Growing vegetables
Najme Zeinali Pour; Fatemeh Aghebati
Abstract
Introduction
Portulaca oleraceae is used in many countries for a variety of purposes, including human nutrition and the conversion and pharmaceutical industries. The edible parts of Portulaca oleracea are the young organs, especially the brittle leaves and stems. Over time, this medicinal herb ...
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Introduction
Portulaca oleraceae is used in many countries for a variety of purposes, including human nutrition and the conversion and pharmaceutical industries. The edible parts of Portulaca oleracea are the young organs, especially the brittle leaves and stems. Over time, this medicinal herb has been forgotten. Drought, on the other hand, is a factor in the decline of crops and horticulture around the world. Given the vastness of arid and semi-arid regions in Iran and also the reduction of access to water resources, appropriate arrangements should be made for the optimal use of water in the agricultural sector. Changing the planting pattern and using useful and resistant alternative species such as drought-tolerant medicinal plants can enable the optimal use of limited water resources. GABA is an important non-protein amino acid that plays a positive role in increasing plant resistance to stress.
Materials and Methods
This experiment was carried out in 2020 as a factorial based on a completely randomized design with three replications in the vegetable research greenhouse of the Faculty of Agriculture, Shahid Bahonar University of Kerman. Experimental treatments included different levels of GABA (0, 20, and 40 mM). Treatment with different concentrations of GABA was done in two stages of 6 and 12 leaves of portulaca oleracea and foliar application and application of dehydration stress in three levels of control, medium and severe at irrigation intervals of 7, 14, and 21 days from 6 leaf stage of plants to the end.
Results and Discussion
According to the analysis of variance, the effect of GABA at different concentrations and dehydration stress on plant height was significant at the level of 5% probability. Based on the mean comparison test, the highest plant height was obtained in GABA treatment of 40 mM and irrigation intervals of 7 days (control), and the lowest of this trait was obtained in GABA zero treatment and irrigation intervals of 21 days (highest stress level). The results of analysis of variance showed that the effect of GABA at different concentrations and dehydration stress on vegetative yield was significant, the interaction between irrigation intervals and GABA was significant at 5% level. Based on the mean comparison test, the highest vegetative yield was obtained in GABA treatment of 40 mM and irrigation intervals of 7 days and the lowest in control treatment and irrigation intervals of 21 days. According to the results of the analysis of variance table, the effect of GABA at different concentrations and dehydration stress on the amount of malondialdehyde was significant at the level of 1% probability. Based on the means comparison test, the highest amount of this trait was obtained in the control treatment. Comparison of the mean of the data showed that the effect of GABA at different concentrations and dehydration stress caused a significant difference in the probability level of 1% in the proline content of the data. Based on the mean comparison test, the highest amount of proline was observed in GABA treatment of 40 mM and irrigation intervals of 21 days and the lowest amount was observed in control treatment and irrigation intervals of 7 days. As can be seen in the comparison table of means, the highest activity of superoxide dismutase enzyme was obtained in GABA treatment at 40 mM and irrigation intervals of 14 days and the lowest in control treatment and irrigation intervals was 7 days (Table 2). The results of this study showed that the effect of GABA at different concentrations and dehydration stress on the activity of catalase was significant at the level of 1% probability. As can be seen in the comparison table of means, the highest level of catalase activity was 40 mM in GABA treatment and 21 days irrigation intervals and the lowest in GABA treatment was 40 mM and irrigation intervals were 7 days.
Conclusion
The results of this study indicate that GABA is able to greatly alleviate the oxidative stress caused by dehydration in Portulaca oleracea. This effect is quite evident in oxidative parameters, especially the activity of antioxidant enzymes. The concentration of 40 mM GABA was the most effective treatment in mitigating the effects of irrigation. The results show that the use of GABA makes Portulaca oleracea tolerant to dehydration stress.
Naser Abbaspour; Lavin Babaei; Alireza Farrokhzad
Abstract
Introduction: Water stress is considered as a main environmental factor limiting crop growth and yield, including grape in Mediterranean areas.Selection for drought-tolerantvarieties is possible through investigation of their performance under stress conditions. The estimation of physiological characteristics ...
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Introduction: Water stress is considered as a main environmental factor limiting crop growth and yield, including grape in Mediterranean areas.Selection for drought-tolerantvarieties is possible through investigation of their performance under stress conditions. The estimation of physiological characteristics as reliable indices can be used as a tool to select tolerant plants. For this reason, varieties and genotypes of one plant species are usually investigated through physiological characteristics and its relation to drought tolerance. Investigation of the effects of water stress on some growth and physiological characteristics in grape plants has revealed that plant height, number of leaves and nodes, leaf area and the percentage of dry weightdecreased under increasing drought stress. Salicylic Acid is a naturally occurring plant hormone whichinfluences various morphological and physiological functions in plant. It can act as an important signaling molecule and has diverse effects on biotic and abiotic stresses tolerance capacity.
Materials and Methods: In this research, two-yearold grapesplanted in plastic pots containingingredients of humus, soil and sand (1:2:1) were used. The experiment was conducted using a factorial based on randomized complete block design with three factors including irrigation periods (every 5, 10 and 15 days), salicylic acid concentrations (0, 1 and 2 mM) and grape cultivars (Rasheh andBidanesefid) with 3 replications in thegreenhouse of faculty of agricultureinUrmia University. Plant height, stem diameter and leaf area and chlorophyll indicesweremeasuredby usingruler, digital caliper (Model22855 NO: Z), leaf Area Meter (ModelAM200) and SPAD-502 chlorophyll meter (Minolta Crop, Japan),respectively. In order to determine proline content, malondialdehyde (MDA), total protein and total soluble sugars, spectrophotometric methods [51,25,6and28] were utilized,respectively.
Results and Discussion: Based on comparing the averages related to the interaction of various levels of drought and salicylic acid, increasing watering intervals resulted in significant decrease in parameters of plant height, stem diameter, leaf area, leaf number and chlorophyll index,and increase inproline content, malondialdehyde, total protein and total soluble sugars.Furthermore, according to the obtained results, plant height, stem diameter, leaf number, chlorophyll index, accumulation of prolineandtotal protein in grape cv. Rashehwere higher than Bidanesefidone.Drought effected the mitotic division, andelongation and expansion of cells, leading to reduced growth and crop yield. It was concluded that plant height, stem diameter, and leaf area decreased noticeably byincreasing water stress. The reduction in plant height could be attributed to decline in the cell enlargement and higher rate ofleaf senescence in the plant under water stress. The reduction in leaf number under severe water deficit was partially due to leaf senescence. Reduction inthe number of leaves could be a response by plants to minimize the transpiration surface. Sorghum plants have also been reported to have a similarbehaviorthroughwhichthey conserve water by reducing the number of leaves. When exposed to chronic water deficit, they showed an initial decrease in the daily increment of leaf area and eventually a decrease due to accelerated senescence. Dropping of the leaves during severe stress markedly reduces the evaporative surface and allows the plant to conserve water.It is well known that proline contents in leaves of many plants are enhanced by several stresses including drought stress. The efficiency of exogenous SA depends on multiple causes such as the species, developmental stage of the plant, manner of application and concentration of SA.Plant height, stem diameter, leaf number, leaf area, leaf total soluble sugar and chlorophyll index increased by applying 2 mM salicylic acid comparedwith 0 and 1 mM doses. The findings of this study showed that salicylic acid was able to enhance the tolerant capacity of the grape plant to the drought stress. According to theobtained results, Rashehcultivar showed a greater resistance to drought stress. Salicylic acid prohibits auxin and cytokinin loss in plants and thus enhances cell division and plant growth. Salicylic acid maintainsphotosynthetic aspects like chlorophyll content at proper level and thus helps plants to grow and developwell. In this study, the drought stress increased the amount of MDA.MDA and other aldehydes in the dry conditions are the result ofactive oxygen species (ROS) such as super oxide radical, peroxide, hydrogen and radical hydroxide, whichareproduced underoxidative stress conditions. The species of active oxygen leads to lipids' per oxidation as a result of injury or damage to the cellular membrane, especially chloroplast membrane.Salicylic acid increases the activity of antioxidant enzymes such as CAT, POD and SOD which in turn protect plants against ROS generation and lipid peroxidation. Salicylic acid treatment also providesa considerable protection from the enzyme nitrate reductase, thereby maintaining the level of diverse proteins in leaves.Mohammadkhani and Heidari (48) found that the initial increase in total soluble proteins during drought stress was due to the expression of new stress proteins.
Maryam Jabbarzadeh; َAli Tehranifar; Jafar Amiri; Bahram Abedy
Abstract
Introduction: Salinity is one of the most important environmental factors that regulates plant growth and development, and limits plant production. Researchers have shown that some plant growth regulators such as nitric oxide improve the plants resistance to environmental stresses such as heat, cold, ...
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Introduction: Salinity is one of the most important environmental factors that regulates plant growth and development, and limits plant production. Researchers have shown that some plant growth regulators such as nitric oxide improve the plants resistance to environmental stresses such as heat, cold, drought and salinity. Sodium nitroprusside (SNP) commonly has been used as nitric oxide (NO) donor in plants. NO is a diffusible gaseous free radical. Low concentrations of NO inhibit the production of reactive oxygen species and protect plants against ROS damages. The aim of this study was to evaluate the role of SNP as NO donor on salt tolerance of Calendula officinalis and its effects on some morphological, physiological and biochemical characteristics of this plant.
Materials and Methods: In this study, the effects of salinity (0, 25, 50, 75 and 100 mM) and sodium nitroprusside (0.0, 0.25, 0.50 and 0.75 mM) on morphological and physiological characteristics of Calendula officinalis L. were investigated. Total leaf area and number of leaves were determined in the end of the experiment. Electrolyte leakage was used to asses’ membrane permeability. This procedure was based on Lutts et al.,1995. Soluble sugars were extracted and estimated by the method of Irigoyen et al., 1992. Chlorophyll a, b and carotenoid content were calculated from the absorbance of extract at 653, 666 and 470 nm using the formula of Dere et al., 1998. Proline was extracted by the method of Bates et al., 1973. DPPH radical- scavenging activity of sample was performed as described previously of Cleep et al., 2012. The SAS software was used for the analysis of variance (ANOVA), comparisons with P
Sakineh Hasanzadeh; Fariborz Habibi; Mohammad Esmaeil Amiri
Abstract
Introduction: Pomegranate (Punica granatum L.) belongs to the Punicaceae family and grows in subtropical and Mediterranean climates. Nowadays the widespread usage of inorganic fertilizers has increased and so people concern about their health. The use of organic fertilizer instead of inorganic fertilizers ...
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Introduction: Pomegranate (Punica granatum L.) belongs to the Punicaceae family and grows in subtropical and Mediterranean climates. Nowadays the widespread usage of inorganic fertilizers has increased and so people concern about their health. The use of organic fertilizer instead of inorganic fertilizers is one of the methods of preserving health. Pomegranate is one of the most important products of Iran. This fruit plant is cultivated in some regions in arid and semi-arid areas. Due to the long growing season of pomegranate, droughtstress is one of the main limiting factors in the development of pomegranate orchards in Iran. Utilization of amino acids can help to increase efficiency and improve the quality of the fruit under environmental stress. Thus, this study aims to findany possibility to increase the production and quality of the fruit during the drought. The goalof this study was to study the effect of organic Aminol-Forte fertilizer on physiological and biochemical responses of pomegranate cv. Naderi under drought stress conditions.
Materials and Methods: This research was carried out in AbShirin field located on the old road 40 km from Qom-Kashan during 2011. Asplit plot experiment based on randomized complete block design was conducted with two factors, irrigation treatment in three levels (100% required water, 75% required water and 50% required water) and Aminol-Forte fertilizer treatment in four levels (0, 2, 3 and 4 ml/l). Spraying was conducted in four stages (pre-anthesis, after fruit set, fruit growth andtwo weeks per-harvest). In the end of the experiment, chlorophyll index, soluble sugars, insoluble sugars, proline, canopy degree and stomatal conductance were measured. Statistical analysis was performed using SPSS 17 program. Means were separated according to the Duncan’s multiple range test (DMRT) at 0.01 level of probability.
Results and Discussion: Analysis of variance of Aminol-forte fertilizer spraying on physiological and biochemical responses of pomegranate cv. Naderi under drought stress conditions showed that between irrigation treatment for chlorophyll index, proline and stomatal conductance were significant at 1% level of probability, and at 5% level of probability soluble sugarand insoluble sugar and canopy degree were significant. Fertilizer treatment at 1% level of probability was significant for proline and at 5% level of probability was significant for soluble sugars. Interaction was significant for soluble sugars, proline and canopy degree. Means showed that by increasing fertilizer level, soluble sugars content, proline and stomatal conductance significantly increased insoluble sugars and chlorophyll index decreased insignificantly. By decreasing irrigation levels, chlorophyll index, soluble sugars and proline significantly increased, meanwhile insoluble sugars and stomatal conductance significantly decreased. The highest chlorophyll index (65.44 SPAD) and the lowest chlorophyll index (56.48 SPAD) were obtained in 75% required water with 2 ml/l of fertilizer level and 100% required water with 3 ml/l of fertilizer level, respectively. The highest soluble sugars (14.94 mg/g) and the lowest soluble sugars (11.64 mg/l) were obtained in 50% required water with 0 ml/l of fertilizer level and 100% required water 2 ml/l of fertilizer level, respectively. The highest insoluble sugars (9.99 mg/g) and the lowest insoluble sugars (6.82 mg/l) were measured in 100% required water with 3 ml/l of fertilizer level and 50% required water with 2 ml/l of fertilizer level, respectively. The highest proline content (2.51μmol/l) and the lowest proline content (1.05μmol/l) were obtained in 50% required water with 4 ml/l of fertilizer level and 100% required water with 0 ml/l of fertilizer level, respectively. The highest canopy degree (-7.31˚c) and the lowest canopy degree (-9.38˚c) were measured in 50% required water with 4 ml/l of fertilizer level and 100% required water with 4 ml/l of fertilizer level, respectively. The highest stomatal conductance (38.23 mmol/m2/s) and the lowest stomatal conductance (9.7 mmol/m2/s) were obtained in 50% required water with 2 ml/l of fertilizer level and 100% required water with 3 ml/l of fertilizer level, respectively.
Conclusion: By increasing the level of Aminol-Forte fertilizer from 0 to 4 ml/l, soluble sugars content, proline and stomatal conductance significantly increased meanwhile insoluble sugars and the chlorophyll index decreased. Drought stress increased soluble sugars content, chlorophyll index, canopy degree and proline but, insoluble sugars and stomatal conductance decreased. According obtained results, it can be said, spraying of Aminol-Forte fertilizer containing amino acid could significantly reduce the negative effects of drought stress. In this study, the best results in terms of stress and no stress were obtained in 3 and 4 ml/l of Aminol-Forte fertilizer.
