Introduction: Glycine Betaine has potential impacts on enhancing the tolerance of plants against various environmental abiotic stresses. There are two methods of increasing Glycine Betaine level in plants in which Glycine Betaine does not accumulate naturally, the exogenous application of Glycine Betaine and the introduction of GBbiosynthetic pathway into plants, via transgenes. When Glycine Betaine is applied to the leaves of tomato plants, most of the Glycine Betaine that is taken up by the leaves is localized in the cytosol which is significantly reduced adverse effects of abiotic stresses (Park et al., 2006). Even in non-stress conditions, there are several environmental factors (water scarcity between irrigation times, soil salinity, mid-day heat, etc. ) that can affect the plant yield. This study tried to find the effectiveness of exogenous application of Glycine Betaine on tomato plant in non-stress condition. Materials and Methods: The experimental was conducted in 2015 as the randomized complete block design based on factorial with four replications. Treatments included three levels of Glycine Betaine application level (0, 3, 6 kg. ha-1 ) and three times of application including planting, floral initiation and fruit set. 0, 3 and 6 kgha-1 Glycine Betaine applied -1 with 200 lit. ha water and applied with back sprayer. The experimental field was located 10 km southeast of Mashhad. Irrigation with 6-day interval was done to represent non-stress condition. Electrolyte leakage, SPAD number and Relative Water Content (RWC) were measured. Dry matter, leaf area, days from planting to flowering, days from flowering to fruit set, total fruit numbers, ripe fruit numbers, green fruit numbers, average fruit size, and total yield were determined during the study. Harvest time was determined by meteorological forecast and before the first freezing stress in fall. The data were analyzed by SAS software and the means were compared by Duncan. Results and Discussion: Results showed that the times of application had significant effects on some measured parameters. Glycine Betaine application at planting stage led to increasing vegetative stage and delayed flowering time for 6 days. The highest leaf area (1464. 4 cm 2 ) was also obtained from the same application. Different times of Glycine Betaine application had no significant effects on total yield. However, using at planting time resulted in higher green/total fruit ratio. Evaluation the rate of Glycine Betaine application showed that the highest leaf area (1370 cm 2 ) and the highest dry matter (1206 g. ha-1 ) were obtained from 3 kg. ha-1 application rate. Treatments without GB application resulted in the highest yield (74. 7 ton. ha-1 ), but increasing the rate from 0 to 3 kg. ha-1, led to 94% increasing in green fruit numbers (8. 4 to 16. 2 respectively). Conclusions: Exogenous application of Glycine Betaine showed different effects on tomato plants due to time and rate of application. The highest yield was obtained from control treatment (no application) (74 ton ha-1 ) and 3 and 6 -1 kg. ha applications, decreased yield 15 and 30 percent, respectively. However, the vegetative stage was lengthened and the numbers of green fruits was increased by 3 kg. ha-1 rate. It seems that if the growing season was extended, and enough time was provided to fruit ripening, total yield could be increased by low concentration of Glysine Betaine application up to 25% compared to control. But high rate of Glycine Betaine may cause toxic effects on tomato and reduce the yield.

Background and Objectives: Coronilla varia or crownvetch is belonging to the Fabaceae family that is wildly distributed in different parts of Iran. The rapid spread of roots and shoots, as well as the ability to grow in stressful conditions, has caused it to be used to control soil erosion. In addition, the possibility of moving and regrowth has made Coronilla an appropriate alternative to turfgrass in green spaces. The aim of this study was to evaluate the response of Coronilla to freezing stress and the effect of glycine betaine on reducing seedling damage. Materials and Methods: a factorial experiment was conducted in a completely randomized design with three replications. Low temperature for one hour in five levels [25 (control), 0,-5,-10 and-15 °, C] were used as the first factor and spraying with glycine betaine (one day before freezing stress) on two levels (0 and 100 mM) was considered as the second factor. After freezing stress, freezing injury, and physiological (relative water content, ion leakage) and biochemical (chlorophyll, proline, lipid peroxidation, protein, and peroxidase) attributes were measured. Results: According to the results, exposure to freezing temperatures (-10 and-15 °, C) increased the damage to Coronilla shoots. The absence of the difference between 0 and-5 °, C indicates that the temperature of-5 °, C is tolerable for the Coronilla. Foliar application of glycine betaine reduced leaf damage. The results showed that under freezing stress the relative water content of leaves and roots decreases. The lowest relative water content of leaf with 57. 18% and 59. 02% was related to severe stress at-10 and-15 °, C, respectively. Under freezing temperatures, the amount of ion leakage of roots and leaves increased, so that under severe stress of low temperature-15 °, C compared to 25 °, C, the amount of ion leakage of leaves increased by 27%. With decreasing temperature, the chlorophyll content of the leaves first increased at 0 °, C compared to 25 °, C, then decreased at temperatures below 0 °, C. While the use of glycine betaine (100 mM) increased the leaf chlorophyll content under freezing conditions. The results showed that with lowering temperatures, the amount of proline in leaf and root increased. In addition, foliar application of glycine betaine increased leaf proline by 7%. On the other hand, freezing stress led to a decrease in leaf (16%) and root (26%) protein at-10 °, C in Coronilla. In addition, compared to control with lowering the temperature, the high accumulation of malondialdehyde (leaf, 193%,root, 141%), and the activity of peroxidase enzyme in leaves (66%) and roots (156%) recorded. Conclusion: Based on the results, it can be concluded that physiological and biochemical traits of Coronilla were affected by freezing stress. According to the results, leaf vulnerability was higher than the root. Low temperature caused damage to Coronilla by reducing the relative water content and ion leakage of leaves and roots. While spraying with 100 mM glycine betaine reduced the negative effects of freezing stress. Also, foliar application of glycine betaine effectively alleviates the adverse effects of freezing injury in Coronilla by increasing the accumulation of compatible osmolytes such as proline in leaves and roots.

In order to study the effect of different amounts of potassium silicate and potassium sulfate on growth traits of pistachio seedlings cv. Badami-E-Riz Kerman, an experiment was done as factorial with three factors, including two levels of salinity as source of NaCl (0 and 90 mM), three levels of silicon as source of potassium silicate (0, 50 and 100 mgL-1) and three levels of potassium as source of potassium sulfate (0, 1 and 2%), in compeletely randomized design with three replications. 45 days after the emergence of seeds, seedlings were exposed to salt stress foliar application of potassium silicate and potassium sulfate, both a week before and after starting salinity stress. The results showed that salinity decreased leaf relative water content, water use efficiency, leaf total soluble protein and increased electrolytes leakage, proline, soluble sugars, phenolic compounds in leaf and glycine betaine in leaf and root. Foliar application of potassium silicate and potassium sulfate increased leaf relative water content, water use efficiency, leaf total soluble protein, proline, soluble sugars, phenolic compounds and glycine betaine in leaf and roots, and reduced electrolytes leakage under salinity conditions. The most effective treatments were 50 mgL-1 potassium silicate and 2% potassium sulfate.

Nineteen bread wheat genotypes were selected to examine the effect of glycine betaine (GB, 100 mM) on various photosynthetic gas exchange parameters under drought stress and to study the relationship of these parameters with non-enzymatic antioxidants. Drought stress caused a significant decline in net CO2 assimilation rate (Pn), stomatal conductance (gs), intercellular CO2 concentration (Ci) and transpiration rate (E) among the studied wheat genotypes, with the tolerant genotypes characterized by higher net photosynthetic rate, lower drought susceptibility index (DSI), and higher maintenance of glutathione content (GSH) and ascorbic acid (AsA) levels than the sensitive ones. GB application significantly improved the photosynthetic characteristics, particularly Pn and gs, of studied wheat genotypes which could be due to more utilization of glutathione and increased levels of ascorbic acid in flag leaves under drought stress. But this response was observed to be genotype specific. Positive correlation of AsA with DSI in GB treated plants, and of Pn with GSH under drought stress and GB applied conditions suggested the role of these non-enzymatic antioxidants in sustaining photosynthetic efficiency and yield stability under prolonged field drought stress conditions.

In order to evaluate the effect of drought stress and salicylic acid on mineral content and some physiological traits of soybean genotypes (Glycine max L. ) a greenhouse experiment was conducted as factorial based on completely randomized design with three replications in Mohaghegh Ardabil University in 2014. The first factor consisted of three levels of water deficit (85%, 65% and 45% field capacity), the second factor consisted of three concentration of salicylic acid (0 or distilled water, 0. 4 and 0. 8 mM) and the third included soybean genotypes (Williams, L17 and D42X19). The results showed that water deficit increased the amount of sodium, sodium to potassium ratio, electrolyte leakage, malondialdehyde and glycine betaine and decreased leaf relative water content and leaf area per plant. Soybean genotypes responded differently to water deficit. Williams and L17 had the highest and lowest concentrations of calcium, potassium, relative water content and leaf area per plant, respectively. Salicylic acid decreases the amount of lipid peroxidation, electrolyte leakage and increased concentrations of glycine betaine and leaf area per plant. Interaction of salicylic acid and genotype on traits was significant. Application of 0. 4 mM salicylic acid exhibited afavorable effects on the accumulation of calcium, potassium, phosphorus and increasing the relative water content and maintaining the integrity of cell membranes and ameliorated the inhibitory effects of water deficit in soybean genotypes especially in Williams. Foliar application with 0. 4 mM salicylic acid reduced adverse impact of water deficit stress in Williams cultivar.

In order to evaluate the effects of methanol and drought stress on chlorophyll fluorescence parameters, chlorophyll and relative water content in sugar beet, a study was conducted in 2008 in Iran. Aqueous solutions 0 (control), 7, 14, 21, 28, 35% (v/v) methanol and each solution contained 0.2% glycine and second factor was drought stress (irrigation after 70% depletion of available water) and normal irrigation (irrigation after 40% depletion of available water). These solutions were sprayed over head 3 times in two week intervals on foliage parts of sugar beet. Results of this experiment indicated that there was not significant difference between levels of solutions on minimum chlorophyll fluorescence (f0), fluorescence variable (Fv) and maximum chlorophyll fluorescence (fm), but there was significant difference between levels of solutions on photochemical capacity of photosystem 2 (Fv/fm) at 5% probability level.

To evaluate the effects of methanol and drought stress on chlorophyll fluorescence parameters, chlorophyll and relative water content in sugar beet, a study was conducted in 2008 in Maahdasht (Karaj, Iran). Aqueous solutions of 0 (control), 7, 14, 21, 28, 35% (v/v) methanol with each solution containing 0.2% glycine and a second factor, namely drought stress (irrigation after 70% depletion of available water) and normal irrigation (irrigation after 40% depletion of available water) constituted the treatments. The solutions were sprayed overhead, 3 times in two week intervals on foliage parts of the crop sugar beet. Results indicated that there was no significant difference between levels of solution on minimum chlorophyll fluorescence (F0), fluorescence variavle (FV) and maximum chlorophyll fluorescence (FM), but there was a significant difference observed between levels of solutions on photochemical capacity of photosystem 2 (FV/FM) at a 5% probability level. Analysis of variance revealed that before a third foliar application, chlorophyll content did not show any significant difference, whereas there was a significant difference observed among levels of solutions on chlorophyll content after the third application at a 5% probability level.Also results indicated that drought stress significantly decreased photochemical capacity of photosystem 2 (FV/FM), fluorescence variavle (FV) and maximum chlorophyll fluorescence (FM) at 5% probability level. As for minimum chlorophyll fluorescence (F0) no significant difference was observed between the two levels of irrigation. Also drought stress significantly increased chlorophyll content at 5% probability level. Both factors (levels of solution and different irrigation levels) affected relative water content (RWC) at 1% probability level. The highest correlation was observed between white sugar yield and photochemical capacity of photosystem 2 (FV/FM). In this study interactive effect was not found to be significant.

In order to investigate the effect of mycorrhizal fungi symbiosis and glycine betaine foliar application on some quantitative and qualitative characteristics of rainfed wheat, this experiment was carried out in the Rainfed Research Station of Agricultural and Natural Resources Education and Research Center of West Azerbaijan, Iran during 2017-19 cropping seasons. The experiment was performed as a factorial randomized complete block design with three replications. The first factor was mycorrhizal fungi inoculum at three levels: (1) control, (2) inoculation of seeds before sowing with mycorrhizal fungus inoculum of  Rhizaphagus irregularis (GI) at a rate of 2%, (3) inoculation of seeds before sowing with mycorrhizal fungi inoculum as a mixture of three species of Funneliformis mosseae, Rhizaphagus irregularis  and Claroideoglomus etunicatum  (GM) at a rate of 2% and the second factor was glycinebetaine in two levels (1) control (water spraying) and foliar application of glycinebetaine. The results showed that root colonization was significantly affected by mycorrhizal fungal treatments and increased from 9.89% in control to 30.57% and 40.71% in GI and GM treatments, respectively. Using GM and GI inoculum, wheat grain yield increased by 269 and 187 kg ha-1, respectively. Application of mycorrhizal inoculum increased grain protein content and concentration of phosphorus (P) and zinc (Zn) in the grain. In all the mentioned traits, GM treatment had higher efficiency than GI treatment. Glycine betaine increased seed yield by 160 kg/ha. Foliar application of glycine betaine increased grain yield by 160 kg ha-1. The highest grain yield in GM treatment + glycine betaine foliar application was 2163 kg ha-1 which was 196 kg more than the control treatment. Generally, the results suggested that the application of MI inoculant + foliar application of GB were highly effective in improving the grain yield, harvest index, and quality parameters of rainfed wheat in semi-arid regions.