جستجوی مقالات مرتبط با کلیدواژه "آنتی اکسیدانت" در نشریات گروه "زراعت"

Plants are exposed to various environmental stresses during growth and development under natural and agricultural conditions. Drought is one of the most severe abiotic stresses that greatly affects plant yield. Metabolic changes under stress cause the morphological and physiological changes in the plant which may eventually lead to reduced yield. Barley is one of the most important cereals which a large part of the human population in many parts of the world are dependent on it as a source of food and animal feed.

In order to investigate the effects of drought stress on some morphological and physiological traits in barley as one of the most important crop, this experiment was carried out in the greenhouse of the agriculture faculty, Ferdowsi University of Mashhad in 2019 in a factorial based on a randomized complete block design with three replications. Experimental factors were included: different levels of drought stress including 100% of field capacity (control or no stress), 80, 60 and 40% of field capacity and two barley cultivars containing semi-sensitive (Fajr30) and drought tolerant (Dasht). First, the seeds of both cultivars were planted in trays filled with coco peat, perlite and sand, and after two weeks, the seedlings were transferred to pots filled with garden soil. The pots were watered daily and after one month (4 to 6 leaf stage) until the end of the growing season, they were subjected to drought stress treatments. During the vegetative stage, morphological traits such as plant height (from crown to end of plant), stem diameter, number of leaves, number of tillers, leaf area and number of stomata below and above the leaf were examined using common methods. Physiological traits including proline, soluble sugars, photosynthetic pigments and antioxidant enzymes (catalase and peroxidase) were also measured. Analysis of variance was performed using JMP statistical software version 8 and the mean of treatments was compared using LSD test at the level of 5%.

The results of this experiment showed that the effect of cultivar and drought stress were significant for many of the studied traits. The highest plant height, stem diameter, number of leaves and tillers and leaf area index were observed in plants without stress (100% FC), which was significant compared to other stress level. Also, the comparison of the two cultivars showed that Dasht, as a drought tolerant cultivar, has more leaves and tillers but less leaf area and stomata than the semi-sensitive cultivar Fajr30. In other words, the tolerant cultivar produces more leaves but smaller under stress condition which finally reduces the leaf area compared to the sensitive cultivar. This can be a good solution for drought resistance through reduce evaporation from the leaf surface as well as shading. In addition, osmotic regulators such as proline and soluble sugars and the activity of antioxidant enzymes including catalase and peroxidase increased under drought stress and it was higher in tolerant cultivar. In fact, it seems that tolerant cultivar can tolerate drought stress through activating their immune system by producing osmoprotectant and increasing the activity of antioxidant enzymes.

In general, results showed that proline, soluble sugars and antioxidant enzymes play a role in the mechanism of stress tolerance and their metabolism is affected by drought stress. The results of this experiment suggest that the accumulation of these osmoprotectans and morphological changes can be part of the drought resistance mechanisms in the drought tolerant genotype of barley, which can ultimately be used in breeding programs to improve drought tolerance. In general, the results of this experiment showed that both barley cultivars responded to drought stress, but Dasht cultivar showed more tolerance in these conditions.

Safflower is a plant that has been considered due to its high medicinal and nutritional value, especially in the extraction of edible oils in developed countries. Drought is one of the most important harmful factors in arid and semi-arid regions of the world that affects plant production. Modifiers play an important role in plant adaptation to stress conditions. Among these compounds are the hormone gibberellic acid and the antioxidant ascorbic acid, which increase plant tolerance to adverse environmental conditions. The present study investigated the effect of gibberellic acid and ascorbic acid on seed germination parameters and some enzymatic indices of safflower under drought stress.

The experiment was conducted as a factorial based on a completely randomized design with three replications in the Agricultural Science Laboratory of Iranshahr University in 2020. Experimental treatments included three levels of control (pretreatment with distilled water), pretreatment with gibberellic acid and ascorbic acid, and four levels of drought stress (0, -3, -6, and -9 bar). Drought stress was applied using polyethylene glycol 6000. Seed germination was carried out inside a germinator at 25 ° C for 14 days in darkness. Germination traits and enzymatic indices were measured using standard methods.

The results of variance showed that most germination and growth indices of safflower seedlings decreased with increasing drought stress. Also, drought stress led to changes in the activity of antioxidant enzymes. Seed priming with gibberellic acid and ascorbic acid increased germination indices and seedling growth and improved enzymatic activity, including catalase, peroxidase, and superoxide dismutase in comparison with untreated seeds. Priming with gibberellic acid had a significant advantage. Seed priming in drought stress conditions has increased germination rate, protein content, and catalase, peroxidase, and ascorbic dismutase activity, respectively, compared to the control.

In general, seed priming of safflower using gibberellic acid changed the activity of antioxidant enzymes. These activities ultimately moderated the negative effects of drought stress and increased germination parameters.

The role of gibberellic acid and ascorbic acid on safflower seed germination traits was investigated.
The effect of gibberellic acid and ascorbic acid on the activity of antioxidant enzymes and soluble protein during seed germination was investigated.

In order to investigate the effect of ellagic acid on the growth of seedling and the qualities of soybean in accelerated aging conditions, a pilot was designed in 2019 in the research laboratory of the Shahrood University of Technology. The treatments included aging seed in two levels (unaged seeds and aged seeds) and priming at seven levels (control, distilled water, 25, 75, 50, 100, 125 mg/L with ellagic acid). A pilot study as a factorial experiment with a completely random-base design (CRD) in three replications was carried out under a germinator environment in accordance with standards. To prepare aged seeds in the laboratory, the seeds were incubated at 41°C and 95% relative humidity for 72 hours. Seed priming was soaking with ellagic acid for 6 hours in accordance with the principles of seed aeration. The aging reduced Vigor Index, Allometric Growth Ratio and Seed Reserves Use Rate. The increasing of the malondialdehyde had a negative effect on germination percentage through the influence of Vigor Index and α-amylase activity enzyme. The application of ellagic acid increased the germination percentage in unaged seeds and aged seeds through increasing the activity of α-amylase activity enzyme. The priming of seeds with ellagic acid reduced the malondialdehyde and electrical conductivity. Based on the results of research, the application of 50 mg/L of ellagic acid can be introduced as the best concentration of this material. It can also be suggested that the use of ellagic acid as a seed priming improves the effects of seed aging on soybeans.

In order to investigate the effect of biopriming of wheat seeds with Trichoderma and Aspergillusalong with ZnSo4 on improving germination indices and the tolerance threshold of wheat to zinc a factorial experiment was done based on a completely randomized design with three replications. Experimental treatments included six levels of zinc (0, 0.6, 6, 60, 300 and 600 mg/L) and four fungal treatments (no inoculation, inoculation with Trichoderma harzianum, Trichoderma longibrachiatum and Aspergillus niger). Nonetheless, based on the results, the coexistence of wheat seedlings with Trichoderma fungi especially Aspergillus fungi reduced the lipid peroxidation of the membrane in all application levels of zinc. Also, based on the results, the highest proline content was observed in the highest level of zinc in inoculated wheat seedlings by T. harzianum (fourfold increase as compared to the uninoculated control) and in other levels of zinc in seedlings inoculated with A. niger. However, the results showed a negative relationship between malondialdehyde (MDA) content and superoxide dismutase (SOD) activity and growth indices of wheat seedlings. There was also a negative relationship between MDAecontent with both SOD activity and growth indices of wheat seedlings. Inoculation of wheat seedlings with fungal treatments with higher production of SOD may led to higher resistance and avoidance to higher concentrations of Zn. Overall, the results showed an increase in the tolerance threshold of wheat seedlings to a concentration of 60 mg/L and therefore, more effectiveness of this micronutrient in seeds inoculated with Trichoderma and Aspergillus especially inoculated with Trichoderma longibrachiatum.

Sugar beet has long-growth period and high-water use. Thus, managing to reduce water consumption and decline growth period causes to increase the crop productivity. Sugar beet provides more than one-half of sugar produced in the United States and about 40% of sugar production in the world. The root of this crop contains 13- 22% sugar content. In general sugar beet also has a major role in the human diet and it is the mainstay parts of the agriculture economy in Iran. The leaves of sugar beet comprise the main light receptor organ for a crop. Leaf area development early during the season causes more efficient use of sunlight since it is important to the formation and expansion of the canopy. Sugar beet in the primary growth stages needs a warm and sunny climate and optimum water supply for optimal photosynthesis and photoassimilate partitioning.

This purpose study was performed in the research field of Hamedan in 2016. The experiment was conducted in a split-split plot based on RCB design with four replications. Experimental treatments were planting date at two levels as main plot (May 14 and June 28), irrigation at two levels as sub-plot (full irrigation and 75% of full irrigation or water requirement), and cultivar at 3 levels (two premature hybrids and the resistant cultivar to Rhizoctonia (Arya)) as sub-sub-plot at 2016 crop season. Studied traits were root yield, sugar content, sugar yield, and Enzyme activities such as SOD, PO, leaf chlorophyll, and some physiological and morphologic traits. SAS software version 9.1 was used to analyze the data. Also, the mean of the studied parameters was compared using the least significant difference test (LSD) at the level of 5 percent probability.

Based on the results of the analysis of variance, the difference between planting dates in terms of superoxide dismutase content, root yield, sugar yield, white sugar yield, and water use efficiency was significant at the level of 1% probability. There was a significant difference between irrigation levels in terms of superoxide dismutase and water use efficiency at 1% probability level and membrane lipid peroxidation content, peroxidase enzyme, chlorophyll a, chlorophyll b, and carotenoid content at 5% probability level. There was a significant difference between the studied genotypes in terms of root yield and sugar yield at a probability level of 1% and in terms of white sugar yield and water use efficiency at a probability level of 5%. The interaction effect of culture date on genotype was significant in terms of the effect on the percentage of white sugar and yield of white sugar at the level of 1% probability. The interaction effect of irrigation levels in genotype was significant only on water use efficiency at the level of 1% probability. The results showed that irrigation level 75% of plant water requirement compared to 100% level increased, hydrogen peroxide content, membrane lipid peroxidation, peroxidase activity and superoxide dismutase activity by 14.83, 25, 17.38, and 26%, respectively and reduced chlorophyll a, chlorophyll b and carotenoid content by 15%, 12%, and 14%, respectively. Also, the amount of superoxide dismutase activity and root yield on planting on May 14 was 33% and 26% higher than planting on July 28, respectively. Root yield in 33868 and 33872 hybrids was higher than Aria cultivar. The results also showed that the difference between the planting dates of May 14 and June 28 in the two hybrids 33868 and 33872 was not significant in terms of sugar content, white sugar yield, and water use efficiency. Also, the planting date of June 28 increased the percentage of white sugar in both hybrids. Finally, two hybrids, 33868 and 33872, obtained the highest water efficiency in the treatment of 75% of the required water.

In the conditions that there is a possibility of delay in the cultivation of sugar beet, planting two hybrids, two hybrids 33868 and 33872, is recommended.

To evaluate the effect of zinc nano-chelate and mycorrhizae on the biochemical properties of leaf and root yield under different irrigation levels, a split-plot design based on randomized complete block design with three replications was conducted in 2019. Irrigation treatments including irrigation after 60-, 90-, and 120-mm of evaporation from class A pan were allocated to the main plots and fertilizer treatments (control, inoculation with mycorrhiza, zinc nano-chelate, and zinc nano-chelate + mycorrhiza) to the sub-plots. In this study, irrigation after 120 mm of evaporation reduced the amount of chlorophyll a (17.01%), chlorophyll b (8.09%), carotenoid content (28.78%) and superoxide enzyme inhibition (31.14%), and increased leaf flavonoid content (25.47%), compared with irrigation after 60 mm of evaporation. Among the fertilizer treatments, zinc nano-chelate + mycorrhiza treatment had the highest chlorophyll-a (9.30 mg/g fresh weight), chlorophyll b (3.84 mg/g), carotenoid content (3.94 mg/g), superoxide enzyme inhibition (33.53 percent). The interaction effect of irrigation and fertilizer in irrigation after 60 mm of evaporation along with nano-chelate zinc + mycorrhiza fertilizer treatment had the highest nitric acid radical inhibition (23.45 percent) and root yield (82.62 t/ha), and the lowest leaf proline content (0.49 mg/g), as well as leaf phenol content (34.19 mg of gallic acid/ g dry weight). In this study, application of mycorrhiza, especially under water deficit conditions, through improving biochemical properties and regulation of antioxidant enzymes activity, was able to moderate the effect of water stress on root yield and also increase root yield compared with control.

Chickpea is one of the valuable pulses and rich source of protein. In most years, in west of Iran, the amount of rainfall is low and the distribution of rainfall is not suitable. In many cases, rainfed lands are affected by drought stress. On the other hand, most rainfed lands have low fertility, especially in nitrogen and phosphorus nutrients. In higher plants, salicylic acid applied to reduce the dangerous effects of drought stress. Different varieties of chickpeas show different responses to environmental changes. This experiment was carried out in order to investigate the effect of salicylic acid and biofertilizers on the physiological characteristics of two chickpea cultivars. 

This experiment was done in factorial based on randomized complete block design with three replications in Kermanshah under rainfed conditions in the 2016. Kermanshah is located at an altitude of 1319 m of sea level (Latitude: 34°21′ N and Longitude: 47°9′ E). Experimental treatments included two chickpea cultivars (Bivanij and Azad), foliar spraying of salicylic acid (non-application, 0.5 and 1 mill molar concentrations) and biological fertilizer (non-application of biofertilizers, bio-superphosphate bacteria (Pseudomonas+Enterobacter), biosulfur bacteria (Thiobacillus spp.), a rhizobium bacterium (Mesorhizobium ciceri), and mycorrhiza fungus (Rhizophagus irregularis). Each plot was six m2 (four meters long and 1.5 meters wide) with 6 lines (density= 40 plants per m2, sowing line spacing= 25 cm, sowing distance on each line= 10 cm and sowing depth= 7 cm). The sowing date was March 19. The studied traits were relative water content, relative water loss, chlorophyll a, chlorophyll b, total chlorophyll, chlorophyll a/b ratio, carotenoids, hydrogen peroxide, catalase and peroxidase enzyme activity and grain yield.

Foliar spraying of salicylic acid and the application of biofertilizers increased the production of hydrogen peroxide and decreased the activity of catalase and peroxidase enzymes. The highest catalase activity were obtained in Bivanij cultivar×non-application of salicylic acid, Bivanij cultivar×non-use of biofertilizer, non-application of salicylic acid and the lowest catalase activity were obtained in Azad cultivar×one mM salicylic acid, Bivanij cultivar×bio-superphosphate and one mM salicylic acid×biosulfur application. The highest and lowest peroxidase activity were obtained under non-application of salicylic acid×non-application of biofertilizer and one mM salicylic acid×rhizobium application, respectively. The highest relative water loss (RWL) was obtained in Bivanij cultivar×non-application of biofertilizer, while the lowest RWL was observed in Azad cultivar×biosulfur application biofertilizer. Relatively, the content of chlorophyll a, chlorophyll a/b, total chlorophyll and carotenoids increased with the application of biofertilizers. Bivanij cultivar had a higher grain yield than Azad cultivar. In both Bivanij and Azad varieties, the highest grain yield was obtained from the use of rhizobium and mycorrhiza biofertilizers. The highest grain yield (1626 kg.ha-1) was observed from the application of the concentration of 0.5 mM of salicylic acid and rhizobium biofertilizer. In both Bivanij and Azad varieties, the highest catalase activity was observed due to non-use of salicylic acid and non-application of biofertilizer. 

In general, at all three levels of salicylic acid, the highest peroxidase activity was observed in the absence of biofertilizer application. It is possible that biofertilizers reduce both nutrient deficiencies and drought stress, thus reducing peroxidase activity. In general, in this experiment, in terms of grain yield and physiological traits affecting grain yield, between the cultivars, native Bivanij cultivar, among the salicylic acid levels, the concentration of 0.5 mmol and among the biofertilizers, rhizobium biofertilizer were superior treatments.

Identification and development of salinity cultivation cultivars, one of the ways to improve performance. The development of salt-tolerant cultivars is a potentially effective approach for minimizing yield losses.In order to investigate the effects of salinity on the qualitative and quantitative traits of rainfed and irrigated barley cultivars, this experiment was conducted in Crop Physiology Laboratory of Shahed University in 2019. Experimental factors included barley cultivars (Reyhan, Jolgeh, Khorram and Izeh) in response to four salinity levels (no salinity as control and salinity of 5, 10, 15 and 20 ds/m with Qom lake salt).The experiment was conducted as a factorial experiment in a completely randomized design with three replications. The measured traits included germination indices, photosynthetic pigments, soluble compounds and two antioxidant enzymes. Results showed that the highest germination components such as germination percentage (79.71%), germination rate (5.18 seeds per day), root length (6.55 cm), stem length (8.46 cm), longitudinal index (70.1) and the weight of the seedlings (165.17) in the absence of salinity stress.. With increasing salinity levels, RWC, membrane stability index and protein content of cultivars decreased and the content of carotenoid, proline, MDA and antioxidant enzymes superoxide dismutase and ascorbate peroxidase were highest in salinity. Among the studied barley cultivars, Khorram had the highest percentage and rate of germination as well as soluble compounds at the highest salinity level. This cultivar appears to have significant germination and growth under salinity stress conditions. In the later stages it is possible to recommend flat and Izeh cultivars.

To study the effects of nitrogen levels on morphophysiological and antioxidants properties of calendula under deferent irrigation regimes a split plot experiment based on a randomized complete block design with three replications was conducted at the Urmia Agricultural Station of Saat Lo for two cropping seasons 2016-17. Treatments were four levels of irrigation (irrigation after 5, 10, 15 and 20 days) assigned to main plots, and application of 0, 80, 160 and 240 kg.ha-1 nitrogen to subplots. Results showed that the effects of irrigation intervals on all studied traits waer significant. There were significant differences among nitrogen levels on all traits except proline content. Interaction of two treatments was significant on leaf area index, stomatal conduction coefficient, chlorophyll b, essential oil percentage, and essential oil yield. Resulats also indicated that, with increasing irrigation intervals from 5 to 20 days, relative water content, chlorophyll, carotenoid, and dry flower yield were reduced by 36.64, 35.27, 24.31 and 45.77 percent respectively. Proline content, catalase superoxide dismutase, and malondialdehyde activities were increased by 24.72, 33.04, 35.51 and 20.86 percent, respectively. Among the nitrogen fertilizer levels, 160 kg ha-1 increased, relative water content, chlorophyll a, carotenoid and dry flower yield by 16.18, 4.24, 23.68  and 28.26 percent, respectively, while it reduced the activity of catalase, superoxide dismutase, and malondialdehyde by 18.10, 21.23 and 29.69 percent respectively as compared to control. The highest leaf area index, stomatal conduction coefficient, chlorophyll b were increased by the use of 160 kg.ha-1 nitrogen fertilizer and irrigation intervals of 5 days. The highest percentage of essential oil of the flower and essential oil yield were also belonged to the application of 160 kg.ha-1 nitrogen and irrigation interval of 10 days. To obtain better quality and higher essential oil yield from calendula, irrigation interval of 10 days and application of 160 kg.ha-1 nitrogen fertilizer is recommended.

Drought stress is one of the major factors limiting plants growth. Salicylic acid (SA) is a natural phenolic compound playing an important regulatory role in plant different processes. Studies have indicated that external application of SA increased plant tolerance to several abiotic stresses, including osmotic stress, drought, salinity, ozone or UV radiation. The purpose of this study was to evaluate the interactive effects of different humidity regimes and application methods of SA on some physiological and biochemical parameters, grain yield and determination of the most suitable application method of salicylic acid in black cumin.

This study was conducted based on randomized complete design with factorial arrangement of treatment and three replications at Gonbad Kavous university research field in 2018 growing season. Different irrigation regimes at four levels including no irrigation (rainfed), once irrigation at flowering stage, once irrigation at grain filling stage and double irrigation at flowering and grain filling stages and salicylic acid factor at three levels including non- application (control), seed priming (with 0.5 mM concentration), foliar spraying (with 0.5 mM concentration) were studied. After applying of treatments, some traits including total chlorophyll content, antioxidant enzymes activity (catalase, peroxidase and ascorbate peroxidase), leaf relative water content, leaf water saturated deficiency, 1000 grain weight, grain yield, biological yield and harvest index were evaluated.

The results showed that interaction effects of irrigation and salicylic acid on all evaluated traits were significant except for biological yield. Salicylic acid foliar spraying increased activity of peroxidase and ascorbate peroxidase antioxidant enzymes in all irrigation treatments while not significantly affecting catalase enzyme activity. Means comparison revealed that the highest total chlorophyll content (26.2 mg/g FW), RWC (72.44%) and seed yield (1329 kg/ha) obtained from SA foliar spraying application and double irrigation treatment.

Results indicated that SA application especially foliar spraying activated antioxidant system and also improved plant moisture condition and chlorophyll content which finally resulted in enhanced growth and desirable yield under different humidity treatments. Therefore, application of SA can be introduced as an effective approach for regulation and decrease of stress effects and desirable yield production in areas subjected to water deficit.

IntroductionSunflower is one of the major and most important non-conventional oilseed crops in the world due to its excellent oil quality. Though sunflower is known as a drought tolerant crop or grown under dry land conditions, substantial yield increases are obtained with frequent irrigation. Drought stress damages the thylakoid membrane, disturb its functions, and ultimately decrease Photosynthesis and crop. Drought stress usually induces the accumulation of reactive oxygen species (ROS), which cause oxidative damage to plants. If not effectively and rapidly removed from plants, ROS can damage a wide range of cellular macromolecules such as lipids, enzymes and DNA. Plants can protect themselves against oxidative damage by antioxidant system including antioxidative enzymes and nonenzymatic compounds. Materials and Methods This study was done in agricultural research farm of the Islamic Azad University, mahabad Branch in south of West Azerbaijan, Iran during 2014 to 2016. The experiment was laid out in a split plot on the basis of randomized complete block design with three replications. The main plots included two irrigation regimes (Irrigation after 50 mm evaporation from class A pan and irrigation after 100 mm evaporation from class A pan, as control and water stress conditions, respectively) and the sub plots included three seed praiming with salicylic acid (0 (control), 100 and 200ppm) and seed praiming with ascorbic acid (0 (control), 50 and 100ppm). Common Sunflower seeds (cv. Euroflore) were soaked for 6 h in salicylic acid and ascorbic acid solutions. In this research superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), Di-tyrosine (D.T), Malondialdehyde (MDA), grain yield and oil perecentage was measured.Finally all data were analyzed by SAS. 9.2 statistical software and the means were compared by Duncan′s Multiple Range Test at the 5% probability level by MSTAT-C. Result and discussion Analysis of variance showed, there was significant difference between irrigation levels in terms of effect on all traits. Effect of salicylic acid and salicylic acid and ascorbic acid interaction on all traits was significant except of malondialdehyde. The effect of ascorbic acid and salicylic acid whit irrigation levels interaction on all traits except of amount of D-tyrosine was significant. Finally interaction of irrigation levels and ascorbic acid on the proline, catalase and malondialdehyde were significant. In this study water deficit increased amount of proline, catalase, superoxide dismutase, glutathione peroxidase, D-tyrosine and Malondialdehyde by 9.75, 19.18, 36.83, 14.36,17.51 23.97 and 25.10 percent, and decreased amount of grain yield and oil percentage by 51.26 and 24.48% compared with control treatment. Also priming with salicylic acid and ascorbic acid, individually or combined together increased amount of proline, catalase and glutathione peroxidase and D-tyrosine, and decreased amount of malondialdehyde compared with control treatment. Furthermore the highest grain yield (2.72 t/ha) and oil content (52.09) were belonged 200ppm of salicylic acid with 100 ppm of ascorbic acid, Also, level of 200ppm of salicylic acid and 100ppm of ascorbic acid increased the activity of proline, catalase, superoxide dismutase and glutathione peroxidase and D-tyrosine enzymes, grain yield and oil percent by 9.21, 50.35, 54.25, 49.18,48.24, 36.68 and 39.31percent compared to control treatment, respectively. Conclusions The present study indicated that drought stress increased oxidative damage, membrane lipid peroxidation and MDA content as well as antioxidant enzymes (SOD, CAT and GPX) activities, proline level and oil percentage but decresed grain yield in sunflower, nevertheless seeds priming with salsilic (especially 200 ppm) and ascorbic acid (especially 100 ppm) induced protection against drought stress via maintenance of membrane integrity by decline in MDA content and more increase in antioxidant enzymes activities (especially SOD) as well as prolin accumulation, grain yield and and oil percentage. Our results showed priming with salicylic acid and ascorbic acid it can induce drought tolerance in sunflower and improve grain yield and oil content in underwater stress conditions.

Soil salinity is one of the most important problems in crop production. Improvement in salt tolerance in major food crops is an important way for the economic utilization of saline area.The effects of pretreatment of salicylic acid on phoenix canariensis seed germination, lipids peroxidation, superoxide dismutase (SOD), catalase (CAT), polyphenol oxidase (PPO) peroxidase (POX) activity in salt stress condition were investigated. Treatments of Phoenix canariensis seedlings with different concentrations of salicylic acid (SA) for seedling growth were: (0, 0.5, 1 and 2 mM). Salt stress was inducted by NaCl solution (0, 100, 200 and 200 mM). After three mounths, number of germinated seed, radical length, seedling length and dry weight were recorded. Antioxidant enzymes activity and lipid peroxidation were analysed too. The results showed that high concentration of NaCl (400mM) decreased germination to 8.57 % than control. Influence of SA was significant and increased percent of germination in stressed and control treatments. Enzymes assay showed enzyme activity increased in salt stress conditions and SA reduced activity of antioxidant enzyme. In general, SA treatment reduced damage of salinity on seedling growth and accelerated the restoration of growth processes.

Recently, the use of cut flowers has increased, and some of these cut flowers (Lily, Rose etc.) are among the most used for decorative purposes. With this boom in popularity has also come a rise in the need for commercial use, and very little academic literature exists on how to best utilize the preservative solutions (here 8-HQC and essential oils) to prolong cut flowers vase life keeping their full quality. The vase life of Lily is usually short due to vascular occlusion. The use of synthetic chemical fungicides to protect cut flowers raises environmental and human health concerns because of chemical residue routinely found on food meant for consumption. Thus, biocides showing insignificant toxicity to human and organisms are more desirable and less likely to cause negative environmental effects. The chemical composition of essential oils extracted from the endemic Iranian plants Satureja hortensis L., Thymus vulgaris L. and Citrus limon L. was studied in order to evaluate their efficacy as a substitute for synthetic chemical that was used as preservative-solutions. The effects of essential oils (250 mg L-1) individually and 8-hydroxyquinoline citrate (8-HQC) with sucrose 3% were evaluated. Cut flowers were pulsed for 12 h in different preservative solutions, followed by storage in dry and wet conditions (in distilled water) at 8˚C for 15 days, and then all treated cut flowers were kept in room temperature to evaluate commercial vase life. At the end of commercial vase life, parameters such as relative fresh weight, amount of chlorophyll, phenol, anthocyanin, protein and carbohydrate, vase life and antioxidant enzyme activities were measured. In this experiment, flowering stems were arranged using a completely randomized design. Limonene was identified as major component of C. limon L. essential oil, whereas Carvacrol was the major component in S. hortensis L. and Th. vulgaris L. Results showed that applying all essential oil treatments or 8-HQC increased positive characteristics and vase life compared with control. However, among all these treatments, the flowers treated with Thyme essential oil plus 3% sucrose or 8-HQC were kept in wet storage condition showed best vase life. Based on our results, new antimicrobial agents such as limonene, thymol and carvacrol in combination with 3% sucrose had a positive effect on the vase-life and relative fresh weight. The senescence of cut flowers is associated with a series of highly regulated physiological and biochemical processes, including breakage of water balance, degradation of photosynthetic pigment, decrease in metabolic constituents, and loss of membrane integrity. In our experiment, Thyme essential and 8-HQC oil treatments were reduced degradation of leaf protein and chlorophyll content which was seen in the controls. Essential oils derived from plants such as T. vulgaris are particularly valuable because of their antibacterial and antioxidant properties. In conclusion, using various concentrations of essential oils and 8-HQC in preservative solutions showed promising prospects for the utilization of natural essential oils or plant extracts in extending lily vase-life. The proposed mechanism of action, e.g. inhibition of the growth of bacteria in the vase water or inside the xylem vessels of the flower stem needs further elucidation.

To investigate salinity tolerance in two safflower cultivars and identify the most important traits affecting salinity tolerance in safflower cultivars (Carthamus tinctorius L.), a greenhouse experiment was conducted as factorial arrangement based on completely randomized design with four replications. Treatments were irrigation water salinity (2, 4, 8 and 12 dS/m) and safflower cultivars (Sofeh and Zendehrud). Plant dry weight in Sofeh cultivar decreased 13, 30 and 58% respectively, while, plant dry weight of Zendehrud cultivar reduced 9, 28 and 40% under salinity levels. The higher concentration of chlorophyll a, b, SPAD, peroxidase and superoxide dismutase activity was found in Zendehrud cultivar under all salinity levels. Enhancement of Na concentration in shoot and root, proline and malondialdehyde was greater in Sofeh cultivar compared to Zendehrud cultivar. Linear regression analysis revealed significant and negative relationships between plant dry weight with Na concentration in leaf and root and proline content. Plant dry weight was significantly and positively associated with Kﳖ ratio, peroxidase, superoxide dismutase and chlorophyll a. In general, it was concluded that Na concentration in root, shoot (stem leaf), peroxidase and superoxide dismutase activity can be used as reliable indicators in identifying salinity tolerant cultivars of safflower

Seed deterioration is a natural phenomenon that occurs in all seeds and leads to gradual decline of seed viability during storage. However, the rate of seeds age depends upon their physiological status, genetic constitution and storage conditions. The lipid peroxidation through the production of free radical plays an important role in the loss of seed viability during seed storage.
Material and In order to investigate the effect of deterioration on germination indices and enzymes activity of the flax oil seed, a factorial experiment was conducted based on a Completely Randomized Design with four replications in the seed laboratory of Yasouj University in 2015. The factors included 4 levels of temperature (15, 25, 35 and 45oC) and moisture content (5, 9, 13 and 17%). With relation intended seed moisture, Hampton and Teckrony (1995) was calculated. After determining the moisture content of the seeds in envelopes of aluminum foil was placed, then the amount of water the need added and to ensure that the packaging and moisture exchange with the outside world for 24 hours at 15 °C were identical to the seed moisture and then for 6 months in storage conditions at temperatures of 15, 25, 35 and 45oC were kept.
Analysis of variance showed that the single effects including temperature and seed moisture content experimental treatments for traits including germination percentage, germination rate, seedling vigor index (weight), activity enzymes antioxidant catalase, superoxide dismutase and ascorbate peroxidase, soluble proteins, electrical conductivity and oil percentage were significant (P≤0.01). Also, the interaction temperature and seed moisture content of all treatments except for enzyme, activity of superoxide dismutase and ascorbate peroxidase were significant (P≤0.01) but were significant (P≤0.05) for the activity of superoxide dismutase and ascorbate peroxidase. The results showed that with increasing temperature and moisture content, all the physiological and biochemical traits, except for electrical conductivity, decreased. The decrease in germination was also associated with a decrease in the activity of antioxidant catalase, superoxide dismutase and ascorbate peroxidase and as a result the antioxidant system was not sufficient to protect seeds against free radical damage. With the increase in reactive oxygen species, lipids peroxidation increased, probably due to the destruction of cell membranes, increased electrical conductivity seed the negative correlation between the electrical conductivity and the activity of the enzymes antioxidant indicator of the issue.
Thus, oil flax seed deterioration was closely related to decrease in the activities of free radical detoxifying enzymes and increased lipid peroxidation. In general, the best flax seed storage condition is at 15°C and 5 percent moisture content.

This study was laid out to study the effect of accelerate aging duration onenzymatic and non-enzymatic antioxidant activity and biochemical characteristics of barley (Hordeum vulgare L.) seeds in Islamic Azad University, Boroujerd branch, at 2015 summer, that laid out in completely randomized design with four replications. Treatments included 5 accelerated ageing days (control and 1, 2, 3, 4 and 5 days). Results of analysis of variance showed that effect of ageing on germination percentage, electrical conductivity, soluble sugar, soluble protein,proline, acid ascorbic, catalase, peroxidase and ascorbat peroxidase enzymes were significant. Mean comparison results showed that, increase of ageing duration decreased germination percentage of barley seeds but, Malondialdeid, H2O2 content and electrical conductivity were increased. Soluble sugar and soluble protein were increased until 3 and 2 aging days respectively then decreased. With increasing of aging levels until two days proline content increased then decreased but, ascorbic acid production procedure was decreasing and ascorbic acid production in 1-4 ageing days was more than control. Ageing changed catalase, peroxidase and ascorbat peroxidase amount. With increasing of aging levels until 3 days catalase activity increased and until 2 days peroxidase and ascorbat peroxidase activity were increased then decreased. Lower ageing levels induced enzymatic and non-enzymatic damaging less than higher ageing levels but, with increasing of accelerated ageing until 5 days reactive oxygen species accumulation over come on these antioxidant systems. In this condition seed damage increased that laid to decrease of vigor and seed germination percentage.

Treated with different coating and application of methyl salicylate and salicylic acid are used for reduce chilling injury and maintain the quality of citrus fruit during storage. This experiment was carried out Citrus Research Institute of Ramsar in 91 years in order to study enzyme activity that involved in reducing chilling injury and Maintain the fruit quality based on Split Plot design with three replications. Fruits was treated and then placed in the cool storage at 5°C and 95 percent relative humidity)RH( for 80 days. Each 20 days with sampling investigated fruit enzyme activity was measured. Results showed the highest PAL enzyme activity was in fruits treated with methyl salicylate and the lowest was in fruits coated with the Bretix wax. The highest SOD enzyme activity related to Moro fruits which treated with methyl salicylate is in the first 20 days of storage )23/19 umg/FW(. The APX enzyme activity increased in both cultivars Thomson and Moro during storage. Relatively, treatments caused the change in APx, SOD and PAl enzyme activity.

Citrus often were encountered with periodic droughts. For this reason, drought effect on six-month-old seedlings of Poncirus (PT) (Poncirus trifoliata Raf.),Troyer citrange (TC) (Citrus sinensis Osbec. × Poncirus trifoliata Raf.),Citrumello (CR) (Citrus paradisi M. × Citrus sinensis Osbec.),Sour orange (SO) (Citrus aurantium L.),andCleopatra mandarin (CM) (Citrus reshni L.) were tested on 2014 in Ramsar Citrus Research Institute. This research was conducted as factorial experiment based on completely randomized design with three replications. The factors included commercial Citrus rootstocks and two level of irrigation. The results showed that maximum quantities of proline, total soluble sugars, malondialdehyde and carotenoid and minimum quantities of total, b and a chlorophyll were observed in drought stress. Maximum accumulation of proline (ordered 306.41 and 281.65 µmol/gdw) and total soluble sugars (ordered 233.79 and 137.9 mg/gdw) and minimum accumulation of malondialdehyde (ordered 179.21 and 204.1 µmol/gdw) were observed in SO and CM rootstocks under drought stress. Decreasing amount of total and chlorophyll a in CM and chl b in SO rootstock was more than other rootstocks and decreasing amount of total and b, a chlorophyll in CR was least. Furthermore, increasing amount of carotenoid in SO and CM was most and the least amounts in PT was observed. On the basis of the study, trifoliate rootstocks as Poncirus, Troyer citrange and Citrumello tolerate as much as drought.

er to investigated the effect of flooding, different nutrition levels an anti-oxidant characteristics, chlorophyll fluorescence, amount of chlorophyll (a, b) and Carotenoids leaves Soybean (Glycine max (L.) Merr), cultivar DPX research at the University of Agricultural Sciences and Natural Resources, Gorgan, in a completely randomized design to factorial arrangement with three replications was done in 2012. The experiment consists of three levels of nitrogen nutrition treatments factor (1 – non inoculation plus nitrogen fertilizer 2 - inoculated with bacteria (Bradyrhizobium japonicum) 3 - non inoculation without fertilizer) and flooding stress in four levels (0, 5, 10 and 15 days). Maximum enzyme activity of Ascorbate peroxidase was in first treatment (non inoculation plus nitrogen fertilizer) in flooded on day zero. Peroxidase and Catalase enzyme activity at all levels of the nutrition flooded up to 5 days at 10 and 15 days showed an increasing trend, but the flooding had reduced the activity of two enzymes. Flooding during the production of Ascorbic acid (from 0 to 15 days) was increased at all three levels of nitrogen nutrition. The amount of chlorophyll fluorescence, amount of chlorophyll (a, b) and Carotenoids showed a decreasing trend during flooding. Reduce the amount of chlorophyll a, was much more chlorophyll b. overall to intensity increases flooding increased activity of free radical resistance mechanism fall continues, the more damage will be flooded with increasing time.

Drought stress as an abiotic stress causes different biochemical and physiological responses in plants. To study changes in chlorophyll، total soluble protein and antioxidant activity due to drought stress، we conducted an experiment on five durum wheat varieties (selected from the Seed and Plant Improvement Institute in Karaj) at research greenhouse of Imam Khomeini International University in 2010. Five varieties (Seymareh، Karkheh، Dena، Aria and D-79-15) were cultivated in a factorial experiment based on completely randomized design with six replicates in both normal and water stress conditions. The sampling was done at five leaf stage for measuring total soluble protein، catalase (CAT)، peroxidase (POX)، ascorbate peroxidase (APX) and super oxid dismutas (SOD) enzymes activity. Results showed that total soluble protein increased significantly، but total amount of chlorophyll decreased due to drought stress. Amount of chlorophyll a، b and total chlorophyll for cultivar Aria، was maximum. Also، the results showed that activity of CAT، SOD and POX increased due to stress، while stress caused a decrease in the activity of APX. Cultivar Aria had the highest catalase enzyme activity against drought stress and was considered as drought resistant cultivar. Seymareh had the highest POX activity under stress. The lowest POX activity was for line D-79-15 and was recorded more sensitive to stress than other varieties. Dena and Karkheh showed the highest increase in super oxid dismutas and ascorbate peroxidase enzyme activity under stress condition، respectively.