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.
Growing vegetables
S. Khosravi; M. Haghighi; M. Menatkhesh
Abstract
Introduction
Agaricus bisporus is the important mushroom that is cultivated industrially and due to its medicinal properties, it has special nutritional importance in the food basket of the people of the world. It is predicted that with increasing population and changing consumption patterns, ...
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Introduction
Agaricus bisporus is the important mushroom that is cultivated industrially and due to its medicinal properties, it has special nutritional importance in the food basket of the people of the world. It is predicted that with increasing population and changing consumption patterns, food will be one of the most critical issues in the country soon and protein poverty will be one of the most critical leading crises. Mushroom can be the best choice for the supply of essential human protein because they produce protein-rich foods using agricultural waste. Mushrooms are also rich sources of essential amino acids, vitamins (B2, niacin and folate), and minerals. White button mushroom production accounts for about 35% of the total world production of edible mushroom. The production of edible mushroom (Agaricus bisporus) depends on planting, amount of spawn consumed, growing conditions, species and media of cultivated edible mushroom.
Material and methods
The present study aims to investigate the effect of vitamins B and C on growth, yield of button mushroom and its postharvest life. The study was performed in two separate experiments in the mushroom factory and storage. The experiment was performed in the mushroom factory located in Khomeini Shahr city of Isfahan province and experiments related to the laboratory section and the research laboratories of the Faculty of Agriculture, Isfahan University of Technology. In this study, a box culture system was used to grow mushrooms. For this purpose, in order to prepare the culture media and prevent the mixing of culture media containing different treatments, cardboard plastic was used to make the boxes. First, in order to eliminate the pathogens, tiram fungicide is used for 24 hours. Cartonoplasts were then placed at specific distances of 30 cm by 30 cm. To eliminate pathogens, the composts were steamed in an autoclave at 121 ° C at a pressure of 1.34 atmospheres for 15 minutes and boarded and treatments were applied. Treatments include 3 levels of vitamin C (0, 3 and 6 mg / kg) (C0, C1 and 2C), 3 levels of vitamin B (0, 0.5 and 1 mg / kg) (B0, B1 and B2) was performed by factorial experiment in a randomized complete block design with 4 replications (40). Vitamin B complex, including vitamins B1, B2, B6, B12 and B9 were prepared in a ratio of 1: 2: 2: 5: 4. The treatments were applied to the composts used in the bed after boarding and before applying topsoil. When the mushrooms reached the commercial harvest level, i.e., the cap was 2.5 to 8 cm, but the cap was not opened, the factors related to vegetative growth were measured as follows. The number of mushrooms during the harvest period was counted for all treatments and at the end of the period, the average number of mushrooms per unit area was calculated. Cap diameter and base of each fungus were measured with a caliper during the harvest period for all mushrooms. In order to estimate yield, the mushroom harvested daily were weighed from all replications of each treatment.
Result
The results showed that the nutritional supplements used in this study were effective in increasing vegetative growth and yield and the highest number of mushrooms and dry weight were related to vitamin treatment. The interaction effect of vitamin C and vitamin B on the quantitative and qualitative characteristics of edible mushrooms at harvest time showed that dry weight increased at C1 and C2 with increasing concentration of B2 and decreased at C0. Cap diameter increased at all concentrations of vitamin C with increasing concentration of B2 and C2 had the highest amount. Base diameter was highest in C1 with increasing all concentrations of B vitamins compared to other treatments and lowest in C2 with concentration of B0. Ion leakage in C2 increased with increasing concentration of B2 and decreased in C0 and C1. The number of mushroom in C1 and C2 decreased with the addition of vitamin B and the highest number in C2 increased with the concentration of B0. The weight of grade 2 at C0 and C1 decreased with increasing concentrations of B2 and B1, respectively. Total yield was increased at all concentrations of vitamin C using B1. The highest total yield was observed in C1 treatment with B2 application. Total performance in control and C2 treatment decreased with increasing B2. Harvest time hardness increased in all three vitamin C treatments by increasing the concentration of B1, but increasing the concentration of B2 compared to B1 decreased. The highest increase was observed in the control treatment of vitamin C and the highest decrease was observed in the treatment of C2. Harvest time whiteness increased in C0 and C2 with the addition of vitamin B and decreased in C1. In general, in the control treatment of vitamin C in the two concentrations of B1 and B2, the highest amount of whitening time was observed. The highest amount of ash was observed in C2 with B2 application. In the postharvest experiment, the highest hardness after 32 days of storage was related to vitamin B treatment and the highest postharvest hardness, postharvest whiteness, and whiteness after 32 days of storage were related to vitamin C treatment. Also, the results of comparing the mean of interactions showed that the total yield in all three vitamin B treatments increased with the application of 3 mg/kg. The results of the second experiment showed that the rate of water loss in C1 with the addition of B2 concentration was the highest and in the control treatment was the lowest. The hardness increased after 32 days of storage in the control treatment and C2 with the application of B1, but decreased in C1 and C2 with the use of B2. The highest amount of whiteness was observed in C1 after 32 days of storage by increasing the concentration of C1, which was not statistically significant with the control treatment. It seems that there is not much difference between different concentrations of vitamin C in vegetative and postharvest fungal traits, but better results have been obtained by increasing the concentration of vitamin B. The results indicate that the effect of supplements on the yield of edible mushrooms is different so that adding appropriate amounts of supplements to the culture medium significantly increases crop yield. The results of this study showed that vitamin C1 treatment resulted in the highest dry and total weight, cap diameter, base diameter, and number of mushrooms. Wetter and drier cap and base diameters, ion leakage and water loss, were the highest in vitamin B2 treatment.
M. Haghighi; A. Sheibanirad
Abstract
Introduction: Plants are constantly faced with abiotic and biotic stresses during their whole life. Abiotic stresses are various adverse environmental factors, including drought, high salinity, heavy metals, cold or heat shock, and ozone. Resulting in dehydration and osmotic stress, drought has caused ...
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Introduction: Plants are constantly faced with abiotic and biotic stresses during their whole life. Abiotic stresses are various adverse environmental factors, including drought, high salinity, heavy metals, cold or heat shock, and ozone. Resulting in dehydration and osmotic stress, drought has caused a dramatic reduction in crop production globally. Grafting can reduce the content of Malondialdehyde (MDA); prevent the accumulation of reactive oxygen species (ROS); increase activities of antioxidant enzymes; and maintain fresh and dry weights, grain yield, and relative water content in a variety of plants in response to drought stress. On the other hand, a range of abiotic and biotic elicitors can confer tolerance to drought stress in plants. Grafting of herbaceous fruit vegetables can reduce detrimental effects of biotic and abiotic challenges and cultural practices. Grafting can increase yield of cucurbits, initiate shoot growth, aid in resistance against nematodes and viruses, withstand high and low temperatures, improve nutrient and water absorption, resist against high concentration of salt, drought and waterlogging stresses. Grafting elite commercial cultivars onto selected vigorous rootstocks is a special method of adapting plants to counteract environmental stresses. Grafting is currently regarded as a rapid alternative tool to the relatively slow breeding methodology for increasing the environmental-stress tolerance of fruiting vegetables. Potential approach to reduce losses in production and improve water use efficiency under drought conditions in high-yielding genotypes would be to graft these varieties onto proper rootstocks capable of reducing the effect of water stress on the shoot and to increase tolerance to abiotic stresses. Cucumber (Cucumis sativus L.) is one of the main greenhouse vegetable crops widely grown in Saudi Arabia. The total greenhouse area for cucumber production in 2013 was 2605 hectares produced 236,087 tons. Major factor influencing growth and yield of cucumber is water quantity. The effects of different rootstocks on plant growth, yield, fruit quality and water consumption in cucumber was studied. The highest yield was obtained from 9075 (19.02 kg m2), which was 24.5 and 23.5% higher than in the non-grafted and self-grafted treatments, respectively. The plant height also increased with the use of rootstocks. The increase in the dry weights of the leaves and fruits depended on rootstocks. They concluded that grafting improved plant growth and yield depending on the rootstock genotype. Grafting has the potential to be as a strategy to increase the tolerance of plants to promote water use efficiency (WUE). The present study was aimed to evaluate the grafting biochemical and physiological effects on inducing drought stress resistance in cucumber. Materials and Methods: This experiment was conducted in complete randomized design with three replications and treatments are included grafted and ungrafted plants, and water potential level 0 (control), -0.4 and -0.8 MP. The Isfahan endemic cucumber specious as a scion with the hole method grafted on Ferro rootstock. The physiological and growth traits were measured. Photosynthesis (stomata conductance, photosynthesis, water use efficiency), growth (root and stem growth), and antioxidants (SOD, POD, protein) parameters, and transpiration were measured. Results and Discussion: Result indicated that grafting with increasing root nutrient absorption and its development drought stress resistance improved. Although, grafting reduced potassium content. Grafting and the interaction of rootstock ×scion impressed many morphological and physiological characteristics. Under stress condition, some features improved plant water relationship, growth and development. Gas exchange indices like photosynthesis, transpiration and stomatal conductance were lower in grafted plant compare to ungrafted plants. Proline content was significantly increased in grafted treatments compare to ungrafted ones. Higher potassium under -0.8 MP in grafted plants showed the maintenance osmotic stability and potassium hemostasis were the draught stress mechanism in resistant rootstocks. Conclusion: Finally, grafting as an efficient method to increase cucumber yield and improve drought resistance recommend. These results suggest that the use of drought tolerant Cucurbita rootstock can improve cucumber photosynthetic capacity under drought stress and consequently crop performance. The results revealed that grafted plants had better vegetative growth than ungrafted (control) ones. Furthermore, photosynthetic parameter, antioxidant activity and fresh and dry weight of stem and leaves were improved, but grafting had no significant effect on fruit quality and yield. In conclusion it is recommended that grafting procedure in some crops include cucumber should be done only after assuring the benefits and risks of grafted seedlings.
Growing vegetables
S. Khosravi; M. Haghighi
Abstract
Introduction: Brassinosteroids promote plant growth by enhancing some metabolic activities such as photosynthesis, nucleic acid biosynthesis, proteins and carbohydrates. Mechanisms of resistance and tolerance in plants have been developed to tolerate water deficit stress. One way to deal with drought ...
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Introduction: Brassinosteroids promote plant growth by enhancing some metabolic activities such as photosynthesis, nucleic acid biosynthesis, proteins and carbohydrates. Mechanisms of resistance and tolerance in plants have been developed to tolerate water deficit stress. One way to deal with drought is to use plant growth regulators. Brassinosteroids were first extracted from the pollen of turnip (Brassica napus) and were considered as the sixth group of plant growth regulators. These compounds stimulate growth and cell division and affect electrical properties, membrane permeability, stability and activity of membrane enzymes. Nowadays, brassinosteroids have been extracted from various plants and their structure and function have been identified.Materials and Methods: This experiment was conducted in a factorial experiment based on a completely randomized design on Capsicum annuum L. Castello cultivar under the average daily temperature of 25 °C and 18 °C at 75% relative humidity in greenhouses. Research conducted by the College of Agriculture, Isfahan University of Technology, with four drought treatments using polyethylene glycol 6000 solutions at four levels of 0, -6, -7, and -8 bar. Brassinosteroids were sprayed in two 1 μM control levels. Pepper seeds planted in transplanting trays containing 1 to 2 volumes perlite and vermiculite substrate. When the actual leaf of seedlings appeared, the root thoroughly rinsed with distilled water and then were transferred to black plastic containers with a diameter of 16 and height 13cm and 1L volume containing Johnson's nutrient solution including four dry treatments using 6000 polyethylene glycol solution and aerated in control for 15 minutes every 5 minutes. At the end of the experiment, vegetative factors such as fresh and dry weight of different parts of the plant, plant length, and volume, and physiological factors such as proline and abscisic acid content and chlorophyll fluorescence changes were measured.Results: The results of the analysis of variance table showed that brassinosteroid had no significant effect on most vegetative traits except root volume and weight and all physiological traits except chlorophyll fluorescence and the mentioned traits increased with the application of 1 mM brassinosteroid. However, the main effects of drought except for amino acid and the interaction of drought and brassinosteroids were significant on all traits. The results of the main drought effects showed that the root fresh weight at -8 bar and dry weight at -7 bar significantly decreased, whereas fresh and dry weight of the shoots at lower than -6 bar. The onset of decline showed that the root length and volume appeared to decrease with the onset of stress by -6 bar and the plant length also reduced with the first stress level. Drought stress at -6 bar level decreased chlorophyll fluorescence, chlorophyll index and Abscisic acid while at -7 bar decreased protein and increased proline. The results also showed that the amount of sulfuric, essential and unnecessary amino acids were significantly reduced by drought stress and brassinosteroid had no effect. Total amino acid content decreased with drought stress but there was no significant difference with control. With increasing drought stress, the fresh and dry weights of shoots decreased and the intensity of shoots decreased. The intensity of shoot growth decreased with the use of brassinosteroids at moderate stress but the mentioned trait showed the same adverse effects at all levels of stress. Brasinosteroid application decreased stress indices such as proline (7%) and abscisic acid (50%) and this decrease was more pronounced in proline, especially in more severe treatments. Amino acid and protein levels decreased with drought stress, and the use of brassinosteroids could not be effectively affected by this reduction, especially for the compounds and the amount of amino acids.The results of biplot analysis showed that the vegetative and protein traits had better mean in stress condition in the presence and absence of stress and in higher stress severity and application of brassinosteroid affected root fresh weight and abscisic acid content more than the other traits. While in mild stress it seemed to be more effectively on the steroid and most of the vegetative and physiological traits than the control.Conclusion: It seems that the application of brassinosteroids on pepper seedling in drought stress at a concentration of 1 μM is effective in maintaining vegetative properties and reducing negative effects of stress and reducing stress indices.
F. Dezhabad; M. Haghighi
Abstract
Introduction: Most plants, especially those that are native to hot areas, show signs of injury when exposed to low temperatures. Damages caused by cold stress occurs at the cell and organs level, which reflects it at the plant surface. Color change, chlorosis, general reduction of growth, cellular tissue ...
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Introduction: Most plants, especially those that are native to hot areas, show signs of injury when exposed to low temperatures. Damages caused by cold stress occurs at the cell and organs level, which reflects it at the plant surface. Color change, chlorosis, general reduction of growth, cellular tissue destruction, non-absorption of nutrients, reduction of photosynthesis, non-transferring photosynthetic materials are from early effects of cold stress. Cellular responses to colds including loss of thoracic pressure, vacuolization, collapse of cytoplasmic membrane balance, cytoplasmic flow loss, and general organ dysfunction. The susceptibility of the plant to frost is different depending on the type of plant, variety, tissue morphology and other cellular characteristics, as well as the cold conditions of the period, time and cold intensity. In addition, it seems that organs of the plant have different degrees of cold tolerance. If the temperature of the aerial part is favorable, the low temperature of the root zone can be one of the factors limiting the root system and plant growth. The consumption of balanced boron content by neutralizing the negative effects of cold stress and mechanisms such as maintaining the structure of the membrane, improving and increasing root growth, increasing the synthesis of proteins needed for the plant, adjustment of stomatal movements and improved stomatal conductance, increased cell division, increased nitrogen metabolism and chlorophyll production, and its consequence was increased photosynthesis and dry matter production, increased activity of antioxidants, calcium / potassium ratio adjustment, optimizing the transfer of calcium in the plant, adjusting the amount of water and conducting it in the cell, increasing the moisture content and relative content of leaf water, transferring soluble materials and increasing water use efficiency creates a relative resistance to low temperature stress. Although the root temperature is very effective in plant growth, it has been less attractive. Therefore, the aim of this study was to investigate the effect of low temperature of root and shoot on the ability to restore plant growth and physiological activity in the presence and absence of boron.
Materials and Methods: In order to compare the impact of sudden low temperature stress of root and shoot on recovery of vegetative and physiological traits of tomato, a research was conducted in two separate experiments under controlled conditions in the greenhouse of Faculty of Agriculture, Isfahan University of Technology. Two experiments were factorial based on completely randomized design with 10 replications including two concentrations of boron (0, 0.5, 1 and 1.5 in ppm) and two temperature levels of shoot and root sections (10 degrees’ Celsius temperature, and 11 rootstock temperatures and 22 ° C optimum and control temperatures). Indicators included photosynthesis rate, respiration rate, stomatal carbon dioxide, stomatal conductance, chlorophyll fluorescence, chlorophyll index, water use efficiency, proline, antioxidant, phenol secretion from root and leaf extracts, leaf relative water content, soluble protein concentration, ion leakage, leaf water potential, root and shoot dry weights and starch content. Finally, the analysis of the results was done by statistical software statistic and comparing the meanings by LSD test at 5% level.
Result and discussion: The results showed that the highest amount of photosynthesis, root dry weight and dry weight of the aerial part were in the consumption of 0.5 ppm of boron during abrupt stresses of low temperature on the root after the recovery period. The highest amount of stem proline and electrolyte leakage were also obtained from 0.5-1.5 ppm of boron consumption during abrupt low temperature on the shoot part. According to the results, it was found that when stress has entered from the root zone to the aerial part of the plant, the plant was in the better conditions after the recovery period. It seems that when a cold stress occurred on the roots, the plant can produced more antioxidant substances, including phenol and proline, while counteracting the relative water content of the leaves were more effective with radical agents. Thus, in normal conditions, the roots of the plant operated at a lower temperature than the airspace. They also exhibited more adaptations to the lower air at the lower temperature than the air section and the plant is less damaged. At levels above the boron element due to the effect of boron toxicity and the production of excess free oxygen radicals, the plant probably suffered more severe damage than cold damage.
Conclusions: Sudden low temperatures stresses on the root and shoot had negative effects on the recovery of the vegetative and physiological traits of tomatoes. When lower temperatures were imposed on the shoot, the plant suffered much more damages. Consumption of 0.5 ppm of boron during cold stress by creating optimal conditions for growth also caused the relative neutralization.
maryam haghighi; Bahareh Naghavi
Abstract
Introduction: Salinity has deleterious effect through ion toxicity and changes nutrient balance on plant growth parameter. For decreasing the hazardous effect of salinity stress, some effort has done to reduce uptake and accumulation of Na. Adding of Ca decreased these deleterious effect of salinity. ...
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Introduction: Salinity has deleterious effect through ion toxicity and changes nutrient balance on plant growth parameter. For decreasing the hazardous effect of salinity stress, some effort has done to reduce uptake and accumulation of Na. Adding of Ca decreased these deleterious effect of salinity. Calcium ions have significant effects on the physiological processes of plants and improve the morphological and biochemical factors of plants under salinity stress. The effect of calcium on reducing the harmful impacts of salinity from sodium depends on the plant type, calcium concentration and sodium source. Recently, the addition of nanoparticles to plants as fertilizers has attracted the attention of researchers because of its unpredictable effects, such as faster and easier penetration into the membrane of the cell. A few studies have examined the effect of different nanoparticles on the growth and physiology of plants. So, a research was conducted to investigate the effects of salinity and supplemental calcium in the form of spraying into two metal and nano-metal forms on vegetative growth of tomato plants under crop cultivation conditions.
Materials and Methods: To study the effect of CaCl2 and Nano-Ca on tomato (Lycopersicon escuhentum var. Falcato), a factorial experiment based on completely randomized design (CRD) with 4 replicates was designed with NaCl (0, 25 and 50 mM) and Ca and N-Ca (0, 150 and 200 mg/l) in Isfahan University of Technology greenhouse. Indicators include chlorophyll index, relative water content, ion leakage, leaf water potential, root and shoot dry weights, root and shoot length and root volume were measured. Finally, the analysis of the results was done by statistical statistic software and comparing the meanings by LSD test at 5% level.
Result and Discussion: Results showed that Ca and Nano-Ca was effective on decreasing hazardous effect of salinity on fresh and dry weight of shoot and root volume and Ca was more effective than Nano-Ca. In high salinity level (50mM NaCl), application of 150 mg/l Ca increased fresh and dry weight of root, fresh weigh of shoot and root volume by 60, 63, 50 and 70 % compare to control ,respectively. As well as, the highest root length and shoot was observed in this treatment. Application of 200 mg/l calcium and 150 mg/l of nano-calcium significantly improved chlorophyll content in 50 mM sodium chloride treatment. The plant's compatibility mechanism is very complex in the salinity conditions, from reasons for the growth of the plant under saline conditions are the accumulation of toxic ions, chlorine and sodium in plant tissues, which reduces enzyme activity and changes the pattern of carbohydrate distribution. Loss of the fresh and dry weight shoots and root of tomato has been reported in salinity conditions, which can be attributed to reduce plant growth due to the decrease in leaf area growth and thus the reduction of photosynthesis and the production of proteins. There is little research on the use of nanoparticles in plant growth and the use of nano-calcium has been used to reduce salinity stress for the first time, but the beneficial effects of some nano-materials on plants have been proven. With the use of titanium and nano-titanium in spinach, nano-titanium increases the fresh and dry weight of the plant relative to the use of titanium. In this study, the effects of calcium salinity stress were observed, but nano-calcium had less effects than calcium, and probably due to the fact that the concentrations of nano-calcium were used, using less concentrations in future research to achieve possible concentrations are suggested.
Conclusions: The use of nano-calcium to reduce salt stress was used for the first time in this experiment. The results of this experiment showed that the application of 150 mg calcium per liter on many tomato traits such as root and shoot fresh weight, root length shoots and root volume were effective under salinity stress, especially intense salinity (50 mM sodium chloride). The comparison of the effects of calcium and nano-calcium showed that the particle size reduction hadn’t shown a significant effect on calcium salt modification and may be due to the concentrations of nano-calcium. Therefore, nanotechnology needs more research in the application of nano-calcium and other nano-materials. Ca also alleviated the hazardous effects of salinity but comparing Ca and nano-Ca showed that nano-Ca has not significant alleviating effect on salinity stress.
maryam haghighi; Atena Sheibanirad
Abstract
Introduction: Soil salinity is a global problem that affects approx. 20 % of irrigated land and reduces crop yields significantly. Since, salinity is one of the most important abiotic stress and limiting factor for plant growth all around the world. It is necessary to find some way to ameliorate these ...
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Introduction: Soil salinity is a global problem that affects approx. 20 % of irrigated land and reduces crop yields significantly. Since, salinity is one of the most important abiotic stress and limiting factor for plant growth all around the world. It is necessary to find some way to ameliorate these damages. The physiological responses of a plant to salinity are often complex and multi-faceted, which makes experiments difficult to design and interpret. At basic level, the response of plants to salinity can be described in two main phases: the shoot ion-independent response occurs first, within minutes to days, and is thought to be related to Na+sensing and signaling. Tomato is one the most popular crop in open door and greenhouse cultivation which could face with salinity stresses. Salinity with inducing osmotic stress could have irreversible damages on plant growth and function. Three main salinity tolerance mechanisms have been proposed: on exclusion – the net exclusion of toxic ions from the shoot; tissue tolerance – the compartmentalization of toxic ions into specific tissues, cells and subcellular organelles; and shoot ion-independent tolerance – the maintenance of growth and water uptake independent of the extent of Na+ accumulation in the shoot. In order to face with stresses plant make some internal signals which cause producing different compound and inducing stress resistance. Salicylic acid is one these resistances induced agent. Azealic acid is an organic compound which could increase salicylic acid accumulation in plants.
Materials and Methods: So that, the present experiment was conducted to evaluate the effect of azealic acid and saline irrigation on tomato vegetative and photosynthetic parameters in factorial design based on CRD with three replications. The treatments were salinity level (0, 100, 150 and 200 mM) and azealic acid (0, 8, 10, and 24 mg l-1). The experiment was conducted in pot and in the greenhouse. Gradually in a week salinity treatments applied for plants after that each week once azelaic treatments also applied in each plant. Two weeks later each gas exchange parameters and all parameters needed fresh plant were measured and at the end all parameters with dry matter measured. The photosynthesis traits like transpiration, photosynthesis rate, mesophyll conductance, stomata conductance some stress indices like proline and antioxidant phenol were measured.
Results and Discussion: Results indicated that with increasing salinity level biomass production reduced. It seems that with azealic supplement especially in AZ2 treatment with improving photosynthetic water use efficiency, stomatal and mesophyll conductance has positive effect on photosynthesis. Under low salinity level azealic acid was an effective treatment in photosynthetic parameters although when salinity exceeds more than 100 mM photosynthetic parameters even with azealic acid application reduced. Azealic acid causes a kind of osmotic balance following that the proline content of these treatment reduced. In all salinity levels when azaleic acid applied the phenolic compound increased significantly and the highest was in AZ3. Azaleic acid reduced the Na concentration of leaves it causing the most tolerate reason against salinity when the azaleic acid applied. Although the photosynthetic rate increased with azaleic acid it is not because of chlorophyll content, because the chlorophyll content decreased with azaleic acid. The increase of photosynthesis could be due to decreasing Na concentration of leaves and increasing defense system of plants. Chlorophyll florescence decreased even with azaleic acid in salinity, it means that azaleic acid cannot completely compensate the stress harmful effect. The growth was improved with azaleic acid in salinity; the improvement was greater in root weight compare with shoot weight. Azaleic acid not only prevent decreasing the weight but also improved them in salinity. In defense system of tomato it seems that antioxidant and phenol content were more effective than proline because they are increased with azaleic acid in saline condition effectively compare with proline.
Conclusions: Finally, it seems that until 100mM salinity level azealic acid with maintaining gas exchange capacity in optimum level and inducing osmotic balance could reduce salinity damages. Conclusively, when azaleic acid was applied in 8mg/l that it improved photosynthetic traits like stomata conductance, mesophyll conductance, and photosynthetic water use efficiency compare with control. Azaleic acid can improve the photosynthetic traits when salinity was in low level like 100mM. Proline which is amino acid role as a defense system of plants increased the osmotic adjustment in plant in response to azaleic acid
maryam haghighi; maryam mozafariyan
Abstract
Decreasing irrigation via partial root zoon drying (PRD) save water and decreased production expenses. For comparing common irrigation and PRD on tomato cv. Falcato an experiment was designed in Massey University of New Zealand. Treatments were control (irrigation in a Field capacity in each irrigation ...
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Decreasing irrigation via partial root zoon drying (PRD) save water and decreased production expenses. For comparing common irrigation and PRD on tomato cv. Falcato an experiment was designed in Massey University of New Zealand. Treatments were control (irrigation in a Field capacity in each irrigation to whole root zoon) and PRD (irrigation in a half of Field capacity in each irrigation to one side of root zoon). The results were shown that superoxide dismutase and peroxidase activity increased in PRD compare with control. Photosynthesis, mesophyll conductance, photosynthesis water efficiency, fresh and dry weight of root and shoot decreased in PRD. NACE (Nutrient Acquisition Efficiency) of leaf was the highest for Zn and Na and the lowest for P when PRD applied compare with control. Yield indices like MP increased significantly by 63% compare to first harvest. YSI (Yield Stability Index) increased by 46% in third harvest compare with second one. The TOL (Tolerance index) increased by 80% in last harvest compare with first one. GMP (Geometric Mean Productivity) in the second harvest increased by 62% compare to first one.
M. Haghighi; mohsen kafi
Abstract
Information of heavy metal toxicity about physiological aspect of lettuce is limited. Therefore an experiment was conducted in CRD designed with 7 replications on lettuce (Lactuca sativa L.). Treatments were cadmium in 3 concentration (0, 2 and 4 mg/L) added to Hoagland solution. Results were shown that ...
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Information of heavy metal toxicity about physiological aspect of lettuce is limited. Therefore an experiment was conducted in CRD designed with 7 replications on lettuce (Lactuca sativa L.). Treatments were cadmium in 3 concentration (0, 2 and 4 mg/L) added to Hoagland solution. Results were shown that increasing in cadmium of nutrient solution caused increasing in SOD, POD antioxidant and proline contents of leaf tissues, in addition, cadmium decreased the amount of fresh weight and organic acid. Applying 2 and 4 mg/L cadmium in nutrient solution produced POD, SOD and Proline around 8 and 53%, 55 and 106%, 39 and 119% in 2 and 4 mg/L cadmium, respectively. Whereas in the same concentrations of cadmium protein decreased 25 and 5 %, respectively. Under cadmium stress, toxic effects decline photosynthesis more than chlorophyll content.
M. Haghighi; M. Mozafariyan; Z. Afifipour
Abstract
The superabsorbent polymer withholding water and disperse it gradually to roots increase soil water capacity. To study the effect of superabsorbent polymer on decreasing water stress effect as well as increasing irrigation efficiency a factorial experiment based on randomized block design with 4 replicates ...
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The superabsorbent polymer withholding water and disperse it gradually to roots increase soil water capacity. To study the effect of superabsorbent polymer on decreasing water stress effect as well as increasing irrigation efficiency a factorial experiment based on randomized block design with 4 replicates was design. Treatments were 0, 10 and 20 % V superabsorbent and irrigation levels 25, 50 and 100% field capacity in greenhouse of Shiraz University. The results were shown that drought stress decreased chlorophyll content, fresh and dry weight but did not effect on fruit parameters at 5%. Superabsorbent improved tomato growth in stress condition and in 50% FC,10% superabsorbent increased relative water content to 14%and fresh weight of root to 60%. Chlorophyll content increased to 22% in 25%FC with 20% superabsorbent relative water content and root fresh weight increased 28 and 53% respectively. In 25%FC with 20% superabsorbent. Superabsorbent elevated hazardous effect of drought stress and with holding the water in root zoon cues normal plant growth.
maryam haghighi; mohsen kafi
Abstract
Abstract
Lettuce is one of the best accumulators of heavy metals and nitrate between leafy vegetables. Through this research, it was tried to decreased cadmium absorption with humic acid (HA) and studies the effect of HA on the accumulation and metabolism of nitrate. Plants were grown in the peat/perlite ...
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Abstract
Lettuce is one of the best accumulators of heavy metals and nitrate between leafy vegetables. Through this research, it was tried to decreased cadmium absorption with humic acid (HA) and studies the effect of HA on the accumulation and metabolism of nitrate. Plants were grown in the peat/perlite and irrigated with Hoagland solution with addition of cadmium (2 and 4 mg L -1) and HA (100 and 1000 mg L-1). Results showed that Cd in media increased Cd of leaves and decreased protein and fresh weight but it has not any effect on the N, P and nitrate concentration and nitrate reductase activity. With increasing concentration of HA, increasing in fresh weight, N, protein concentration and decreasing in Cd concentration in leaves was observed. Using of HA and Cd together in nutrient solution showed that HA decreased absorption of Cd. So toxic effect of Cd decreased on the physiological changes of lettuce and do not accumulate nitrate in leaves, as well. More investigations should be done for using HA on the polluted soil for planting of lettuce.
Keywords: Nitrogen, Phosphorus, Nitrate, Heavy metal, Nitrate reductase
maryam haghighi; mohsen kafi; Toktam sadat Taghavi; karim kashi; Gholam Reza Savaghebi
Abstract
Abstract
study on photosynthetic and enzym Activity changes in lettuce under cadmium stress has been done in greenhouse. Of zhejang university in Chine The experimental design was a CRD factorial design organized in hydroponic system with 7 replications. Cadmium was added to nutrient solution in CdCl2 ...
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Abstract
study on photosynthetic and enzym Activity changes in lettuce under cadmium stress has been done in greenhouse. Of zhejang university in Chine The experimental design was a CRD factorial design organized in hydroponic system with 7 replications. Cadmium was added to nutrient solution in CdCl2 in three concentrations (0, 2, 4 mg/l). Stomatal photosynthetic factors (transpiration, stomatal and mesophyl conductance, internal CO2 concentration), enzyme activity changes (Proxidase and Superoxid Dismutase),chlorophyll, leaf length and number, biomass, transfer coefficient, was measured. Results showed that peroxidase and superoxide dismutase increased but biomass, photosynthesis, transpiration, stomatal conductance, internal CO2 concentration and leaf length was decreased as cadmium increased in nutrient solution, transfer coefficient was increased also.
Key Words: Photosynthesis, Chlorophyll, Stomata, Antioxidant, ,Cadmium, Lettuce
