amount of weight loss and the percentage of TSS increased, and the amount of TA, tissue firmness, TPC and DPPHsc decreased. The amount of TPC and antioxidant capacity was higher in samples with higher concentration coating. In the samples with higher concentration of aloe vera, the destruction of ascorbic acid and microbial contamination was less. Also, according to sensory evaluators, coated samples had a higher score. Therefore, it seems that the use of aloe vera coating has a good ability to maintain the quality of the nectarine fruit and can be considered as a healthy and effective treatment.

This research was conducted in order to investigate the effect of aqueous extract of different organs of harmel (Peganum harmala) on the growth and germination of Amaranthus retroflexus and Chenopodium album in two experiments (laboratory and greenhouse) respectively, based on CRD with three replications and RCBD with four replications. The treatments included aqueous harmel extracts in concentrations of 10% and 20% root, 10% and 20% Aerial organ and control. with increasing extract concentration, the growth traits and total chlorophyll of both plants decreased significantly. The highest and lowest levels of inhibition rates were associated with 20% stem extract and 10% root extract, respectively, but total soluble sugars and antioxidant activity of weeds increased with increasing levels of harmel root and stem extract. shoot extract decreased the germination speed in Chenopodium and Amaranthus by 87.35% and 91.22%, respectively, compared to the control. In Amaranthus the length index of the plant by 63.33% and 96.67% respectively. the highest root and shoot concentrations (20%) decreased. The length of root by 50.49 and 86.94%, In Amaranthus and 47.87 and 81.80% in Chenopodium compared to the control. The highest total soluble sugar was observed at the level of 20% of the stem, and Amaranthus had more total soluble sugar with an increase of 64.9% compared to the control. Most traits in Amaranthus were more sensitive to the allelopathic effects of harmel compared to Chenopodium. extract of shoot was stronger than the root extract, which can be used in the preparation of herbicides with natural sources.

The cultivation of quinoa (Chenopodium quinoa Willd), an annual plant with high nutritional and economic significance, is expanding throughout the world. Quinoa is a traditional Andean seed crop highly tolerant to abiotic stresses. Since most seed crop cultivars are sensitive to drought stress, quinoa is regarded as a valuable candidate for the plant's exposure to harsh environmental conditions. Due to the importance of quinoa in arid regions, the effects of seed priming on yield and certain morphological and physiological traits were investigated in this study.

A factorial split-plot experiment based on a randomized complete block was designed with four replications was conducted in 2019 at Damghan Research Farm Station. The experimental treatments included drought stress based on the plant's water requirement at three levels (100% (control), 75%, and 50%) as the main factor, and sub-factors included three cultivars (Titicaca, Q26, and Q29) as well as priming at two levels (no priming and hydropriming) as a factorial experiment into sub-levels. To perform water requirement (WR) treatment, WR were calculated using the CROPWAT program and then applied to the 6-leaf stage plants.

The results demonstrated that drought stress (50% WR) reduced  relative leaf water content (13.1%), leaf membrane stability index (21.2%), chlorophyll content (38.7%), 1000-seed weight (18.2%), number of panicles per plant (27.5%), number of seeds per panicle (7.71%), and seed yield (40.4%). The use of hydropriming increased the membrane stability index, leaf chlorophyll content, 1000-seed weight, and the number of panicles per plant. Under 50% WR, the activity of antioxidant enzymes such as catalase and leaf ascorbate peroxidase increased by 139.58 and 42.55 percent, respectively, compared to the control. Additionally, drought stress increased quinoa seed protein content and decreased seed yield.. The percentage of seed yield reduction in drought stress was 50% and 75% of WR and was lower in Titicaca than the other two cultivars.  The comparison of the mean of irrigation interactions in the cultivars revealed that 100% WR produced the maximum quantities of Chl a, Chl b, and carotenoids in all three cultivars. Additionally, seed priming boosted the Chl a, and Chl b concentrations in Titicaca and Q26. Furthermore, the highest biological yield in the Damghan region was achieved in Q26 with 100% WR. Under normal irrigation conditions, Q26 cultivar had the highest seed yield, whereas under drought stress conditions, the seed yield of all cultivars decreased significantly. Nevertheless, this decline in the Titicaca cultivar was 12% less than in Q26 and Q29. The findings of the mean comparison revealed that priming improved seed yield in all three cultivars, with the Q29 cultivar producing the maximum seed yield at 1,452.03 kg/ha.

In general, Titicaca cultivar was more resistant to drought stress than other cultivars, hence its cultivation is encouraged in the Damghan region. Within the scope of this study, the use of hydropriming to improve quinoa's physiological features in conditions of drought stress is suggested. In conclusion, the results demonstrated that seed priming significantly increased seed yield, biological yield, leaf area index, and chlorophyll content in drought-stressed quinoa cultivars. These results indicated that seed priming can play a significant role in enhancing quinoa's drought resistance under low irrigation conditions. This study could contribute to the understanding of seed priming effects, which could be applied as an effective strategy to mitigate the negative effects of drought stress on quinoa cultivars.

This study was conducted to investigate the effect of mulch application from organic matter residues in forest area, rice fields, tea and peanut orchards and irrigation water deficit on different morpho-physiological and biochemical characteristics of forage sorghum in field conditions. This research was carried out as a factorial experiment in a randomized complete block design with three replications in selected research farms in Deilman area of Siahkal city under the supervision of Tarbiat Modares University, Department of Agronomy and Lahijan Agricultural Jihad Extension Experts in 2018. Factorial combinations of three levels of water deficit stress 15%, 30% and 45% of less than FC and six organic mulch, no mulch, rice straw mulch, paddy rice husk mulch, peanut shell mulch, tea waste mulch and leaf mold mulch were used. The results showed that under moderate stress conditions, rice straw mulch and rice paddy husk treatment showed the highest forage yield and plant photosynthesis rate of 39.13 and 26.65%, respectively, compared to the control treatment. Also, under conditions of severe stress, rice straw mulch, rice paddy husk and peanut shell mulch increased the economic efficiency of water and dry weight of weeds by 63.48, 55.21 and 46.40%, respectively, compared to the control. Application of organic matter mulch, especially rice straw, rice paddy husk and peanut shell mulch, prevented a reduction of 6.08, 13.70 and 16.75% of grain yield compared to the control under moderate stress conditions, respectively. In general, organic matter mulch has a high ability to increase grain and forage yield, photosynthetic rate, antioxidant activity and economic efficiency of water, as well as reduce field weeds in stress conditions and make a significant contribution to improving drought resistance in Forage Sorghum. Finally, the use of organic matter mulch in the cultivation of forage sorghum under seasonal drought stress conditions is recommended.

Pomegranate (Punica granatum L.) is one of the most important native sub-tropical fruits in Iran. Because high economic importance of the pomegranates, it is very important to maintain the fruit quality after harvest. In this research, the effects of post-harvest treatment with calcium chloride and Nano packaging on physicochemical properties of pomegranate fruit including aril and seed weight, peel color, pH, total soluble solids, vitamin C, antioxidant activity, anthocyanin and total phenolics content of Shishe kab pomegranate were studied in a factorial completely randomized design with four replications. The first factor was immersion in calcium chloride at different concentrations (0, 0.5, 1 and 2%) and the second factor was a Dekco Nano-based polyethylene packaging with non-packaging as control. After two months of storage at 5 ±1˚С, the results showed a reduction in aril weight in control, but it was not decreased in CaCl2 treated fruit. Moreover, CaCl2 decreased the pH, and enhanced the peel color indices and antioxidant activity of the fruit. The highest antioxidant activity and color index was observed in fruit treated with 2% and 0.5 % CaCl2, respectively. The highest amounts of vitamin C content (8700 mg/ 100gr fresh weight) and anthocyanins (377 mg/L) were observed in fruit treated with 2 and 0.5% CaCl2, respectively. The interaction effects of of calcium chloride and nano packaging on the amount of total soluble solids was significant and the highest total soluble solids content was recorded in control fruit (17.40 brix).

In order to investigate the effects of selenium and nitrogen on some growth and biochemical characteristics of edible onion (Cultivar Yellow Isfahan), a factorial experiment was conducted base on randomized complete block design with three replications at Razi University in year 2017. In this experiment, the first factor includes the time of split of nitrogen fertilizer (based on soil test, which includes 500 kg urea per hectare) in six levels including control, total fertilization at the time of transplantation, half fertilization at the time of transplantation, third fertilization at the time of transplantation, half fertilization at the time of transplantation+ half fertilization at the time of bulb initiation, third fertilization at the time of transplantation+ third fertilization at the time of bulb initiation+ third fertilization at the time of bulb growth and three levels of selenium (0, 10 and 50 mg.L-1 sodium selenate). The highest yield (21.44 Kg.m-2), fresh weight (251.83 g.bulb-1), the bulb length (84.19 mm), bulb diameter (78.66 mm), total phenol (19.87 mg.g-1 FW: fresh weight), total phenol (19.87 mg.g-1 FW: fresh weight), total flavonoid (9.30 mg.g-1 FW: fresh weight) and antioxidant activity (11.44 %) of the onion bulb were observed with nitrogen application of in three stages (third fertilization recommended at the time of transplantation+ third fertilization at the time of bulb initiation+ third fertilization at the time of bulb growth). Selenium had a positive effect on yield, fresh weight, length and diameter of bulb and total flavonoid in onion. Therefore, use of sodium selenate along with nitrogen plays an important role in improvement the growth and physiological characteristics of onion such as bulb dry weight (84.73 g.bulb-1) and nitrogen use efficiency (1 Kg.mg-1 DW: dry weight). In conclusion, split application of of 500 kg.ha-1 urea at the time transplantation, bulb initiation and bulb formation equally one third in each stage, and 50 mg.L-1 sodium selenate can be recommended for onion production.

The aim of this was to investigate the effect of high and low temperature stress on growth, photosynthesis and antioxidant changes in vegetative growth stage of tomato. Tomato plants which were grown in hydroponics system exposed to temperature stress at 40 ºC and 10 ºC compared with plants grown in the greenhouse at optimum temperature of 25±2 as control. All plants were transfer to optimum condition in the greenhouse after stress treatments and growth parameters were measured after 10 days. The results of the comparison between these three temperatures showed that the highest fresh weight of shoot was observed at control treatment. In high temperature stress conditions observed 56.7% decrease fresh weight compared to control treatment and in low temperature stress conditions observed 65.3 decrease. Similarly, fresh weight of root was highest in control treatment and heat stress 45% and low temperature stress 64.6% showed decrease compared to optimum temperature conditions. Root volume was reduced by temperature stress significantly and photosynthesis rate was the highest in control treatment and lowest under high temperature stress. In general, it can be stated that temperature stress in this study affected growth and photosynthetic traits more than antioxidant traits.

Nowadays, with the change in lifestyles and feeding habits of the people, the demand for safe ready to eat and high quality products is increasing. Due to the sensitivity of fresh cut products to decay extension, the use of modern technologies for maintaining the quality and shelf life of these products is necessary. In this study, the effect of chitosan nano emulsion in combination with salicylic acid, as an edible coating, to increase the shelf life of nectarin fresh cuts was studied. Nectarines fresh cut were coated with nano chitosan emulsion at 0.4 % and salicylic acid at 2 mM, and packed and stored at 0±1°Cwith 90 to 95% R.H for 16 days. Fruit quality indices including TSS, TA,pH, weight loss, total phenolics content and total antioxidant activity were evaluated at harvest and during storage. The results showed that the edible coating significantly affected fruit total soluble solids (TSS), titratable acidity (TA), pH, weight loss, total phenolics content and total antioxidant activity. This findings demonstrate the synergistic effects of salicylic acid and chitosan nano emulsions, as a safe method with no side effects of the chemicals, in increasing the shelf life and preserving the quality of fresh cut ‘Red Gold’nectarines.

The aim of this study was to evaluate the salt tolerance of two cultivars of fig (‘Kushki’ and ‘Rounou’) under in vitro conditions. Salinity treatment was performed using different concentrations of sodium chloride (0, 40, 80 and 120 mM). The results showed that salinity significantly reduced fresh and dry weight, shoot length and leaf number in both cultivars after three weeks’ treatment with sodium chloride. However, the decline was more in the ‘Kushki’. In both cultivars, the activity of antioxidant enzymes were increased with increase in the concentration of sodium chloride, and this increase was significantly higher in Kushki cultivar. The amount of sodium accumulation and Na+/K+ratio in leaves and roots of ‘Rounou’ was significantly higher than Kushki cultivar. At 120 mM concentration, all traits were significantly reduced. Seedlings of the two cultivars showed different responses for most of the evaluated traits. According to the results of this study, the Kushki cultivar was more tolerant than the Rounou cultivar to the salinity stress.

Secondary metabolites are a diverse group of molecules that help to compatibility of plants especially in face of stress. Flavonoids and anthocyanins are parts of these compounds. In this study, effect of manganese (concentration of 80 ppm) on enzymatic and non-enzymatic activity rates of cum, 18-21 days after germination, was measured at 4 different times of 0 (control), 24, 48, 72 and 92 hours after stress applying. All of the experiments were performed with 3 independent replications and completely randomized design. Analysis of variance and comparison of means were done using SAS after measurement of different concentrations. Due to manganese stress, content of total flavonoid and anthocyanin and activity of some antioxidant enzymes increased significantly compared to control, as the most enzymatic and non-enzymatic activity rates were observed 48 hours after stress applying. Guaiacol peroxides enzyme showed the most and the least activity rates 24 hours (88.24% higher than control) and 96 hours after stress, respectively. Total results showed that increased flavonoid and anthocyanin after stress applying were consequences of oxidative stress originating from manganese absorption and activation of plant antioxidant system.