جستجوی مقالات مرتبط با کلیدواژه « تنش شوری » در نشریات گروه « باغبانی »

Phosphorus (P) is one of the most important nutritional elements of plants and it is necessary for the development of plant roots. Due to the high cost of chemical fertilizers, it is important to use cheap sources such as rock phosphate (RP) to supply P needed by plants. The efficiency of RP is low and its use alone cannot supply the P required by the plant. One of the ways to increase the efficiency of RP is to use phosphate solubilizing bacteria (PSB). Considering the salinity of soil and irrigation water in many pistachio-growing areas of Iran, the use of salt-resistant PSB can increase their resistance to salt stress in addition to supplying the P required by pistachios.

In order to investigate the role of PSB in supplying the required P of pistachio seedlings under saline conditions, a factorial experiment was conducted in the form of a completely randomized design with 3 replications in greenhouse conditions. The factors included PSB at three levels [control (PSB0), Pseudomonas sp. 1 (PSB1) and Pseudomonas sp. 2 (PSB2)], RP at two levels (0 and 30 mg P from rock RP) and irrigation water salinity at three levels (0, 5 and 10 dS/m). The bacteria used in this study were able to produce ACC-deaminase, indole acetic acid and dissolve tricalcium phosphate in vitro. For inoculation, inoculum containing each bacterium with a population of 108 cells/ml was prepared in the nutrient broth medium and each pistachio seed (P. vera L. cv. Badami) was inoculated with 500 µL of bacterial inoculum. The plants were irrigated with non-saline water for four weeks and then with saline water until harvesting based on experimental treatments. During the growth period, the soil moisture of the pots was kept at about 80% of the field capacity by weight method. Finally, shoot and root sampling was performed and various characteristics such as shoot and root dry weight, chlorophyll, carotenoids, proline, soluble sugars, RWC, MSI and phosphorus as well as sodium concentrations were measured. Analysis of variance of traits was performed using SAS software and the means were compared using the LSD method with a probability level of P≤0.05.

The results showed that water salinity decreased the dry weight of shoot and root, chlorophyll a, chlorophyll b, carotenoids, relative water content (RWC) and membrane stability index (MSI) of leaf and p concentration of shoot and root of pistachio seedlings. Auxin produced by bacteria can directly increase cell division and growth or indirectly increase ACC-deaminase production. On the other hand, proline, soluble sugars and sodium were accumulated in the leaves of seedlings with increasing water salinity. According to the results, although the use of RP alone did not show significant effect on the studied indicators, its simultaneous use with PSB had the greatest role in improving the growth of pistachio seedlings, especially in saline conditions. The highest amount of dry weight of shoot (1.89 g.plant) and root (1.59 g.plant), chlorophyll b (1.30 mg/g fresh weight), carotenoids (1.35 mg/g fresh weight), soluble sugars (59.1 mg/g fresh weight), proline (36.7 mg.g-1 fresh weight), leaf RWC (91 %), leaf MSI (84%) and the P concentration of shoot (0.39 %) and root (0.35 %) was obtained from the simultaneous application of RP and PSB (especially PSB2) in non-saline conditions. The PSB increase soil P availability by reducing of soil pH by release of protons and organic acids and mineralization by production of acid phosphatases. Bacteria, in addition to increasing soil P availability, improve phosphorus uptake and chlorophyll content in plants by affecting root morphology and its development in soil. On the other hand, inoculation with PSB (both separately and together with rock phosphate) reduced sodium accumulation in the aerial parts and roots of pistachio seedlings.

Unlike pistachio trees, the tolerance of pistachio seedlings to salt stress is low. According to the results, the salinity symptoms were visible in the pistachio seedling leaves at the water salinity level of 10 dS/m, which caused the drying of the lower leaves and the burning of the edges of the young leaves. On the other hand, although the application of RP alone did not have significant effect on increasing the tolerance of plants to salt stress, the simultaneous use of RP with PSB increased growth, the accumulation of proline and soluble sugars, the concentration of chlorophyll and carotenoids, the amount of RWC and MSI and P concentration of pistachio seedlings, especially in saline conditions. Therefore, the use of PSB can help the growth and establishment of pistachio seedlings under salinity stress conditions and increase the efficiency of RP and supply P needed by the seedlings.

Basil (Ocimum basilicum L.) is an annual herbaceous plant belonging to the mint family (Lamiaceae). Its fresh and dried leaves and essential oils are used in the food, pharmaceutical, and cosmetic industries. In recent years, the use of symbiosis with plant beneficial rhizospheric microorganisms including rhizobacteria and endophytic fungi has been considered as a cost-efficient and sustainable strategy to alleviate the adverse effects of environmental stresses such as salinity. Therefore, the present study was conducted in the research greenhouse of Urmia University. It evaluated the effect of inoculation with growth-promoting microorganisms on some growth, physiological, and phytochemical characteristics of basil plants under salt-stress conditions. This research was conducted as a factorial experiment in a completely randomized design with three replications. The experimental factors were inoculation with microorganisms at three levels (control without inoculation, inoculation with Serendipita indica, and inoculation with a mixture of Pseudomonas areuginosa, P. putida, and P. fluorescens) and salinity stress at four levels (0, 40, 80 and 120 mM of NaCl). For inoculation, the germinated seeds were separately inoculated with S. indica suspension (5×105 spores per ml) and inoculum containing a mixture of Pseudomonas bacteria (1.61×109 cells per ml) and planted in prepared pots. The pots were irrigated with ordinary tap water until the plants were eight-leafed, and from this stage onwards, salinity stress treatments were applied by dissolving different concentrations of NaCl in the irrigation water and continued until the full flowering stage. In the full flowering stage, plant samples were collected and root colonization percentage by fungus, growth parameters (plant height, stem diameter, number and total length of lateral branches, leaf number and area, inflorescence length, fresh and dry weight of leaf and stem), leaf relative water content (RWC), photosynthetic pigments, concentration of leaf nutrients (N, P, K, Na and Cl), essential oil content and yield were evaluated. For essential oil extraction, shade-dried samples were hydro-distilled using a Clevenger-type apparatus. The results showed that due to salinity stress, the percentage of root colonization by S. indica, growth parameters, RWC, photosynthetic pigments, essential oil content, yield, N, P, and K content, and K/Na ratio decreased while Na and Cl content increased. In addition, all evaluated parameters in inoculated plants were higher than in non-inoculated plants except Na and Cl content. The highest and lowest rates of growth parameters, RWC (74.47 and 72.39%), essential oil yield (0.23 and 0.17 ml/pot), and N content of leaves (1.36 and 1.14%) were obtained in plants inoculated with S. indica and non-inoculated plants, respectively. The highest and lowest amounts of chlorophyll a (0.87 and 0.74 mg/g fw), chlorophyll b (0.41 and 0.37 mg/g fw), essential oil percentage (1.24 and 1.05%), K content (5.15 and 3.97%), P content (0.29 and 0.24%) and the K/Na ratio (10.05 and 4.07), were observed in plants inoculated with a mixture of Pseudomonas bacteria and non-inoculated plants, respectively. Also, the lowest Na (1.34%) and Cl (2.93%) accumulation was observed in plants inoculated with Pseudomonas bacteria and S. indica fungus, respectively. According to the results of this study, the use of plant growth-promoting microorganisms (S. indica fungus and a mixture of Pseudomonas bacteria) can alleviate adverse effects of salinity stress on the growth and essential oil production of the basil plant by increasing the absorption of water and nutrients, preserving photosynthetic pigments and reducing the accumulation of toxic ions.

Fluorescence parameters and chlorophyll content are the most important factors to determine the photosynthetic capacity during the life of plants. In this research, the effect of SiO2 nanoparticles was investigated on the characteristics of RWC, membrane stability, photosynthetic pigments and the functioning of photosystem II under sodium chloride salinity stress conditions in five olive cultivars. Two olive cultivars (Koroneiki and Conservalia as salinity-resistant and sensitive controls, respectively) and three selected genotypes (Deira, Kolahfaraj and Shiraz) at two levels of salinity (0 and 150 mM sodium chloride) and three levels of nanoparticles of SiO2 (0, 1 and 2 mM) were investigated. The results showed that in all investigated cultivars, membrane stability and relative water content decreased in sodium chloride salinity treated plants. On the other hand, the application of SiO2 nanoparticles increased the relative water content, membrane stability and the amount of photosynthetic pigment in both control and salinity conditions. Shiraz genotype is more tolerant to sodium chloride salinity due to its superiority in most traits related to salinity tolerance compared to other cultivars. The results showed that application of SiO2 nanoparticles increased photosynthetic pigments under salinity stress. In general, it can be concluded that salinity stress reduced the content of photosynthetic pigments, relative water content, membrane stability and also the performance of photosystem II, and SiO2 nanoparticles improved these traits. It seems that the application of SiO2 at a concentration of 2 mM reduces the destructive effects of sodium chloride salinity stress in the studied olive cultivars.

Various methods of stress directly affected the growth and production yield of numerous plants. For example, environmental stress reduces the tomato manufacturing by the disrupting its natural metabolism, or, salinity stresses affect the it is growth and development from the germination stage to the fruit ripening stage. Salinity in tomatoes by stimulating the biosynthesis of growth regulators such as ethylene and abscisic acid leads to the acceleration of the aging of the leaves. Therefore, development of different methods to induce salinity stress tolerance in plants is necessary. Some approaches were studied to develop the salinity tolerant plants such as genetic breeding, environmental improvements and usage of phytohormones and signal molecules. Salicylic acid or orthohydroxybenzoic acid plays an important role in regulating the physiological and biochemical responses of plants to stress conditions, which improves the plant's resistance to adverse environmental conditions. For instance, salicylic acid is a facile and effective way to increase plant productivity under salt stress conditions. Considering the positive effects of salicylic acid in modulating the effects of salinity, this study was conducted with the aim of investigating the effects of salicylic acid’s usage in modulating the harmful effects of salinity on some vegetative, physiological, quantitative and qualitative characteristics of two tomato cultivars of Baneh local mass and Semi Dwarf line.

To investigate the effect of salicylic acid in modulating the effects of salinity stress in tomato, a factorial experiment was conducted in the form of a randomized complete block design, with 12 treatments, in 3 replications and with a total of 36 experimental units in the hydroponic greenhouse of the Department of Horticulture, Faculty of Agriculture, and university of Tabriz. The treatments included two levels of salicylic acid (0 and 1 mM) and salinity levels (0, 35 and 70 mM NaCl) on two tomato cultivars of Baneh and Semi Dwarf.

The results showed that in Baneh and Semi Dwarf cultivars, the increase in salinity levels caused a decrease in vegetative indices, meanwhile the treatment of salicylic acid along with salt stress increased same indices. Also, salt stress caused yield reduction in both Baneh and Semi Dwarf cultivars. By examining the qualitative indicators, it was observed that titratable acidity and vitamin C increased with salt stress and salicylic acid treatment in both cultivars. In terms of physiological indicators, the amount of proline increased at different salinity levels with salicylic acid treatment, but the amount of leaf chlorophyll index decreased with the increase of same condition.

The results of testing the effect of salicylic acid and the effects of salinity stress on vegetative, quantitative, qualitative and physiological indicators in Baneh and Semi Dwarf tomatoes showed a remarkable difference in terms of significance. In terms of vegetative traits; Plant height, leaf area index, shoot wet in Baneh and Semi Dwarf cultivars decreased with increasing salinity levels of vegetative indices, but salicylic acid treatment along with salinity stress increased same indices. Indicators such as yield, fresh weight of fruit, and percentage of dry matter of fruit showed different responses to different levels of salinity and salicylic acid treatment. The fresh weight of fruit increased with the application of salicylic acid. Also, salt stress caused an increase in the percentage of dry matter of the fruit. But salt stress caused yield reduction in both Baneh and Semi Dwarf cultivars. In terms of quality indicators; the amount of titratable acidity and vitamin C increased with salt stress and salicylic acid treatment in both cultivars. In terms of physiological indicators, the level of proline increased across various salinity levels with salicylic acid treatment. However, the leaf chlorophyll index decreased with rising salinity levels, even in the presence of salicylic acid treatment. Overall, salinity stress caused a decrease in most analyzed traits in the Baneh and Semi Dwarf cultivars. Nevertheless, it led to improvements in certain quality traits. Additionally, salicylic acid treatment enhanced the mentioned indices in most of the examined traits in both cultivars. Therefore, considering the positive effects of salicylic acid treatment on Baneh and Semi Dwarf cultivars under salinity stress conditions, its use is recommended.

Cultivation development of adaptable Thymus daenensis Celak to specific environmental conditions through population improvement requires the creation of a genetic pool rich of superior genotypes and exploitation of this diversity to identify genotypes with high combinability. In this research, to study the genetic diversity and combinability of different T. daenensis ecotypes under salinity, a factorial greenhouse experiment was conducted in a randomized complete block design with three replications. The factors included salinity stress (0 and 90 mM NaCl) and ecotype (12 half-sib families derived from a polycross between 12 T. daenensis ecotypes). Salinity decreased all the measured traits (except for proline and carotenoids content) significantly compared to the control. The ecotypes differed significantly from each other in terms of length and leaf width, length of lateral branches, aerial parts dry weight, essential oil content, and proline content. Essential oil content and leaf width obtained the highest phenotypic and genotypic coefficient of variation. General heritability of the studied traits varied from 4.61% (leaf length) to 81.07% (leaf width). The highest general heritability was assigned to leaf width, essential oil content, and aerial parts dry weight. Regarding the higher genotypic and phenotypic coefficient of variation, heritability, and genetic advance of the traits including essential oil content and aerial parts dry weight, these traits could be considered as the most important criteria for the parents selection in the breeding programs of T. daenensis. The results showed that the ecotypes Malayer2, Zagheh, Arak, and Ilam had high combinability in terms of essential oil content. Considering the sufficient genetic diversity observed between the studied ecotypes along with their adequate combinability, it could be recommended to breed T. daenensis through the strategy of improving the population by producing synthetic cultivars for normal (non-stress) and salinity conditions.

In order to study the morphologies and biochemistry of ornamental cabbage under salt stress, a factorial experiment was carried out based on completely randomized design in three replications. The treatments included salinity at three levels (4 and 8 dS.m-1 and control (no salinity) and growth stimulating bacteria at three levels (no inoculation Pseudomonas putida and Bacillus subtilis). Plant growth characteristics, including plant height, number of leaves, fresh and dry weight of leaves, fresh and dry weight of plant and root, showed a significant decrease compared to the control treatment with increasing salinity stress, and inoculation with growth-promoting bacteria, especially Pseudomonas putida, improved these attributes. Antioxidant activity and total phenol increased with increasing salinity, so that the highest amount of phenol and antioxidant was observed at treatment 8 dS/m (1.08 mg/g FW and 62.52 μmol/g FW, respectively). On the other hand, the use of Bacillus bacteria could increase the amount of total phenol and antioxidants in contrast with salinity (1.08 mg/g FW and 62.78 μmol/g FW). The amount of proline in leaves also had an increasing trend at different levels of salinity stress, and its highest level was observed at the highest level of salinity stress and the application of Bacillus subtilis bacteria. The interaction between bacteria and salinity stress reduced the accumulation of sodium element and increased the amount of potassium element. The results of this experiment showed that growth-promoting bacteria, especially Pseudomonas putida bacteria, reduce the damage caused by salt stress in ornamental cabbage plants.

 Barberry is one of the important agricultural products of Iran and has an important role in the economy of farmers, especially in South Khorasan province. Salinity as abiotic stress can cause an ionic or osmotic imbalance in plant cells. Salt stress also restricts plant growth and development by affecting water reducing availability and affecting plant production. Despite the relatively high tolerance of barberry to environmental stresses, increasing soil salinity and irrigation water in barberry growing areas, the growth, and yield of this agricultural product have decreased. The use of plant growth-promoting rhizobacteria (PGPR) is a new method that has been shown to increase the tolerance of various plants to salinity stress.

 Due to the lack of information about the effect of salinity on the growth and establishment of barberry off-shoot and the role of beneficial soil bacteria in increasing the tolerance of this plant to salinity stress, this study aimed to investigate the role of bacteria on growth, physiological and biochemical properties and uptake of nutrients by barberry off-shoot at different levels of irrigation water salinity. For this purpose, a factorial study was conducted in a randomized complete block design with 3 replications. Experimental factors included plant growth-stimulating bacteria at three levels (control (Without inoculation) and inoculation with Pseudomonas sp. P1 and Pseudomonas sp. P2) and salinity of irrigation water at three levels (control, 6 and 12 dS/m from sodium chloride source). The bacteria used in this study were able to produce indole acetic acid, siderophore, ACC deaminase enzyme, and dissolve insoluble phosphate (tricalcium phosphate) in vitro. For inoculation, inoculum containing each bacterium with a population of 108 cells/ml was prepared in the Nutrient Broth medium and added to the root medium. The plants were irrigated with non-saline water for one month and then with saline water for two months based on experimental treatments. Finally, leaf sampling was performed and various characteristics such as leaf dry weight, chlorophyll, proline, total sugar, RWC and phosphorus, potassium, sodium, and chloride concentrations were measured. Analysis of variance of traits was performed using SAS software and the means were compared using the LSD method with a probability level of P≤0.05.

 The results showed that the salinity of irrigation water reduced leaf dry weight, chlorophyll and carotenoid concentration, relative water content, and potassium to sodium ratio of barberry leaves. Decreased photosynthetic pigments under salinity may be due to decreased synthesis of the main chlorophyll pigment complex, oxidative damage to chloroplast lipids, pigments, and proteins, or increased chlorophyllase activity. In contrast, with increasing salinity, the amount of proline and total sugar and the concentration of phosphorus, sodium, and chlorine in leaves increased. Bacterial inoculation also increased leaf dry weight, chlorophyll, carotenoids, potassium concentration, relative water content, and potassium to sodium ratio, especially in saline conditions. Also in saline conditions, the concentrations of sodium, chlorine, phosphorus, proline, and total sugar in the leaves of barberry off-shoot inoculated with bacteria decreased. It seems that PGPR plays a significant role in the regulation of cellular osmolites, including proline and soluble sugars, by producing various metabolites and increasing the absorption of water and nutrients. The highest amount of leaf dry weight (0.70 g), total chlorophyll (0.92 mg g-1 fresh weight), carotenoids (0.51 mg g-1 fresh weight), leaf potassium (0.48 %), and total leaf sugar (43.7 mg g-1 dry weight) was obtained from the application of PGPR in conditions without salinity stress. Also, the use of bacteria in saline conditions decreased the amount of phosphorus and total sugar and in non-saline conditions increased the amount of these parameters. PGPR through various mechanisms such as the production of auxin, organic and mineral acids, and secretion of proton and phosphatase enzymes increase the availability of phosphorus for the plant, root growth, and absorption of water and nutrients. Increased absorption of water and nutrients has led to increased leaf growth and development and therefore reduced phosphorus concentration (dilution effect).

 According to the results, PGPR by increasing the absorption of water and nutrients such as phosphorus and potassium caused osmotic regulation in the plant and thus increased the tolerance of barberry off-shoot to salinity stress of irrigation water. The ability of these bacteria to improve plant growth in saline conditions could be due to the production of auxin, siderophore, dissolution of tricalcium phosphate, and especially the production of the enzyme ACC-deaminase (as observed in vitro). Therefore, these bacteria can be used to improve the nutrition growth and establishment of barberry off-shoot.

Salinity stress is one of the most important constraint for yield of medicinal plants. In order to investigation the effects of silicon nanoparticle foliar spraying on growth characteristic, physiological and biochemical parameters of dragonhead (Dracocephalum moldavica L.) under salinity stress condition a factorial experiments based on completely randomized design with three repetitions and each repetition, including two pots in hydroponic conditions was carried out at research greenhouse of Mohaghegh Ardabili University at 2018-2019. Experimental factors consisting salinity stress at four levels (0, 50, 100 and 150 mM of Nacl) and foliar spraying of silicon nanoparticle at three levels (0, 100 and 500 mg/l). Morphological studied traits including plant height, fresh and dry weight of plant, physiological parameters such as chlorophyll, electrolyte leakage, relative water contents and biochemical parameters such as proline and antioxidant enzyme activity were measured. Results indicated that salinity stress significantly decreased morphological traits include plant height, fresh and dry weight of plant and physiological parameters such chlorophyll and relative water content of leaves were reduced, while free proline content of leaves and electrolyte leakage from cell membranes were increased. Foliar spraying of silicon nanoparticle alleviated salinity stress effects on dragonhead plants via increases in growth characteristics and enhancing antioxidant enzyme activity such as ascorbate peroxidase and super oxide desmutase. Five hundreds mg/mL of nanosilicon showed the maximum effect on diminishing negative effects of salt stress on most of the parameters. Therefore, the use of nano-form of silicon element is proposed as alleviator of salt stress in dragonhead.

Salinity is one of the most common abiotic stresses that affects growth and secondary metabolism in medicinal plants. In this study, the effects of two times foliar application of nano titanium dioxide on some agronomic traits of ajowan (Carum copticum) under salinity stress was investigated in a pot experiment. This study was conducted as a factorial experiment with completely randomized design and three replications. The factors included three levels of salinity (0, 50, and 100 mg L-1) and 5 concentrations of TiO2 nanoparticles (0, 10, 20, 40, and 80 mg L-1). Salinity treatments were implemented by adding NaCl to irrigation water of pots containing clay soil three times per week. The results showed that long-term irrigation with slightly saline water significantly decreased dry matter yield, height, total chlorophyll, weight of 100 seeds, number of seeds per plant, and seed yield and increased lipid peroxidation and the activities of catalase ( CAT ) and peroxidase (POX). Impact of 50 mg L-1 salt was not significant on essential oil percentage and essence yield; but 100 mg L-1 salt significantly (33.1%) decreased essential oil content. Foliar spraying of plants with 20 and 40 mg L-1 nano titanium dioxide had the most positive impact on growth and seed yield and significantly lowered lipid peroxidation via enhancing the activities of antioxidant enzymes under salt stress. Foliar spraying with 40 mg L-1 nano titanium dioxide significantly improved essential oil concentration (43.3%) and total essential oil yield (59.7%) under 100 mg L-1 salinity condition. The effect of foliar spraying with 80 mg L-1 nano titanium dioxide on some of the measured attributes was less than the impact of applying 20 and 40 mg L-1 nano titanium dioxide. These results suggest that foliar application of nano titanium dioxide with appropriate concentration improves salt tolerance, seed yield and essential oil content in ajowan.

Quinoa (Chenopodium quinoa Willd.) is a plant with high nutritional value and growth potential, thus has a proper production in adverse environmental conditions. However, the enhancement of plant growth in these conditions could be achieved by different approaches. The use of endophytic microorganisms such as Serendipita indica fungus may help plant growth, especially under salt-stressed conditions. In this research, an experiment was performed using a factorial completely randomized design with three replications in a sterile sandy loam soil under greenhouse conditions. Experimental factors included two levels of S. indica (inoculation and non-inoculation) and salinity levels of 1.47 (initial electrical conductivity of soil), 5, 10, 20 and 30 dS/m which prepared by sodium chloride solution. The results showed that the interaction effect of salinity and fungal inoculation was significant for all measured characteristics (P < 0.05) except for proline. The inoculation of S. indica was able to increase the fresh weight of quinoa shoot by 18.5, 15.0, 39.4 and 45.4% compared to the non-inoculated treatment at salinity levels of 1.47, 5, 10 and 20 dS/m, respectively. The inoculation caused an increase in shoot fresh weight by 18% at initial electrical conductivity (5 dS/m), while a marked increase (~41%) was observed in inoculated plants compared to the no fungus treatment at EC level of 20 dS/m. The fungus increased the root weight by 12.9, 20.1 and 31.5% at salinity levels of 1.47, 5 and 10 dS/m compared to the non-fungal treatment, respectively. Compared to the non-fungal plants, the electrolyte leakage was significantly reduced in the inoculated plants at 10 dS/m. Fungal inoculation had pronounced effect on relative water content (RWC) of leaf at 5 dS/m and increased RWC by 23%, compared to the non-fungus treatment. Moreover, the increasing of salinity stress up to 30 dS/m reduced the percentage of root colonization by 19.9% compared to the non-fungus control. Overall, the application of S. indica significantly increased the biomass production of quinoa under salinity stress conditions.

Soil salinity is one of the most important abiotic stress that by disrupting mineral balance, affects the growth and fertility of plants. In order to investigate the effects of calcium and potassium nutrition on increasing the apple trees tolerance to salinity stress, a factorial experiment with a completely randomized design was conducted in two years, in which six nutritional solutions were used to simulate different levels of salt stress conditions by several amounts of calcium, potassium, magnesium and sodium chloride. According to the results, trees grafted on MM111 showed the earliest and the most frequent symptoms of chlorosis and necrosis in both years, and the trees grafted on M9 rootstocks showed less symptoms than two other rootstocks during the both years. In both years of experiment, correlation between percentage of necrotized leaves, leaf loss and decreasing vegetative growth with leaves chloride content was higher than their correlation with leaf sodium content. Also, the results showed that in both years of experiment, the D nutritional solution (5 mM KNO3, 3.5 mM Ca (NO3)2, 3.57 mM MgSO4 & 6 mM NaCl), could suppress the symptoms of stress in the trees and maintained their growth. Trees grafted on M9 rootstocks, were healthier during the stress period, and also after this period they had higher survival and recovery ability than the two other rootstocks.

In photosynthetic microorganisms, a series of electron carriers (such as flavodoxin) with the similar function to ferredoxin are expressed following the adverse reduction of ferredoxin under stress conditions. Fld gene reduces disorders of abiotic stresses in the electron transfer processes of photosynthesis. In order to investigate the morphological characteristics of transgenic walnuts harboring Fld ‎gene under salinity stress, a factorial experiment was conducted based on completely randomized design with four replications. In this experiment, transgenic Persian walnut plants expressing Fld (L2, L3, L13 and L17) and ‘Chandler’ as control under different levels ‎of NaCl ‎ (0, 100, and 200 mM) were evaluated under in vitro conditions. According to the results, L13 had the maximum number of healthy leaves (1.14), callus diameter (1.36mm) and number of regenerated leaves (1.13) using 200 mM NaCl. Transgenic lines maintained their natural growth in mild stress after 35 days under 200 mM NaCl, while non-transgenic plants showed injury symptoms in this treatment. In vitro studies showed that the transfer of Fld gene to Persian walnut ‘Chandler’, which is a salt-sensitive plant, improved its growth traits under salinity stress.

To investigate the effect of irrigation volume and nutrient consumption on yield and yield components of cherry tomatoes, a greenhouse experiment was conducted as split plots in a completely randomized design. The results showed that the maximum plant height, stem diameter, number of fruits per plant, fruit yield per harvest, total fruit yield, and shoots dry weight were obtained in the treatment of 20 liters of water per square meter per day with nutrient solution application of micronutrients with concentrations of one and a half times the Hoagland solution. The highest water use efficiency obtained from the treatments of 15 and 20 liters of water per square meter per day and consumption of nutrient solution one and a half times the concentration of micronutrients in Hoagland solution with averages of 6.55 and 6.10 g final yield of fresh fruit each plant per liter of water consumption per plant, respectively. Correlation coefficients between the traits also showed a positive and significant relationship between total fruit yield with all studied traits, so that the highest correlation (r = 0.93) had with trait of number of fruits per plant and the lowest correlation (r = 0.7) had with trait of stem diameter.

Salinity is one of the most important abiotic environmental stresses which restricts the growth and production of plants. On the other hand, silicon (Si) is the second most abundant element in the soil and alleviates the biotic and abiotic stresses in the plants. For this purpose, a greenhouse experiment was conducted as a factorial in a completely randomized statistical design with three replications to investigate the effects of silicon and nano-silicon (50 and 100 mg l-1) on some morphophysiological and phytochemical properties of peppermint (Mentha piperita L.) under salinity stress at the different levels of sodium chloride (0, 50, and 100 mg l-1) in 2019. The results showed that the salinity stress significantly reduced the fresh and dry weight of aerial parts and root, and chlorophyll, total phenol, and protein contents. The activity of superoxide dismutase and peroxidase enzymes and essential oil percentage differed at the different salinity levels. The amount of proline also increased significantly due to the sodium chloride treatment of 100 mg l-1. The plants treatment with the different levels of silicon and nano-silicon reduced the negative effects of salinity stress on the evaluated indices. The nano-silicon treatment of 100 mg l-1 showed the highest inhibition of salinity stress effects on the growth indices, antioxidant enzymes activity, and essential oil percentage. Therefore, according to the results of this research, the foliar application of silicon and nano-silicon could be recommended to reduce the negative effects of salinity stress on peppermint.

In order to study the effect of different levels of Daljin growth regulator on agronomic and physiological traits of barley under salt stress, a factorial experiment was conducted in a completely randomized design at the Faculty of Agriculture, Islamic Azad University, Varamin-Pishva Branch, in 2016-2017. The treatments consisted of salt stresses at zero (control), 75 and 150 mM, and foliar application of Daljin in zero (control), 0.5, 1 and 2 at 1000. The measured traits included 1000 seed weight, yield of a plant, seed protein percent, proline, catalase and leaf relative water content. The results showed that salt stress reduced the weight of 1000 seeds, yield of a plant, relative water content of leaves and increased protein content of grain, catalase and proline. Also, Daljin spraying resulted in 1000 seed weight gain, yield of a plant, relative water content of leaves and proline. In the salinity conditions of 75 mM, the highest yield of a plant was related to treatments 1 and 2 at 1000 Daljin (8.49 and 8.9 grams respectively). The highest protein content of the seeds was 16.6% in the 150 mM salinity treatments and in the absence of spraying. It can be concluded from the results of positive effects of Daljin, especially in salt stress conditions, and the reduction of the negative effects of salinity in barley plants, and the highest positive effect was obtained by spraying 1 and 2 at 1000 dalijin.

The aim of this research was to evaluate the effect of application of exogenous jasmonic acid (JA) and abscisic acid (ABA) at different salinity regimes, on primary and secondary metabolic changes of 'Kurdistan' and 'Queen Elisa' strawberry leaves. The reduction of adverse effects of sudden salt stress and gradual salt stress regime by increasing total phenolic content and total antioxidant capacity, has been confirmed in 'Kurdistan' and 'Queen Elisa' after application of JA and ABA. The presence of the two hormones under non-saline conditions significantly increased total soluble protein content but less than 10 mM L-1 of sudden salt stress adverse effects were noticed. Abscisic acid and JA caused a clear increase in total soluble proteins of 'Kurdistan' leaves at both gradual salt stress and non-saline conditions. The role of JA and ABA in aspartic acid increment at gradual salt regime was notable. Salt stress induced tyrosine increase and both hormones enhanced asparagine, alanine, histidine, and GABA contents, respectively. The study reveals that JA and ABA are important plant stress hormones and application of ABA accompanied by different JA concentrations activated the protective mechanism of the strawberry plant against NaCl stress.

In this study, to evaluate the effect of foliar-applied iodate (5 and 50 mg/l KIO3) on the improvement of tolerance to salt stress (50 mM NaCl) in strawberry plants (Fragaria × ananassa Duch.), an experiment was under taken in complete randomized block design (RBD). The photosynthetic apparatus of strawberry was damaged at 50 mM NaCl, as indicated by a decrease in performance index (PIabs) coupled with lower values of photosynthetic electron transport chain components including the electron transport flux (φEo) and the inferred oxygen evolving complex activity (Fv/Fo) as well as higher levels of malondialdehyde (MDA). Plants treated with a low concentration of KIO3 (5 mg/l) showed an increase in the leaf dry weight, total protein and soluble sugars content with respect to no KIO3 supply under salinity stress. Additionally, low concentration of KIO3 raised free radical scavenging activities of strawberry leaf because of an enhancement of total phenolic content as well as CAT activity. In contrast, plants supplemented by 50 mg/l KIO3 exhibited an extreme stress for the photosynthetic parameters ofstrawberry, as demonstrated by the changes in the Fv/Fo as well as higher levels of MDA was similar to that observed in salt treatments. While KIO3 at 5 mg/l could increase photosystem performance index under salt-stress conditions in addition to the stimulation of antioxidant system, KIO3 at 50 mg/l could not ameliorate the negative effect of salt on strawberry and led to toxicity and caused damage to photochemical reactions, which is mainly overlooked by other authors.

In this study, effects of humic acid, mycorrhizal fungi and madder residue on some growth characteristics and nutrients uptake of evening primrose (Oenothera biennis L.) were investigated under soil salinity stress. The experiment was conducted as factorial based on a completely randomized design. Six levels of fertilizers including control (without soil amendments), 1.5 and 3 g L-1 mycorrhizal fungi, 16 and 32 mg L-1 humic acid, and 25% v/v madder residue were used in the presence ofthree levels of soil salinity (4, 7, and 12 dS m-1) with three replications. Results showed that in salinity of 4 dS m-1 the maximum number of flowers, flowering duration and dry weight of flowers were obtained in 32 mg L-1 humic acid. In salinity level of 7 dS m-1 the treated plants with 1.5 mg kg-1 mycorrhizal fungi showed the maximum number of flowers, flowering duration, and the highest uptake of Na, K and P. In salinity level of 12 dS m-1 the maximum number of flowers, dry weight of flower, total protein, peroxidase activity, and the lowest Na uptake were observed in plants treated with madder residue. Using organic and biological fertilizers induced flowering in salinity of 12 dS m-1. Generally, all organic and biological fertilizers treatments in all salinity levels caused increasing growth and yield of plant.

In order to Evaluation of yield and its related traits in Wheat cultivars treated with fluorescent Pseudomonads under salt stress , experiment desing was a split plot design with three repetitions in the year of 1394-95 in the research greenhouse at the Faculty of agriculture and natural resources, Persian Gulf University, Bushehr was implemented. Salinity stress was considered as a major factor in four levels (0, 50, 100 and 150 mm NaCl), wheat cultivars (Kuhdasht, dehdasht, Karim and Bam) as a first sub-plots and four strains of fluorescens pseudomonads (WKZ1-93، 2-79، WB1-7 and WBO-3) along with a control treatment (no bacteria) were considered as the second subplots.. The results analysis of variance of the experimental data determined there was a significant difference between salinity levels in all studied traits except spike weight and spike number and the interaction of salinity × variety in all measured traits except for peduncle length and other simple and cross effects were significantly different in each trait. Results of correlation coefficient showed the highest correlation between grain yield and peduncle length (r = 0.58**).In stepwise regression, peduncle length, spike length, grain weight, plant height and number of grains per spike were entered the model and confirmed the 51% of the total yield variations. Path analysis for grain yield revealed a direct and positive impact of peduncle length, spike length and 1000-grain weight and indirect effect of 1000-grain weight through peduncle length and peduncle length through spike length on yield.