Growing vegetables
Keyvan Poorhossein; bahram abedy; Mahmoud Shour
Abstract
Introduction Urban agriculture is one of the basic characteristics of urban schematization, which helps to increase the quality of urban life via reducing the climate pollution, preserving and increasing biodiversity, as well as re-utilizing urban waste. Therefore, in recent years, urban agriculture ...
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Introduction Urban agriculture is one of the basic characteristics of urban schematization, which helps to increase the quality of urban life via reducing the climate pollution, preserving and increasing biodiversity, as well as re-utilizing urban waste. Therefore, in recent years, urban agriculture has gained significant importance due to its economic, social and cultural benefits. However, studies have indicated that urban soils can contain high concentrations of certain infrequent elements such as lead and cadmium. These heavy metals can be distinguished from other pollutants because they cannot be bio-degraded; but they accumulate in living organisms and subsequently cause diseases and various disorders even in relatively lower concentrations. Plants, like other organisms, have defense mechanisms that are activated in stressful conditions. Thus, under stress, enzymatic antioxidant systems and non-enzymatic metabolites enhance, due to the production of reactive oxygen species. Peppermint plant (Mentha piperita L) has an essential oil with medicinal properties. High levels of heavy metals cause chlorosis and necrosis, increase the accumulation of reactive oxygen species (ROS) and oxidative stress in mint plants. The present study was conducted on a regional scale in order to investigate heavy metal pollution and determine their impacts on some physiological and biochemical traits as well as the concentration of Cd and Pb in peppermint plants grown in urban green spaces.Material and methodsThis study was conducted to assess the amount of heavy metal absorption and its effect on some biochemical properties of peppermint plant (Mentha piperita L.), in Mashhad city in 2021.The experiment was carried out as a factorial in the form of randomized complete block design in three replications. The first factor (location) were Faz4 Park (with high degree of contamination) and Nasim Park (with low degree of contamination). The second factor was the times of harvest (June15, July15 and August 15). At the time of every harvest fully developed leaves were collected to evaluate physiological and biochemical traits.Results and discussionThe results of analysis of variance indicated that the effect of location was significant on all traits except for the yield of essential oil. Also, the effect of harvest time was significant on all traits except for peroxidase activity and the yield of essential oil. However, the interaction of location and harvest was significant only on phenol, flavonoid, proline, cadmium and lead concentration. The results indicated that the ascorbate peroxidase, catalase and peroxidase activities were higher in Faz 4 Park. Moreover, the highest activities of ascorbate peroxidase, catalase and peroxidase were recorded in Faz 4 + first harvest. Heavy metals cause the production of reactive free radicals and also increase the activity of antioxidant enzymes. However, the chlorophyll a, b, carotenoid and total chlorophyll contents were higher in Nasim. Thus, the highest contents of Chla, Chlb, Chltotal and carotenoid were observed in Nasim + first harvest. The higher amount of chlorophyll and carotenoids in the first harvest is due to the optimal growth conditions such as day length and sunlight and ambient temperature. In addition total phenol, flavonoid, proline, Cd and Pb elements indicated a reducing trend in Faz 4 compared to Nasim Park in different harvest times, but the amount of these traits were higher in the first harvest than in the subsequent harvests. Increased amount of total phenol in the first harvest can be related to the high air temperature at the first harvest which caused stressful conditions in this stage. Proline production also improves under heavy metal stress in order to protect the plant against toxicity. Nevertheless, the percentage of essential oil showed an increasing trend via enhancing the absorption of Pb and Cd in Faz 4 compared to Nasim Park. The higher percentage of essential oil in Faz 4 can be due to the lower growth of leaves due to the presence of more heavy elements in this area. In general, despite the fact that only the concentration of Pb was higher than the world standard level in both parks, the contamination with Cd and Pb (especially Pb) was more in Faz 4 than in Nasim Park, which was a factor in diminishing the growth traits of peppermint plants. In a case of harvest times, the first harvest recorded better growth characteristics and higher absorption of heavy metals due to the higher strength of the plant, while in the third harvest, due to spending more energy for regrowth, it had lower growth characteristics and weaker absorption of Pb and Cd metals. It was cadmium.
Postharvest physiology
Z. Pakkish; S. Mohajerpour; S. Saadati
Abstract
Introduction
Fresh fruits and vegetables are physiologically active and perishable after harvest. Continued metabolic processes such as transpiration or respiration may significantly affect their quality and thus shorten their useful life. Since keeping at low temperatures and without freezing for ...
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Introduction
Fresh fruits and vegetables are physiologically active and perishable after harvest. Continued metabolic processes such as transpiration or respiration may significantly affect their quality and thus shorten their useful life. Since keeping at low temperatures and without freezing for a long time effectively reduces the physiological activity of the products, it can be used as a strategy to maintain the quality of the products and increase their life after harvesting. Among the most economically important tropical fruits, ripe green bananas are very sensitive to cold and when stored below the threshold temperature, they show all the symptoms of frost damage. While banana cultivars, maturity stage, and ripening all influence cold sensitivity, there's a growing interest in extending the shelf life of produce using natural, plant-friendly compounds. Gamma-aminobutyric acid (GABA), a naturally occurring four-carbon, non-protein amino acid found in plants, animals, and bacteria, is a promising candidate in this area.Abiotic stresses such as cold, heat, drought, ultraviolet rays and low oxygen can cause the accumulation of GABA in plants. Generally, the purpose of this research was to investigate the effect of gamma-aminobutyric acid treatment to improve freezing and antioxidant properties of Cavendish banana at 5 degrees Celsius for 24 days in 90% relative humidity.
Materials and Methods
Cavendish banana fruits (Musa acuminata cv. Cavendish) at the time of commercial maturity (ripe green) were obtained from a banana garden in Kerman and immediately transferred to the horticultural science laboratory of Shahid Bahoner University, Kerman. Healthy and uniform fruits were selected in terms of size, shape, color, and degree of ripening, and after washing with water and drying them, frost tolerance, malondialdehyde, and antioxidants were measured for zero day. GABA (Sigma-Aldrich, USA) required after weighing was dissolved in water and prepared in two concentrations of 2.5 and 5 mM. The fruits were divided into three groups of 54 and each repetition included 18 fruits. The first and second groups were immersed in GABA solution of 2.5 mM and 5 mM for 5 minutes, respectively. The third group was immersed in distilled water for 5 minutes and was used as a control (Khaliq et al., 2023). Each treatment was repeated three times. Then, all the fruits were dried in the air for one hour and kept for 24 days at 5 degrees Celsius and relative humidity of 85-90%. Biochemical observations were measured on days 0, 4, 8, 12, 16, 20 and 24 of storage.
Results and Discussion
The results of this research showed that frost damage gradually increased during the storage period and the control fruits showed significantly more frost damage symptoms than the fruits treated with GABA. GABA treatments of 2.5 and 5 mM at the end of the storage period reduced the amount of frost damage by 55.64 and 69.95%, respectively, compared to control fruits. As shown in Figure 1b, MDA content as an index of membrane lipid peroxidation in the control and GABA-treated fruit showed an upward trend, which was associated with the destruction of banana fruit membrane under cold stress. Compared to control, banana fruits treated with GABA showed lower MDA accumulation during the entire storage period at 4 degrees Celsius. On the last day of storage, GABA treatment with a concentration of 2.5 mM and 5 mM reduced the amount of MDA in banana fruits by 30.99% and 59.80%, respectively, compared to the control. Post-harvest treatment with GABA reduced frostbite, ion leakage and MDA levels in banana fruits, thereby maintaining fruit quality during low temperature storage. GABA treatment increased the activity of catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and superoxide dismutase (SOD) enzymes in banana fruit compared to the control under low temperature storage. The activity of antioxidant enzymes CAT, APX, POD and SOD increased significantly until the 20th day of storage at low temperature, especially in the 5 mM GABA treatment compared to the other two treatments, and then decreased slightly at the end of the storage period. An increase in the concentration of oxygen free radicals, including hydrogen peroxide, leads to an increase in catalase enzyme activity. Catalase enzyme is often present in the peroxisome and causes the decomposition of hydrogen peroxide into water and oxygen. The specific activity of catalase enzyme increased during cold storage, especially in GABA treatments, so it seems that this enzyme is an efficient scavenger for removing hydrogen peroxide and thus causes better protection of cells against peroxidation. In the ascorbate-glutathione cycle, the ascorbate peroxidase enzyme reduces the amount of hydrogen peroxide by using ascorbate as an electron donor. In the present study, the activity of ascorbate peroxidase enzyme in GABA treatment was significantly higher than the control, which indicates the importance of the role of ascorbate peroxidase in plant tissues against oxidative damage. Guaiacol peroxidase enzyme is another antioxidant enzyme that decomposes hydrogen peroxide into water and oxygen. Peroxidase enzyme plays a role in the oxidation of precursors of phenolic compounds, lignin production, and removal of free radicals. The activity of peroxidase enzyme showed a similar trend in all three treatments, although its activity in GABA treatments was more than the control. Therefore, this enzyme effectively eliminated free radicals in banana fruits. In confirmation of these findings, it was reported in research that the activity of peroxidase enzyme increased in fir cuttings during the cold period. In research, post-harvest treatment of GABA with a concentration of 5 mM reduced frostbite and increased the activity of antioxidant enzymes such as CAT, APX, POD and SOD in peach fruits.
Conclusion
The results of this research showed that the applied post-harvest treatments reduced the signs of frostbite and preserved the antioxidant properties of banana fruits. Among the treatments, 5 mM concentration of GABA was the most effective treatment in the storage period. Therefore, GABA treatment can be used as a practical solution to reduce frostbite and preserve the antioxidant properties of Cavendish bananas during long-term storage.
Postharvest physiology
Behzad Kaviani; Mohammad Reza Safari Motlagh; Sara Hataminejad
Abstract
Introduction Chrysanthemum (Chrysanthemum morifolum L.) is one of the most important cut flowers in the world, which currently ranks second in the world after rose in terms of economy and cultivation. Stem end blockage and water stress are two problems in decreasing the vase life of chrysanthemum ...
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Introduction Chrysanthemum (Chrysanthemum morifolum L.) is one of the most important cut flowers in the world, which currently ranks second in the world after rose in terms of economy and cultivation. Stem end blockage and water stress are two problems in decreasing the vase life of chrysanthemum cut flowers. Cut flowers undergo physiological and biochemical alterations which often lead to an early senescence. Steps to delay the senescence process rely on consideration of many aspects of handling process particularly the preservative solution that will influence the quality and longevity of the flowers. Many flowers are harvested before they are fully developed, to ensure a long postharvest life and to minimize mechanical damages which may occur during handling. Many researches have been performed to prolong the vase life of chrysanthemum cut flowers with different treatments like essential oils, organic acids and nanoparticles. Essential oils are aromatic oily liquids obtained from some aromatic plant materials. In vase solution, microorganisms cause stem obstruction and accelerate the aging of petals. Microorganisms and their toxic products restrict water uptake by blocking the end of the stem. Water balance, which is an important factor in maintaining the quality and longevity of cut flowers and the inability to uptake water are the main causes of senescence. The presence of disinfectants in the vase solution prevents the growth of microorganisms, protects the vessels against disintegration, and ultimately increases the vase life. Most of nanoparticles have antibacterial effects and their application in vase solution hinders microorganism growth and vascular blockage. Nanoparticles have high area-to-volume ratio, high efficiency, and low toxicity. Some nanoparticles penetrate into the cells of bacteria, disrupt their respiration chain, and cause disorder in their cell division, thereby killing them. They also inhibit the accumulation of bacteria in vase solution and stem end of cut flowers. Various studies have reported the positive impact of nanoparticles on decreasing microbial load, reducing transpiration from leaf surface, and preserving water uptake. Studies on postharvest longevity of chrysanthemum cut flowers using these compounds is low. Therefore, the aim of the present study was to evaluate the effect of orange spring essential oil, fulvic acid and cupper nanoparticles on vase life and some physiological parameters of chrysanthemum cut flowers. Materials and MethodsThe experiment was performed based on randomized completely design with three replicates in order to investigate the effect of different levels of fulvic acid (50, 100 and 150 mg l–1), orange spring essential oil (10, 30 and 50%) and copper nanoparticles (5, 10 and 20 mg l–1) in comparison to control (distilled water + 3% sucrose + 30 mg l–1 8-hydroxyquinoline sulphate) on postharvest parameters of chrysanthemum cut flowers. Measured parameters included vase life, solution uptake, vase solution bacterial population, stem end bacterial population, decreasing the brix degree, decreasing fresh weight, dry matter, total chlorophyll content, carotenoid content, protein content, and peroxidase and superoxide dismutase activity. Data were analyzed by SPSS statistical software package and means were compared with the LSD test at the probably level of 95%. Results and DiscussionAccording to the obtained results, the effect of treatments on improving the quality characteristics of chrysanthemum cut flowers after harvest was significant. Results showed that the high vase life (16.33-17.00 days) was obtained with all three copper nanoparticles concentrations. The vase life of chrysanthemum cut flowers was extended to 17 days by the addition of 20 mg l–1 copper nanoparticles in preservative solution in compared to control with 14 days’ vase life. Least solution bacteria colonies was obtained through the use of 5 mg l–1 copper nanoparticle. On the other hand, least stem end bacteria colonies was obtained using 10 and 30% orange spring essential oil. Solution uptake in these treatments was high, too. The effects of different treatments on some other physiological traits and antioxidant enzymes activity were measured. Many studies have been carried out on the effect of essences (herbal extracts) as antimicrobial agents on prolonging the vase life of cut flowers. In most of these studies, these essences could prolong postharvest life. Essences have been studied with the intension of incorporating them into integrated pest management to avoid or reduce the use of synthetic bactericides and fungicides. They also have antioxidant properties. Application of herbal extracts improved water absorption in rose cut flowers by preventing the vessel obstruction. The above results are similar to the results of this study. In most cases, when the cut flowers were treated with nanoparticles, they exhibited longer vase life, higher water uptake, and lower stem-end bacteria than the control flowers.
Postharvest physiology
K. Hosseinzadeh Moghaddam; B. Kaviani; D. Hashemabadi; Sh. Sedaghathoor; M.R. Safarimotlagh
Abstract
IntroductionKiwi (Actinidia deliciosa) is rich in minerals, vitamins and antioxidants. Kiwi fruit is sensitive to ethylene and has high perishability. There are some physical and chemical methods to delay aging and maintain postharvest quality of fruits. Light irradiation is a physical and pollution-free ...
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IntroductionKiwi (Actinidia deliciosa) is rich in minerals, vitamins and antioxidants. Kiwi fruit is sensitive to ethylene and has high perishability. There are some physical and chemical methods to delay aging and maintain postharvest quality of fruits. Light irradiation is a physical and pollution-free method that has been reported to be effective in controlling fruit decay and increasing its shelf life. Sodium nitroprusside (SNP) acts as an important signal in some physiological activities of the plant. SNP improved the quality and durability after fruit harvest in some fruits.Amino acids are effective in delaying the aging process and increasing the postharvest life of horticultural crops. Arginine plays an important and vital role in plant growth and development processes. The positive effect of arginine in increasing the shelf life of some fruits has been reported. The aim of this study was to increase the shelf life and quantitative and qualitative characteristics of ‘Hayward’ kiwi fruit after harvesting with the use of blue light, SNP and arginine. Material and MethodsHealthy and uniform fruits were selected and exposed to blue light (6, 12 and 24 h) at a wavelength range of 470 nm by LED lamps, SNP (0.5, 1 and 2 mM) and arginine (0.5, 1 and 2 mM). The experiment was performed in a completely random design with 10 treatments in 3 replications with 30 plots and 10 fruits per plot. After immersing the fruits at different levels of arginine, SNP and distilled water (control treatment), the surface of the fruits was dried and then sterilized. The fruits were monitored daily and their quantitative and qualitative properties were recorded during the experiment. Parameters of shelf life, tissue firmness, flavor index, loss of fresh weight, proline, ionic leakage, malondialdehyde (MDA), and dry matter, as well the activity of ascorbate peroxidase (APX), peroxidase (POD) and superoxide dismutase (SOD) enzymes were measured. Analysis of data obtained from sampling during the experimental period and laboratory were performed using SPSS statistical software and comparisons of means was done based on LSD statistical test. Results and DiscussionThe results showed that SNP at a concentration of 2 mM caused the highest shelf life (117.20 days) and the highest proline content (80.14 mg/kg) in kiwi fruits. The reason for this increased shelf life may be that SNP delays ethylene production process by activating the genetic and biochemical mechanisms, thus increase the postharvest life of ethylene-sensitive products. The highest firmness (4.56 kg/cm2) and the lowest fresh weight loss (1.26%) was obtained in fruits treated with 12 h of blue light. Some of the most important causes of this finding are that blue light delays the peak time of ethylene production, and as a fungal agent, reduces fruits decay after harvesting. The data showed that 12-h irradiation of blue light and 2 mM SNP caused a significant increase in the amount of antioxidant enzymes (SOD, POD and APX) of kiwifruit. Other traits such as flavor index, dry matter content, ion leakage and malondialdehyde were also measured. Blue light treatment can effectively reduce the decay of many fruits during postharvest storage. The study on kiwifruit showed that the qualitative treatments of different lights on various cultivars at different times had a significant effect on some physiological, morphological and gene expression traits. LED irradiation was found to be a suitable method for improving the quality of nutrients and the quality of flavor after harvest of some fruits. SNP was a good treatment to maintain fruit quality and improve disease resistance in kiwi cultivar ‘Bruno’ during storage. Fruits treatment with arginine is a promising technology to reduce cold and brown damages by stimulating the activity of antioxidant enzymes. Plant resistance to environmental stresses due to the use of arginine is in order to the effect of this substance on polyamine accumulation through increasing arginine decarboxylase and ornithine decarboxylase enzymes and increasing proline accumulation by enhancing ornithine amino-transferase enzyme activity as well as increasing nitric oxide through increasing the activity of nitric oxide synthase enzyme. Quality of kiwi fruit decreases during storage due to rapid softening and contamination with some fungi. In this study, effective treatments were used to reduce these complications. Overall, the results of this study showed that 2 mM SNP caused the highest shelf life. The highest firmness and the lowest fresh weight loss were observed in fruits treated with 12 h blue light. 12-h irradiation of blue light and 2 mM SNP caused a significant increase in the antioxidant enzymes of kiwifruit.
Postharvest physiology
M. Rahemi; M.H. Nazaran; S. Abolghasemi; S. Sedaghat; M. Zare
Abstract
Introduction
Low temperature storage is the most important method used to preserve harvested products. Keeping products at low temperatures, above the freezing point up to 10 degrees Celsius, can cause frost damage in fruits and vegetables, especially tropical and subtropical products. The use of heat ...
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Introduction
Low temperature storage is the most important method used to preserve harvested products. Keeping products at low temperatures, above the freezing point up to 10 degrees Celsius, can cause frost damage in fruits and vegetables, especially tropical and subtropical products. The use of heat treatments as safe, organic and alternative physical methods is increasing, these treatments are used to maintain the quality after harvesting and also to prevent frostbite of garden products. Also, one of the recommended methods to reduce fruit waste is to increase the calcium concentration of the fruit by using calcium solutions. Calcium is one of the most important mineral elements that is involved in determining the quality of the fruit and its shelf life. Studies conducted on the use of nano fertilizers in some species of fruit trees has shown their potential role in improving the yield of the product and the physical and chemical properties of the fruitThis study was conducted to investigate the effect of postharvest treatments of calcium chloride and nano chelated calcium fertilizers on chilling injury and physiological characteristics of local orange fruits stored at 2 ±0.5° C and 85% relative humidity for 60 to 120 days.
Materials and Methods
In this research, orange fruits of the local cultivar Citrus sinensis at the stage of commercial maturity based on the taste index (10TSS/TA⋍) were prepared from Darab city of Fars province and transferred to the Physiology Laboratory of Horticultural Sciences Department of Shiraz University. Then the fruits were disinfected with 2% sodium hypochlorite and washed with distilled water. Treatments included calcium chloride and nano chelated calcium fertilizers at different concentrations of zero, 3 and 6 dissolved in cold water (20°C) and hot water at 45 °C for 25 and 15 min, respectively. Sampling was done on days 60 and 120. To simulate shelf life conditions, before measuring the parameters, the fruits were kept at laboratory temperature for two days. In this research, the changes in fruit tissue firmness, freezing index, weight loss percentage, soluble solids, total acidity, ascorbic acid, ion leakage, potassium ion leakage, malondialdehyde, calcium content of fruit skin and flesh, fruit color, catalase enzymes and peroxidase were measured. Data analysis was done using SAS software version 4.9 and comparison of averages was done by LSD test at 5% probability level.
Results and Discussion
There was a significant difference between nano chelated calcium and calcium chloride in calcium enrichment in pulp and fruit skin Calcium chloride and nano chelated calcium treatments dissolved in hot water reduced weight loss, soluble solids content, acidity, ascorbic acid, ion leakage and malondialdehyde and the activity of the antioxidant enzymes catalase and peroxidase. Nano chelated calcium increased calcium content by 44% in fruit skin and up to 41% in fruit pulp compared to calcium chloride. Nano chelated calcium 3 and 6 % showed more stability in fruit weight (159 and 400%, respectively) compared to calcium chloride after two months of storage. After 60 and 120 days of storage, the content of ascorbic acid in fruits treated with 6 nano chelated calcium was 73% higher than calcium chloride. Nano chelated calcium 3 % compared to calcium chloride prevented 39.6 of potassium ion leakage during 60 days of storage. The amount of ascorbic acid in the 3% and 6% nano calcium treatment and the tissue hardness in the 3% nano calcium chelate treatment after two months of storage were estimated to be higher than the control and calcium chloride. Calcium nano chelate 6% improved the calcium content of fruit flesh and skin due to increased permeability. Warm water pretreatment with calcium compounds is an efficient and recommendable treatment for the preservation of orange fruits in cold storage conditions due to the improvement and reduction of the severity of the increase in indicators related to the occurrence of frost damage in the skin of fruits.
Conclusion
One of the primary concerns during storage is the loss of fruit weight. Calcium nano chelate, in comparison to the control and calcium chloride treatments, exhibited the least weight loss over the two months of storage. This is attributed to the critical role of calcium in influencing the shelf life of fruits. It was observed that immersing fruits in calcium compounds dissolved in hot water and utilizing 6% nano chelated calcium had a significant positive impact on enhancing and preserving the quality of orange fruits during cold storage.
Postharvest physiology
H. Soleymani; M. Aelaei; M. Arghavani
Abstract
Introduction
Rose is one of the important cut flowers, which has different types. Extending the vase life of rose-cut flowers is very important in the floriculture industry. Every year, due to the lack of proper storage conditions after harvesting, the efficiency of rose production decreases. ...
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Introduction
Rose is one of the important cut flowers, which has different types. Extending the vase life of rose-cut flowers is very important in the floriculture industry. Every year, due to the lack of proper storage conditions after harvesting, the efficiency of rose production decreases. Therefore, always using materials that help increase the shelf life of cut flowers is valuable. Today, substances that improve the quality of cut flowers are very important. They include materials such as calcium and silver. Nanoparticles are materials with sizes smaller than 100 nanometers. On the other hand, the important role of calcium and silver in improving quality of the cut flowers is interesting for scientists. In this research, the effect of pre-harvest application of calcium nanoparticles along with the post-harvest application of silver nanoparticles on the morpho-physiological characteristics of rose cut flowers (CV: Classic Cezanne) was investigated.
Material and Methods
The current research was carried out during the year 2021 in a commercial rose production greenhouse in Nazarabad city. calcium nanoparticles with different concentrations (0, 5 and 10 mg.L-1) were sprayed on rose bushes every ten days (two months before harvest). After harvesting the flowers and transferring them to the laboratory, silver nanoparticles were added to the flower preservation solution at different concentrations (0, 5 and 10 mg.L-1). After harvesting, the traits (vase life, flower diameter, fresh weight, vase solution uptake, total protein, malondialdehyde and superoxide dismutase) were evaluated on the treated flowers (on days 0, 4, 8 and 12). Experiment was performed as factorial based on completely randomized design, included 9 treatments with 3 replications.
Results and Discussion
Based on the results of analysis of variance of treatment with calcium nanoparticles and silver nanoparticles for the quality of shelf life at the 1% level of Duncan's test, it showed a significant difference. Also, based on the results, the highest amount of vase life is related to the treatment of calcium nanoparticles with a concentration of 10 mg.L-1 with the silver nanoparticle treatment in the time after harvesting was at concentrations of 5 and 10 mg (11 days) and the lowest amount was related to the control treatment (7 days).Vase life increased under the effect of treatment with calcium nanoparticles and silver nanoparticles (10 mg.L-1) and caused an increase of 4 days compared to the control (0 mg.L-1) The treatments decreased the amount of malondialdehyde and also increased the relative amount of absorbed solution, total protein and superoxide dismutase enzyme. Based on the results of this study, calcium and silver nanoparticles improved qualitative traits. The simultaneous treatment of calcium and silver nanoparticles (concentration 10 mg.L-1) compared to the control (0 mg.L-1) caused an increase (14%) in flower diameter, fresh weight (12%), vase solution uptake (46%), superoxide dismutase (21%) and malondialdehyde reduction (37%). Two other important findings emerged from this work: (1) The nanoparticles used in this experiment caused the activation of the enzyme antioxidant system in the treatments (2) The simultaneous treatment of nanoparticles calcium before harvesting and silver nanoparticles treatment after harvesting by activating the antioxidant enzyme system and maintaining the ability to absorb the solution increased the vase life of rose cut flowers. In general, the treatment with calcium nanoparticles at a concentration of 10 mg. L-1 before harvesting and the treatment with silver nanoparticles at a concentration of 10 mg.L-1 after harvesting were the most effective treatments in most traits.
Conclusion
Calcium is one of the most effective factors in increasing the vase life of rose cut flowers. Treatments containing calcium increase absorption of vase solution uptake. The treatment of calcium nanoparticles increases the total protein and superoxide enzyme compared to the control, so that the simultaneous use of silver and calcium nanoparticles increases the vase life of rose-cut flowers compared to the control. Calcium probably activated a chain of reactions by activating the message transmission system and caused the expression of genes involved in the antioxidant system of the samples. silver nanoparticles by affecting the absorption of vase solution uptake and reducing the amount of malondialdehyde and increasing the total protein and superoxide dismutase enzyme compared to the control, increase the vase life of cut flowers. According to the results obtained from the present research, it can be concluded that use of calcium nanoparticles with silver nanoparticles had great effects on most of traits in compared to control treatment. The use of calcium nanoparticles with silver nanoparticles improves the vase life conditions by increasing water uptake and consequently increasing the relative fresh weight.
Growing vegetables
S. Parsajoo; F. Dashti
Abstract
Introduction
Plants are sometimes exposed to several stresses during their growth and development. Salinity stress is one of the most common abiotic stresses that significantly reduces the growth and yield of most plant species. A large part of the soils and a significant volume of all water resources ...
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Introduction
Plants are sometimes exposed to several stresses during their growth and development. Salinity stress is one of the most common abiotic stresses that significantly reduces the growth and yield of most plant species. A large part of the soils and a significant volume of all water resources in Iran are affected by salinity to varying degrees. Due to the rapid population growth and the need for more food and the water crisis, the use of unconventional water such as salt water or wells and treated wastewater in agriculture has received more attention. Soil and water salinity is one of the integrative problems in agriculture and is one of the most important barriers to crop production in the world. Salinity stress reduces the ratio of carbon dioxide to oxygen in the leaves by closing the leaves stomata and prevents the stabilization of carbon dioxide. Under these conditions, the formation rate of reactive oxygen species in chloroplasts and mitochondria increases, the electrons produced react with oxygen by photosynthesis and lead to the production of oxygen free radicals. These affects the growth, yield and quality of agricultural products. The use of antioxidant compounds can moderate the effects of this stress. Many compounds have been used to reduce the harmful effects of salinity stress. Ascorbic acid is a water soluble antioxidant and has some effects on plant resistance against environmental stresses by neutralizing free radicals. Researches showed that ascorbic acid increased plant resistance on various stresses such as salinity and drought. It has been widely used to control the effects of salinity stress. The aim of this study was to investigate the effect of ascorbic acid on resistance to salinity stress in bell pepper seedlings.
Materials and Methods
This study was done as a factorial experiment in a completely randomized design including ascorbic acid treatment (0, 1, 3 and 5 mM) and salinity stress of sodium chloride (0 and 100 mM) in 3 replications. The seeds of bell pepper Cv. California Wonder were planted in a seedling tray containing cocopeat. After emergence of cotyledons, they were fertilized with complete fertilizer (N20, P20, K20). At the stage of three true leaves the salinity treatment were started. One week before the beginning of salinity treatment, ascorbic acid was sprayed on plants and repeated two more times by seven days interval. Salinity treatment was applied by irigation for three weeks. After producing 5 leaves, a few growth properties (plant fresh and dry weight, root fresh and dry weight, leaf number and leaf area), biochemical characteristics (amounts of total chlorophyll, proline, soluble proteins, ion leakage and malondialdehyde and activity of Catalase an Proxidase enzymes) and amounts of some elements (K, P, Na, Fe, Zn and Cu) were measured.
Results and Discussion
Based on the results, the simple effect of salinity stress, ascorbic acid and the combined effect of them on ion leakage and amounts of malondialdehyde were significant at the level of 1% probability. Salinity stress increased the amounts of ion leakage and malondialdehyde and application of 5 mM ascorbic acid reduced the amount of these traits to 41.01% and 46.58% compared to the control respectively. The effect of salinity stress, ascorbic acid and the combined effect of them on the concentration of proline and chlorophyll in the leaves of bell pepper were significant at the level of 1% probability. Salinity stress increased the amount of proline but decreased chlorophyll and leaf protein of pepper seedlings and application of 5 mM ascorbic acid increased them to 79.42% and 46.57% compare to control respectively. Under salinity stress the uptake of iron, zinc, copper and phosphorus decreased; using of 5 mM ascorbic acid increasing accumulation of these elements in leaves .On the other hand ascorbic asid could decrease the amounts of sodium accumulation in seedling,s leaves. The results showed that, salinity decreased growth indices (number of leaves, leaf surface, fresh weight of roots and plants) and ascorbic acid reduced the effect of salinity stress on growth parameters. Under salinity stress, 5 mM ascorbic acid treatment increased the leaf surface to 36.30% compared to salinity without ascorbic acid tretment. The effects of salinity stress and the combined effect of salinity stress and ascorbic acid on the amount of catalase and peroxidase enzymes were significant at the level of 1% probability. The effect of ascorbic acid was significant for catalase at 5% probability level and peroxidase at 1% probability level. Although salinity increased the amounts of the antioxidant catalase and peroxidase enzymes but ascorbic acid could increased the activity of them in saline condition.
Conclusion
It seems that application of ascorbic acid as an antioxidant could reduce the effects of salinity stress by increasing the activity of catalase and peroxidase enzymes, reducing sodium uptake and increasing the uptake of phosphorus, potassium, iron, zinc and copper. These could have positive effects on the growth parameters of bell pepper seedlings in salinity conditions. Generally, on based of obtained results, spraying 5 mM Ascorbic acid on bell pepper seedlings modified the resistance of them in salinity stress conditions.
Growing vegetables
M. Sajedimehr; M. Haghighi; M. Mehnatkesh
Abstract
Introduction
Drought stress is one of the most important factors limiting plant growth and production and leads to a reduction of more than 50% in the average production of most crops worldwide. Drought stress due to increased soil osmotic potential, especially in greenhouses where fertilizer consumption ...
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Introduction
Drought stress is one of the most important factors limiting plant growth and production and leads to a reduction of more than 50% in the average production of most crops worldwide. Drought stress due to increased soil osmotic potential, especially in greenhouses where fertilizer consumption is high, is one of the greenhouse crop problems.
Material and Methods
In the present study, two concentrations of polyethylene glycol at three levels of 0 (D1), -1.48 (D2), 4-91 (D3 ds/m to create different levels of drought stress due to osmotic changes in culture medium and application of KCl two levels (0 (K1) and 6 (K2) mmol / l) was used to reduce the possible effects. The experiment was performed as a factorial experiment in a completely randomized design with three replications. To apply drought stress, pot water was measured using a tensiometer, and when the drought reached below the field capacity (FC), irrigation with different concentrations of PEG and once a week spraying with KCl at the desired concentrations was done. Cucumber seeds were planted directly in 5 kg plastic pots containing a mixture of potting soil, including soil + sand + animal manure in the ratio of 1 + 2 + 0.5. The number of seedlings in each pot was 2 to 3 kg, which was reduced to one seedling seventeen days after sowing the seeds in the stage of three to four leaves. KCl spraying and spraying began in the three to the four-leaf stage of the seedlings and lasted for about a month. The plants were kept in the greenhouse during the experiment with an average temperature of 25 ° C and relative humidity of 70%. At the end of the experiment, dry weight, fresh weight, chlorophyll, chlorophyll fluorescence, flavonoids, carotenoids, proline, phenol, total protein, abscisic acid, superoxide, and ascorbate peroxidase, antioxidants, and catalase were measured.
Result
The results showed that the effect of foliar application of potassium in all traits except chlorophyll fluorescence and superoxide dismutase was significant (P <0.01). According to the obtained results, ccontrol treatment increased the amount of antioxidants and catalase, but the application of K2 on most of the measured parameters, including dry weight, fresh weight, chlorophyll, flavonoids, carotenoids, proline, phenol, total protein, abscisic acid, and superoxide disodium showed a positive effect. In D3 with the addition of K2 the highest amount of phenol and protein was observed. Also, the content of abscisic acid in all treatments increased with the addition of K2 and the highest amount was observed in D3 which can be concluded that the use of potassium at a concentration of 6 mM Acceptable cut. According to the results obtained in this study, it can be stated that the plant tries to maintain its osmotic pressure in the face of drought stress, and this is done by increasing osmolites such as proline and antioxidant enzymes that help maintain plant cell pressure and torsion. Potassium application can reduce the adverse effects of drought stress by improving the activity of antioxidant enzymes and preserving chlorophyll. Thus, the cell continues its vital activities and ultimately produces more acceptable performance under these conditions. In other words, increasing the antioxidant activity in drought conditions along with the application of potassium leads to a higher inhibitory capacity of reactive oxygen species and production stability in these conditions. Therefore, to compensate for at least some harmful effects of stress and help the plant to return to normal growth conditions after re-irrigation, foliar application of such elements can be effective in drought resistance of the plant and play a role. Based on the findings of this study, it seems that the application of potassium with a concentration of 6 mM is the most effective.
Pomology
Sh. Sorori; A. Asgharzade; A. Marjani; M. Samadi
Abstract
Introduction Drought is one of the most important environmental stresses. It limits crop production in the world and has adverse impacts on growth of plants and their metabolic processes. By changing some of the metabolic processes, drought stress changes the behaviour of plants and, eventually, ...
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Introduction Drought is one of the most important environmental stresses. It limits crop production in the world and has adverse impacts on growth of plants and their metabolic processes. By changing some of the metabolic processes, drought stress changes the behaviour of plants and, eventually, makes them resistant to some stresses. Given the water crisis in Iran, and since most of the available water is used in the agriculture sector, there is a need to change the current cropping pattern. The substitution of low-water-use for high-water-use plants could be an important water management strategy. Every physiological and biochemical factor involved in water conservation in plants is an effective factor in introducing tolerant varieties.Materials and MethodsThe required chemicals ( 80% acetone, 95% ethanol, ninhydrin, glacial acetic acid, benzene, proline, pure glucose, anthrone, sulfuric acid, potassium phosphate, polyvinylpyrrolidone [PVP], EDTA, hydrogen peroxide and guaiacol) were purchased from the Merck Company. This study was carried out in the spring and summer of 2019 in the Research Greenhouse of Islamic Azad University of Bojnourd. The rooted cuttings of 18 dominant grape varieties in the region (Kolahdari, KajAngoor, Fakhri, sefid Beryan, Divaneh, Sahebi, La’l, Siyah, Shiregi, Garmeh, Khalili, SanjariKajAngoor, Keshmeshi, Ghareghat, Maskeh, Asgari, Flame Seedless and White Seedless) were planted in plastic pots with a diameter of 35 cm and a height of 40 cm. The soil was a mixture of blown sand, leaf litter, and garden soil in the 1:1:1 ratio. Before the experiment, all pots were irrigated to reach field capacity.The factorial experiment was conducted using completely randomized design with three replications. The first factor was irrigation cessation (15-day drought stress) and control (irrigation to field capacity level). The second factor was variety (18 varieties).To apply the stress condition, irrigation cessation continued until leaf wilting signs were appeared. Based on previous experience, the duration of tolerance to drought stress was approximately 2 weeks. During the experiment, the minimum and maximum greenhouse temperatures were, respectively, 18.5 °C and 34 °C and natural light was used.Results and Discussion The results of analysis variance showed that drought stress significantly increased the amount of electrolyte leakage (6.29), and activities of peroxidase (0.056 katal per ml) and catalase (0.92 katal per ml). It also decreased leaf relative water content (61.95%), relative chlorophyll content (16.85) and contents of chlorophyll a (3.45 mg/g), chlorophyll b (1.12 mg/g) and carotenoids (2.84 mg/g).Grape varieties respond differently to drought stress and, in general, water scarcity reduces their leaf RWC and chlorophyll contents. According to Schutz and Fangmier (2001), a decrease in chlorophyll content under stress conditions is because of an increase in the production of oxygen radicals in the cell. These free radicals can cause peroxidation and decomposition of the pigments. The intensity and greenness of the leaves reduce with decreasing the chlorophyll concentration and accelerating the process of aging.Reduced greenness of the leaves under long-term stress conditions may be partially due to reduced nitrogen flow into the tissues and changing activities of such enzymes as nitrate reductase. Since nitrogen is a constituent of a chlorophyll molecule, its deficiency in plants may slow down the formation of chlorophyll. Lawlor and Cornic (2002) showed the effectiveness of carotenoid, as an auxiliary pigment, in protecting thylakoid membranes and preventing chlorophyll photo-oxidation. Drought stress increases the activity of the peroxidase and catalase enzymes in both drought-sensitive and -resistant varieties; however, the activity of antioxidative enzymes is significantly higher in the stress-resistant varieties.The studied cultivars were divided into the three groups include of tolerant (White Seedless, Garmeh, Maskeh, Flame Seedless, Fakhri, Khalili and Divaneh), semi-susceptible (Kolahdari, Sefid Beryan, Sahebi, Laal, Shiregi, Kaj Angoor Sanjari and Asgari) and sensitive (Siah, Ghare-Ghat, Kaj Angoor Sanjari and Keshmeshi) cultivars to drought stress. Among the studied cultivars, White Seedless had the highest levels of relative leaf water (77.81%), relative chlorophyll content (28.62), carotenoids (4.81 mg/g) and the lowest amount of electrolyte leakage (31.5) and Garmeh the highest chlorophyll a (6.64 mg/g) and chlorophyll b (2.12 mg/g) contents and peroxidase (0.0618 katal per ml) and catalase activities (0.959 katal per ml).Conclusion The grape plant adaptation to drought stress is the result of changes in many morphological, physiological, and biochemical mechanisms, which cause changes in the rate of electrolyte leakage, leaf RWC, proline content, soluble solids, speed of photosynthesis, enzymatic activities, etc. The results showed that the white seedless variety had the highest leaf RWC, relative chlorophyll content, carotenoid content, and the lowest electrolyte leakage. Besides, Garmeh variety with the highest chlorophyll a and b, peroxidase, and catalase contents is amongst the most resistant varieties.
Ornamental plants
R. Abdi; Z. Jabbarzadeh
Abstract
Introduction The genus Rosa from the family Rosaceae with over 150 species is one of the most important ornamental plants in the world. From a commercial point of view, cut roses play a key role in trade of cut flowers. Nitric oxide regulates key physiological processes that depend on the concentration ...
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Introduction The genus Rosa from the family Rosaceae with over 150 species is one of the most important ornamental plants in the world. From a commercial point of view, cut roses play a key role in trade of cut flowers. Nitric oxide regulates key physiological processes that depend on the concentration of this compound such as hypocotyls growth, defensive responses, growth and development, photosynthesis, and phytoalexin generation in stressful conditions. Polyamines are key biomolecules that have a role to play in the regulation of many plants’ growth and development processes and their responses to different environmental stimuli. This study was performed to investigate the effect of foliar application of sodium nitroprusside (as a NO donor) and putrescine (as a polyamine) on ‘Avalanche’ rose in hydroponic conditions.Materials and Methods This study was conducted in the research and production greenhouses of Urmia University and the research laboratory of the Department of Horticultural Sciences of the Faculty of Agriculture in 2019-2020 on rose (Rosa hybrida ‘Avalanche). This experiment was conducted as a factorial trial based on completely randomized design with two factors including sodium nitroprusside in four concentrations of 0, 50, 100 and 200 μM and putrescine in four concentrations of 0, 1, 2 and 4 mM with 3 replications as a foliar application under hydroponic conditions in greenhouses and in pots. The treatments were applied two weeks after transplantation, every 15 day-interval for 4 months. In order to investigate the effects of putrescine and sodium nitroprusside on some morphological and physiological characteristics of plants, two weeks after the end of treatments, sampling was performed to measure morphological and physiological characteristics. The measured indicators included: fresh and dry weight of flowering stem, chlorophyll a, b and total chlorophyll, carotenoids and also in the postharvest stage were guaiacol peroxidase and ascorbate peroxidase enzymes activity and bending of flowering stem. The SAS software version 9.2 was used to analyze the variance and compare the mean of the studied traits. Comparison of means was performed using the Tukey’s range test method at a probability level of 1 and 5%. Also, Excel (2016) software was used to draw the graph.Results According to the means comparison of measured parameters, sodium nitroprusside along with putrescine increase the flowering stem fresh and dry weight, photosynthetic pigments of leaves and antioxidant enzymes activities at the postharvest stages. Sodium nitroprusside at a concentration of 50 μM with 4 mM putrescine increased the fresh and dry weight of the flowering stem. Also, the concentration of 100 μM sodium nitroprusside with 4 mM putrescine significantly increased chlorophyll a, b, total chlorophyll and carotenoid content compared to control. It should be noted that preharvest application of sodium nitroprusside along with putrescine cause to improve postharvest characteristics of rose. In this research, application of 100 and 200 μM SNP alone or with different concentrations of putrescine increased guaiacol peroxidase and ascorbate peroxidase activity and reduced bending of flowering stem of rose ‘Avalanche’ at the postharvest stage. Probably polyamines (such as putrescine) and nitric oxide increase photosynthesis potential with increasing photosynthetic pigments and protecting cell membranes thus increase growth and flowering traits of plants such as increasing the flowering stem weight of rose in this research. At postharvest stage, senescence of flowers is an inevitable phenomenon that cause to produce free radicles in plants. Free radicles injure the plant membranes lipids and change the antioxidant enzymes activities. This despite the fact that nitric oxide and putrescine protect antioxidant enzymes against free radicles as a result can improve vase life of rose. Conclusion Based on the results of the present study, it can be concluded that putrescine, with SNP, improves growth characteristics as well as increases the postharvest traits and quality of cut flowers of rose. According to the results, it is observed that among the different concentrations of putrescine, the concentration of 4 mM had the greatest effect on the growth and physiological parameters of rose while the concentration of 100 and 200 μM sodium nitroprusside had a greatest effect on physiological characteristics and postharvest traits of rose. In general, both SNP and putrescine had a positive and favorable effects on improving growth and postharvest indices, but the effective concentration varied depending on the type of parameter.
Medicinal Plants
A. Shamsaddin saied; M. Ramroudi
Abstract
Introduction: Biochar is a carbonaceous substance obtained from heating plant residues and wastes in an oxygen-containing medium with or without oxygen. Thermal decomposition of biomass in an oxygen-free medium is called thermophilicity (pyrolysis). Temperature is one of the factors influencing the characteristics ...
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Introduction: Biochar is a carbonaceous substance obtained from heating plant residues and wastes in an oxygen-containing medium with or without oxygen. Thermal decomposition of biomass in an oxygen-free medium is called thermophilicity (pyrolysis). Temperature is one of the factors influencing the characteristics of biochar. One of the objectives of this experiment is to investigate the effect of different temperatures on the biochar characteristics of cattle manure. The use of biochar as a soil conditioner and source of organic carbon in agricultural soils with minimal environmental damage is considered. Marigold is an annual plant that is used in industry and pharmacy in addition to food. Another aim of this experiment is to investigate the effect of biochar use from different temperatures on marigold under salinity stress.Materials and Methods: For biochar preparation, after collecting cattle manure from Bardsir farms, air drying and sieving were used for pyrolysis process for four hours at different temperatures (300, 400, 500, 600 °C). Then pH, EC, carbon stability, ash and biochar performance were measured. In order to evaluate the effects of biochar resulting from different heat-treated temperatures on salinity tolerance of marigold, a factorial experiment was conducted in a completely randomized design in the greenhouse. The two factors studied included salinity levels (0, 4, 8 and 12 dS.m-1) and biochar resulting from different thermocouple temperatures (0, 300, 400, 500 and 600 °C). The biochar rate was considered to be 20%. One month after salinity treatment, seedlings were evaluated for osmotic metabolites activity and growth characteristics of marigold seedlings.Results and Discussion: The results of ANOVA showed that all biochar properties were significantly affected by temperature factor. With increasing the pyrolysis temperature from 300 to 600 °C, pH and EC increased by 16.29% and 60.37%, respectively, and the ash content increased by 1.5 folds, but biochar performance and bulk density decreased by 52.28% and 48.1%, respectively. The highest carbon stability was observed at 500 °C, which increased by 20% compared to 300 °C. The results showed a significant negative effect of salinity stress on stem height, number and area of marigold leaves, so that with increasing salinity to 12 dS.m-1, 31.09, 17.28 and 45.7% decrease were observed in these traits, respectively. The physiological characteristics of marigold were significantly affected by the simple and interaction effects of salinity and biochar stress. In salinity treatments (0, 4, 8 and 12 dS.m-1) with increasing pyrolysis temperature from 300 to 600 °C 2.2, 2.04, 1.97 and 1.92 folds increase in leaf potassium concentration and 1.54, 2.26, 3.00 and 2.45 folds less than the control treatment in the amount of leaf proline was observed, respectively. The activities of catalase, ascorbate peroxidase and guaiacol peroxidase enzymes were also significantly affected by the interaction of salinity stress and heat temperature. The highest enzyme activity in biochar was from 600 °C, which increased up to 8 dS.m-1 for catalase and up to 4 dS.m-1 for ascorbate peroxidase and guaiacol peroxidase.Conclusion: In general, biochar salinity is its most important undesirable properties, which increases with increasing pyrolysis temperature, so the recommendation of biochar application in saline soils requires further studies. In the present study, the use of biochar under salinity stress did not have a significant positive effect on the development of marigold resistance and salinity stress tolerance.
A. Safarzadeh; G. Barzin; D. Talei
Abstract
Introduction: The salinity affliction of land constitutes a major threat amongst the various forms of soil degradation. Arbuscular mycorrhiza fungus can be useful as a bio-fertilizer in providing plant nutrition and reducing the effects of environmental stresses on plants. On the other hand, nitric oxide ...
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Introduction: The salinity affliction of land constitutes a major threat amongst the various forms of soil degradation. Arbuscular mycorrhiza fungus can be useful as a bio-fertilizer in providing plant nutrition and reducing the effects of environmental stresses on plants. On the other hand, nitric oxide plays a role in many environmental and non-environmental stresses, including drought and salinity stresses. Liquorice (Glycyrrhiza globra Linn.), commonly known as Mulahatti and Yashtimadhu, is the highest priority value crop which can be successfully cultivated on salt-affected and degraded lands. It is a small perennial leguminous herb of the family Fabaceae (Papilionaceae) native to the Mediterranean region and central and southwest Asia, and cultivated in Italy, Russia, France, UK, USA, Germany, Spain, China, Pakistan, Afghanistan, Iran, Iraq, Uzbekistan, Turkey, Turkmenistan and north-western India. This research was carried out with the aim of investigating the effect of nitric oxide modification on coexistence with arbuscular mycorrhizal fungus on some of the physiological traits of licorice under the salt stress of sodium chloride.
Materials and Methods: This research was a factorial experiment based on completely randomized block design with three replications. Factors consisted of five levels of NaCl-salinity (0 as control, 50, 100, 150 and 200 mM), two levels of nitric oxide (0 and 0.2 mM) and two levels of mycorrhizal fungi (the presence and absence of mycorrhizal). To do this, 10 kg pot of pumice mixture and pumice (1 to 1 ratio) were poured into 60 plastic containers (30 x 20 cm; 10 L) and sterilized by alcohol. The seeds germinated in petri dishes after adequate growth, they were transferred to the pots (all seeds were germinated and grown in the same conditions). In each pot, five seedlings were cultured and irrigated with distilled water until a two-leaf stage. After that, the treatment was carried out by a Hoagland solution. Application of saline treatments and nitric oxide (from sodium nitroproced as nitric oxide source) was performed 45-days. Finally, after 60 days of planting, sampling was carried out to measure the physiological traits from the middle leaves of each pot, and after being placed in an aluminum foil with ice-containing flux, it was transferred to the laboratory and then transferred to 80 o C. The evaluated traits were leaf flavonoids by Swain (52) method, proline content by Bates et al. (6) method, MDA with Ohkawa et al. (40) method, CAT activity by Pereira et al. (44) method, POD activity by Korori (28) method and SOD activity by Giannopolitis and Reis (21) method. The data were analyzed by SPSS 22 (IBM SPSS Statistics 22.0) software application. The data was normalized and inferential statistics such as analysis of variance and mean comparison of treatments were calculated using Duncan's multiple range test.
Results and Discussion: The results showed that the salinity stress had significant effect on flavonoid content, proline content, malondialdehyde rate and antioxidant activity of catalase, peroxidase and superoxide dismutase. Salinity had increased levels of malondialdehyde, proline content, and the activity of antioxidant enzymes (catalase, peroxidase, and superoxide dismutase). The coexistence of mycorrhiza fungus in combination with nitric oxide or alone reduced the number of flavonoids and increased proline content at each level of salinity stress. Nitric oxide had no significant effect on measured traits but was more effective in combination with Mycorrhiza fungi. In general, sodium chloride salinity stress had a negative effect on the physiological traits of liquorice, but the use of nitric oxide with arbuscular mycorrhizal fungus reduced the negative effects of stress. In general, it can be said that the removal and decontamination of active oxygen species is an important part of salinity tolerance in plants. In the present study, salinity stresses have significantly increased the amount of MDA, which is an indicator of plant response to stress. In addition to salinity stress, nitric oxide stress has been induced to reduce the effects of high salt concentration on some of the indices, thus reducing nitric oxide in high concentrations of MDA. Application of saline treatment significantly increased the activity of the three antioxidant enzymes CAT, POD, and SOD. The results showed that salinity stress had a decreasing effect on studied traits, but the application of arbuscular mycorrhizal fungus with nitric oxide reduced the negative effects of sodium chloride salinity stress on liquorice plant.
Ali Tajabadipour; mohammadreza fattahi; zabihollah zamani; Fatemeh Nasibi; Hossein Hokmabadi
Abstract
Introduction: Spring cold injury is one of the main limiting factors to production and distribution of pistachio. Pistachio is one of the most valuable and exported agricultural crops of Iran. Since, spring frosts results to considerabe damage to this plant, hence, it is important to investigate methods ...
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Introduction: Spring cold injury is one of the main limiting factors to production and distribution of pistachio. Pistachio is one of the most valuable and exported agricultural crops of Iran. Since, spring frosts results to considerabe damage to this plant, hence, it is important to investigate methods for reducing freezing damage. For this reason, selection of rootstocks and cultivars are an important objective in breeding programs. Freezing temperatures (below 0ºC) cause the movement of water from the protoplast to the extracellular space, resulting in the growth of extracellular ice crystals and ultimately, cell dehydration. Plants have developed complex processes to survive and recover from unfavorable conditions. To tolerate cold stresses, plants develop multiple mechanisms, including the accumulation of cryoprotective molecules and proteins, alterations in membrane lipid composition, and primary and secondary metabolite composition, as well as changes in global gene and protein expression Frost affects cell membranes, which become less permeable, and even break, giving rise to the leakage of solute from damaged cells. There is often a good correlation between ion leakage and freezing tolerance (22). Sugars may depress the freezing point of the tissue and act as a nutrient and energy reserve, alter phase properties of membranes in the dry state and act as cryoprotectants to preserve protein structure and function. Other compounds acting similarly are lipids, soluble proteins and free proline (44). Proline seems to have diverse roles under osmotic stress conditions, such as stabilization of proteins, membranes and subcellular structures and protecting cellular functions by scavenging reactive oxygen species (23). The aim of the present study was to evaluate different degrees of sensitivity to low temperatures in different genotypes and ‘Ahmad-Aghaii’ cultivar in relation to physiological and biochemical changes in field conditions.
Materials and Methods: In order to determine the effects of rootstock on pistachio cultivar ‘Ahmad-Aghaii’ under freezing stress conditions, an experiment was carried out as factorial based on a randomized completely design (RCD) with four replications. Treatments consisted of two levels: 1- rootstock genotype (four cold sensitive and tolerant rootstocks) and 2- temperatures (-2 and -4 ºC). The sampling was performed in full bloom stage from apical branches of pistachio cultivar ‘Ahmad-Aghaii’ budded on these rootstock genotypes. The branches in pots contain distillted water treated under -2 and -4 °C for 2 h. After treatment, the chilling index was determined. Flower clusters were used for measuring physiological and biochemical parameters. All determinations were carried out in four triplicates and data were subjected to analysis of variance. Analysis of variance was performed using the ANOVA procedure. Statistical analyses were performed according to the SAS software. Significant differences between means were determined by Duncan’s multiple range tests. P values less than 0.05 were considered statistically significant.
Results and Discussion: The results showed that chilling index was significantly lower in the cold-tolerant rootstocks than cold-sensitive rootstocks at -2 and -4 ºC. Also, Results indicated that electrolyte leakage, hydrogen peroxide (H2O2) and malondialdehyde (MDA) were significantly lower in tolerant rootstocks than sensitive ones. The content of soluble carbohydrate, total protein and proline were significantly higher intolerant rootstocks than sensitive ones. The activity of anti-oxidant enzymes ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and catalase (CAT) in tolerant rootstocks was greater than sensitive rootstocks. The reaction of temperature and rootstock indicated that electronic leakage, proline, H2O2,و and MDA significantly increased in -4 ºC. The activity of anti-oxidant enzymes APX, GPX and CAT decreased in -4 ºC as compared to -2 °C especially in cold-sensitive rootstocks. Some researchers believe that the accumulation of proline is as an index to select the drought-resistance varieties (26, 48). Stated that there was no comprehensive information about the relationship between the accumulation of proline and tension resistance. Research on apricot and peach confirmed the results of the present study because this pattern is also seen in their proline level (26 and 41). While the starch concentration decreases during the dormancy, the amount of proline increases which is in accordance with their results (36).
Conclusions: In this study, the damage of the membrane increased with decreasing temperature. The results showed that the rootstocks could increase the resistance to cold by increasing the amount of soluble sugars, protein, proline and the activity of the antioxidant system in the shoots and leaves of the scion. Regarding physiological and biochemical studies, it was determined that ‘Ahmad-Aghaii’ cultivar budded on cold tolerant rootstocks had higher soluble sugars, total protein, proline and CAT, APX and GPX enzymes activity and had less chilling index, ion leakage, H2O2 and MDA, which indicates less damage to the membrane of the cell and its contents compared with the cultivar 'Ahmad-Aghaii' budding to sensitive rootstocks. Consequently, the findings of this study selected TR1 as the most tolerant rootstock compared to other ones.
Nasrin Farhadi; Saeideh Alizadeh Salteh
Abstract
Introduction: Allium hirtifolium commonly known as Persian shallot is an important wild medicinal plant from Alliaceae family. Persian shallot commonly known as mooseer in Iran is a perennial diploid plant that is native to Iran and grows as a wild plant throughout in the Zagross Mountains range, western ...
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Introduction: Allium hirtifolium commonly known as Persian shallot is an important wild medicinal plant from Alliaceae family. Persian shallot commonly known as mooseer in Iran is a perennial diploid plant that is native to Iran and grows as a wild plant throughout in the Zagross Mountains range, western and southwestern Iran. It is a bulbous herb and usually consists of a single main bulb or rarely two bulbs. Each bulb has a weight of about 8-15 times of a garlic clove. The bulbs of mooseer has been widely used as a traditional herb and spice plant, added to a variety of foods such as salads, pickles, yogurt and different sauces. Conventionally, Persian shallot propagates through bulbs and seeds but these two methods are not commercially efficient due to low growth rate of bulbs and deep dormancy, low viability and germination rate of seeds. In addition, the natural habitat of this plant is under increasing pressure as a result of excessive incorrect harvest that caused to damage the plant density in Iran rangelands. So, improving the efficiency of A. hirtifolium propagation is necessary. A number of positive effects on the growth and productivity of some plants through cytokinin application have been registered by earlier research. The current study aimed to evaluate the effects of pretreatment and foliar application of forchlorfenuron as a safe cytokinin on improving the bulb production, phytochemical compounds and antioxidant attributes of Persian shallot.
Materials and Methods: This experiment was done at research green house of Tabriz University in 2015-2016. For pretreated of Persian shallot bulbs, they were soaked in 0, 50 and 10 mg l-1 forchlorfenuron solutions for 24 h. Then they were cultured in pots contained perlite and vermicompost with 3:1 ratio. Foliar application was applied 2, 4 and 6 weeks after culture with 0, 50, 100 and 150 mg l-1 concentrations of forchlorfenuron. At the end of growth season the number of leaves, number of bublets, fresh and dry weight of bulblet were recorded. The phytochemical compound (protein, phenol and allicin), antioxidant enzymes (catalase, peroxidase, ascorbate peroxidases and superoxide dismutase) and antioxidant activity of bulbs were assayed with spectrophotometry methods.
Results and Discussion: Foliar applications of plant growth regulators such as cytokinins in agriculture crops are reported to be useful in controlling multiple physiological processes, including flower initiation, shoot elongation, bulb production, fruit set and as well as affected the quality characters of products. In this study despite the bulblets number that did not influence by treatments, pretreatment and foliar application of forchlorfenuron significantly increased the leaves number, fresh and dry weight of bulbs in comparison with control plants. The highest leaves number (4.49 per plant) was obtained from pretreatments. The highest fresh weight (91.77 g) was recorded at 5 and 10 mg l-1 pretreatment and 100 mg l-1 (91.63 g) foliar application. The interaction effect of treatments on dry weight was significant and the highest dry weight (19.75 g) was recorded at 10 mg l-1 pretreatment with 100 and 150 mg l-1 foliar application. Allicin content did not show significant variation between treatments and in average was 0.859 mg g-1 FW. Total phenol content significantly influenced by treatments and the highest phenol content (1.585 mg GAE g-1 FW) was recorded at 5 mg l-1 pretreatment with 100 mg l-1 foliar application. The antioxidant enzymes included catalase, peroxidase and ascorbate peroxidase that showed significant increasing under forchlorfenuron treatments. Due to significant effects of forchlorfenuron on antioxidant compounds and enzymes of Persian shallot bulbs, the assay of antioxidant activity also showed a significant increasing in treated bulbs. The maximum percent of antioxidant activity (74.522) was obtained from 100 mg l-1 foliar application. Exogenous application of cytokinins plays an effective role by protecting the fluidity and integrity of plant cell membranes. They properly mediate enzymatic (SOD, APX, and CAT) and non-enzymatic machinery with the result of preventing cell membrane damage by oxidative stress.
Conclusions: Considerable improvement in biochemical and antioxidant attributes of Persian shallot was recorded with pretreatment and foliar application of forchlorfenuron. The present data support the potential uses of the forchlorfenuron for improving the production of weighty bulbs with the high antioxidants attributes in Allium hirtifolium. Pretreated and foliar application at 5 mg l-1 and 100 mg l-1 concentrations of forchlorfenuron, respectively showed the best results and is recommendable for A. hirtifolim production.
M. Mashayekhi; M.E. Amiri; F. Habibi
Abstract
Introduction: Salinity is the most significant abiotic factor limiting crop productivity and several physiological responses, including modification of ion balance, water status, mineral nutrition, stomatal behavior, photosynthetic efficiency and so on. The GF677 (Prunuspersica×Prunusamygdalus) is widelyusedas ...
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Introduction: Salinity is the most significant abiotic factor limiting crop productivity and several physiological responses, including modification of ion balance, water status, mineral nutrition, stomatal behavior, photosynthetic efficiency and so on. The GF677 (Prunuspersica×Prunusamygdalus) is widelyusedas rootstock for peach and almond. It is mainly used as a rootstock because of its resistance to drought, calcic soil and Fe deficiency. Nowadays, using tissue culture techniques is very popular for the selection of plant resistant to abiotic stress (in vitro salinity); because in vitro conditions are more controllable than in vivo conditions and the large number of genotypes can be evaluated in a limited space. For example, in the field, plants are exposed to variable biological and climatic conditions which result in some interaction effects. In other words, the nutrition and climatic effects are easily controllable in the in vitro conditions all over the year. The objective of this study is to identify biochemical markers of salinity stress of GF677 rootstock under in vitro conditions.
Materials and Methods: Plantlets of GF677 rootstock were subcultured into the Murashige and Skoog (MS) proliferation medium containing1 mg/l BA (6-Benzyladenine)and 0.1 mg/l NAA (naphthaline acetic acid) with different concentrations (0, 40, 80 and 120 mM) of sodium chloride (NaCl) with four replicates. Cultures were transferred to the growth chamber with temperature of 25±2°C, relative humidity of 70%, under a 16/8 h (day/night) photoperiod. Data were collected at the end of the experiment (6th weeks). Antioxidant enzymes activity (catalase and peroxidase),total protein content, proline content, soluble sugars, and Na and Cl were measured. The experiments were set up in a completely randomized design (CRD) with four replicates (a vessel in each replicate) and statistical analysis was performed using MSTAT-C program. Means were separated according to the Duncan’s multiple range test (DNMRT) at 0.05 level of probability.
Results and Discussion: After six weeks, the results showed that by increasing salinity levelsin the culture medium, antioxidant enzymes activity (catalase and peroxidase),total protein content, proline content and soluble sugars increased significantly. The antioxidant enzyme activities (catalase and peroxidase) were increased significantly in the GF677 rootstock by increasing salinity levels. Catalase activity increased with increasing salinity levels, such that the maximum value (0.61 [abs/min /mg protein (f.m)]) was observed in 80 mM sodium chloride treatment. The lowest catalase activity (0.11 mg [abs/min /mg protein (f.m)]) was observed in 120 mM. The highest of peroxidase enzyme activity (0.109 and 0.105 [abs/min /mg protein (f.m)]), was obtained in 80 and 40 mM, respectively. Also, by increasing the salinity level, total protein content increased significantly in GF677 plantlets. The highest total protein was observed in 80 mM sodium chloride. By increasing salinity levels, proline content increased compared to the control at the GF677 rootstock, but no significant difference was observed between salinity levels. The highest accumulation of proline was obtained in 80 and 120 mM, respectively, while the lowest proline was obtained in control. By increasing salinity levels, soluble sugars increased in GF677 rootstock. The highest accumulation of soluble sugars was obtained in 80 mM. By increasing salinity levels in the cultural medium, the uptakeof sodium (Na+) and chlorine (Cl-) significantly increased in GF677 rootstocks over the six-week culture period. The highest uptake of Na and Cl ions in plant tissue was observed in 4th week. The results showed that with increasing salinity levels (80 to 120 mM), leaf chlorophyll index (SPAD unit) decreased in GF677 rootstock. The lowest chlorophyll index was observed in 120 mM treatment, while the highest leaf chlorophyll index was obtained in the control treatment.
Conclusion: According to the results and analysis of biochemical and enzymatic responses,it can be concluded that GF677 is a concentration tolerant to salinity up to 120 mM. The highest amount of biochemical responses and enzymatic activity was observed at 80 mM, where the continued growth of the plant was in terms of salinity. The rootstock was due to antioxidant defense mechanisms such as antioxidant systems, osmotic adjustment by proline and soluble sugars and increasing protein synthesis can sustain growth even under salinity conditions, as a tolerant rootstock was used for peach and almond cultivars.
R. Gholinegad; A. sirousmehr; B. Fakheri
Abstract
In order to study the effects of drought stress and organic fertilizers (compost and vermicompost) on some physiological and biochemical characteristics of borage, an experiment with complete randomized block design in split plot arrangement with three replications was conducted in Zabol University, ...
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In order to study the effects of drought stress and organic fertilizers (compost and vermicompost) on some physiological and biochemical characteristics of borage, an experiment with complete randomized block design in split plot arrangement with three replications was conducted in Zabol University, Zabol, Iran. The treatments included 3 levels of stress as a witness or 100% of field capacity, 80%field capacity(mild stress) and 60% field capacity (tension) as the main factor and use organic fertilizers, including control (nofertilizer), consuming 40 tons of compost per ha, and consumes 4 ton of vermicompost per ha, were considered as minor. Results showed that chlorophyll index (SPAD) decreased with increasing severity of dehydration and the amount of chlorophyll fluorescence were added. The highest chlorophyll a (11.383 mg/g) in conditions stress and application of compost obtained and it was reduced with increasing stress intensity level and the lowest (5.763mg/g) in severe stress and lack of fertilizer application, respectively. The same trend was observed for total chlorophyll content. Most of the enzymes catalase, ascorbate peroxidase and polyphenol oxidase in conditions of severe stress and lack of application and at least 100% of field capacity and compost application, respectively. Proline at 60% field capacity and no application of any fertilizer (20.213 mmol/g wet weight) was a significant difference with other compounds treatments. Drought stress affected the dry weight of the borage plant and cut it and dry yield (6.134826 kg/per ha) in the water level control was not a significant difference with mild stress (80% field capacity). Overall production in drought conditions and the amount of enzyme scavengers, hydrogen peroxide and free radicals increases , then, in order to have acceptable performance of dry borage, crop irrigation to 80% capacity seems appropriate.
