Growing vegetables
Farhad Shakarami; sadegh Mousavi-Frad; Abdolhossein Rezaei Nejad; Farhad Beiranvand
Abstract
Introduction
Salinity in water and soil stands as a crucial environmental factor that significantly hampers global agricultural production. Over recent decades, the escalating demand for irrigation in arid and semi-arid regions has intensified this issue, making it a major agricultural challenge. Salinity ...
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Introduction
Salinity in water and soil stands as a crucial environmental factor that significantly hampers global agricultural production. Over recent decades, the escalating demand for irrigation in arid and semi-arid regions has intensified this issue, making it a major agricultural challenge. Salinity stress, characterized by reduced water absorption, heightened salt uptake (especially sodium, chlorine, and boron), and the generation of reactive oxygen species, induces oxidative stress in plants, severely impacting their growth and overall performance. To enhance plant tolerance to salinity stress, elicitors are employed as a short-term and viable solution to mitigate the adverse effects of stress. Copper, serving as a cofactor and essential element for numerous enzymes involved in photosynthesis and respiration processes, plays a crucial role in sustaining natural plant growth and metabolism. Copper ions function as cofactors in enzymes like superoxide dismutase (Cu/Zn SOD) and polyphenol oxidase, contributing to the removal of reactive oxygen species. However, the absence of this element in plants cultivated in alkaline and saline soils of arid and semi-arid regions can lead to nutritional disorders. In this context, copper nanoparticles emerge as a suitable alternative to chemical fertilizers due to their quicker and more efficient impact. Their use not only mitigates the negative consequences of excessive fertilizer application but also reduces the frequency of application. The Persian leek (Allium ampeloprasum subsp. Persicum) is a valuable edible-medicinal plant native to Iran, belonging to the Amaryllidaceae family. It holds significance in Iran as a key leafy vegetable, valued for its freshness and high processing potential among horticultural plants. Given the nutritional and medicinal importance of Persian leek and the prevalence of salinity stress, this study aims to explore the impact of copper nanoparticle spray in modifying the effects of salinity stress on the morphophysiological and biochemical characteristics of Persian leek.
Materials and methods
A factorial experiment was conducted using a completely randomized design with three replications in the research greenhouses of Lorestan University's Faculty of Agriculture. The experimental conditions included daytime temperatures ranging from 20 to 28 °C, nighttime temperatures from 15 to 20 °C, relative humidity set at 60-70%, and a light intensity of 400-500 µmol m-2 s-1. The first factor involved foliar spraying of copper nanoparticles at control levels (zero), 150, and 300 mg/liter, while the second factor comprised salinity stress at control levels (zero), 50, 100, and 150 mM sodium chloride. F1 seeds were obtained from Pakan Bazr Company and planted in 1.5-liter pots, with each pot containing three plants. The copper nanoparticles were applied through foliar spraying twice on the shoot parts at the four-leaf and six-leaf stages. Salinity stress was introduced one week after the foliar application, implemented through irrigation once every three days at a level corresponding to 90% of the field capacity. The soil mixture comprised an equal ratio of agricultural soil, cow manure, and sand, maintaining a clay-sand loam texture. Following three months of applying salt stress, a comprehensive assessment of morphophysiological characteristics was carried out. This included the measurement of plant height, stem and bulb diameter, leaf count, fresh and dry weights of stem, root leaf, root volume and length, shoot/root ratio, dry matter (%), stress tolerance index, relative water content (RWC), electrolyte leakage, malondialdehyde content, photosynthetic pigments, chlorophyll stability index, as well as the activity of peroxidase and ascorbate peroxidase.
Results and Discussion
The results indicated that salinity stress had a detrimental impact on various aspects of plant growth, including a decrease in plant height, stem and bulb diameter, leaf number, and the fresh and dry weights of the stem, bulb, and root. Additionally, there was a reduction in root volume and length, along with decreased levels of photosynthetic pigments. The percentage of electrolyte leakage, malondialdehyde content, and the activity of antioxidant enzymes, namely peroxidase and ascorbate peroxidase, also increased, highlighting the adverse effects of salinity stress on plant development. The decline in plant growth can be attributed to multiple factors, including diminished cell division, ionic imbalance, reduced water absorption, impaired uptake of essential elements, and the impact of toxic ions, particularly sodium and chlorine. Other contributing factors include impaired absorption, regeneration, and metabolism of nitrogen and protein, as well as stomatal closure, collectively resulting in reduced photosynthetic efficiency. Salinity stress further leads to a reduction in soil water potential and an increase in the osmotic pressure of the soil solution. Consequently, the plant requires more energy to absorb water from the soil, leading to increased respiration and alterations in the hormonal balance of plant tissues, ultimately causing a decrease in growth and negative effects on the plant. The application of copper nanoparticles at both concentrations demonstrated positive effects on various growth components, including plant height, stem and bulb diameter, leaf count, and the fresh and dry weights of the stem, bulb, and root, as well as increased root volume and length. Additionally, the use of copper nanoparticles resulted in a decrease in the percentage of electrolyte leakage and malondialdehyde content, coupled with an increase in the concentration of photosynthetic pigments and the activity of antioxidant enzymes, including peroxidase and ascorbate peroxidase. Notably, the concentration of 150 mg/liter exhibited a more pronounced effect in enhancing plant growth, with a diminishing impact observed at higher concentrations. Copper \nanoparticles improve plant growth under stress conditions by influencing the content of cellular antioxidants and modulating the hormonal balance of plant tissues.
Conclusion
The findings of this study indicated that increased salinity stress led to higher electrolyte leakage and malondialdehyde content, along with a reduction in RWC and photosynthetic pigments. These changes caused a decline in the morpho-physiological characteristics of Persian leek. However, salinity stress also increased the activity of peroxidase and ascorbate peroxidase enzymes. Foliar application of copper nanoparticles under these conditions had beneficial effects on the plants. Specifically, at a concentration of 150 mg/liter, the negative effects of salinity stress on the morpho-physiological indices of Persian leek were alleviated. This improvement was due to an increase in the activity of antioxidant enzymes, RWC, and the concentration of photosynthetic pigments.
Medicinal Plants
H. Kiani; Y. Sohrabi
Abstract
Introduction: In fact, drought is stress that restricts the plant photosynthesis and also it causes of chlorophyll content changes and damage to photosynthetic structures. One of the important reasons that environmental stresses such as drought reduce the growth and photosynthesis ability of the plant ...
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Introduction: In fact, drought is stress that restricts the plant photosynthesis and also it causes of chlorophyll content changes and damage to photosynthetic structures. One of the important reasons that environmental stresses such as drought reduce the growth and photosynthesis ability of the plant is a disturbance in the balance between production and removal of free oxygen radicals. Transpiration is a necessary process for photosynthesis and growth of plants but depending on the conditions that may be harmful in some cases. Therefore, the use of anti-transpirant can be one of the most effective methods for reducing the amount of water lost through transpiration and adjustment the reduction of the yield due to water deficiency in arid and semi-arid regions. Climate change happened on earth and the intensification of stresses caused by it, especially drought stress in arid and semi-arid regions such as Iran. Therefore, finding strategies that can reduce the effects of water shortages on plant growth and yield can be very important. The aim of the present study was to investigate the effect of irrigation regimes and application of different concentrations of tragacanth (naturally dried exudate from some Astragalus species) on black cumin plant. Materials and Methods: This research was carried out in a factorial experiment based on completely randomized design with three replications in a greenhouse of the Agriculture College of Kurdistan University in 2018. The experimental factors were including irrigation at three levels of 100% (full irrigation), 70% (mild drought stress), and 40% (severe drought stress) of field capacity of soil and spraying with tragacanth extract at six concentrations of 0, 1.25, 2.5, 5, 7.5, and 10 g/L. Spraying of this material was done using a back sprayer (Shark model) with a constant pressure of 2.4 bar and a volume of 250 liters of water per hectare., The normality test was performed using the Mini Tab software, before the data were analyzed. After ensuring the normality of data, analysis of variance was performed using SAS ver. 9.3. LSD (Least significant difference) was used to compare the mean of treatments. The graphs are drawn using Excel software. Results and Discussion: The results showed that increased drought stress intensity (irrigation reduction) led to the reduced leaf relative water content, Total chlorophyll content, efficiency of photosystem II, plant height, number of capsules per plant, mean number of seeds per plant, biological yield and grain yield. The positive effects of tragacanth consumption on reducing and modifying the effects of drought stress on different levels of irrigation and different concentrations of tragacanth were different. In the present study, under full irrigation conditions, lower concentrations of tragacanth were useful, while in drought stress conditions, higher concentrations of tragacanth (except 10 g/L) were useful. In full irrigation, the concentration of 1.25 g/L was positive for all studied traits. In mild drought stress, the use of higher concentrations of tragacanth up to 5 g/L had the best effect and more concentrations resulted in a reverse effect on studied traits. In severe drought stress, the use of more concentrations of tragacanth extract was beneficial and improved the studied traits up to 7.5 g/L, but 10 g/L had a negative effect on these traits.Conclusion: The results of this study indicated that the different effects of various concentrations of tragacanth material in different levels of irrigation on studied traits of black cumin. Therefore, it can be concluded that the application of different concentrations of tragacanth gum was completely dependent on the plant's water status. Therefore, using higher concentrations of tragacanth gum in drought stress conditions had a more positive effect on the plant, and vice versa, using a lower concentration of this material was useful in full irrigation. The effect of tragacanth gum on reducing and modifying the effects of drought stress in different plants requires further studies and extensive research. Tragacanth gum can be introduced as a new anti-transpirant agent with natural origin and its application can be useful and recommended in areas exposed to drought stress.
N. Moallemi; E. Khaleghi; Z. Jafari zadeh
Abstract
Introduction: Plant establishment is difficult in some arid and semi-arid regions of Iran because of lacking rainfall and inadequate distribution and extreme heat. Previous studies stated that plant water parameters and growth characteristics such as plant height, fresh and dry weight of root, stem and ...
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Introduction: Plant establishment is difficult in some arid and semi-arid regions of Iran because of lacking rainfall and inadequate distribution and extreme heat. Previous studies stated that plant water parameters and growth characteristics such as plant height, fresh and dry weight of root, stem and leaf, which is known as the first reaction of plants, were decreased under drought stress. Therefor it is necessary to use practices with objectives to decease the effects of drought stress on plants and increasing water use efficiency. Several studies showed that various morphological and physiological characteristics in plants were influenced by ascorbic acid. In fact, ascorbic acid increased plant resistance to drought stress. The purpose of this research was to investigate the effect of ascorbic acid application on growth traits of ‘Baghmalek’ olive under 100%, 66% and 33% ETcrop < /sub> by analyzing growth traits and relative water content, stem water potential and stomata resistance. Material and Methods: This research was carried out in order to assess the effects of three levels of water deficit (100, 66 and 33 percent of evapotranspiration (ETcrop < /sub>)) and four concentrations of ascorbic acid (0, 250, 500 and 750 mg l-1) on some growth and physiological parameters of young olive plants cv. ‘Baghmalek’as a factorial experiment based on a randomized complete block design with three replications. Fresh and dry root, stem and leaf weight, leaf number, leaf area, stem diameter, relative water content, stem water potential and stomata resistance were measured in this research. Two years old olive trees (Olea europaea cv. ‘Baghmelak’) were used. Seventy two plants were grown in 10 L pots, containing a mixture of field soil: sand: manure (1:1:1). Plants were sprayed with four concentrations of ascorbic acid and irrigated every 10 days, based on the amount of evapotranspiration of plant (ETcrop < /sub>). Parameters such as relative water content, stem water potential and stomata resistance were measured at last week of the experiment and the other parameters were measured every week. Data analysis were performed using MSTATC software and means comparison were carried out by Duncan's multiple range test (DMRT) at 5% and 1% of probability levels. Results and Discussion: The results indicated the growth quality was better in plants treated with 250 mg l-1 ascorbic acid under water stress. Fresh and dry weight of root, stem and leaf growth, stem diameter, leaf number, leaf area were higher in plants treated with 250 mgl-1 ascorbic acid than untreated plants. Interaction between water deficit stress ×ascorbic acid revealed information in plant characters such as fresh and dry weight, stem diameter and leaf area simply declined as sources of water (from 100 to 66 and 33 percent) become limited, in particular in the trees which not receiving ascorbic acid treatments. However, application of 250 and 500 mg l-1 ascorbic acid enhanced the amount of relative content of leaf and water potential of stem in trees under water deficit stress. While stomata resistance was decreased in trees receiving ascorbic acid treatments. Some researcher declared that limitation of photosynthesis could be one of the most important factors for decreasing growth under water deficit stress. In addition, relative water content, cell turgor potential, reduced cell division, cell enlargement and growth plant could be affected by water deficit stress. Also the results indicated that leaf area (5952 cm), leaf number (151.7), stem diameter (6.49 mm), stem length (63.33 cm), root dry weight (18.16 g) and leaf fresh weight (9.35 g) were obtained in irrigated plants with 33% ETcrop < /sub> and untreated with ascorbic acid. Our results showed leaf number (158.7), stem length (74 cm), root fresh weight (78.08 g), stem fresh and dry weight (46.45 and 28.43 g, respectively) and leaf fresh and dry weight (13.35 and 8.45 g, respectively) were highest in irrigated plants with 100% ETcrop < /sub> and treated with 250 mg l-1 ascorbic acid. Conclusion: Water deficit stress could affect directly on relative water content, cell turgor potential and reduce cell division, cell enlargement, plants photosynthesis and plant growth. The use of ascorbic acid could effect on plants resistance to drought. In addition, various morphological and physiological traits could be influence by ascorbic acid. The results of this research indicated that 250 mg l-1 ascorbic acid concentration had more effects on water deficit and it seems ascorbic acid can be used to reducing the negative effects of drought in some regions that rainfall shortage and drought is important problems.
yahya selahvarzi; S. Sarfaraz; M. Zabihi; M. Kamali
Abstract
Introduction: Drought is known as one of the most important factors limiting the growth and production of plants in urban landscape. Drought has limited production of 25% of the world's agricultural lands. Water allocated to the landscape irrigation has high value and should be used optimally ...
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Introduction: Drought is known as one of the most important factors limiting the growth and production of plants in urban landscape. Drought has limited production of 25% of the world's agricultural lands. Water allocated to the landscape irrigation has high value and should be used optimally with high efficiency. Soil texture is a classification instrument used both in the field and laboratory to determine soil classes based on their physical texture. Soil texture can be determined using qualitative methods such as texture by feel, and quantitative methods such as the hydrometer method. Soil texture has agricultural applications such as determining crop suitability and predicting the response of the soil to environmental and management conditions such as drought or calcium (lime) requirements. Soil texture focuses on the particles that are less than two millimeters in diameter which include sand, silt, and clay. Soil texture affects the water content and drainage ability of soils. This is because texture controls the nature of soil pores, i.e. the voids or spaces between the mineral particles in a clay soil. For example, there are many minute pores or micro pores between the tiny clay particles. Being small, they tend to retain water but to exclude air. As a result, clay soils are prone to drain poorly and to become waterlogged. By contrast, sandy soils are dry soils. On the other hand, application of new techniques to maintain soil moisture is essential. One of these techniques for increasing soil water retention is use of natural moisture absorbing materials such as zeolite. Zeolites are one of the new and effective substances to improve the soil water retention and preserve water and minerals in the soil. Zeolites contain elements such as potassium, calcium, sodium, silicon, aluminum, magnesium, iron and phosphorus that can be considered as the best dietary supplement and fertilizer and play an important role in the utilization and production of the most agricultural products. Ligustrum vulgar L., belongs to the Oleaceae family, is native to warm regions, European and Asian countries including Iran. This plant is one of the most widely used perennial plants in the landscape spaces. This study was designed to investigate the effects of drought stress and soil texture on growth and some qualitative and quantitative traits of the Ligustrum vulgare. Materials and Method: In order to investigate the effect of zeolite and soil texture on quantitative and qualitative traits of Ligustrum vulgare under drought stress, a factorial experiment was conducted based on completely randomized design with three replications, in the greenhouse of Agricultural Faculty, Ferdowsi University of Mashhad in 2019. The treatments consisted of four types of soil texture (100% soil, 100% sand, 80% soil + 20% zeolite, 80% sand + 20% zeolite) and three levels of irrigation (25, 50 and 100% field capacity). Plant height, number of leaves, number of lateral branches, maximum root length, root volume, shoot and root dry weight and length of lateral branches were measured in each pot. Physiochemical traits such as relative water content, electrolyte leakage and photosynthetic pigments were also measured. Statistical analysis of data was analyzed by JMP8 software. Graphs were plotted using excel and all mean comparisons were performed by LSD test at p < 0.05%. Results and Discussion: According to the results, decreasing irrigation levels reduced vegetative traits such as fresh weight and dry weight. Relative water content also decreased, but ion leakage increased by decreasing irrigation levels. The highest stem fresh weight (18 g), root fresh weight (29 g), total fresh weight (56 g) and total dry weight (20 g) were observed in soil + zeolite, and the highest leaves fresh weight, root volume and plant height were obtained in soil and soil + zeolite treatments. The lowest root volume was observed in sand and zeolite treatments which had no significant differences. In addition, ion leakage was lower in the treatments containing zeolite than the other treatments. The highest amount of SPAD (72) and chlorophyll b (31.5 mg / g fresh weight) were observed in sand + zeolite treatment and 25% field capacity. According to the results, it seems that soil and soil + zeolite in low irrigation conditions were more suitable environment for growth of Ligustrum vulgare and sandy bedding would reduce plant growth in normal conditions as well as under drought stress.
M. Fazeli Rostampour
Abstract
Introduction: Yaghooti grape (Vitis vinifera L.) is an important variety in Iran and also it is the most important horticultural product of Sistan region. This variety is of interest for economical aspect. Because continuous drought in Sistan region has been a serious threat to the grape production, ...
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Introduction: Yaghooti grape (Vitis vinifera L.) is an important variety in Iran and also it is the most important horticultural product of Sistan region. This variety is of interest for economical aspect. Because continuous drought in Sistan region has been a serious threat to the grape production, local farmers have to manage the problem by reducing the volume and irrigation intervals. The canopy plays a key role in radiation energy capture via photosynthesis apparatus, water use as regulated by transpiration, and microclimate of ripening grapes and also grape yield, quality, vigor, and the prevention of grape diseases. Since vines has high vegetative growth makes them compete with the reproductive growth, therefore vines be pruned every year.
Materials and Methods: In order to evaluate the effects of irrigation regime and green pruning on some physiological traits and fruit yield of Yaghooti grape, the present research was conducted in the research and extensional garden of Zahak city during 2017-2018. An experiment was carried out in the form of a split plot based on randomized complete block design with three replications. Three irrigation regimes of 100, 75 and 50 percent of the grape water requirement based on the potential evapotranspiration of grape and green pruning with three levels including the control plot or the local practice of not green pruning (P1), pruning the green branches starting from the sixth leaf above the last grape bunch (P2) and pruning the green branches starting from the sixth leaf above the last grape bunch along with green pruning of the green branches without fruit and pruning the unproductive brunches (P3) were allocated to main and sub-plots, respectively. ‘Yaghooti vines were 8 years old and trained as a traditional system. The vines were spaced 3 × 3 m. Water requirement of grape was determined according to the FAO method using data from a Class A evaporation pan. The analysis of variance for each variable was performed with the PROC GLM procedure in SAS 9.4. Multiple linear regression was used to determine the relationships of leaf relative water content, proline, soluble sugars, relative membrane permeability, chlorophyll index, and leaf area to fruit yield.
Results and Discussion: By reducing water consumption from 100 to 75% of grape water requirement, leaf relative water content, fruit juice acidity, chlorophyll index, leaf area and fruit yield decreased 10.1, 6.5, 8.6, 11 and 18.8%, respectively and also proline, soluble sugars and relative membrane permeability increased 67.3, 8.75 and 44.84%, respectively. The P3 treatment compared to control induced an increase in relative leaf water content, chlorophyll index, and fruit yield by 14.7, 12.2 and 25%, respectively as well as a reduction in proline, soluble sugars, relative membrane permeability, fruit juice acidity and leaf area index by 18.34%, 12.1%, 6.8%, 8.3% and 21.3%, respectively. Also the results indicated that providing the 100% of the water requirement combined with pruning the green branches starting from the sixth leaf above the last grape bunch in combination with green pruning of the green branches without fruit and pruning the unproductive brunches (P3) caused the highest grape fruit yield (7797 kg ha-1). Also the interaction effect of meeting 75% of the water requirement and the green pruning had the same result as that of meeting 100%of water requirement under no green pruning conditions. In other words, the green pruning could result in saving 25% of water used by the grape cv. Yaghooti without reducing fruit yield. The multiple linear regression analysis indicated that proline and leaf area were the most important traits impacting fruit yield in Yaghooti cultivar.
Conclusion: Reducing the water potential of vine causes different responses. The most important are a decrease in number cells of fruit, vegetative growth, leaf area, relative leaf water content, chlorophyll content, fruit yield, and increase in the compatible osmolytes. The growing shoots are a strong sink for the consumption of photosynthetic materials. The above mentioned effect causes an increase in the branch overgrowth and its overshadowing. All this factors compete with vine fruit production. So, green pruning and removal of apical dominance eliminates a strong place of nutrient absorption. In other words, green pruning results in a greater accumulation being used by flowers and fruits, causing sufficient light penetration into the crown and reducing evapotranspiration, leading to an increased water consumption and fruit yield.
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.
L. Shekari; M. M. Kamelmanesh; M. Mozafarian; F. Sadeghi
Abstract
Introduction: Aluminum (Al), cobalt (Co), sodium (Na), selenium (Se), and silicon (Si) are considered as beneficial elements for plants. They are not required for all plants but they can improve the growth and development of some plant species. Selenium is an essential element for human with antioxidant ...
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Introduction: Aluminum (Al), cobalt (Co), sodium (Na), selenium (Se), and silicon (Si) are considered as beneficial elements for plants. They are not required for all plants but they can improve the growth and development of some plant species. Selenium is an essential element for human with antioxidant and antivirus functions but is not considered essential for higher plants. Selenium is reported to be protective against cancer and more than 40 types of diseases are associated with Se deficiency. The amounts of selenium in food also depend on the amount of the element in the soil. However, its beneficial role in improving plant growth and stress tolerances is well established. Plants revealed different physiological reactions into the Se levels, some specious accumulate it unlike some which are sensitive and Se is a toxic element for them. Some studies showed that Se can reduce adverse effects of salinity, drought, high and low temperatures and also heavy metal stress by enhancing antioxidant defense and MG detoxification systems. Pepper is one of the most important vegetable crops which have strong antioxidant properties. The effect of Se on vegetable especially on hot pepper is not well documented.
Materials and Methods: Present experiment was designed in order to study the effects of different concentrations of selenium on vegetative growth and physiological trait of hot pepper (Capsicum annum cv. kenya) in hydroponic conditions in the greenhouse at the Department of Horticulture Science, Islamic Azad University of Shiraz (Iran) under natural light with a day/night average temperature of 25/17 °C, relative humidity of 50±8.5% and photoperiod 14/10 (day/night). This experiment was carried out based on completed randomized design (CRD) with 5 Se levels at (0 as control, 3, 5, 7 and 10 µM) with 3 replications. 30 days old seedling with uniform size were selected and transplanted into 4 L pot containing a mixture of peat moss and perlite (1:1). The nutrient solution was a modified Hoagland’s solution and each plant received 400 mL nutrient daily. Selenium concentrations were added by 0, 3, 7 µM Na2SeO3 (Merck, Germany) 10 days after transplanting. Leaf number (by counting), leaf area (with leaf area meter), relative water content (RWC), membrane stability index (MSI), chlorophyll and carotenoids content were determined one month after treatment applications. All data were subjected to one-way ANOVA by Statistix 8 (Tallahassee FL, USA) and the means were compared for significance by the least significant difference (LSD) test at p < 0.05.
Results and Discussion: The results showed that selenium supplement at 5 µM significantly increased relative water content by 12.8% compared to control. Se increased root growth and thus absorbed more water and increased RWC in present experiment. Selenium at 7 and 10 µM Se increased membrane stability index by 33.61 and 80.06, respectively, compared to control which may be due to increasing potassium by Se application. Selenium at 3 and 5 µM increased leaf area by 24.6% and 25.1% relation to plants which were grown without Se supplementation. Leaf number increased by application of 5 µM Se about 15.14% and chlorophyll a, b and total increased by 64.67%, 38.5% and, 55.8%, respectively, in comparison with plants grown without Se application. Carotenoid content was not affected by different Se concentrations. Se increase chlorophyll content by increasing Mg and Fe absorption, or protect of chlorophyll content against chloroplast enzymes. The highest leaf area was observed at 3 µM Se in comparison with other treatments. Se at 5 µM is beneficial for growth, photosynthesis pigments, and leaf area and leaf number. Se application had no beneficial influence on lateral shoot. The highest starch concentration was observed at 5 µM Se in comparison with other treatments and control (by about 60% in comparison with plants were grown without Se application).
Conclusion: In general, the result of present study indicated that selenium at low concentrations improved plant growth (such as leaf area and leaf number), physiological trait (relative water content and membrane stability index) and photosynthesis pigments (chlorophyll a and b) of hot pepper in hydroponic conditions. Also, it is suggested that this experiment should be repeated on some other important vegetable during growth and reproductive stages in hydroponic and soil condition and also on hot pepper quality and quantity of fruit.
M. Zadeh Bagheri; F. Al-Boali; H. Sadeghi; Sh. Javanmardi
Abstract
In this complete random block study we aimed to assess the morphologic reactions of Petunia under water deficiency. We used four irrigation treatments (irrigation amount of 25%, 50%, 75%, and 100% of the field's irrigation capacity. The study consisted of 8 repetitions during 6 months in the greenhouse. ...
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In this complete random block study we aimed to assess the morphologic reactions of Petunia under water deficiency. We used four irrigation treatments (irrigation amount of 25%, 50%, 75%, and 100% of the field's irrigation capacity. The study consisted of 8 repetitions during 6 months in the greenhouse. Data were analyzed using SPSS software, version 12.0 and the mean data were compared with each other using the least standard deviation (LSD) at a 5% level. The results showed that the root's length, weight, and dry weight, the wet to dry weight ration of the branch, number of branches, number of flowers, relative water content of the leaf, and chlorophyll content reduced. However, the flower period, profil content, and the potassium and sodium percentage increased. The Petunia can sustain low irrigation and can be used as a resistant plant to poor water conditions in green spaces.
Z. Khazaei; M. Sayyary; M. Seydi
Abstract
Drought, withnegative impacts on plant growth and development, isa major abiotic stress. In order to decreasing drought stress injuries and recognizing red peppers tolerance physiology against drought stress in greenhouse conditions, an experiment with three levels of drought stress (irrigation at 100, ...
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Drought, withnegative impacts on plant growth and development, isa major abiotic stress. In order to decreasing drought stress injuries and recognizing red peppers tolerance physiology against drought stress in greenhouse conditions, an experiment with three levels of drought stress (irrigation at 100, 60 and 30% of field capacity) and four concentrations of 5-aminolevolinic acid ((ALA; 0, 0.25, 0.5, and 1 mM)with four replications in an experimental was 3×4 factorial experiments in a randomized completely design was conducted in greenhouse of Agricultural Faculty of Ilam University. In the end of experiments, parameters such as ascorbate peroxidase activity, total antioxidant activity, malondialdehyde content, ascorbic acid, relative water content, plant height and number of lateral buds was evaluated. The results showed that with increasing drought stress severity the growth parameters decreased significantly but ascorbate peroxidase activities, total antioxidant capacity, malondialdehyde and ascorbic acid content increased. Foliar application of AHA reduced malondialdehyde content and improved other evaluated traits. ALA protected cell membranes by reducing malondialdehyde content and lipid peroxidation. In addition, ALA with increasing ascorbate peroxidase activity, total antioxidant capacity and ascorbic acid contents in plants improved physiological traits and drought stress resistance.
