proline

Drought stress, as one of the main abiotic stresses, affects plant growth and performance by affecting various physiological and biochemical processes, such as membrane integrity, photosynthetic pigments, osmotic adjustments, water relations, and secondary metabolism. Drought stress in plants causes oxidative stress due to the production of reactive oxygen species (ROS) during photosynthesis and respiration. ROS directly damage proteins, fats, nucleic acids and cell membrane, and due to the increase in membrane permeability, the rate of electrolyte leakeage and malondialdehyde increases. Plants mainly reduce the damage of these oxides by controlling the antioxidant system and regulating the content of osmosis compounds. Enzymatic antioxidant system: It includes antioxidant enzymes such as catalase, superoxidase dismutase, peroxidase and non-enzymatic antioxidant system including compounds such as ascorbate, glutathione, as well as phenol and flavonoids. Savory (Satureja hortensis L.) is one of the most important medicinal plants that grows in different parts of the world, including Iran. Biofertilizers play a prominent role in the growth and development of plants by improving the absorption of nutrients and sufficient water through changes in the physicochemical properties of the soil. The purpose of this study is to investigate the effect of drought stress, plant growth-promoting bacteria (PGPRS) and vermicompost on the physiological and biochemiclal traits of savory plant. In drought stress conditions, the application of organic fertilizers prevents the soil from drying out by maintaining moisture.   

In order to investigate the effect of inoculation with  Pseudomonas P15 bacteria, Streptomyces and vermicompost on some physiological and phytochemical traits of savory plant (S. hortensis L.) under drought stress conditions, a factorial experimental based on a randomized complete block design with three replications was conducted at the Research Farm at the Mohaghegh Ardabili University, Iran, during 2016-2017.The experimental factors include inoculation with microorganisms at three levels (control (without inoculation), inoculation with Pseudomonas P15 and Streptomyces bacteria),    vermicompost at four levels (0, 1, 1.5 and 2 tons). per hectare) and drought stress in three levels (S1: full irrigation, S2: water cut at 50% of flowering and S3: water cut at the beginning of flowering). 

The results showed that drought stress, inoculation with   microorganisms and vermicompost had a significant effect on the measured traits (chlorophyll, carotenoid, RWC, protein, electrolyte leakeage, proline, and antioxidant enzymes. Under drought stress conditions, the amount of chlorophyll, carotenoid, RWC and protein decreased. While the amount of electrolyte leakeage, proline, and antioxidant enzymes increased. Also, the values of all the measured traits, except the amount of electrolyte leakeage and proline, in plants inoculated with bacteria and vermicompost application were more than non-inoculated plants. The highest and lowest values of the RWC (94.44 and 62.33 percent) were obserwed in plants inoculated with Streptomyces bacteria under non-stress conditions and in non-inoculated plants under drought stress at the beginning of flowering respectively. Also, the highest amount of chlorophyll a, b and total (25.36, 20.25 and 45.61 mg/g FW) was obtained in non-stress conditions, application of two tons per hectare of vermicompost and inoculation with Streptomyces bacteria. While the lowest amount of chlorophyll a, b and total (16.73, 9.63 and 23.69 mg/g FW) was obtained in non- inoculation plants and without application of vermicompost under drought stress at the beginning of flowering. It seems under drought stress conditions, the application of organic fertilizers prevents soil drying by maintaining moisture, thereby improving the relative water content of the leaves. Also, the use of organic fertilizers such as vermicompost improves the absorption of nitrogen that leading to greater synthesis of photosynthetic pigments such as chlorophyll and carotenoids.

The findings of this research showed that inoculation with growth-stimulating microorganisms and the use of vermicompost can moderate the adverse effects of water stress on the growth and performance of savory plants by maintaining chlorophyll levels and increasing antioxidant activity. According to the results of this study, it can be stated that the application of Streptomyces bacteria and 2 tons per hectare of vermicompost in the field leads to sustainable production and yield of S. hortensis under drought stress conditions by improving physiological traits.

The percentage and rate of seed germination are critical factors leading to high yield in agriculture, but it has a diminishing effect on environmental stress. Seed pretreatment is one of the ways to increase the strength and velocity of seed germination to deal with salt stress. The purpose of this study was to investigate the effect of seed pretreatment by peppermint (0.5, 1, and 2%) and seaweed extract (0.5, 1, and 2%) with control on the growth and biochemical traits of Thymus daenensis seedling under salinity stress (0, 50, 100, and 150 mM NaCl) conditions. This experiment was conducted as a factorial as a completely randomized design in four replications at the seedling growth stage. The results showed that seed pretreatment with peppermint and seaweed extract increased the percentage, velocity, and time of germination as well as the number of germinated seeds, in the absence of salinity stress. In seedling growth characteristics, although they were better in the absence of salinity stress, the pretreatment of the seeds significantly reduced the effects of salinity stress compared to the control conditions. The highest amount of chlorophyll in this condition was obtained in seeds treated with 2% seaweed extract. The highest activity of catalase enzyme and polyphenol oxidase enzyme was obtained in 100 and 150 mM salinity stress conditions and seeds treated with 1 and 2% seaweed extract, respectively. Salinity stress had caused a decrease in growth parameters, but seaweed extract pretreatment had improved the conditions.

 Quinoa (Chenopodium quinoa Wild.) is a pseudocereal that is one of the oldest crops in the Americas and a native plant in the Andes region. Compared to other grains, quinoa has more protein and a more balanced amino acid composition with 8-5% lysine and 1.5-2.4% methionine.
Drought, heat, salinity, etc. are types of abiotic stresses that reduce plant growth and cause a sharp drop in crop yield due to various changes at the physiological, morphological, and molecular levels. In addition, drought stress may cause the production of reactive oxygen species in plants, which damage lipid and protein structures and cause the cell membrane to lose permeability and selectivity. Leakage of intracellular ions leads to disturbance in metabolism, chloroplast decomposition, and reduction of chlorophyll content.
Glycine betaine not only acts as an osmotic regulator but also stabilizes the structure and activity of enzymes and protein complexes and maintains the integrity of membranes against the damaging effects of drought. Glycine betaine treatment increases the growth, survival, and tolerance of plants to different stress conditions by regulating different metabolic processes, improving the rate of absorption of pure CO2, maintaining proteins, enzymes, and lipids of the photosynthetic apparatus, and maintaining the flow of electrons through thylakoid membranes.
This research was conducted to investigate the effect of glycine betaine foliar application on agronomic, biochemical, and physiological traits of quinoa under water stress conditions.

 The experiment of split plots based on randomized complete blocks design with three replications was performed at the station of Research in the 2020-2021 and 2021-2022 crop years, Agriculture and Natural Resources Center in Kerman province of Iran. The main factor included three levels of irrigation treatment (irrigation to the full maturity stage (control), irrigation to the beginning of the flowering stage, and irrigation to the beginning of the development stage) and the secondary factor included two levels of glycine betaine (0 and 3 mM). Biological and seed yields and harvest index, biochemical traits including proline and total phenol and flavonoid contents, and physiological traits including the activity of antioxidant enzymes such as catalase, ascorbate peroxidase, peroxidase, and polyphenol oxidase were measured. Variance analysis of all traits and LSD mean comparison test at five percent level was conducted with SAS software version 9.2.

 The effect of irrigation factor and glycine betaine and their interaction effect on the most measured traits were significant. The highest biological and seed yields were observed in control condition and the application of glycine betaine. The lowest of them were in plants grown under irrigation condition to the beginning of the flowering stage and non-application of glycine betaine. Water stress was increased the content of proline and total phenol and flavonoid and the activity of antioxidant enzymes in both level of glycine betaine. The foliar application of glycine betaine caused an increase in the biological and seed yields and biochemical and physiological traits at all three irrigation conditions.

 Under water stress conditions at both glycine betaine levels, the biological and seed yields decreased while the biochemical and physiological traits increased. These results show that the quinoa plant responds to water stress with enzymatic and non-enzymatic defense systems. The application of glycine betaine led to the improvement of biological and seed yields and biochemical and physiological traits in all three irrigation treatments. So, glycine betaine can be used to compensate for the harmful effects of water stress in quinoa.  

Communication between cells in organic plants for growth and development is done by chemical messengers called hormones. Meanwhile, GA3 is one of the most well-known plant hormones that cause various growth reactions in the plant, and most of their activity is the longitudinal growth between the nodes. Cytokinin is another type of plant phytohormones whose most important effect is in the process of cell division. In this research, the effect of cytokinin and gibberellin hormones on some chemical compounds and the dry weight of the Stevia plant shoot was studied under controlled conditions. A factorial experiment was conducted in the form of a completely randomized design in the greenhouse of Razavi Khorasan Agricultural Research and Training Center in three replications in 2017. Factors included gibberellin (0, 50 and 100 ppm) and cytokinin (0, 50 and 100 ppm). The average temperature of the greenhouse was approximately 25 to 30 degrees Celsius and its humidity was 65%. Irrigation was done regularly every three days. Before treatment, the potted plants were adapted to the greenhouse environment for two weeks. The treatment was carried out as foliar spraying, in this way, for six weeks and before watering at 10 am for each plant, 20 cc at the beginning and 50 cc at the end of the growth were sprayed with the desired solutions so that the leaves were completely wet. At the end of the experiment, the aerial parts were removed from the ground and placed in paper envelopes inside a ventilated oven with a temperature of 70°C for 48 hours. The samples were weighed immediately after leaving the oven with a scale of 0.001. The results showed that the highest amount of soluble sugars was obtained from the application of 50 ppm of gibberellin along with 100 ppm of cytokinin (1.61 mg/g dry weight of leaves), which showed an increase of about 25% compared to the control. The amount of leaf protein was significant only in the presence of different concentrations of gibberellin hormone. The highest amount of proline was obtained from the combined application of 100 ppm gibberellin and 0 ppm cytokinin (1.31 mg/g fresh weight of leaf), which showed an increase of about 63% compared to the control. Foliar spraying with gibberellin hormone decreased the amount of chlorophyll a. The highest amount of chlorophyll b was obtained from simultaneous application of 50 ppm levels of cytokinin and gibberellin. The lowest dry weight of the shoot was shown in the presence of the combined treatment of two hormones at the level of 100 ppm, and the highest value was obtained at the level of 100 ppm of gibberellin hormone. The results of the correlation coefficients showed that the dry weight of the shoot had a positive and significant correlation with the amount of proline (r=0.63**). It seems that the hormone auxin (acidification and loosening of the cell wall) and gibberellin enable elongation and growth by changing the characteristics of the cell wall. Therefore, based on the results of this experiment, the increase in the dry weight of aerial parts can be attributed to the effect of gibberellin and different ratios of hormones inside the plant. In general, the results showed that gibberellin levels were more effective than cytokinin hormone on the biochemical and morphological indicators of stevia plant; So that the maximum dry weight of shoot was obtained from the effect of 100 ppm gibberellin hormone. Photosynthetic pigments showed different reactions to different concentrations of studied hormones. The effect of 100 ppm concentration of gibberellin on the amount of protein, soluble sugars and proline was significant compared to other levels.

Malva sylvestris, commonly known as the common mallow, is a flowering plant species in the genus Malva. It is native to Europe, North Africa, and Western Asia, and has been introduced to other parts of the world. The plant has been known since ancient times and is considered the "type-species" for the genus. The leaves are edible and the plant (and seeds) are used as herbal remedies. Malva sylvestris is either a perennial or biennial plant. It spreads readily from seed and can self-seed prolifically. The seeds resemble small wheels or discs. The plant is known to be susceptible to a virus called Malva vein clearing potyvirus, which is transmitted by aphids. It also contains compounds such as malvin, malonylmalvin, and the naphthoquinone malvone A. The aim of this article is to evaluate the various (nine) ecotypes of Iranian Malva sylvestris L. by analyzing their morphological and physiological characteristics. By employing a step-by-step regression approach, the study seeks to identify significant traits that differentiate these ecotypes. The research intends to enhance understanding of the adaptive strategies of Malva sylvestris in diverse environmental conditions. Ultimately, the findings aim to contribute valuable insights for conservation efforts and the potential use of these ecotypes in horticulture and agriculture. This comprehensive evaluation will also provide a foundation for future studies on the species' ecological adaptability. In this study, 9 ecotypes of Malva sylvestris were collected in 2017 from different habitats in Iran (Mashhad, Torbat-e Heydariyeh, Fariman, Zabol, Zarand, Jiroft, Rudbar, Bandar Abbas and Khorramdasht) (Table 1) and identified in the Herbarium of Torbat-e Heydariyeh University. They were then cultivated in a completely randomized design with three replications in late February 2018 in the greenhouse of the Agricultural Research Institute of the University of Zabol and evaluated in May 2019. The seeds of each ecotype were planted in 5-liter pots (after germination and thinning, five plants of each ecotype were kept in each pot) in a growing medium consisting of an equal mixture of agricultural soil, coco peat, perlite, and well-rotted animal manure. Irrigation was calculated based on the temperature conditions in Sistan and the greenhouse, as well as the field capacity of the pot mixture, and was carried out regularly until flowering. At full flowering, the stem diameter and length of three plants from each pot were randomly measured and their means were considered for each treatment. At this stage, the number of flowers with seeds and the number of leaves of each plant were counted. Fresh and dry weights of root, stem and whole plant were measured with a digital scale (0.01 g accuracy). For dry weight measurement, fresh samples were placed in an oven at 70°C for 48 hours. Chlorophyll a, chlorophyll b and carotenoid contents were determined. The absorbance of the samples for chlorophyll a and b and carotenoids was measured at wavelengths of 663, 645 and 470 nm, respectively, using a spectrophotometer. Proline, soluble carbohydrates, and protein were measured. Pearson correlation coefficients were used to calculate simple correlation coefficients between morphological traits. Statistical analysis of traits was performed using SAS Ver. 9 and Excel software, and means were compared by Duncan's method at 1% and 5% probability levels. The highest stem diameter (9.58 mm), root length (61.22 cm), root weight (18.86 g), root dry weight (4.84 g), and proline content (0.614) belonged to Mashhad ecotype. The number of leaves had a negative and significant correlation with the fresh weight of the plant, while it had a positive and significant correlation with plant height and shoot dry weight. Other traits did not show a significant correlation with the number of leaves per plant. The highest correlation was observed between morphological traits between fresh weight and leaf dry weight (P<0.01) and in phytochemical traits between carotenoid and chlorophyll b (P<0.05). Based on stepwise regression in the presented models, root weight and plant dry weight had the most positive effect on root length, but stem diameter and plant weight had the most negative effect. Chlorophyll b had the most negative and direct effect on proline yield, but chlorophyll a, carotenoids, carbohydrates, and total protein had the most positive effects, respectively. The variance analysis results indicated significant differences among the various ecotypes of Malva sylvestris regarding morphological and phytochemical traits (P<0.01) (Tables 2 and 3). Mean comparisons revealed that the Mashhad ecotype excelled in stem diameter, root length, and fresh and dry root weight, while the Rudbar ecotype showed the highest fresh weight in aerial parts. The Bandar Abbas ecotype had superior fresh and dry weights of aerial parts, leaf count, flower count, and seed count, and the Torbat-e Heydariyeh ecotype was notable for flower and seed counts per plant (Table 4). The tallest stem (40.55 cm) was recorded in the Jiroft ecotype, while the shortest (1.81 cm) was from Mashhad. The greatest stem diameter (9.58 mm) belonged to the Mashhad ecotype, and the smallest (3.54 mm) was found in Zabol. Root length also varied, with the Mashhad ecotype having the longest (61.22 cm) and Rudbar the shortest (9.55 cm) (Table 4). The highest fresh and dry root weights were observed in the Mashhad ecotype, while the Jiroft ecotype had the lowest. In the results of step-wise correlation and regression analysis of the medicinal plant Malva sylvestris L., the highest positive regression coefficients for yield were related to the traits of proline content, root fresh weight, and plant dry weight, which indicates their more fundamental role in increasing yield and their potential for improvement. Overall, the present study showed that root-related traits had an important effect on the final yield in the Mashhad population of Malva sylvestris L., and the Mashhad ecotype also showed the most desirable performance in terms of the evaluated traits. Due to its high performance in these traits, the Mashhad ecotype is recommended for researchers, universities, and private sectors involved in the cultivation and domestication of medicinal plants.

90% of Iran's land area is in arid and semi-arid areas. It is expected that by 2025, about two-thirds of the world's agricultural lands will face a water deficit. The yield also decreases by 50 to 90% under drought stress conditions compared to non-stressed conditions. Among the different types of stress, drought stress at the end of the season is the most important stress in Mediterranean areas such as many areas of Iran. Therefore, the yield of small grains cultivated in these areas is affected by drought stress at the terminal of the season. Salinity and drought stress increases the concentration of dissolved solutes in the root environment, increases the osmotic potential of the soil, decreases the absorption of nutrients and decreases the mobility of zinc and iron elements in the soil solution. Elements in the plant can be compensated and tolerance to saline conditions can be increased. Researchers reported that the application of zinc increased the grain yield of wheat and barley cultivars. Researchers reported that the application of zinc increased the grain yield of wheat and barley cultivars. In stress conditions due to reduction of stomatal conductance and limited access to CO2 for carboxylation reactions, the rate of photosynthesis decreases and increasing stomatal resistance is a suitable defense strategy for the survival of wheat and barley. Due to the cultivation of barley in these moderate areas and the role of the micronutrient element zinc in reducing the effects of drought and salinity stress, this research was carried out in different varieties of barley using different amounts of zinc sulfate. This research was carried out in November of the agricultural year 2017-2018 in two areas: 1) Kobutrabad Agricultural Research Station (drought stress by removing water after spike emergence); 2) Rudasht Station (rrigation with salt water 10 dS/m). Planting was carried out by machine planter in November in both regions. In the dry area of Kabutrabad, the plots containing 6 rows of 6 meters with the distance between the rows of 20 cm (the planting area of each plot is 7.2 square meters) with a density of 400 grains per square meter were done. Data analysis and step-by-step regression were performed using SAS9.1 software and mean comparison was performed by LSD test at 5% probability level. If the interaction effect is significant, cutting (slicing) and comparison of means was done by Lsmeans test at 5% probability level. The results showed that barley cultivars under drought stress had higher thousand-grain weight, grain yield and biological yield and lower proline content than under salt stress. Drought stress at the end of the season compared to salinity stress during the growing season had higher thousand-grain weight, grain yield and biological yield and lower proline content. Foliar application of 0.5% zinc sulfate had higher grain yield (4763 kg/ha about 34%) and biological yield (4763 kg/ha about 26%) than without foliar application and is recommended. It should be noted that there was no difference in the amount of proline between cultivars in drought stress, but in salt stress, tolerant and semi-tolerant cultivars had more proline content than the stress-sensitive line. In drought stress, Armaghan (semi drought tolerant) and Goharan (drought tolerant) cultivars had more chlorophyll a in the application of zinc sulfate. It seems that the mechanism of increasing the tolerance and performance of Armaghan and Goharan cultivars under drought stress conditions is the increase in the amount of chlorophyll a due to the application of zinc sulfate. For this purpose, foliar spraying of suitable cultivars (Armaghan and Goharan) is recommended in drought stress conditions.Grain yield had positive correlation with traits of plant height (p = 0.01, r = 0.33), spike length (p = 0.05, r = 0.31), number of grain per spike (p = 0.01, r = 0.35), biological yield (p = 0.01,  r = 0.96), amount of chlorophyll a (p = 0.01, r = 0.44), amount of chlorophyll b (p = 0.05, r = 0.29) and zinc element (p = 0.01, r = 0.39), which is the highest correlation between grain yield and biological yield (r2 = 0.99). In terms of grain and biological yield, Armaghan and Goharan cultivars are recommended under drought stress and Armaghan and Mehr cultivars are recommended under salt stress with a concentration of 0.5% zinc sulfate. In salinity stress, the minimum and maximum grain yield and biological yield were obtained respectively in foliar spraying of 0.1 and 0.5% zinc sulfate in all genotypes. It seems that foliar application of 0.5% zinc sulfate is sufficient for all barley cultivars under salinity stress, and foliar application with a higher concentration of zinc sulfate is not recommended due to the decrease in grain and biological yield in this stress.

This experiment was conducted in order to investigate the effect of seed coating with biochar and activated carbon on some quinoa seed germination indicators, and it was implemented as a factorial in the form of a completely randomized design with four replications in 2019, in Yasouj University's Faculty of Agriculture. The first factor is seed coating in four levels (no coating, coating with activated carbon, coating with biochar and coating with activated carbon + biochar) and the second factor includes salinity stress in four levels (zero, 75, 150 and 225 mM sodium chloride). The results of the interaction of salinity stress and seed coating showed that the highest content of soluble sugar (28.578 mg/g seed FW) and malondialdehyde (2.97 µmol/g seed FW) was obtained by coating with activated carbon in 150 mM salinity stress. Also, the highest amount of seed hydrogen peroxide (0.18 μmol/g seed FW) and proline (10.49 μmol/g seed FW) at the level of 225 mM sodium chloride was obtained by covering the seeds with biochar and active carbon, respectively. Covering seeds with activated carbon and biochar led to an increase in the length of root and shoot under salt stress conditions. However, under salinity stress conditions, root weight and length vigor index of seed improved more by coating seeds with activated carbon. It can be stated that seed coating can greatly reduce the harmful effects of osmotic stress on germination and biochemical traits in quinoa seedlings and improve seedling growth.

A large part of Iran is affected by arid and semi-arid climate and drought has caused many problems in the agricultural sector. The present study aimed to investigate the characteristics of melon under drought stress conditions using animal manure and bentonite. This experiment was conducted as a split-factorial based on a randomized complete block design with three replications in Hirmand city, Iran, during the two cropping years of 2019-2020. Experimental treatments include irrigation after 25, 50, and 75% soil moisture discharge as the main plot and application of bentonite at levels of 2, 3, and 4 t.ha-1 and application of animal manure at the rate of 20, 30, and 40 ton.ha-1 were considered as subplots. According to the results, in the first year of the experiment, fruit yield increased by 2.02 times compared to the control under 50% soil moisture discharge with the application of 4 t.ha-1 of bentonite with 20 ton.ha-1 of animal manure. The results showed that the fruit yield in irrigation conditions after draining 50% of soil moisture with the application of 4 t.ha-1 of bentonite along with 20 ton.ha-1 of animal manure in the first year of the experiment with an average of 2.20 ton.ha-1 and 74.1% compared to the control showed an increase. In order to achieve higher fruit yield, irrigation after draining 50% of soil moisture, application of 4 t.ha-1 of bentonite and 20 ton.ha-1 of animal manure are suggested for cultivation in Hirmand region. In this experiment, the greater effectiveness of fruit weight and yield in the first year can be attributed to the faster growth of shoots and the availability of more nutrients due to the release of manure elements for plant use and the effect of soil interactions in the first year, and the improvement of physical conditions and Soil and plant chemistry in the second year under irrigation conditions after draining 50% of soil moisture. The reason for the higher fruit yield due to the consumption of animal manure can be the result of the vegetative growth caused by the increase in the availability of nutrients, which causes photosynthesis and the production of more photosynthetic substances, followed by the presence of more vascular elements to transfer the cultivated substances to the fruit of the plant. Based on the obtained results, the increase in drought stress increased the activity of catalase and peroxidase enzymes, and the animal manure increased the activity of enzymes to defend the plant under drought stress conditions, in other words, the plant decomposes hydrogen peroxide and increases tolerance against radicals. The effect of animal manure on plant growth can be largely attributed to mineral nutrients, especially absorbed nitrogen. In addition to this, increasing the decomposition of organic materials and mineralization of phosphorus in organic materials and converting them into usable form for plants plays a key role in the soil phosphorus cycle, and along with the use of bentonite, it strengthens the physical, chemical and biological structure of the soil, and finally By increasing the amount of water and the availability of nutrients available to the plant, it has a positive effect on the process of photosynthesis and can increase the length and width of the fruit. According to the results of the experiment, in order to achieve the desired results, irrigation after draining 50% of the soil moisture, application of 4 tons per hectare of bentonite and 20 tons per hectare of manure are suggested for cultivation in Hirmand region.

 Due to Iran's location in the arid and semi-arid region of the world, the possibility of drought is high. Therefore, implementing low irrigation to increase the efficiency of limited water resources is a scientific solution to reduce water consumption. On the other hand, irrigation deficit in cotton  is the most important factor limiting production worldwide, which indicates the need for optimal use of water resources to determine the real water needs of cotton plants. Therefore, development and introduction of drought tolerant cultivars and useful method to improve water productivity and efficiency in the face of drought and water scarcity. The aim of this experiment was to evaluate cotton cultivars by measuring traits related to photosynthetic pigments and yield in order to select drought tolerant cultivars. The present study, evaluated physiological traits of 10 cotton cultivars that were known as tolerant cultivar under irrigation deficit based on the measurement of traits and mechanisms of drought tolerance split-plot arrangement using randomized complete blocks design with three replications in 2021 and 2022 years, in the educational and research farm of Gonbadkavos University (Golestan province), Iran. Experimental research includes two different irrigation regime The main factor of irrigation stress in two levels including low irrigation stress (two times of irrigation in the stages of bud formation and beginning of flowering) and no stress (four times of irrigation in the stages of bud formation, beginning of flowering, beginning of bud formation and beginning of bud opening) and the factor Sub-types of cotton were included in 10 levels (Shayan, Sahel, Sepid, Sajidi, Golestan, Latif, Armaghan, Parto, Mai and Lodos). The studied traits include physiological characteristics such as chlorophyll a, b and carotenoids, proline and boll yield. Photosynthetic pigments were measured by spectrophotometer and its concentration was performed by Arnon (1967) method. Based on the results of this experiment, cultivars with low irrigation stress treatments showed a significant difference in terms of traits related to photosynthetic pigments and non-enzymatic antioxidants and their yield. The study of compound analysis of interaction effect of cultivars in the stress of low irrigation during two crop years showed a significant difference in the yield of Vash and malendialdehyde. Most of the studied traits were affected by the intensity of low irrigation stress and growth stage. The amount of proline increased with the increase of stress so that at the medium stress level of two stages of irrigation (bud formation and beginning of flowering) it increased significantly compared to the condition of no stress. The amount of chlorophyll a was affected by the intensity of stress, but there was no significant change in the amount of chlorophyll b. In the first and second year, the highest yield of rice in non-stress conditions belonged to Sajidi variety with 4596 and 4593 kg/ha-1, respectively, and the lowest yield in water stress conditions in the first and second year belonged to Sepid variety, with 1649 and 1756 kg/ha-1, respectively. The decrease in the yield of cotton was due to the decrease in the number of bolls in the plant under the condition of low irrigation stress. The results of this study indicated the traits of  tolerance cultivars under irrigation deficit. Also, cultivars showed different reactions to the studied traits.  According to the results of the research and the correlation coefficients between the traits, among the water stress tolerant cultivars studied, Golestan and Sajidi cultivars are among the stress tolerant cultivars, Sahil and Sepid cultivars are the sensitive cultivars to water stress, and the other cultivars are the semi-sensitive cultivars. Water stress was introduced.

In recent years, dehydration has led to different reactions in drought-sensitive plants, including red beans. The decreased level of available water resulted in adverse effects on the yield and biochemical characteristics of red beans. The results of variance analysis indicated that irrigation levels and growth stimulants had significant effects on soluble sugar, leaf relative water content, protein percentage, and seed yield. Increased time intervals between irrigations increased the proline content, while decreasing carotenoids and chlorophyll in the whole leaves. Application of humic acid significantly affected the yield and protein percentage in the seeds. As the time interval between irrigations increased, the biochemical and agronomic traits affecting the growth and development of red beans were disturbed, leading to a decrease in the seed yield.

An experiment was conducted in a farm in Pir Musa, Khoy (38°34′26″N 44°53′24″E) at 1157 m above sea level in 2021 to evaluate the effect of growth promoters on biochemical traits and proteins of kidney beams under different irrigation levels. Chemical and physical properties of the farm soil and the climate information of the area during the experiment are listed in Tables 1 and 2, respectively. The experiment was conducted using a SPLAT plot plan in the form of purely random blocks with 3 iteration in 45 terraces. The primary agent was irrigation at three levels of each 8, 14, and 14 days and the secondary agent was five different cases of humic acid 95% (15% fulvic acid, 35% humic acid, 30% seaweed, and 15% potassium), amino acid 25% (25% amino acid, 1% ascorbic acid, 100 ppm vitamin B1, and 25% fulvicol acid), rooting stimulator (18% phosphor, 5% nitrogen, 25% fulvicol acid and 25% organic matter), potassium 30% (30% potassium and 25% amino acid), and no additional material (control). Genetically-modified commercial sun ray cultivar inoculated with Phaseoli strain R117 rhizobium leguminosarum bacteria was used provided by the Soil and Water department of Agricultural Research Center of West Azerbaijan Province. Each experimental terrace was composed of five 4 m-long rows with 60 cm spacing. The space between adjacent plants on each row was 8 cm. There was two unplanted rows between adjacent terraces, and a 1.5 m space was considered between blocks to prevent water penetration during irritations. The seeds were planted by hand on May 15, 2021 at the depth of 4-5 cm. The first irritation was after planting the seeds using a leak pipe and then, all terraces were irrigated each 8, 11, and 14 days. The foliar spraying treatment included amino acid 25%, rooting stimulator, and potassium 30%, but the humic acid 95% treatment was carried out twice with irritation (2 kg per hectare) before flowering and capsule initiation.

The water shortage decreased the carotenoid content of leaves in the red bean plant. The maximum carotenoid content is observed once in 8 days with irrigation levels of 18.41, with the minimum carotenoid content observed for severe stress (irrigation once in 14 days) by 11.06 mg/g. Increasing the irrigation interval significantly reduced the amount of chlorophyll b and an in the leaves so that in the severe stress treatment (irrigation once in 14 days), this reduction was more evident compared to the normal irrigation treatment (irrigation once in 8 days). Moreover, the interaction effect of the two investigated factors was significant on proline, relative leaf water content, soluble sugars, protein percentage, and grain yield. Drought stress increases the number of soluble sugars in red bean plants compared to normal irrigation conditions. The maximum soluble sugar in severe stress (irrigation once every 14 days) is 80.35 mg/g and the control treatment and the minimum soluble sugar in normal irrigation (irrigation once every 8 days) is 36.33 mg/g and control treatment. According to the results of comparing the means, the maximum proline content was observed in the levels of irrigation once every 14 days, and the control treatment (no use) was equal to 18.59 mg/g of fresh weight and the minimum content of proline was observed in the levels of irrigation once every 8 days and Humic acid treatment at the rate of 8.31 mg per fresh weight. In addition, the maximum relative water content of leaves observed in irrigation levels once every 8 days and humic acid treatment and the minimum relative water content of leaves observed in irrigation levels once every 14 days and control treatment (no use), as 86.32 and 51.82, respectively. The grain protein percentage increased following applying drought stress and increasing the irrigation interval, so that the maximum percentage of grain protein was obtained in the treatment of irrigation every 14 days and no stimulants, with the minimum observed in the treatment of irrigation once every 8 days and the use of potassium. So that the maximum grain yield was obtained in the treatment of irrigation once every 8 days and humic acid at the rate of 3076 kg/ha and the minimum in the treatment of irrigation once 14 days and the absence of growth stimulants at the rate of 1221 kg/ha

The results of a one-year experiment show that the biochemical compounds such as proline and soluble sugars increase and the chlorophyll content of the leaves decreases drastically with the application of drought stress in red beans, which leads to a severe drop in grain yield in the treatments under stress.

Watermelon (Citrullus lanatus) belongs to the Cucurbitaceae family. All plants of this family are sensitive to chilling and their planting is done in the warm season. Plants that are always in a wide range of abiotic stresses that have adverse effects on the survival, growth, quality and quantity of agricultural products. In most plants, chilling stress occurs below 10 to 15 °C, and the cucurbitaceae family, including watermelon, shows chilling symptoms at temperatures below 10 °C. Watermelon is one of the most popular tropical products of this family, and the late spring chilling in temperate and cold regions always threatens its seedlings with chilling. γ-aminobutyric acid (GABA) is a non-protein amino acid that can reduce stress in various plants. Therefore, in present research, the effect of GABA treatments as seed priming and foliar spraying was studied on reducing the amount of chilling index and maintaining the quality of watermelon seedlings under cold stress.

The present study was designed and implemented in the research greenhouse of Ilam University in 2018 as a factorial experiment based on a completely randomized design with three repetitions and each repetition including five pots. The first factor included 0, 5 and 10 mM GABA and the second factor was the application method of GABA treatments including seed priming and foliar spraying. The seed priming treatment was applied before planting and the foliar spraying treatment was applied at the seedlings to the stage of four true leaves. At 48 h after foliar spraying, all the seedlings were subjected to cold stress at a temperature of 3 °C for 6 days by 6 h at night. They were placed inside the incubator at night (24:00 to 06:00). 48 h after the end of the cold stress, the seedlings were examined for different traits. The studied traits included chilling index, relative water content, fresh and dry weight of shoot and root, total chlorophyll and carotenoid, malondialdehyde, proline, ion leakage and activity of ascorbate peroxidase and catalase enzymes.

The results showed that the exogenous application of GABA effectively reduced the complications and chilling index, the amount of ion leakage, malondialdehyde and proline in watermelon seedlings, and the RWC, fresh and dry weight of the shoots and roots, total chlorophyll, carotenoids. Also, GABA increased the activity of ascorbate peroxidase and catalase enzymes in watermelon seedlings. This was despite the fact that foliar spraying treatments are more effective than the use of seed priming treatments. Also, in both application methods, the effect of GABA 10 mM in reducing chilling capital and biochemical changes of watermelon seedlings was more than 5 mM. Probably, the exogenous application of GABA has moderated the increase in cell osmolality with the intensity of cold stress by strengthening the antioxidant system and thus reduced the amount of chilling in watermelon seedlings. GABA has been reported as an osmolyte compatible with osmotic stress. As a result, the accumulation of this osmolyte compound in plant cells is used to maintain cell turgor and also to protect the cell membrane, nutrition and metabolism of the plant by preventing the loss of cell water.

The present study showed that keeping watermelon seedlings under cold stress causes symptoms of chilling and reducing the quality of the seedlings, but the exogenous application of GABA moderated the chilling and improved the quality of the seedlings compared to the control samples. In this study, the foliar application of GABA was more effective than seed priming and 10 mM concentration maintained the quality of seedlings better than 5 mM in both application methods. Therefore, based on the present results, the use of GABA 10 mM is recommended as a practical solution to prevent damage in "Orangeglo" watermelon seedlings under cold stress.

Zinc (Zn) plays an important role in plant growth and tolerance to stress and increasing their yield, but it has been reported that zinc nanoparticles have a better role on improving the growth of plants under water stress conditions. One of the factors limiting the growth of sorghum forage plant is water stress. Studies have shown that zinc nanoparticles have a positive impact on plants response to water shortage conditions through improving photosynthesis and enzymaticactivity. Therefore, this study was conducted to investigate the effect of foliar application of nanosized and non-nano zinc oxide on some physiological and forage yield of three sorghum (Sorghum bicolor L.) cultivars under water deficit condition.

This study was performed at the research farm of Shahrood University of Technology in the growing season of 2018-19. The experiment was arranged as split plot factorial based on randomized complete block design with three replications. Water deficit stress treatment in two levels of 10 and 20 days irrigation interval were assigned as main plots and sub plots were the combination of the two factors; sorghum cultivars at three levels: Eresk, Speedfeed and Pegah, and foliar application of zinc in three levels of control, micro and nano-particles forms at concentration of 2 gr l.-1. Foliage spraying of Zinc was performed before flowering stage of sorghum. Sampling and measuring of sorghum pigments, leaf protein, leaf zinc contents and proline were done at flowering stage. Wet and dry forage yield of sorghum was measured at the end of growing season on the 2 squares meter in each plot. All data collected were subjected of analysis of variance (ANOVA) using MSTATC software. Significant differences between means refer to the probability level of 0.05 by LSD test.

The results showed that by increasing the irrigation interval from 10 to 20 days, chlorophyll a, chlorophyll b, carotenoids, leaf protein, leaf zinc content, fresh and dry forage yield decreased significantly. The results indicated that the minimum fresh forage yield (61.48 ton/ha) and dry forage yield (12.03 ton/ha) was observed with non-application of zinc in irrigation interval of 20 days. Water deficit stress causes damage to photosynthesis pigments, stomatal conductance and finally the growth and yield of plants. The results showed that application of zinc in nano or conventional form causes a significant increase in chlorophyll a, chlorophyll b, carotenoids, proline, leaf protein, zinc content, fresh and dry forage yield under stress conditions. The highest fresh and dry forage yield were observed at the rate of 97.4 and 18.8 ton.ha-1 respectively in irrigation interval of 10 days treatment by application of ZnO nano particles. Also, the results showed that, foliar application of zinc in nano and conventional form increased fresh forage yield of sorghum by 37.58 and 32.49 percent compared with control in water deficit stress condition respectively. This can be due to the role of ZnO nano particles that can enhance the rate of photosynthesis by improving gas exchange, chlorophyll fluorescence, carbonic anhydrase activity, and enhanced proline content in plants. Results also showed that in the most of physiological and yield traits and forage yield the local Ersek cultivar was better significantly than Speed ​​Feed and Pegah cultivars.

The foliar application of ZnO conventional and nano particles significantly mitigated water deficit stress and enhanced photosynthesis pigments, proline, leaf protein and zinc contents as well as improved the fresh and dry yield of sorghum.

Summer savory (Satureja hortensis) is an annual herbaceous plant. The leaves of the plant are spear-shaped, opposite, with a short petiole. The leaves and flowering branches of summer savory are used in traditional medicine with known anti-flatulent, anti-heartache, anti-parasitic, stomach tonic, stimulant and expectorant effects. Spraying or foliar feeding is a method to reduce the stabilization of chemical fertilizers in the soil and as a result reduce environmental risks, including reducing soil and water pollution. With this feeding method, elements can be provided to the plant as quickly as possible. Silicon is the second mineral element in the soil after oxygen, and in higher plants, it usually causes the physical strength of the organs by penetrating the stem and leaves, and also improves physiological and metabolic processes, gas exchanges and strengthens the antioxidant system. Also, this element has beneficial effects on the growth, performance and tolerance of some plants against biotic and abiotic stresses. The form of silicon solution in soil is silicic acid Si (OH)4. The amount of silicon in plants is 0.1 to 10% of the dry weight of the plant. The use of fertilizers containing silicon in the soil affects growth and development in two ways. First, the improvement of silicon nutrition strengthens the plant's protection system against adverse environmental conditions. On the other hand, treating soil with compounds containing geochemically active silicon improves the chemical and physical properties of soil and increases the availability of nutrients for plants. The objective of this research was to investigate the influence of silicon application on some physiological and morphological characteristics of summer savory under drought stress conditions.           

In order to investigate the effect of silicon foliar application on the summer savory characteristics under deficit irrigation conditions, a factorial experiment was conducted based on randomized complete blocks design with four replications. The experiment was carried out at the vegetable production farm of Ardabil municipality during the years 2021-2022. The investigated factors included the first, drought stress at three levels (40, 60, and 80% field capacity (FC)) and the second, silicon foliar spraying at four levels (0 (control), 0.5, 1, and 1.5 mM L-1). Drought stress was induced at the stage of 4 to 6 sub-branches and silicon solutions were foliar applied at two stages including a week before the induction of drought stress, and a week after that. Distilled water was also used as control treatment. In the present study, pots with a diameter of 20 cm, a height of 30 cm, a capacity of 3 kg with 3 holes at the bottom were used to cultivate savory plants. Before the induction of drought stress, the savory plants were regularly irrigated up to the field capacity. Drought stress was applied at the stage of 4 to 6 sub-branches based on crop capacity and after the stress induction, sampling was done.

The obtained results showed that drought stress negatively affected plant fresh weight, dry weight, height, soluble sugar content, chlorophyll a, b and total and carotenoid content, but proline content increased by 61.03% under highest level of drought stress comparing to control. The highest soluble sugar content was recorded in savory plants sprayed with silicon 1 mM L-1 and grown under drought level of 40% FC (4.76 mg g-1 FW). On the other hand, the lowest value of this trait was obtained in plants treated with silicon 0.5 mM L-1, and grown under drought level of 80% FC (3.16 mg g-1 FW). In the present study, the decrease in chlorophyll of the savory plant under drought stress could be probably related to the increase in the production of oxygen free radicals, peroxidase and phenolic compounds, because the absorption of excess energy by the photosynthetic system often stimulates the production of reactive oxygen species. Silicon foliar application had a positive and significant effect on the examined traits, so the negative effects of drought stress were alleviated by increasing silicon concentration.

In general, it could be stated that silicon could be used as a useful element to increase the performance of agricultural-garden plants, as well as to increase plants tolerance rate against environmental stresses (including drought stress). On the other hand, the application of silicon up to a concentration of 1.5 mM L-1 had a positive effect on alleviation of the adverse effects of deficit irrigation on savory plant characteristics.

Potato (Solanum tuberosum) is one of the most important food products in the world, which is rich in carbohydrates, proteins, vitamins and other nutrients. Choosing the suitable planting date and cultivars is one of the most important and effective ways to reduce the negative effects of environmental stresses on potato characteristics. Cold stress is one of the limiting factors for production of agricultural crops. One of the adverse effects of this stress is increasing the biosynthesis rate of reactive oxygen species that causes oxidative stress. Plants have enzymatic and non-enzymatic mechanisms to overcome oxidative stress. The enzymatic antioxidant defense system includes different enzymes such as superoxide dismutase, catalase, polyphenol oxidase, guaiacol peroxidases and ascorbate peroxidase, and the non-enzymatic antioxidants include the soluble sugars, proline, carotenoids and other compounds such as flavonoids, and polyphenols. Nowadays, application of antifreeze compounds in agriculture is widely used technique to overcome chilling injuries. These substances are quickly absorbed by plants and increase the metabolic activity rate of plants. As a result, the amount of antifreeze proteins, amino acids, carbohydrates, lipids, vitamins and minerals increases in the plant organs leading to more resistance rate of plant cells against freezing. Potassium is one of the elements that reduces the effects of environmental stresses such as drought, salinity, high temperatures, cold, etc. through the accumulation of soluble carbohydrates and osmotic regulation. Also, potassium plays a role in regulating the activity of enzymes related to the detoxification of reactive oxygen species. The aim of the current study was to investigate the influence of cultivar, planting date and foliar application of antifreeze compounds on some of most important morpho-physiological characteristics of potato crop.           

The current study was conducted as a split-factorial experiment based on randomized complete blocks design with three replications at Ardabil Agricultural and Natural Resources Research Station during two cultivation seasons (2018-2019 and 2019-2020). The investigated factors included planting date in two levels (August 1st and 11th), foliar application of antifreeze compound at two levels (foliar application with a mixture of Frezzebon amino acid + potassium, and water as a control) and potato cultivars at 10 levels (901375, 901475, 902375, 8708-7, 8709-106, 7009-3, 905675, 8707-26, Agria and Savalan). Foliar applications were performed at the end of the growth season as same time as the increased likelihood of cold weather (considering the weather forecasts and the measured temperatures in the field and their correlation, one week before the possibility of temperatures below 7 ºC). Furthermore, before the spraying treatments, samples were taken from the experimental treatments and frozen using liquid nitrogen and stored in a freezer. After 24 h of freezing, the samples were again collected from the experimental treatments and rapidly frozen using liquid nitrogen before being transferred to the laboratory for measurement of the desired characteristics. After collecting the samples, laboratory experiments were conducted at the Faculty of Agriculture of Ardabil University of Medical Sciences and the Agricultural and Natural Resources Research Station in Ardabil.

Based on the obtained results, it was found that the foliar application of the amino acid Freezbon combined with potassium increased the yield, number of tuber per plant, leaf relative water content, proline and the activity of antioxidant enzymes. Also, the planting date of August 1st has the highest yield, number of tuber per plant, leaf relative water content, potassium and proline content, and the activity of catalase, superoxide dismutase and polyphenol oxidase enzymes. In terms of yield, 901475 cultivar had the highest yield (43.02 ton ha-1) and Agria cultivar had the lowest yield (26.35 ton ha-1). Among the cultivars studied, 8708-26 cultivar had the highest leaf relative water content, potassium and sodium content. The maximum content of proline and antioxidant enzymes activity were related to 7009-3 and 8707-26 cultivars. Based on these results, it seems that the planting date of August 1st and the foliar application of Freezbon with potassium can enhance the cold tolerance threshold, growth, and performance of potato cultivars in regions with cold weather by regulating physiological and biochemical responses. The results of the current study in line with the observations of the other conducted researches on different horticultural crops demonstrated that choosing appropriate planting date and application of antifreeze compounds positively influence the accumulation rate of osmoprotectants, cells antioxidant capacity and plant water and nutrient status resulting in a significant increase in cold resistance rate of plant cells.

Foliar application of antifreeze compounds Frezzebon amino acid + potassium, and planting date on August 1st can positively influence potato cultivars yield and physiological characteristics under cold conditions, therefore this foliar treatment and planting date are recommendable to overcome negative effects of cold stress on potato characteristics in cultivation reigns with cold weather.

Savory plant (Satureja hortensis ) belongs to mints family (Lamiaceae). Environmental and abiotic stresses affect the agricultural plants growth and yield in many regions of the world. Salinity is one of the most limiting factors for growth and production of crops in arid and semiarid regions. Soil salinity is a dominant issue for the sustainability of agricultural production. Reduction of vegetative growth, dry weight and cells mass are some of most common adverse effects of salinity. Salinity increases energy consumption to remove excess sodium ions accumulated in the root cells leading to significant reduction in plant growth rate. Nowadays, effective microorganisms (EM) is one of the biological fertilizers which has attracted a lot of attention as a useful tool to increase plant productivity and stress tolerance rate. The micro-organisms existed in EM improve the health and yield performance of agricultural plants by increasing photosynthesis rate, producing biologically active compounds such as hormones and enzymes, controlling soil diseases and accelerating the decomposition of organic matter in the soil. Therefore, the use of EM bio-fertilizer under conditions of environmental limiting factors such as salinity could be highly important to develop horticultural plant cultivation in regions with saline soli or saline water resources. The purpose of the current study was to investigate the morphological and bio-chemical responses of the savory plant to salt stress, and using EM bio-fertilizer to reduce the adverse effects of salt stress.           

In order to investigate the effect of EM bio-fertilizer on the morphological and bio-chemical characteristics of the savory plant under salinity conditions, a factorial experiment was conducted based on randomized complete blocks design with 4 replications at the Faculty of Agriculture, University of Mohaghegh Ardabili, during 2021. In this study, Em treatments were applied at three levels including 0 (control), 1 and 2 %, and salinity was induced at three levels including 0 (control), 6 and 12 dS/m NaCl. Fresh and dry yield of plants and fresh and dry weight of the roots were measured with a digital scale. The content of chlorophyll a and b, and total chlorophyll were measured by a spectrophotometric method. Proline, soluble sugars and total protein were measured as physiological characteristics.

The results showed that the highest height (30.66 cm) was recorded in plants treated with EM 2 % and grown under control condition. The height of plants decreased with increasing salinity level. Also, the highest fresh and dry yield, and fresh and dry weight of root were obtained by applying EM 2 % under control level of salinity. The highest number of leaves was counted in plants treated with EM 2 %, and grown under control level of salinity. The lowest leaf number was related to non-treated plants grown under salinity level of 12 dS/m. The highest recorded contents of chlorophyll a, b and total were 3.11, 1.85 and 4.96 mg/g FW, respectively. The lowest value of these traits (1.14, 0.65, and 1.79 mg/g FW) was recorded in non-treated plants grown under highest level of salinity. Generally, the amount of chlorophyll a, b and total decreased with increasing salinity level, while EM increased the values of these traits. The results showed that the highest amount of soluble proteins was obtained at control level of salinity and application of EM 2 %, with an average of 38.03 mg/g FW, while the lowest value (15.30 mg/g FW) was obtained in non-treated plants under salinity level of 12 dS/m. The amount of soluble sugars increased with increasing stress level. The highest amount of proline (35.4 μmol/g FW) was obtained under salinity level of 12 dS/m. EM increased the content of photosynthetic pigment under salinity conditions which led to increase photosynthetic performance of treated plants. Also, accumulation of proline as osmoprotectant agent in cells of treated plant, definitely led to decrease the activity of reactive oxygen species resulting in lower damages to cells membrane.

In conclusion, results showed that savory plants fed with EM bio-fertilizer had better growth and yield under salinity conditions than the unfed plants. These plants showed more tolerance rate against salt stress due to better absorption rate and physiological responses. So that the highest values of vegetative traits were recorded in plants treated with EM 2 %. Therefore, this treatment could be recommendable to overcome adverse effects of salinity on savory plants characteristics.

Wheat (Triticum aestivum L.) is one of the most strategic crops for food, feed, and biofuel security worldwide. Drought stress is one of the most destructive environmental stresses that limit crop productivity worldwide. Drought stress causes a wide range of physiological changes and disturbances in metabolic processes. Environmental problems caused by the use of chemical fertilizers, production costs, and consumption costs are significant issues that require methods to increase crop production and improve sufficient food for the world's population. Today, the economic damage and destructive effects of the environment due to the excessive use of chemical fertilizers in agriculture are known worldwide, and it is obvious that a suitable alternative must be found for these fertilizers. Currently, biofertilizers are used as an alternative to chemical fertilizers based on the principles of sustainable agriculture and the stress tolerance of plants. Salicylic acid is a plant growth regulator that plays an important role in the plant protection system against biotic and abiotic stresses and can affect many physiological and biochemical processes.

In order to investigate the effect of biological and chemical fertilizers and foliar application of salicylic acid on wheat tolerance to drought stress experiment, a factorial split plot in the form of a randomized complete block design in the 2019-2020 crop year in the research farm of the Faculty of Agriculture of Lorestan University in three replications was performed. The Main plot includes irrigation levels in two levels: A1: without stress (100% of water requirement) and A2: drought stress (50% of water requirement) and sub-plots including fertilizer in five levels, including B0: use of 50% chemical fertilizer, nitrogen and phosphorus fertilizer (B1: use of 100% chemical fertilizer), B2: use of nitroxin biofertilizer with 50% chemical fertilizer, B3: use of mycorrhizal with 50% chemical fertilizer, B4: use of biological fertilizers nitroxin and mycorrhiza with 50% chemical fertilizer, and foliar application treatment at two levels (C1: foliar application with water and C2: foliar application with a concentration of 1 mM salicylic acid).

The results showed that drought stress caused a decrease in grain yield, leaf chlorophyll index (SPAD), and relative water content, as well as an increase in peroxidase, proline, and electrolyte leakage. Combined treatment of biofertilizer nitroxin and mycorrhiza with 50% chemical fertilizer caused an increase of 40.53%, 5.18%, 5.89%, 13.85%, 8.46%, and 8.90%, respectively, in grain yield, leaf chlorophyll index, grain zinc concentration, peroxidase, proline, relative water content of the leaf, and 6.29 % reduction of electrolyte leakage compared to the use of 50% chemical fertilizer. Also, salicylic acid foliar spray treatment caused an increase of 11.45%, 2.82%, 4.32%, 7.46%, 9.19%, and 8.02 % in grain yield, leaf chlorophyll index, grain zinc concentration, peroxidase, proline, relative water content of the leaf, and 18.11 % reduction of electrolyte leakage compared to no foliar spraying of salicylic acid. Combined fertilizer treatments of nitroxin and mycorrhiza with 50% chemical fertilizer and salicylic acid could reduce the effect of drought stress on the traits evaluated in this research.

Fertilizer application of nitroxin and mycorrhiza with 50% chemical fertilizer and salicylic acid foliar spraying could provide favorable conditions for the growth and better performance of the plant by improving the biochemical characteristics of the plant while increasing its resistance to drought stress conditions. In general, it can be concluded that the application of biological fertilizers nitroxin and mycorrhiza with 50% of chemical fertilizers and foliar spraying of salicylic acid can be an effective and alternative fertilizer to reduce the consumption of chemical fertilizers in the conditions of drought stress in Khorram Abad in the direction of sustainable agriculture. As a result, this treatment can be recommended to farmers in order to reduce the consumption of chemical fertilizers in wheat under drought -stress conditions.

Water stress is the most prominent abiotic stress limiting agricultural crop growth and productivity. Deficit irrigation stress as a consequence of the progressive decrease in water availability has been a hot topic regarding food security during the last two decades. Growth and development of plants are influenced by reduction in turgor that results in decreased nutrient acquisition from dry soil. Due to the threat of climate change, there is a need to limit the use of water resources in arid and semi-arid climates. It is therefore important to find new approaches to avoid crop productivity losses in ‘limited fresh-water’ areas. Eggplant (Solanum melongena) is an important non-climacteric fruit grown in tropical and subtropical regions. The estimated total world production for eggplants in 2019 was 51287210 tons. Foliar application of agro-chemicals has widely been used in agriculture as a rapid, low-cost and effective way for enhancing growth and productivity of many vegetable crops under water deficit conditions. Ca is an essential macronutrient for plant growth and development, and is considered as an important intracellular messenger, mediating responses to hormones, stress signals and a variety of developmental processes. Amino acids are important bio-regulators which have promotive effects on plant growth and productivity. Cysteine is the precursor molecule of glutathione, the predominant non-protein thiol, which plays an important role in plant stress responses.

The field experiment was carried out at the Research Farm of Agriculture Faculty, University of Zanjan, Iran, during 2021. The experiment was performed using a split plot based on a randomized complete blocks design with three irrigation regimes (60, 80 and 100 %ETc) as the main plot and foliar spray of two levels of calcium lactate (CaL) (1 and 2 g L-1) and L-cystein (Cys) (0.15 and 0.5 %) as the sub-plot in three replicates. Distilled water was used as a control. Eggplant (cv. Greta RZ) seedlings were transplanted at the 4-5 leaf stage with 35 cm spacing within row and 100 cm spacing between rows. After plant establishment, eggplants were sprayed with different concentrations of CaL and Cys at 6-7 leaf stage. Second and third times of foliar application were performed at 10 and 20 days after the first spraying. Irrigation treatments were applied one week after the first spraying. Number of branch per plant, plant height and leaf area were measured as growth parameters in harvest stage. Total chlorophyll and carotenoid contents, proline, leaf relative water content, stomatal conductance and electrolyte leakage were measured as physiological characteristics. Also plant fruit yield and water use efficiency (WUE) were evaluated.

As the results showed, plant growth, physiological indices and WUE significantly affected by deficit irrigation. Water deficit stress significantly reduced plant length, leaf area and chlorophyll content, and increased carotenoid content. Decreased plant growth may be due to limited cell division, cell enlargement due to turgor loss, and inhibition of various growth metabolites. Foliar spray of CaL and Cys improved plant growth, fruit yield and physiological indices. Leaf relative water content (LRWC) is among the main physiological criteria affecting plant water relations and have been used for assessing drought tolerance. Based on the findings, deficit irrigation caused a significant reduction in LRWC and stomatal conductance, which is due to the reduction of leaf water potential and the decrease of root water absorption rate under drought conditions. The highest value of LRWC and stomatal conductance were obtained in plants sprayed with CaL 2 g L-1 under irrigation 100 %ETc. Free proline is one of the most important osmolytes whose accumulation is a common physiological response to drought stress in higher plants and is probably associated with osmotic regulation and membrane stability under stress condition. WUE, the physiological parameter of crop, describes the relationship between plant water consumption and dry matter production. The proline content and WUE increased under deficit irrigation treatments; in particular with sever deficit irrigation (60 %ETc). The maximum proline content and WUE were observed in plants treated with CaL 2 g L-1 and Cys 0.5 % under deficit irrigation of 60 %ETc. The results showed that deficit irrigation led to a significant increase in electrolyte leakage compared to control, and foliar application of CaL and Cys decreased electrolyte leakage under normal and deficit irrigation conditions. Water deficit stress caused significant reductions in yield. The highest fruit yield was obtained under irrigation of 100 %ETc along with application of CaL 2 g L-1 and Cys 0.5 %.

Water deficit has been shown to adversely affect plant growth and fruit yield. Foliar application of CaL and Cys positively improved plant growth, physiological traits and fruit yield, as well as WUE. According to the results, application of CaL 2 g L-1 or Cys 0.5 % can be proposed to improve growth, fruit yield and WUE of eggplant.

Water shortage is an integral part of our current agriculture, and water stress is one of the most destructive environmental factors which adversely affects agricultural production worldwide. According to several studies, water deficit causes reduction of vegetative growth, leaf area, plant height, dry weight, photosynthesis rate, chlorophyll content, stomatal conductance, enzymatic activities, protein biosynthesis and amino acids accumulation in horticultural plants. Increasing reactive oxygen species (ROS) rate and activity is the one of most damaging effects of drought stress. Cucumber is a tropical crop with high water requirement. Wide leaves and shallow roots have made it a drought-sensitive crop. Based on reports, water deficit and drought stress can seriously affect yield performance and qualitative characteristics of cucumber. Measurements are needed in different aspects to overcome challenges associated with water deficit and water stress in cropping systems. So, in this study glycine amino acid were applied for its possible role under mild water shortage effects on cucumber growth characteristics.

In order to investigate the influence of glycine amino acid application on alleviation of negative effects of deficit irrigation, a greenhouse experiment was conducted based on completely randomized design with four replications. Treatments were assessed at six levels including 60 % FC, 70 % FC, 80 % FC, 60 % FC + glycine 500 mg plant-1, 70 % FC + glycine 500 mg plant-1 and 80 % FC + glycine 500 mg plant-1. Some of most important morphophysiological and biochemical characteristics of cucumber plants such as stem length, stem dry weight, leaf number, leaf area, internode length, growth period duration, fruit number, fruit set, vitamin C, chlorophyll index, total antioxidant, proline, catalase, peroxidase and polyphenol oxidase enzymes content were evaluated.

Result showed that deficit irrigation and glycine amino acid application significantly influenced morphophysiological and biochemical characteristics of cucumber plant. It was observed that vegetative traits including leaf number, leaf area index, stem length and dry weight, length of internode, growth period duration, chlorophyll index, and fruit characteristics including vitamin C content and fruit set were significantly reduced by deficit irrigation levels particularly at 60 % FC. The highest fruit number (86.5) was recorded under 70 % FC and application of glycine. In contrast, antioxidant capacity, proline, catalase, polyphenol oxidase and peroxidase enzymes content increased under 60 % FC. Glycine application could properly alleviate the negative effects of deficit irrigation on plant growth and yield. Studies have shown that glycine application maintains chlorophyll content and photosynthesis rate of plants under stress condition, which is mostly related to increasing stomatal conductance and carboxylation efficiency. Generally, water deficit reduces the yield performance of crops. And, this reduction could be correlated with decreasing leaf area and disruption of nutrients absorption. According to results of this study, maintaining the photosynthetic pigments caused by glycine application resulted in enhanced photosynthesis rate leading to higher yield comparing to control under deficit irrigation conditions.

Generally, the results of the current study demonstrated that deficit irrigation at level of 60 % FC caused induction of drought stress conditions. Induction of water deficit and drought stress higher than 70 % FC led to sever physiological and biochemical changes in cucumber plants resulting in considerable reduction of yield performance and qualitative characteristics. Water deficit increased proline content and antioxidant capacity (increasing the activity rate of antioxidant enzymes including catalase and peroxidase) of cucumber plants. Soil application of glycine amino acid alleviated the adverse effects of deficit irrigation. Because the highest fruit number was counted in 70 % FC + glycine 500 mg plant-1 treatment (with no significant difference with the control (80 % FC)), this treatment could be recommended to growers to save water consumption with no significant changes in yield performance comparing to control level.

Water scarcity due to limited rainfall, high temperatures, and high evapotranspiration is one of the important factors in reducing crops and reducing the efficiency of using dry areas. Iran is one of the arid regions of the world, with an average annual rainfall of 220 mm. wheat cultivation is at serious risk of drought stress. Mycorrhizal fungi, by creating a symbiotic relationship with the roots of most crops, increase the absorption of nutrients such as phosphorus, zinc, and copper, increase water absorption, reduce the negative impact of environmental stresses, and improve the growth and yield of host plants. Therefore, considering the importance of mycorrhiza inoculation in reducing the negative effects of drought stress and improving crop yield, as well as the need to optimize the use of chemical fertilizers for sustainable agriculture, the purpose of this study was to investigate the root growth characteristics and physiological traits of different durum wheat cultivars affected by the combined application of phosphorus fertilizer and mycorrhiza under dryland conditions.

In order to evaluate the effect of mycorrhizal fungi and phosphorous fertilizer on some of the root growth characteristics and physiological traits of durum wheat in rainfed conditions, an experiment was carried out as a factorial based on a randomized complete block design with three replications at Sarableh Agricultural Research station during the growing season 2018–2019. Experiment factors consisted of four cultivars of durum wheat (Dehdasht, Zahab, Saverz, and Saji) and five levels of fertilizer source (control, 25 and 50 kgha-1 P, mycorrhizal fungi, and 25 kgha-1 P). The seeds were sown in rows four meters long and at intervals of 20 cm. The dimensions of each experimental plot were eight square meters, in which eight rows were considered, and the distance between the experimental blocks was considered one meter. Also, the amount of seed used was 120 kg/ha. To measure root-related traits in the field after pollination from a metal cylinder that was manually designed and patterned Was used. To measure the amount of photosynthetic pigment, the leaves of the five-plant flag were randomly sampled. The Analysis of variance and comparison of mean data were performed by a Duncan multi-range test using SAS 9.1 software and the drawing of figures by Excel software.

The results indicated that the application of fertilizer sources significantly improved the traits. The results also showed that the interaction of cultivars and fertilizer sources on root growth characteristics and physiological traits was significant. So that, the highest root area (61.7% increased to control treatment), root special volume (91% increased to control treatment), root tissue density (47.5% increased to control treatment), root volume density (87.1% increased to control treatment), chlorophyll a and b (86.7 and 89.04% increased to control treatment, respectively), and proline (81.9% increased to control treatment) were obtained at Saji cultivar along with application of mycorrhizal fungi + 25 kgha-1 P. The relative water content of leaves also increased in different cultivars with fertilizer application. The application of treatment mycorrhizal fungi + 25 kgha-1 P in Saverz and Saji cultivars increased the relative water content by 84% and 71%, respectively, compared to the control treatment.

According to the results, it was found that the combined application of mycorrhizal fungi with 25 kgha-1 phosphorus fertilizer compared to the control treatment had the most effect on improving and increasing the studied traits. Mycorrhizal fungi seem to increase the root system of crops, and the secretion of phosphorus-soluble organic acids causes more phosphorus uptake, which together increases the surface area and root volume and consequently increases the uptake of water and elements, Which ultimately leads to improved relative leaf water content and photosynthetic pigments. The findings of this study also showed that Saji cultivars showed a better response to mycorrhizal fungi compared to other cultivars. Therefore, according to the obtained results, the Saji cultivar with Mycorrhizal fungi + 25 kgha-1 can be recommended for cultivation under dry land conditions.