Salt stress is a major agro-environmental constraint on crop productivity. In this study, the effect of different levels of salinity stress (0, 25, 50, 75, and 100mM NaCl) on the accumulation of some ions in two Salt-tolerant and susceptible onion cultivars (Esfahan and Behbahan cultivars, respectively) was investigated in 2017. The research was done by a factorial experiment based on a completely randomized design with three replications. The results showed that salinity increased Na and Cl contents and also decreased K content in the leaf and root in both cultivars. However, Na and Cl contents in the leaf and root of the susceptible cultivar were significantly higher than those in the tolerant cultivar, while the K value was less. In both cultivars, the Cl content in the leaf and root decreased with increasing salinity. However, the amount of Ca in the tolerant cultivar was higher than that in the leaves and roots of the susceptible cultivar. Salinity only significantly reduced Mg in the leaves. The amount of phosphate decreased at low salinity levels and increased as salinity increased. Yield injury index was in significantly negative correlation with K, Ca, K/Na, and Ca/Na ratios and in significantly positive correlation with Na and Cl in the leaves and roots. The results indicated the Salt-tolerant cultivar plays a role in reducing the Na and Cl uptake, as well as increasing the absorption and transfer of K and Ca to the leaves. Therefore, it could cause low yield injury under the salinity conditions compared with the susceptible cultivar.

Salt accumulation in the soil profile is a challenge for irrigated agriculture and the study of Salt concentration and its variation in the soil profile under different irrigation systems and management is needed. In this study, Sodium, magnesium, calcium and SAR concentration were studied under three irrigation regimes; farmer management (I1), Irrigation requirement (I2) and I2 plus leaching requirement (I3) in Safaeyeh in Kerman during two cultivation years (1391-1392). According to the results sodium, magnesium, and SAR deceased after irrigation but calcium did not affect by irrigation time. In development growth period, the highest values of SAR, sodium and magnesium were found to be corresponded to 75, 50 and 75 cm soil depth, respectively. The highest values of sodium and magnesium in I3 treatment were 123. 4 and 43. 6 meq/lit which were corresponded to the soil depth of 75cm. The highest value of calcium in I3 treatment was correspond to the soil depth of 25cm which was 52meq/lit. The highest value of SAR (12. 4) was belong to the soil depth of 75 cm which indicates calcium has moved upward and toward the emitter. The interaction effect of irrigation regimes, soil depth, and recording time (before and after irrigation) showed that the highest concentrations of sodium, magnesium and SAR were 131. 8, 74. 4 and 54. 3 meq/lit respectively, which were belong to I3 and 75 cm soil depth before irrigation. The highest amount of SAR was 12. 8 which were belonging to I3 treatment, too. Calcium variations in the soil under I2 and I3 irrigation regimes shows the important of irrigation management for salinity control. The results showed that I2 have better performance than the other irrigation regimes due to less Salt accumulation and SAR values in the root zone.

The main crop in Iran and many other countries is wheat that indicated high genetic variation between varieties related to Salt tolerance. In order to evaluation of Salt effects on growth and Na+ and K+ accumulation, nine varieties and lines were compared with Zagros and Tajan (local varieties). The plants were grown in hydroponics culture solution in growth chamber under control condition. The most tolerant varieties were Milan, Opata/Bow, Pego/Seri and Tan/Pwe//Sara where indicated about 55 percent reduction in dry weight. On the contrary, the most sensitive varieties were Rayan, Zagros and Atilla"s'' Arvand where indicated about 75 percent reduction in dry weight. The leaf area indicated similar pattern to dry weight. The Na+ content was lower in Milan, and Tan/Pwe//Sara varieties in compare to Opata/Bow, Pego/Seri varieties, but most of Na+ accumulate in roots of Opata/Bow, Pego/Seri varieties. Salt sensitive varieties accumulated higher Na+ concentration. The K+ concentration reduced with higher rate in Salt sensitive varieties like Rayan and Zagros in compare to Opata/Bow, Pego/Seri varieties. The results indicated the higher Salt tolerance in Opata/Bow and Pego/Seri varieties. Further experiments in field are necessary for confirmation of this result.

Background: Anthropogenic activities release high concentrations of heavy metals into the aquatic ecosystems, which can be absorbed by the aquatic organisms. In this study, the accumulation of cadmium (Cd) and arsenic (As) was compared in liver, gill and muscle tissues of toothed carp (Aphanius sophiae) in fresh and Salt water.Methods: A total of 175 fish samples were collected from the Shoor River, Iran during the spring and summer of 2011. Samples were divided into two groups for Salt and freshwater experiments.The individuals of each group were also divided into seven groups, a control group and the other six exposed to the concentrations of 5, 10 and 20 mg/L of arsenic and 5, 10 and 20 mg/L of cadmium. The liver, gills and muscle tissues of the specimens were dissected. The tissues were wet digested in acid and the concentrations of metals were measured using an ICP-OES instrument.Results: The concentrations of both metals were significantly different in various organs in both fresh and Salt water and it were in order of liver>gill>muscle (P<0.001). Based on t -test results, no significant difference was observed between the concentrations of As in related tissues of fish cultivated in fresh and Salt water. However, Cd accumulation was significantly higher in the tissues of fish specimens cultivated in freshwater (P<0.001).Conclusion: The bioaccumulation of Cd and As depends on organs, metals, and water condition.

Background and Objectives Two main mechanisms for Salt tolerance in plants are low rate of Salt transport to shoots and tolerance of high leaf Salt concentrations by sequestration of Na within cells vacuoles. Recently research for genetic variation in Na + accumulation within bread wheat has revealed large variation in leaf Na + accumulation in leaf is an important physiological process conferring Salt tolerance to wheat. Many studies have shown that low sodium concentration in leaves correlate with Salt tolerance. Sodium concentration in leaves may be influenced by sodium uptake by roots and transport from root to shoot. Materials and Methods + concentration. The control of Na + In order to understand the Salt tolerance mechanisms and the pattern of Na accumulation, 3 bread wheat cultivars differing in Salt tolerance (Kavir, Mahdavi and Jajan), were evaluated through two factorial experiments based on completely randomized design in three replications. Experiment 1 used 3 cultivars (Kavir, Mahdavi and Jajan) with four Salt treatments (0, 50, 100 and 150 mM NaCl) and experiment 2 used three cultivars (Kavir, Mahdavi and Jajan) with two Salt treatments (0 and 150 mM NaCl). Results + + Leaf Na concentration of genotypes was increased in response to increasing salinity after 14 days but Na + concentration was greater in sensitive genotype (Tajan) than tolerant genotypes (Kavir and Mahdavi). There were no significant differences between genotypes in RGR and shoot: root ratio. Results showed that the differences between genotypes in Na transport were responsible for differences in shoot Na + concentration in the root of all genotypes was the same but Salt tolerant genotypes maintained higher K + concentrations. Na + ratio in shoot. Shoot biomass was significantly reduced at 150 mM NaCl, whereas this reduction was almost the same for all genotypes. Kavir had the highest ability to tolerate high leaf tissue concentrations of Na + +: Na + + and leaf Na concentrations were much lower in Mahdavi than two other cultivars. Discussion It seems that the major effect of salinity on shoot biomass was due to the osmotic effect of Salt, not due to Na + transport rates from roots to shoots may cause different patterns of sodium accumulation through time. The comparison of genotypes suggests that at least there are two main mechanisms for Salt tolerance in hexaploid wheat. One is a lower rate of Na-specific effects within the plant. Differences in Na + accumulation in shoot and the other is tolerance of tissue to high concentrations of Na +.

A factorial experiment based randomized complete block was conducted in order to investigation of two rice (Oryza sativa L.) genotypes responses for Na+, K+, Ca2+, Mg2+, Cl-, Mn2+, P and total soluble sugars accumulation and compartmentation in leaves 3, 4, 5 and 6 to Salt stress. In estimation of the simple correlation between traits, dry weight was negatively correlated with Na+ and Cl-. The observed reduction in seedling growth was higher for IR29 (Salt sensitive) than IR651 (Salt tolerant). Salinity induced high Na+ and Cl- accumulation in leaves of both genotypes and in IR29 was more than IR651. The highest Na+ and Cl- concentrations were in third and fourth leaves of IR29. Total soluble carbohydrates concentration was increased only in leaves 5 and 6 of studied genotypes and had no change in leaves 3 and 4. Obtained results showed that under saline condition, reduction in Ca2+ concentration occurred in IR29 more than IR651, however, was observed in all leaves of both genotypes. There was no regular response of seedlings to salinity in relation to accumulation of Mg2+. Mn2+ and P concentrations had no changes under salinity. Under saline condition, K+/Na+ ratio was decreased in both genotypes but was higher in IR29. IR651 could to preserve high K+/Na+ ratio in sixth leaf than other leaves. Generally, IR651 could to accumulation toxic ions in older leaves for prevent damage to young leaves while high levels of these ions were accumulated in young leaves of IR29. Nacl also caused to imbalance for solutes concentration in leaves of both genotypes.

Salt stress is one of the most chalanging abiotic stresses affecting natural productivity and causing significant crop losses worldwide. A greenhouse experiment was conducted to evaluate the response of two alfalfa cultivars (Bami and Hamedani) to 6 levels of salinity (0 as control, 25, 50, 75, 100, 125mM NaCl) at the College of Agriculture, Shiraz University, Shiraz, Iran in 2008. Plant dry weight per pot in both cultivars decreased with increasing salinity levels. However, Bami as compared to Hamedani, with the lowest Na+ sequestration, produced the greater dry matter weight. Leaf area per pot was significantly affected by Salt stress with Bami cultivar showing a higher leaf area than Hamedani. Na+ accumulation also increased by increase in the salinity level in either one of the cultivars; however, Na+ sequestration of Bami as compared to Hamedani, was lower due to Na+ exclusion mechanisms occurring in this cultivar. Although Cl- accumulation increased with increasing salinity level in either one of the cultivars, cr accumulation was higher in Hamedani than in the other cultivar. Similar to K+/Na+ ratio, Ca2+/Na+ ratio also decreased by an increase in Salt stress levels and there were highly significant differences observed between 25 and 125mM of NaCI in either one of the cultivars. There was a strong positive relationship observed between plant dry matter weight and leaf relative water content for both Bami (R2=0.94) and Hamedani (R2=0.96) cultivars under' Salt stress conditions. All in all, it appears that less adverse effect of salinity on-Bami cultivar has made it suitable for growth in saline soils as compared to Hamedani in saline areas prevalent in south Iran.

Background and Objectives: Abiotic stresses, like salinity, cause an increase in nitrogen compounds such as proline and soluble proteins in plant. One approach to understanding the molecular basis of salinity tolerance is to identify how stress induces changes in levels of soluble sugars. Although it is still unknown whether the Salt tolerance of different rapeseed genotypes correlates with their ability to accumulate these compounds under salinity stress. Thus, it is necessary to study the relationship between accumulation of these compounds and Salt tolerance in rapeseed plant.Materials and Methods: In order to investigate the role of nitrogen compounds in Salt tolerance, an experiment was conducted in a controlled manner, under hydroponic conditions at the college of Agriculture, Shahid Chamran University of Ahvaz, Iran. This experiment was carried out in Completely Randomized Design as split plots with three replications in 2011. Salinity in three levels includes 0, 100 and 150 mM NaCl as main plots and the subplots were composed of three rapeseed genotypes including MHA4921, MHA4026 and Hyola401.Results: Salinity caused a significant reduction in root and shoot biomass and shoot N03-. Results showed that an increase in salinity leads to an increase in proline and soluble proteins contents of all genotypes, but this increase was greater in MHA4026 (Salt sensitive genotype) than in two other. (Salt tolerant) genotypes, at the highest level of salinity. Soluble sugar content in shoots increased with increasing NaCl in three genotypes, but this variation was greater in Salt tolerant genotypes. Soluble sugar shoot/root ratio was greater in MHA4921 and Hyola401 but the difference between Hyola401 and MHA4026 was not-significant. Discussion: Proline accumulation under Salt stress seems to be a symptom of injury amount rather than an indicator of Salt tolerance. In rapeseed plant under Salt stress proline, soluble sugar and soluble proteins increased but the amount of proline and soluble proteins in sensitive genotype was higher than that in Salt tolerant genotype. The ability of rapeseed plant to accumulate soluble sugars in response to salinity may be one of the major criteria for Salt tolerance.