Tamarix nilotica is a perennial halophyte growing naturally at the Mediterranean coastal salt marshes. Vegetative parts were collected in two successive winters and summers to investigate the seasonal effects on the ecomorphological and physiological responses of T. nilotica. The results indicated that either in winter or summer seasons, T. nilotica can reduce the effect of soil salinity by excreting salts outside its body through salt glands. Summer season was characterized by low content of soil moisture (due to rare rainfall), high soil EC, high light intensity and high temperature; there-fore, plant induced certain morphoanatomical changes in leaves and stem to face the previously mentioned adverse conditions. The most remarkable changes to reduce transpiration process was found by decreasing leaf area and increasing cuticle thickness and mesophyll tissue thickness. In addition, the most marked physiological changes in summer were the significant in-crease in total phenols, proline, free amino acids and total soluble sugars. These compounds can work as osmotic regulators and/or antioxidants. These features enhance the defensive mechanism against dehydration and permit T. nilotica to tolerate the stress conditions in salt marsh habitat.

The combined data from two growing seasons in a field experiment study by using two irrigation systems (surface and subsurface drip) in terms of additional water for sugar beet plants under saline conditions are used to estimate root and sugar yield, water use efficiency and root penetration power at the time of harvest. Water salinity levels of 6000 and 8000 ppm were applied to irrigate sugar beet from the time of planting on October 3 to the time of harvest on April 22 with three additions of water (limited 1750, moderate 2500 and optimum 3250 m3/fed). The results are summarized as follows: The heaviest root and highest sugar yield as well as highest water use efficiency were recorded when using subsurface irrigation system, 6000 ppm water salinity level, and moderate or optimum irrigation water (2500 or 3250 m3/fed). Oppositely, the highest penetration power values were obtained using drip irrigation systems with low water quantity (1750 m3/fed) and high-water salinity level (8000 ppm).

The main objective of this investigation was to evaluate the determination effect of salt tolerance of five new almond× peach hybrid rootstocks namely hybrid 1, 2, 3, 4 and 5 through their vegetative growth parameters and chemical concentrations. This evaluation aimed to recommend these rootstocks for the commercial use. This experiment was carried out at the Horticulture Research Institute, Agriculture Research Center, Giza, Egypt, during two successive seasons (2018-2019 and 2019- 2020) respectively. Rootstocks chosen for this study included new almond× peach rootstocks which are resistant to nematode. Salinity irrigated water included four levels of NaCl salt which was 500, 1000, 1500, 2000 ppm and the control which was the usual irrigated water. Results cleared that increasing salinity levels led to reduction in all growth parameters including seedling stem diameter, heights, average leaves number and buds per one, leaf area, fresh and dry weights. High salinity levels declined gradually mineral concentrations like N, P, K, Mg%, Fe and Mn ppm. Moreover the highest level of salinity conducted to the highest level of Na and Cl ppm concentrations. Chlorophyll values take the same trend while proline values take the opposite trend with high salinity due to it considered an indicator to high salinity. Moreover, there were differences between rootstocks to salinity tolerance. Hybrid No.5 was the most resistant hybrid to high salinity concentration followed by hybrid No.4 while hybrid No.3 was the least one. Hybrid No.5 reached the highest values of growth parameters and it shared with hybrid No.4 the highest values of N, P and K, Mg concentrations and the highest levels of Fe, Mn, Na and Cl. Chlorophyll values take the same trend with slightly differences with hybrid No.4. On the other hand hybrid No.3 was the least hybrid in all growth measurements, mineral concentration and chlorophyll except proline concentration it recorded the highest value. From the above investigation we can recommend hybrid number5 or hybrid number4 which had the best results compared to other seedlings rootstock under experiment salinity conditions.

The present work was aimed to evaluate Chenopodium quinoa cultivar CICA (Chenopodium quinoa Willd. cv. CICA), in field experiments, as a new and non-traditional leafy crop in Egypt under saline (ECe 17.9 dSm-1) and non-saline (ECe 1.9 dSm-1) soil conditions. Production of biomass, some morphological, physiochemical and yield components traits were estimated at 40 days from sowing date. Biomass production of young quinoa shoot under saline soil was significantly higher by 25% than non-saline soil. Quinoa plants cultivated under saline soil also showed significant high performances for most of morphological traits. Although salinity led to accumulate Na+ concentrations in the leaves by six folds higher than that found in the leaves produced under non-saline soil conditions, but no significant reduction has been observed for K+ concentrations. Moreover, salinity was significantly increased magnesium concentrations in quinoa leaves. On the other hand, no significant increase has been detected of proline or total soluble carbohydrates concentrations in leaves of quinoa grown under saline soil as compared to non-saline soil. This clearly indicated that quinoa plants, during early growth stage, tended to utilize inorganic ions rather than organic solutes to regulate its osmotic potential under saline conditions. Chlorophyll a, chlorophyll b and carotenoid concentrations were significantly decreased under saline soil. Also, concentrations of crude fiber, crude fat and iron in the leaves of quinoa plants grown under saline soil conditions were significantly decreased. Meanwhile, salinity has no significant influence on crude protein concentrations. These results revealed that the quinoa has the ability to grow and produce considerable high leafy vegetable yield with good quality, in terms of high protein, in land unsuitable for conventional vegetable crops.

Salinity is one of the major environmental factors limiting crop productivity. For this reason, two greenhouse experiments were conducted in Faculty of Agriculture, Cairo University, Egypt, during the year 2015 using two rice varieties to evaluate the effects of various levels of osmotic stress caused by polyethylene-glycol 6000 (PEG) and NaCl. Furthermore, it was tested whether the inhibitory effect of salinity on growth, sodium and chloride concentration by two different varieties was greater under NaCl or PEG treatment. The first experiment was undertaken to separate osmotic and ionic aspects of salinity damage to rice (Oryza sativa L.).Seedlings of IR28 (salt-sensitive) and Nona Bokra (salt-tolerant) rice varieties were transferred to salinized nutrient solution containing 85 mol m-3NaCl (-3.0 bars) with or without   PEG 6000 (-2.0 bars, 45 gL-1).  Plants were grown up to 30 days in the salinized solutions. The second experiment was designed to determine the effect of salinity (85 mol m-3NaCl) with or without PEG 6000 (-0.5 bar, 11 g L-1)on growth, uptake and transport of sodium and chloride in two rice varieties differing in salt tolerance.  The results indicated that survival of salt-tolerant variety (Nona Bokra) was increased significantly by adding PEG (-2.0 bars). The addition of PEG also reduced the rate of death of rice plants compared with NaCl alone. Also, data showed that PEG 6000 (0.5 bar, 11 gL-1) reduce sodium concentration in root of IR28 and   Nona Bokra but its effect upon sodium concentration in shoot of the two varieties was more pronounced than the reduction of Na+ concentration in root.  Highly significant differences were obtained between zero and 11 gL-1 PEG. The result of this study is strongly indicated that addition of PEG dramatically lessened the toxicity of NaCl to rice seedlings.

Salinity is a stress factor affecting the production of crop in many regions.  Calcium can reduce Na+ transport to shoots in rice. Two greenhouse experiments were conducted in Faculty of Agriculture, Cairo University, Egypt, during 2015 growing season of rice to evaluate the effect of different calcium concentrations on survival percent along with uptake of Na+ and Cl- ions by two varieties of rice (Oryza sativa L.) differing in salt-tolerance. The first experiment was undertaken to study the effect of different calcium concentrations on survival percent of IR28 (salt-sensitive) and Nona Bokra (Salt-tolerant) seedlings which were transferred to salinized nutrient solution containing 0.5% NaCl and a variable calcium concentrations at 4, 40, 100 and 200 ppm; plants were grown up to 40 days. The second experiment investigated the effect of different calcium concentrations on growth, uptake and transport of Na+ and Cl- ions in the two rice varieties differing in salt-tolerance. The seedlings were transferred to salinized nutrient solution containing 0.5% NaCl and calcium ion concentrations at two levels, 4 and 40 ppm. Plants were harvested at 0, 1, 3, 5 and 7 days from salinization. The results indicated that the salt-tolerant variety (Nona Bokra) survived for more than 40 days under exposure to 0.5% NaCl when calcium concentration of the culture solution ranged from 40 to 200 ppm Ca++. The low calcium ion concentration (4 ppm) depressed the growth of plants at 5 and 7 days after salinization.  In Nona Bokra, the shoot had less sodium and Cl than the root. This implies that the salt tolerance of Nona Bokra may be attributed to the restricted translocation of Na+ and Cl- from the root to the shoot. Sodium as well as cloride content in the shoot of IR28 was more than twice that of Nona Bokra.  An adequate amount of Ca+2 tended to lower the salt injury caused by high levels of salinity in rice plants. The effect of calcium ion on salt tolerance varied greatly between Nona Bokra and IR28 varieties.

This study aimed to determine the effect of different salinity and anti-transpiration levels on the growth and biochemical composition of Panicum maximum plants (Guinea grass) during the spring and summer of 2020. Two different anti-transpiration treatments [molasses (sugarcane) (5 mL/L), kaolin (50 g/L) and control] and three salinity levels (S1 well water as the control and salinity S2 2000 ppm; S3 4000 ppm, S4 6000 ppm) were used in 12 treatments in 72 pots (3 anti-transpiration treatments × 4 salinity treatments × 6 replicates); a randomized complete design was used. Results revealed that the plants achieved the highest plant height (123.77 cm) and dry weight (521.87 g/m2) with kaolin and no salt addition treatment during summer. A higher percentage of proteins and carbohydrates were found in spring than in summer, but there was no significant difference in the salinity levels. A high percentage of ash and fiber contents was also observed during summer, with no significant differences between the anti-transpiration treatments. It could be concluded that P. maximum, as one of the most important fodder crops, could be cultivated in marginal lands, especially during the summer season.

In total, 50 Rhizobium isolates were isolated from the mature root nodules of common beans plants (Phaseolus vulgaris) grown in different nine governorates of Egypt. PHB was optimized by the identified strain using response surface methodology. A total of 11 parameters (pH, incubation period, inoculum size, temperature, agitation speed, mannitol, sucrose, yeast extract, glycine, K2HPO4, and MgSO4) were analyzed for their significant effects on PHB production by the Plackett–Burman design (PBD). Sucrose, yeast extract, glycine, and MgSO4 were the main significant factors affecting PHB accumulation. Central composite design (CCD) of the response surface methodology was used to determine the optimum levels of the selected factors. Rhizobium phaseoli reached the maximum production (4.997 g/L) at run 36 in the presence of 25 g/L of sucrose, 0.0 g/L of yeast extract, 0.87 g/L of glycine, 0.3 g/L of MgSO4, and 5% of inoculation size. In vitro experiments were carried out to test the effect of different stress conditions (pH: 6–11, temperature: 5°C–50°C, salinity: 0.01%–7%, and drought: 0%–5% w/v) on the growth of Rhizobium phaseoli. The results showed that Rhizobium phaseoli can withstand 3% –5% NaCl, high temperature of 30°C– 45°C, alkalinity at pH value of 8 – 10, and drought stress at 3% – 5% w/v polyethylene glycol with growth loss of 50% when grown on modified medium and 75% when grown on the basal one. In vivo experiments were done to study the effect of drought stress levels on the growth parameters of common bean plants. In general, all the treatments with Rhizobium phaseoli grown on the modified medium were superior to Rhizobium phaseoli grown on the basal medium. Also, they showed high tolerance of drought conditions.

Wheat is an essential staple food in the developing world, where demand is projected to grow exponentially in the future; simultaneously, climate changes are projected to reduce supply in the near future. One of the main consequences of climate change is salinity, which negatively impacts the world's cultivated area and therefore affects the global wheat production. Our objectives are to study the population structure of several Egyptian and international wheat accessions and to identify the genetic factors controlling the salinity stress response of bread wheat. In addition, we have attempt to identify genes that control some important agronomic parameters of wheat under salinity stress were identified. The wheat germplasm panel consisted of 70 accessions obtained from Egypt, Syria and Iran. The assessment of salinity tolerance was conducted over the years of 2018 and 2019 in the field and in the greenhouse. The genome association analysis (GWAS) and population structure analysis was conducted using six SCoT, five SSR and 93 SNP markers. Analysis of the population structure using allele frequency and phylogenetic analysis indicated that the studied wheat accessions were belong to four population groups. Where, for the most portion, Egyptian, Syrian and Iranian accessions are clustered depending on their country of origin. The GWAS analysis revealed 13 SNP markers that were significantly associated with morpho-agronomic wheat traits during salinity stress. These markers were closely related to genes that are known to have a direct link to wheat response to salinity stress such as CYP709B2, MDIS2, STAYGREEN, PIP5K9, and MSSP2 genes. This study revealed the genetic structure of adapted and imported wheat accessions, which could be used to select potential wheat accessions for local breeding programs. In addition, the SNP genotyping assay is a very potential technology that could be efficiently applied to detect genes that control bread wheat response to salinity stress.

Salinity is a major limiting factor for tomato crop growth and productivity especially in arid and semi arid lands region. Therefore this study was conducted to study the effect of applying sugar beet molasses, priming tomato seedling in saline water and Fe-EDHHA on mitigating salinity negative effects on tomato (Lycopersicon esculentum L.)  hybrid super strain B (salinity sensitive hybrid). Seedlings of tomato hybrid were transplanted on April 4th in both seasons 2014 and 2015 in pots contains washed sandy soil, and irrigated with saline water with EC of  2000, 3000 and 4000 ppm. Beet molasses and Fe – EDHHA were applied at  rates of 200 and 300 kg / fed. for beet molasses and 3 and 4 kg / fed. for Fe – EDHHA. Priming tomato seedlings in saline water treatment was applied at 5 and 6 dS/m for 24 hours.  Data showed that all plant growth aspects such as plant height, leaf area, plant fresh and dry weights were improved under beet molasses, Fe and priming tomato seedlings in saline water treatments compared to none treated plants (control). Yield parameters also followed the same trend. Among treatments, beet molasses at a rate of 200 kg / fed. recorded the highest significant effect in mitigating salinity negative effects. It could be concluded that beet molasses, priming tomato seedling in saline water and Fe – EDHHA treatments were more effective and efficient in mitigating salinity stress on tomato plants.