مجله تنشهای محیطی در علوم زراعی
سال سیزدهم شماره 1 (بهار 1399)

Potato (Solanum tuberosum) is an important crop in tropical countries. Salinity stress is the crucial factor that seriously limits agricultural production in various regions especially in arid and semi-arid areas. Salicylic acid is a bioactive molecule that synthesizes via enzymatic and non-enzymatic pathways under stress conditions in different organs of plant, regulates and adjustments defense reactions of plant. Salicylic acid (SA) is known as a signalling molecule that modifies plant responses to pathogen infection. Many studies have shown that this compound can protect plant under oxidative stresses and maintain chlorophyll. In addition to being an important component of biotic stress tolerance mechanism, SA also regulates various aspects of plant responses to abiotic stresses through extensive signalling cross-talk with other growth hormones. However, exact mechanisms by which SA protects plants during abiotic stresses remain obscure. Salinity stress is the crucial factor that seriously limits agricultural production in various regions especially in arid and semi-arid areas. Salicylic acid is a bioactive molecule that synthesizes via enzymatic and non-enzymatic pathways under stress conditions in different organs of plant, regulates and adjustments defense reactions of plant. Salicylic acid (SA) is known as a signalling molecule that modifies plant responses to pathogen infection. Many studies have shown that this compound can protect plant under oxidative stresses and maintain chlorophyll. In addition to being an important component of biotic stress tolerance mechanism, SA also regulates various aspects of plant responses to abiotic stresses through extensive signalling cross-talk with other growth hormones. However, exact mechanisms by which SA protects plants during abiotic stresses remain obscure.

This experiment was conducted at the plant tissue culture laboratory of Horticultural Sciences, Department, University of Tabriz, Iran, during spring–summer of 2017. The present study was aimed to investigate of salicylic acid effect on betaine aldehyde dehydrogenase gene expression and glycine betainesynthesis in Solanum tuberosum cv. Agria under salinity stress on in vitro condition. The experiment treatments included four level of salycilic acid (0, 1, 10 and 100 mM) and two level of sodium chloride (0 and 70 mM). In the present study, MS media culture was used and sodium nitroprusside was applied for increasing the betaine aldehyde dehydrogenase gene expression (the responsible gene of glycine betaine synthesis) under salinity stress. Four weeks after treatment, total RNA of treated explants was extracted and semi quantitative RT-PCR was used for the analysis of expression of betaine aldehyde dehydrogenase gene.

and semi quantitative RT-PCR was used for the analysis of expression of betaine aldehyde dehydrogenase gene. The glycinbetainecontent was measured with iodide potassium. The survey of betaine aldehyde dehydrogenase gene expression showed increased under salinity stress. Also salicylic acid increased the glycine betaine content in grown plantlets which were grown under normal condition.The expression pattern of glycine betain gene showed tha by increasing of salicylic acid and sodiuom chloride concentration the expression of glycine betain gene has been increased in all samples. however under salinity stress this compound showed negative effect on glycinbetaine content.

In conclusion, antioxidant activity, total phenol and protein were increased salinity stress. In addition, antioxidant activity and glycine betaine content during salt stress period was decreased application of nitric oxide. The glycine betaine content of plantlets in general condition with application of sodium Salicylic acid increased but under salinity stress, Salicylic acid had negative effect on glycine betaine content. The results of this research showed that exogenous application of salicylic acid increased the expression level of genes and lead to enhancement of plant tolerance to salinity stress. Further studies are necessary to determine optimum concentration and duration of Salicylic acid application in order to achieve maximum benefit in Solanum tuberosum tissue culture.

Soybean (Glycine max L.) is one of the most important oil seeds and its importance refer to its role in providing the essential fats needed to complete the human food pyramid similar to other oilseeds. In Iran, after cotton and canola, the highest cultivated land is dedicated to soybeans. The yield of plants such as soybeans is significantly reduced due to environmental stresses, especially drought stress. Thus the aim of the present study was an investigation of soybean advanced lines and parental varieties under non-stress and under water stress conditions to compare different genotypes and identification of more tolerant lines to water stress.

Plant materials consisted of 30 soybean genotypes including three parental varieties Sahar, Williams, Katoul and 27 advanced lines. The lines were derived from parental varieties Sahar×K778, Sahar×Hamilton, Sahar×Gorgan3, Sahar×Williams, Williams×Katoul, Hamilton×Katoul, Sahar×Katoul, Williams×K778, Williams×Hamilton, Gorgan3×Williams. The plants were cultivated in a filed with a total area of 400 m2 at Ezberam, Siahkal (N 37°1.3′8 ̋N, 49°54′10.5 ̋E) in the Guilan province of Iran in spring and summer 2016 as randomized block complete design under normal and water stress conditions with three replications. A total of 14 traits were measured including plant height, number of nodes, first pod height from ground, number of branches, total weight of plant, number of pods, weight of total pods, number of filled pods, weight of filled pods, pod length, number of seeds per pod, number of total seeds, weight of total of seeds and 100- seed weight.

The combined analysis of variance revealed genotypes difference and genotype×conditions interaction were significant (p<0.01) for all of the traits except pod length that indicated high diversity among soybean genotypes and different responses of genotypes to normal and water stress conditions for measured traits. According to the cluster analysis Ward method, all genotypes were assigned to three groups under normal condition. The first group consist of five advanced lines Williams×Katoul3123, Williams×Katoul(4), Williams×Hamilton(2), Sahar×Hamilton(4), Gorgan3×Williams(2) and Katoul had higher mean based on all of agronomic and yield traits such as number and weight of pods, weight of total seeds and 100- seed weight than other genotypes. Under water stress condition genotypes were classified into three groups that third group consisting of four lines Sahar×Katoul(4), Williams×Hamilton(1), Williams×K778(3) and Williams×Katoul(4) had higher performance based on important yield traits including number of pod, weight of pod, number and weight of filled pods, number of seeds per pod, number of seeds in plant, total weight of seeds in plant and 100- seed weight than other genotypes.

According to comparisons mean, Gorgan3×Williams(2) had the highest weight of total pods (94.4gr), number of branches (14.11), number and weight seeds in plant (284.22 and 66.98 gr respectively) and 100-seed weight (35.74gr) under normal condition and the highest weight of total pods (63.28 gr), weight of filled pods (61.91gr), number and weight seeds in plant (236.44 and 44.11gr respectively) and 100-seed weight (33.67gr) belonged to Williams×Katoul(4). Also according to cluster analysis to comparing soybean genotypes under normal and water stress conditions, Williams×Katoul(4) in both groupings, belonged to the better group, indicating that the line was superior to other lines and its parents in terms of total traits. Totally, advanced lines performed better than their parents, especially under water stress condition. Also according to principal component analysis and biplot of two first PC, Gorgan3×Williams(2) under normal condition and Williams×Katoul(4) under both of conditions were better than other lines and parental varieties.

The annual rain in Iran is about one third of world average (235-260 milliliters). Arid, semi-arid, super arid and desert weather conditions constitute about 85% of Iran’s area which is due to low rain in central and southern regions. The researches have shown that all the country is confronted with dryness that greatly affects agriculture. If this condition continues, generating agricultural products such as bean will definitely face some problems. Now, the global production of soybean is more than 310 million tons equals 80 billion dollars. Soybean is one of the important products in Iran’s agriculture. According to the last published statistics, the area under cultivation of soybean in country is about 80 thousand hectares and Golestan, Mazandaran and Ardabil have allocated the rank of first to third to themselves. Functionally, it is about 110 to 130 thousand tons per year. Soybean has nutritional value for human, livestock and soil. Since drought stress is the most important environmental stress which has severely led to reduction in plants’ growth, reduction of bush generation and function of crops more than any other environmental factor; thus, health of soil and environment is necessary to provide nutritional security in order to identify the resistant plants and their cultivation be developed. Numerous methods have been used to select the high quality items under the condition of stress in the farm and greenhouse. Regarding that the genetic base of resistance to drought stress has many complexities, proper and extensive phenotypic assessment on the farm together with identifying the desirable physiological features will be useful in natural environments. Hence, this plant and identifying the genotypes resistant to drought stress were carried out to develop the cultivation.

To evaluate the dehydration and evaluation of tolerance to drought stress in soybean genotypes in 2017, a research was conducted as a factorial test in form of total random blocks in three repetition in greenhouse in Damsvand County. The first factor contained 50 soybean genotypes and second factor included two levels of normal irrigation and irrigation disruption in time of podding. Assessing genotypes was conducted by using tolerance to drought indexes: SNPI,MSTI,YR,RDI DI,ATI,SSPI, MP,GMP,HARM,SSI,STI,TOL,YI,YSI,. The dimensions of vases were about 35 in 45 centimeters which were filled by soil, sand and fertilizer in proportion of 1: 1: 3. Five seeds were planted in each vase. They were irrigated every four day. In time of stopping the irrigation, about 50% of pods were constituted. Cultivation was done on 10th of Tir, 2017. And statistical analysis were done by SAS and JMP software. Diagrams were drawn by Excel software. There are significant variety of soybeans.

Comparisons showed that resistant and sensitive genotypes shall be separated on the basis of tolerance to drought indexes, as such that genotypes 2, 14, 21, 38, 49 indicated high function in both environment and genotypes 25 and 23 showed high function in stress conditions. In order to recognize the most effective indexes, the indexes which have the highest correlation with the weight of seeds in both stressful and lack of stress conditions will be reliable and according to the obtained conclusions, some of tolerance to drought indexes had the highest significant correlation with the function in normal ans stressful conditions. Decomposing into main components make this ability to differentiate between the indexes introducing resistant genotypes and the indexes introducing sensitive genotypes, and accordingly, cluster decomposition of 8 groups among 50 genotypes determined that finally some of genotypes had desirable function in both environments. In order to recognize the most effective indexes, the indexes which have the highest correlation with the weight of seeds in both stressful and lack of stress conditions will be reliable and according to the obtained conclusions, Harmonic mean(HARM), geometric mean productivity(GMP), mean productivity(MP), stress tolerance index(STI), yield index(YI), Abiotic tolerance index (ATI), Drought resistance index) DI), Yield stability index(YSI), Stress susceptibility percentage index (SNPI), modified stress tolerance index(MSTIk1 and MSTIk2) of tolerance to drought indexes had the highest significant correlation with the function in normal ans stressful conditions. genotypes 2, 14, 21, 23, 42 and 49 have suitable function in both environments.

To investigate water stress tolerance indexes, estimation of genetic diversity for coleoptile length and other agricultural variables such as grain yield and its components and also investigating of the role of coleoptile length in response to water stress and its relation to yield and its components in wheat cultivars in arid and semi-arid regions of Iran.

This study was performed in a randomized complete block design with 3 replications and 50 wheat genotypes under stress and non-stress water conditions. In this evaluation, the STI index was calculated based on grain yield of genotypes under stress conditions. For investigating the association of traits and drought tolerance index with coleoptile length the coefficient of correlation was calculated Analysis of variance of genotypes was performed using SAS software (ver. 9.1) for all traits.

Analysis of variance showed that there was a significant difference between genotypes for plant height, days to heading, grain yield, spike weight, awn length, grain per spike, 1000-grian weight, and spike length in both stress and non-stress water conditions, however this was not significant for number of spike per unit. The results showed that except for awn length and spike weight, mean values of all traits in non-stress conditions were more than stress condition. The coleoptile length of genotypes was variable from 2.41 cm to 4.91 cm. The range for all traits in both stress and non-stress conditions was relatively high which indicated a high diversity between the studied cultivars. Among the nine studied traits, six of them suffered a decline in growth due to drought stress and so that reduction in number of spike with 4.38%, grain yield with 13% and spike weight with 14% were more obvious. In this evaluation, the STI index was calculated based on grain yield of genotypes under stress conditions. Six cultivars including Shirudi, Orum, Pasteur, S-90-5, Ofogh, and Sistan were the most tolerant and cultivar Star had the least amount of STI index. The highest positive correlation of coleoptile length.in both environmental conditions was occurred about plant height and number of spike. Correlation coefficients of plant height with coleoptile length under stress and non-stress conditions were was 0.56 and 0.43, respectively, and its correlations with number of spike were 0.16 and 0.165, too. A negative correlation between coleoptile length and STI index was observed in both stress and non-stress conditions. The correlation coefficient of coleoptile length with some agronomic changed in terms of size and direction over stress than non-stress conditions, therefore this could be inferred to effective role of coleoptile in the balance of plant and moisture conditions.

In general, the results of this study showed that the cultivars had a significant difference between sowing date and spike appearance, plant height, spike length, spike weight, 1000-grian weight, awn length, grain per spike and grain yield.

In order to evaluate the drought tolerance of 19 barley genotypes using physiological traits, an experiment was carried out in randomized complete blocks with 3 replications under non-stress and terminal drought stress conditions at agricultural research station of Islamic Azad University, Ardabil branch in 2016. Non-stress plots were irrigated when available soil water reached to 60% using tensiometer measurements. In drought stress environment, plants were grown in rainfed condition and drought was imposed after flowering stage by a rain exclusion shelter. After exposure of plants to drought stress, Specific Leaf Area (SLA), Excised Leaf Water Loss (ELWL), leaf Relative Water Content (RWC), Stomatal Conductance (Gs), Chlorophyll Fluorescent (Fv/Fm) and Rate of Ground Cover (RGC) were measured in flag leaves of 10 randomly selected plants. Results of ANOVA showed that SLA, ELWL, RWC and GC affected by drought, however Fv/FM and stomatal conductance did not affected. Stress severity index was obtained as 0.45, indicating a moderate drought stress imposed to genotypes. G×E interaction was significant in all of the traits indicating the severity of the drought stress. In non-stress condition, genotype number 13 with 5040 kg/ha, had the highest grain yield. Under drought stress condition, genotypes number 13 and 15 with 2710 and 2550 kg/ha, had the highest grain yield respectively. Based on grain yield of the genotypes in both environments, genotypes number 13, 18(Bereke-54 check), 9, 4, 19 (Makouee check) and 15 had the highest stress tolerance index (STI). Under stress, genotypes number 15, 1, 18, 2, 3, 10, 13, 12 and 9 had the highest RWC, genotypes number 18, 13, 14 and 8 had the lowest ELWL, genotypes number 15, 9, 19, 18, 1, 13, 17, 4, 16, 5 and 12 had the highest Gs, genotypes number 9, 13, 8, 12, 14, 10, 11 and 15 had the highest RGC (early vigor), genotypes number 4, 3, 13, 15, 4, 12, 9, 17, 19, 1 and 11 had the highest SLA. In non-stress condition yield correlated only with RGC this trait was the only trait remained in final regression model and explained the 34.7% of grain yield variation. Under stress condition, yield positively correlated with RWC, SLA, Gs, RGC and negatively correlated with ELWL. In stepwise multiple regression analysis under drought stress condition, Gs, RGC and ELWL remained in final model with 0.489, 0.512 and 0.381 standard partial regression coefficients respectively(as direct effect). These three characters described 69.3% of grain yield variation. Cluster analysis using Euclidian distance by Ward’s method could successfully separate sensitive and tolerant genotypes. In this analysis, genotypes number 1, 4, 9, 12, 13, 15, 17, 18 and 19 were located in superior cluster, having higher Gs, RWC, SLA and lower Fv/FM. Finally genotype number 13 (the most high yielding genotype) had the second, third, fourth and sixth ranks in RGC, SLA, Fv/FM and Gs. The results of this experiment showed that RGC, having the highest correlation with yield and lower genotype × environment interaction can be consider as the most suitable indirect criteria for selection of drought tolerance in barley. Traits such as Gs, ELWL, RWC and SLA can be consider in the next priority, due to significant correlations with yield under drought stress.

In west Azerbaijan for food production including barley, water stress is one of the most important threats and water deficit stress at grain filling stage do it damage every year. One approach for reducing of damage of water deficit stress is introducing of drought tolerant new barley variety. Effect interaction of water and nitrogen is complicated on plant. Under full irrigation condition, rate of nitrogen for grain mostly grain yield determinative factor, but in water deficit stress condition, high rate of nitrogen increased severity of tension, as a result growth and yield of plant reduced. For achieving of drought tolerant barley genotype, barley genotypes must be evaluated in water deficit stress and full irrigation conditions. The aim of this research was to evaluate the response of barley genotypes to application of different levels of urea fertilizer under different moisture conditions.

This research was carried out in order to evaluate the response of barley genotypes to application of different levels of urea fertilizer under complete irrigation and end season drought stress conditions, as a split plot based on randomized complete blocks design with three replications at Miandoab Agricultural Research and Natural Resources Station during 2014-2016 crop seasons. Four barley genotypes (Bahman, EDBYT-82-6، EDBYT-82-9، EBYT-83-17، EBYT-84-10) at different levels of nitrogen (0, 50, 100, 150 kg/ha urea) were evaluated in full irrigation and grain filing water deficit stress conditions. At planting time, 50 kg/ha urea applied for all treatments. All genotypes were planted with 400 seed/m2 in 6 lines by 5m length and 20cm apart at late of October month. Watering in the fall for a turn to green seeds and their deployment was carried out. In the spring for water deficit stress trial, irrigation at the heading time was cut and for normal trial was performed three times irrigation. Seedbed Preparation, potash and phosphate fertilizer, crop care and harvest for all treatment were the same. Compound analysis of data was carried out on two years. The SAS (Ver, 9.4) and Minitab (V. 16) software were used to data analysis.

The results of combined analysis showed that effect of year, genotype, nitrogen and year*genotype was significant at both irrigation conditions. Mean comparisons showed genotypes of Bahman and EBYT-84-10 genotypes had the greatest grain yield in both of irrigation conditions. Under normal irrigation condition, grain yield increased until 100 kg/ha urea, application of 150 kg/ha of urea had no significant difference comparison to 100 kg/ha urea in view of grain yield, 150 kg/ha of urea produced 35% greater grain yield rather than 0kg/ha treatment. Under water deficit condition, application of 100 kg/ha of urea had no significant difference comparison to 50 kg/ha in view of grain yield, also application of 150 kg/ha of urea decreased 11% grain yield comparison to 0kg/ha treatment. Selection of drought tolerant genotypes in different nitrogen levels based on principal components analysis indicated that genotype Bahman at 0 kg/ha, genotypes Bahman and EBYT-84-10 at 50 and 100 kg/ha, and genotype EBYT-84-10 at 150 kg/ha nitrogen application had the highest drought tolerance.

Results of this study showed response of barley genotypes varied to rate of nitrogen, so under water deficit stress condition, nutritional need of barley genotypes less than full irrigation condition. So, in addition to the raise cost for farmer may be infecting the environment. Therefore, recommended in selecting of drought tolerant barley genotypes, special attention focus to rate of nitrogen.

The water stress-induced limitation on plant growth is mainly caused by reductions in plant carbon balance, which depends on the balance between photosynthesis and respiration. In order to evaluate the water stress tolerant cultivar, photosynthetic parameters were investigated in seedlings of flowering and podding stages of Adel, Azad and Karaj arable chickpeas.

The experiment was conducted as a factorial based on a completely randomized design with three replications under controlled conditions in 1394 with the aim of evaluating the effect of drought stress on 5 levels of 20, 40, 60, 80 and 100% of crop capacity on the photosynthetic index of cultivars. Pea, Adel, Azad and Karaj were planted in 3 stages of seedling, flowering and podding. Total Chl Content (TChl): The chlorophyll index was determined using the Chlorophyll Content Meter (CCM-200 plus, USA). Maximum quantum yield of PSII photochemistry (Fv / Fm), was measured using chlorophyll fluorimeter (Pocket PEA, Hansatech, England). transpiration rate (E) ،net photosynthetic rate (PN) and intercellular CO2 concentration(Ci) were determined in fully expanded leaves using a portable infrared gas analyzer (KR8700 system, Korea) Statistical analyses were made by MASTAT-C. Means were compared using the Duncan’s multiple range test (p 0.05).

Fv/Fm: Drought stress in seedling stage at levels of 20 and 40% of crop capacity resulted in a significant reduction of Fv/Fm ratio in all three cultivars compared to non stress conditions. Results showed that drought stress levels (20, 40 and 60% of crop capacity) in all three cultivars resulted in a significant reduction in the efficiency of photosystem II compared to 80 and 100% of crop capacity. Comparison of mean of data on interaction effects of cultivar and stress in podding stage showed that chickpea cultivars did not differ significantly in this stage of growth in different conditions of drought stress. Related studies showed that the reduction of the Fv/Fm ratio in drought stress conditions, which indicates a reduction in the efficiency of photosystem II, is due to the reduction of electron transfer from the photosystem II to the photosystem I.TChl: In the seedling stage, the results showed that the highest and lowest total chlorophyll index was allocated to Karaj cultivar under non stress condition and free cultivar under severe stress conditions. At flowering stage, the results showed that drought stress at all levels resulted in a significant reduction of this trait compared to non-stress level. In the podding stage, Karaj cultivar was superior to free cultivar at most drought stress levels (20, 60 and 100% crop capacity). Related studies showed a sharp drop in chlorophyll content in high levels of stress, can reduce transmission of the required minerals and water leaves through transpiration reduce the suction of the vessel is wood.Transpiration: The results showed that drought stress at all levels significantly decreased transpiration rates in the cultivars compared to non-stressed conditions. At flowering stage, asignificant decrease in transpiration was observed in all levels of drought stress in all chickpea cultivars. Comparison of meanings in the podding stage was similar to that of flowering stage. Related studies have shown that plants reduce the transpiration by closing the stomata to counteract the drought stress in order to preserve leaf water and prevent it from wasting.Ci: The results showed that in seedling stage, drought stress at levels of 20 and 40% of crop capacity led to a significant reduction of CO2 in leaf cells compared to non stress conditions. In comparison with chickpea cultivars, in flowering and podding stage, Karaj cultivar had the highest amount of intracellular CO2 at all drought levels, which was significant at 20 and 80% of the capacity of this increase compared to the fair and free cultivars. Studies on the selection of susceptible and tolerant drought stress in plants have shown that reducing intracellular CO2 concentration due to the closure of leaf stomata and preventing the entry of CO2 into leaf mesophilic cells.Pn: Comparison of mean of data in flowering seedlings showed that the highest amount of pure photosynthesis in Karaj cultivar was under non stress condition. There was no significant difference between treatments in pod filling stage. The increase of pure photosynthesis in Karaj cultivar compared to two other cultivars (fair and free) indicates that there are mechanisms of tension compatibility in order to prevent the reduction of photosynthesis and tolerance of this variety to drought stress.

This study showed that drought stress in seedling, flowering and podding stages of Adel, Azad and Karaj chickpea cultivars resulted in a significant decrease in pure photosynthesis, transpiration, intracellular CO2, chlorophyll content and photosystem II performance. Although the Karaj cultivar, due to its superiority in most of the studied traits, is compared with the other two cultivars as drought stress tolerant to those two varieties.

 Durum wheat (Triticum durum) is predominantly grown in the Mediterranean area, the northern plains of the United States, Canada, Europe, and many parts of the Asia.(FAO, 2017).A large part of the wheat cultivated land in Iran is located in arid and semi-arid regions. Due to lack of water resources and consequently stress for plants, wheat yieldis significantly reduced. Unde rstanding the effect of drought stress on grain yield is an effective step in durum wheat production.(Garcia del moral et. al., 2003).

A factorial experiment with 2 factors in a completely randomized design with 3 replicates including durum wheat genotypes and water stress was conducted in the research greenhouse of College of Agriculture and Natural Resources of Darab in 2017-2018. Mixtures of 4 durum wheat genotypes (Behrang, Shabrang, Dw-92-4 and Dw-94-14) were planted in binary and quadruple combinations and pure culture. Plants were treated in two levels of water stress including normal irrigation and water stressed. Plants which went under water stress did not watereduntil the plants showed rolled leaves.
 

 The results of analysis of variance of yield and yield components are shown intable 1. Interactions ofwater stress and genotype mixtures on grain yield per plant, number ofseeds per spike, number of seeds per spikelet, one thousand seed weight were significant at the probability level of 0.01 (p≤0.01).This means that the response of the genotype mixtures to the same water stress was not the same and the amount of these losses due to water stress were higher for some of the genotype mixtures than others. (table 1). The results showed that the highest grain yield obtained in shabrang+behrang genotype mixture at normal irrigation level (8.75 g per plant) and the least grain yield was observed  in DW-92-4 pure crop under water stress conditions.(1.1 g per plant). The highest positive and significant correlation were observed between grain yield andplant height, 1000 grain weightand leaf length (r = 0.443 **) (r = 0.434 **) (r = 0.312 **) respectively.Some researchers revealed that grain yield in mixed crop combination with the same seeding rate is 15 to 23 percent superior to pure crop cultivation.(Nazeri et al., 2004).

 In general, the results indicated that the combination of genotypes under normal irrigation conditions, than pure culture as an agro-ecological method have some, positive effects on grain yield and other agronomical traits.The highest positive and significant correlation was observed between grain yield andplant height, 1000 grain weightand leaf length (r = 0.443 **) (r = 0.434 **) (r = 0.312 **). According to the results of this experiment, it seems that under irrigation conditions, the use of genotype mixtures can produce more yield than pure culture of a genotype in greenhouse conditions.

One of the oil seeds that has attracted a lot of attention in these years in the country and is also considered as a major contributor to the plan to reduce the import of vegetable oil. This product is among the world's most oil-bearing grains It has the highest production in recent decades, and nowadays it has achieved the third place after the soybean and palm oil in vegetable oil products. Water is a key factor in the production of crops. The yield of crops in many areas is limited by living or non-living environmental stresses, and therefore, there is a significant difference between actual yield and yield potential of crops. Low moisture content in each of the different stages of growth reduces the absorption of water, nutrients, decreases the transfer of elements within the plant, and ultimately reduces the yield of the grain or the final product. Optimal water use is of great importance, especially in areas where dry climatic conditions And semi-arid dominant that covers about two thirds of Iran's territory. In order to increase yield per unit area, farmers use one of the common fertilization methods including soil utilization through irrigation, seed mixing and solubility. Leaf solubility is one of the fastest ways to meet the needs. The fertilizer is also used in this method to save fertilizer and in addition to the positive economic aspect, the environment is protected from chemical pollution, which is very effective in achieving sustainable agriculture.

In order to investigate the effect of micronutrients application on qualitative and quantitative yield of rapeseed plants in condition drought stress, a field experiment was carried out to in Hamidieh city in 2017-18 in a split plot is an experiment in a randomized complete block design with four replications. The experimental treatments included drought stress in two levels (I1: optimal irrigation, I2: Irrigation off in pod stage) as the main plot and spraying of complete fertilizer in four levels (M0: non-spraying (control), Spraying with concentrations M1: 2 in thousand, M2: 4 per thousand, M3: 6 per thousand) was implemented as a subplot in the region.

The results showed that drought stress had a significant effect on leaf area index, grain yield, grain protein, protein yield, iron and zinc percentage. The highest grain yield in optimal irrigation treatment (with an average of 3110.7 kg /ha) and the lowest grain yield (with an average of 2280.22 kg /ha) was attributed to irrigation cut off treatment at slaughtering stage. Also, with increasing micronutrient levels, leaf area index, grain yield, protein content, protein yield, percentage of iron and zinc increase. The most of these traits were obtained from optimal irrigation and spraying of six to a thousand, which did not have significant difference with treatment of four. In explaining the reason for the increase in the protein content of seeds by the application of micronutrients on zinc and iron, it should be noted that these elements directly contribute to both the process of gene expression and protein synthesis. The deficiency of zinc prevents the activation of a number of antioxidant enzymes, which results in oxidative damage to protein molecules, which also reduces protein function in the plant. The highest grain yield (with a mean of 3290.4 kg /ha) was obtained in irrigation treatment and spray application of four per thousand. In this experiment, micronutrient spraying reduced the damage caused by drought stress to grain yield and also increased the percentage of iron and zinc seeds.

The results of this experiment showed that using micronutrients such as iron and zinc can play an important role in improving grain yield, seed protein content and enrichment of zinc and iron in drought stress conditions. Regarding the drought and depletion crisis in Khuzestan province, nutrient poverty in the province's soils, especially in terms of micronutrients such as zinc and iron, is a foliar application of fertilizer to increase the amount of elemental elements in the plant. Therefore, in general, the results of this research can be argued that in order to achieve maximum quality yield and agronomic traits, rapeseed cultivation with micronutrient foliar application of four thousand in moisture conditions is recommended.

Arbuscular-mycorrhizal fungi (AM) are important in sustainable agriculture because they increase the tolerance to drought stress in host plants. One of the most important aspects of the relationship between the mycorrhiza fungus and the host plant is that it’s physiological and biochemical processes should be such that the host plant can successfully deal with limiting environmental conditions.

The isolates of the fungus used in this study included two Glomus (G.) genus species, G. intraradices and G. mosseae. In this research, their efficiency was evaluated on the improvement of some quantitative traits of corn under irrigated conditions and water stress in a calcareous soil. For this purpose, soil samples were prepared from a depth of 0-30 cm in a cultivated soil with a phosphorus available concentration of less than five mg.kg-1 and its physical and chemical properties were measured according to the standards of the Soil and Water Research Institute, Iran. The experiment based on factorial completely randomized design was carried out in five replications. The first factor was related to the drought stress levels of 60%, 80% and 100% of field capacity moisture (FC) and the second one consisted of two mycorrhizal fungi species, G. intraradices and G. mosseae, and control (non-inoculated). At the beginning of flowering, traits such as plant height, leaf area, chlorophyll index (using Spad-502 Minolta chlorophyll meter), relative humidity, were measured. At harvesting time, shoot dry weight, root dry weight and root colonization percentage were measured in all treatments.

The results revealed that there was a significant difference between the drought stress levels in terms of plant height so that with increasing tension, plant height decreased. The effects of mycorrhizal fungus species were significant in terms of plant height and the highest plant height was obtained in inoculum treatment with G. intraradices. The interaction effects of drought stress and mycorrhizal fungi were also significant in terms of plant height. The highest plant height was obtained in the control treatment at field capacity, which was maintained by G. intraradices with the same moisture content and G. mosseae at 60% of soil moisture content in a statistical class, indicating the effectiveness of G. mosseae in improving Corn growth under moisture stress condition. Drought stress reduced the SPAD chlorophyll index, leaf area, root colonization percent, relative water content (RWC) of leaves, leaf area, root dry weight, and shoot dry weight of maize. In plants inoculated with mycorrhizal inoculation, the chlorophyll index, plant height, root dry weight, leaf surface area and root colonization percent and RWC of leaves were increased. Interactions between drought stress and mycorrhizal species on all mentioned parameters have a significant effect. Although, chlorophyll content was higher in plants inoculated with the fungus G. mosseae specie at 80% FC, but maximum shoot dry weight was obtained at 100% FC and inoculation with fungi G. intraradices treatment. The most root colonization was achieved in plants inoculated with the fungus G. mosseae specie at 60% FC treatment. Overall, the results of this study proved that inoculation of corn seeds with AM fungi increased leaf chlorophyll content and produced dry matter of the plant in moisture regimes less than field capacity. Further increase of the traits studied in this study such as plant height, chlorophyll index, leaf area, relative humidity, root and shoot production as a result of using G. mosseae compared to G. intraradices, suggests that G. mosseae species are more compatible and able to communicate more effectively with the root of corn in drought stress conditions. Therefore, to increase the tolerance of corn to drought stress and increase the water absorption efficiency, G. mosseae species is more efficient in similar conditions of this experiment.

Drought is a common problem that seriously affects the quantity and quality of agricultural produce. More than 50% of the world's regions are located in dry and semi-arid regions. Plant growth decreases in drought stress. Water shortages in the world and in Iran have always been a limiting factor for plant cultivation. Drought is a common problem that seriously affects the quantity and quality of agricultural products, such as medicinal plants. The use of agronomic techniques, including soil biological conditions (using mycorrhiza and Azospirilum) and the use of chemical fertilizers, may be effective in reducing the effects of drought stress.

In this regard, a field experiment was carried out in two regions of Tehran (semi-arid) and Varamin (arid) in the period of 2014-15. The experiment was split factorial in a completely randomized block design with three replications. The main factor consisted of three treatments without water stress, moderate stress and severe stress (irrigation at 50, 40 and 30 percent of field capacity), and the factorial arrangement consisted of three fertilizer regimes (no fertilizer application, 50 and 100 percent Nitrogen + Phosphorus application requirements for plant), mycorrhizal fungi and Azospirilum bacterium (application and non-application) were considered as a subplot. Drought stress treatments at flowering stage (during flowering until the end of the season) were applied based on soil crop capacity. The following steps were applied to apply water deficit treatments, respectively: First, the field capacity was obtained, first, a plot (length of two meters × two meters wide) from each experimental site completely up to the end of the plain wall of the water filled and was enclosed with plastic (to prevent water evaporation and error) to the soil completely saturated with water. After 48 hours, the water was removed by gravity from the coarse porosity, the plastic was removed from the plots, the soil sample was prepared and, after weighing, in an oven at 105° C for 24 clock was placed. The sample was then calibrated with a precision weighing scale and evaporated moisture content (soil moisture content).

The results showed that grain yield and its components (biological yield, 1000 seed weight, number of seeds per plant, number of capsules per plant and number of lateral branches per plant) with irrigation reduction (moderate and severe), were significantly dry weather in the Varamin area decreased. Inoculation of mycorrhiza with combined application of chemical fertilizers and Azospirillum improved seed yield, biological yield, 1000 seed weight, seed number per plant, number of capsules per plant and number of lateral branches per plant under drought stress conditions in arid and semiarid regions. Biological and grain yield in terms of absence of drought stress along with application of chemical and biological fertilizers to the conditions of severe drought stress, with non-application of chemical and biological fertilizers were 60% and 65% respectively for Tehran region and 50% and 59% for Varamin area increased. Reducing the amount of photosynthesis, reducing carbon dioxide absorption, increasing transpiration and decreasing water absorption, increasing leaf temperature due to reduced transpiration and reduced absorption of food can be mentioned due to reduced biological yield and grain yield under drought stress.

In general, drought stress has reduced the yield and the use of biological fertilizers has caused the plant's resistance to drought stress.

In recent years, by minimizing the use of chemical fertilizers and replacing them with biological fertilizers has become important as one of the key principles of sustainable agriculture. Common bean (Phaseolus vulgaris L.) is the world’s most important food legume. This staple considered as a nearly perfect food mainly because of its high protein content and abundant fiber, complex carbohydrates, and other daily food needs such as vitamins (folate) and minerals (Cu, Ca, Fe, Mg, Mn, and Zn). Water used in agricultural production as one of the most important environmental factors affecting plant growth and development, especially in arid and semi-arid climatic conditions of Iran is of special importance. Since biological facility for production increase in agriculture is use of terrestrial useful living tiny, that cause is becoming plant yield and growth increase.

In order to study the effect of plant growth promoting Rhizobacteria and nitrogen chemical fertilizer on yield and yield component of bean (Phaseolus vulgaris L.) under water stress conditions, a split-plot design based on RCBD with three replications was conducted at Agricultural Research Station, College of Agriculture, Ferdowsi University of Mashhad, Iran in 2015. Three levels of irrigation (to supply of 100, 75, and 50 percent water requirement) were assigned to main plots and different types of biofertilizers (1- Nitroxin, containing Azotobacter sp. & Azospirillum sp. as inoculation seed, 2- Biophosphor, containing Phosphate-solubilizing bacteria Bacillus sp. & Pseudomonas sp.) as inoculation seed, 3- Nitrogen chemical fertilizer (100 kg.ha-1 urea form), and 4- Control (no fertilizer) were assigned to sub plots. Irrigation levels according to irrigation requirements in each irrigation period were carried out by water meter device. The growth index of LAI (leaf area index) was determined randomly from 5 competing plants regarding the marginal effects from 1 real completed leaf stage to the end of the growing season (every 7 days; 12 steps). LAI index was calculated using equation (1). Leaf area was calculated by Leaf Area Meter device (Delta T, UK). At the end of growing season, yield and yield component were determined regarding the marginal effects from 5 m2 surfaces. Data analysis of variance and draw charts were done by Minitab Ver. 16, Slide Write Ver. 2, and Excel 2010 softwares. At the end, Means comparing did by Duncan's test at probability 5 percent.LAI= (1/GA) [(LA2+LA1)/2] (Equation 1)Where GA is ground area (m2), LA is leaf area (m2).

According to the result, the effect of fertilizers was significant (P≤0.05) on grain yield, and number of pod per plant, and was very significant (P≤0.01) on number of seeds per pod, and 100 seed weight. Among these fertilizers, Nitroxin fertilizer had the highest effect on traits and was increased these compare to control 92.4, 101.7, 47.3 and 38.7 percent, respectively. Also the effect of irrigation levels on all of traits was very significant (P≤0.01). So that the lowest of traits were observed in 50 percent water requirement of bean and compare to 100 percent water requirement were decreased 68.1, 35.8, 56.3 and 38.1 percent, respectively. Interaction of fertilizer and irrigation was significant (P≤0.05) only on dry matter yield of bean, so that the highest and the lowest of dry matter yield were obtained from Nitroxin+100% water requirement (7741 kg.ha-1) and Control+50% water requirement (880 kg.ha-1), respectively. In general, the results of this experiment declared that there was no significant difference between using of Biophosphor and nitrogen chemical fertilizer concerning the effect on bean traits including: seed yield, pod no. per plant, seed no. per pod, 100 seeds weight.

The results showed that could be possible to produce the healthy production of bean, moreover, attain the optimum yield as equal as to conventional systems.

Safflower (Carthamus tinctorius L.) is one of the oldest oil seeds that due to deep and extensive root system is known for salt as well as drought tolerance. Seed priming with water and salt solution in plant increased germination percent and germination index under stress condition. The reported that seed priming with salicylic acid can protect the plants against abiotic stress. Salicylic acid has role protection in plants that are under environmental stress condition. The reported that salicylic acid increased plants resistance to biotic and abiotic stresses such as drought. Exogenous application of salicylic acid improved crops yield. The research showed that with application of salicylic acid increased the chlorophyll content. Biochar is a solid material that created from carbonization each type biomass includes weeds, crops residual and another wastage material with plant origin. Application of biochar increased available phosphorus, potash, magnesium and calcium content as compared without biochar. The reported that application of biochar retained water and nutrition and therefore could be increase wheat yield. The reported that application of biochar increased maize yield by 140% due to increasing of pH and nutrition in duration four years.

To evaluate the effect of biochar and seed priming with salicylic acid and water along with foliar application on physiological traits and oil yield of safflower in dry land condition, an experiment was performed as split- split plot based on randomized complete blocks design in three replications, at the Research Station of Islamic Azad University, Arak Branch, Iran, in during 2016-2017. Experiment factors were included biochar (wood, shoot and leaf of trees) in three levels of 0, 5 and 10 t/ha; seed priming in three levels of without priming, priming with water distillated and seed priming with .0.5mM salicylic acid and foliar application in two levels of foliar application with water and 1 mM salicylic acid. The cultivar safflower was ‘Esfahan native’. Seeds primed for 12 h at distillated water and salicylic acid solutions then dried at shade. Biochar was applied at 15 cm depth and under the seed, before from sowing and mixed with soil. Sowing done with 30 cm distanced rows with 15 cm spacing between plants in rows. The seeds were sown at 3-4 cm depth on middle March 2016. Foliar application of water and salicylic acid done in two stages of vegetative and reproductive growth at 17 h evening. Physiological traits measured in heading stage. Data were subjected to analysis of variance using SAS. Means were compared using the Duncan's multiple range test at 5% the confidence level.

Results showed that application of 5 t/ha biochar along with seed priming by salicylic acid increased the excise leaf water retention by 24.9 % compared to control. Application of 5 t/ha biochar decreased ion leakage by 15% and increased oil yield by 20% compared to control. Application of 10 t/ha biochar along with seed priming by salicylic acid increased the chlorophyll a content by 43.4% compared to control. The highest of carotenoids content was obtained from application of 5 t/ha biochar combined with foliar application of water. Application of 5 and 10 t/ha biochar increased the flower fresh wieght. The maximum of head harvest index was recorded from application of 5 t/ha biochar combined with foliar application of water or salicylic acid and also from application of 10 t/ha biochar combined with foliar application of salicylic acid.

The result this research showed that seed priming by water or salicylic acid along with foliar application and application of biochar by shoot water improve and decrease of damage due to stress condition, could be moderated the effect drought stress. Therefore seed priming by water or salicylic acid along with application of 5 t/ha biochar combined with foliar application of water or salicylic acid in two stage in duration of growth improved physiological traits and oil yield of safflower in dry land condition.

Drought stress is one of the important adverse factors that limits plant growth and productivity. Drought stress induces a range of physiological and biochemical responses in plants. Plants also respond and adapt to water deficit at both cellular and molecular levels, for instance through accumulation of osmolytes and proteins specifically involved in stress tolerance. Plants’ responses to water stress are also species and cultivar-dependent characteristics. Foliar application of kaolin has been evaluated for its ability to reduce the negative effects of water stress and to improve the physiology and productivity of Plants. The purpose of this research is to determine the effects of different kaolin concentrations, on the physiological and morphological characteristics of purple basil under deficit irrigation conditions.

In order to investigate of Kaolin on increasing of drought tolerance of Basil, a factorial experiment was conducted based on randomized complete block design with 3 replications in researcher greenhouses of Yazd university during 2017-18 growing season. The treatments were four levels of deficit irrigation including: I1=25%FC, I2=50%FC, I3=75%FC, I4=100%FC field capacity and three levels of kaolin concentrations consisted of K1=0%, K2=3%, K3=6%. In a factorial experiment based on completely randomized design with three replications. After the plants establishment, drought treatments were imposed. After 40 days of applying drought treatments, kaolin was twice sprayed with 7 days interval. The leaves of plants were sampled one week after the last spraying and transferred to the laboratory and the amount of soluble sugars, proline and chlorophyll concentrations were measured. In order to analysis data, analysis two-way ANOVA were used and FLST test compared means after normality test. Statistical analysis was performed using SAS software, and Excel software was used for drawing the charts.

The results showed that the effect of kaolin foliar application and moisture stress was significant on plant height, plant diameter, leaf area, shoot dry weight, root dry weight, root volume, RWC, chlorophyll a, chlorophyll b, total chlorophyll, proline and soluble sugar .

In arid and semi-arid areas, water can be a limiting factor for plant growth and agricultural yields. It is an important input to agricultural production and also an essential requirement for domestic, industrial and municipal activities. Increasing population and standards of living are contributing to a steep rise in demand for fresh water. By using proper irrigation management in farm, we are able to utilize water, soil and fertilizer to produce high yield and quality products. Drip irrigation is considered one of the most efficient irrigation methods. One of the major advantages is its ability to apply water to the soil as often as desired and in smaller quantity than the other irrigation methods. Drip irrigation has been practiced for many years for its effectiveness in reducing soil surface evaporation and it has been widely used in horticultural crops in both greenhouse and open field. Also, deficit irrigation is one of the strategies for efficient use of water and increasing water use efficiency in agricultural district. Deficit irrigation is a suitable solution to gain acceptable and economic performance by using minimum amount of water.

In order to investigate of surface and subsurface drip irrigation systems under soil matric potential on Rosmarinus officinalis L., a field experiment was carried out during 2015 growing seasons at center of seed and plant production of Kerman municipality. The treatments were laid out in randomized complete block design with three replications. The treatments were comprised of three soil matric potentials of 40, 60, and 80 centi-bar for initiation of irrigation in the main plot and sub plot consisted of two drip irrigation systems (surface and subsurface). In this study, surface systems, drip lines were placed on the soil surface at a distance of 15 cm from the plant and subsurface systems, drip lines were placed at a depth of 30 cm. The irrigation time was determined based on the readings of metal Tensimeters. These tensiometers were installed in three depths of 15, 30 and 50 cm of soil and at a distance of 20 cm from the plant. In this regard, in both irrigation systems, a Tensiometer mounted at a depth of 15 cm of soil was used for early growth and growth development, and from Tensiometers mounted at depths of 30 and 50 cm soil, for reading in the middle and final stages of growth. In order to carry out irrigation at the potential point of view, the tensiometers were fully controlled and when the calibrated tensiometer screen showed the desired potential point, irrigation was carried out and the irrigation process continued until the soil moisture reached the crop capacity level. Dry weight, leaf area index (LAI), number of shoots, plant height, water productivity were measured. Data were analysed statistically using SAS Statistical software. Treatment means were compared using LSD test.

The results showed that in comparison to 40 and 60 c-bar tension, parsimony of water usage equal 44.6 mm (21.7 percent) achieved. Moreover dry weight, number of shoots per plant and height of plant decreased 12.5, 12.8 and 11 percent respectively but water use efficiency increased 10.5 percent. Moreover dry weight in subsurface drip irrigation was increased 48 gr.m2 compared with surface irrigation. Also parsimony of water usage equal 10 percent and water use efficiency increased 21.4 percent. Number of shoots per plant and height of plant increased 8.2 and 8.7 percent respectively in subsurface drip irrigation.

According to the results, for Rosmarinus officinalis L. cultivation in Kerman area, application of the 60 centi-bar of soil matric potentials in subsurface drip irrigation system is the best way to increase the water use efficiency for the drought years.

Wheat is a major crop among cereals and plays a critical role in the national economy of developing countries. In Iran, grain yield of wheat reduced by terminal drought stress. Drought stress is one of the most important factors limiting the growth and yield of crops such as wheat as the most important crop in arid and semi-arid regions of the world as well as in Iran. It is growing in a wide range of climatic conditions and plays an important role in Supplying human food needs. This plant is exposed to drought stress at the germination stage and the end of the growth season. Genotypes that can react to drought stress at the germination stage have a better growth in seedlings. The aims of this research is to Investigate the response of the germination components to different levels of drought stress in bread wheat genotypes and also finding drought tolerant genotypes.

This research was conducted to study of drought stress treatments on seed characteristics and seedling growth of wheat Thirty wheat genotypes including Mihan, Aroom, Navid, Alvand, Zarrin, Zare, Sison, Alamoot, Gascogen, Heydari, Rizhav, Baran, Karim, Koohdasht, Pishgam, Star, Pishtaz, Qods, Marvdasht, Sardari, Kavir, Dez, Virinak, Alborz, Hirmand, Roshan, Zagros, Bezostaya, Azar and Sirvan. For this propose, a factorial experiment was conducted using 4 levels of osmotic potential (0, -4, -8, -12, -16 bar) using poly ethylene glycol. Seeds were sown on laboratory and data were recorded and analyzed for percent and speed of germination, length of root and shoot, vigor index and fresh and dry weight of seedling. Data analysis was carried out using SAS (Statistical Analysis System ver 9.1), MSTAT-C, SPSS 18 and means were compared using by Duncan's multiple range tests (P< 0.05).

In agreement with other studies, drought stress condition significantly decreased All Germination traits with increasing levels of stress. The results showed significant differences among genotypes, drought stresses and genotypes × drought stress interaction for most of traits. In this study, 30 wheat genotypes were exposed to drought stress at flowering stage. The genotype Heidari had higher performance for length of root and percent and speed of germination whereas Azar genotype was the worse. Genotype Sardari had higher performance for seedling vigor index and length of shoot whereas Azar genotype was the worse. Genotype Roshan had higher performance for fresh and dry weight of seedling, while Alvand genotype was the worse. The results in control condition was showed that length of root had the highest positive and significant correlation with percent and speed of germination and germination index and under drought stress condition between all of traits were positive and significant correlation. According to principal component analysis, two main components were selected that in total 72 percent of the total variation was explained.Factors analysis was performed using the studied traits, and two factors( based on specific values larger than one) justify about 72% of the variations in the total data, of which the first factor justifies about 53% of the variations, including traits Root length, stem length, percentage and speed of germination, seed index and germination index, and the second factor, which justifies about 19% of the variation, includes somewhat two traits and seedling dry and fresh weight. Therefore, selection based on these two factors showed the most effect on germination of seeds. In order to determine the variation between different genotypes of different types and determine the relationship between genotypes, cluster analysis using Ward method was performed based on 8 indicators and component of the study. Genetic types of wheat were grouped in 4 clusters with similar intra-group characteristics and non-similar groups. It indicated that 9 genotypes in the first cluster, 14 genotypes in the second cluster, 6 genotypes in the third cluster and Karim genotype were placed alone in the fourth cluster. Information contained in each cluster Groups have led to the identification of genotypes with unique traits and will help us select parental cross-breeds.The fourth cluster (including Karim genotype) had the highest mean and deviation from the mean for root length, percentage and speed of germination, seedling fresh weight and germination index. The third cluster included six genotypes such as Rijaw, Starr, Ghods, Marvdasht, Sardari And bright in terms of stem length, vigor index and seedling dry weight had the highest mean. It can also be argued that the Karim and Heidari genotypes can be used for cross-breeding programs in two separate clusters and maximum genetic distance between them.

Due to the presence of Iran in the arid and semi-arid regions of the world, drought and salinity are environmental stresses known as main factors that led to reduce the production of crops in Iran. Drought and salinity are major abiotic stresses that adversely affect crop productivity and quality. Their harmful effects are increasing due to global warming, and human activities such as overutilization of water resources, over-irrigation, and improper drainage, besides natural causes such as high evaporation rates in arid and semi-arid regions that led to decrease available water and increase salt accumulation in this sites. Drought and salinity have osmotic, ionic and nutritional constraint effects on plants. These effects lead to disturb photosynthetic path, growth retardation, metabolic disturbances and oxidative stress. Usually, these stresses happened at the same time especially in arid and semi-arid regions. Therefore, this study was conducted for determination growth and yield response of wheat to drought and salinity happened at the same time.

In order to evaluate the response of unfarm 4 wheat cultivar to different irrigation water and salinity levels, a factorial experiment based on a completely randomized block design with three replications was conducted at research field of agriculture, University of Birjand in 2016-2017. The treatments consisted of different levels of irrigation (I1, I2, I3 and I4, respectively 125, 100, 75 and 50% of plant water requirement and I5 including rain fed with one supplementary irrigation) and two levels of irrigation water salinity (non-saline (S1=1.4 dS.m-1) and Saline (S2= 5.4 dS.m-1) water, respectively). The studied traits included plant height, leaf area, spike length, 1000-seed weight, plant fresh weight, plant dry weight, number of seeds per spike, spike length, biological yield, grain yield, and harvest index.

The results of analysis of variance showed that the significant effect of different levels of irrigation at 0.1% level on all traits including plant height, leaf area, 1000-seed weight, fresh weight of plant, plant dry weight, spike length, number of seeds per spike , biological yield, economic performance and harvest index are (Table 3). In agreement with results of this study Wajid et al., (2002) reported that improvement of wheat yield with increasing irrigation levels. Plant height, 1000-seed weight, grain yield, and harvest index of wheat (Varamin cultivar) were significantly affected by irrigation levels (Eidizadeh et al., 2016). Soleimani (2016) also reported that the yield and yield components of wheat (in the climate of Isfahan) were strongly influenced by different levels of irrigation. The effect of irrigation water salinity was significant at 1% on plant height, leaf area and 1000-seed weight, but its effect on fresh weight of plant, plant dry weight, spike length, number of seeds per spike, biological yield, economic yield, and harvest index was not significant (Table 3). Irrigation water salinity on yield and yield components of different wheat cultivars including Chamran, Sistan, Hajiabad, Parsi, Yavarus, Behrang, U. 520, S-83-3, D-81-18 showed a significant decrease depending on variety. Interaction between irrigation and salinity levels of irrigation water showed a non-significant effect on the leaf area, spike length, and grain yield. The results of this study revealed that the highest and lowest value for different traits was observed at 125% plant water requirement and rain fed with one supplementary, respectively where the loss percent for plant height, leaf area, spike length, 1000-seed weight, plant fresh weight, plant dry weight, spike length, number of seeds per spike, biological yield, economic yield, and harvest index were 37%, 63%, 64%, 66%, 14%, 42%, 62%, 61%, 89%, and 75%, respectively. The results of Yousfi et al., (2010) showed that salinity of irrigation water at levels of 1.8, 12 and 17 dS.m-1 and irrigation at two levels of 100 and 35% of water field capacity by soil on biomass traits plant production, plant height, biomass, leaf chlorophyll and nutrient elements including nitrogen, potassium, calcium, magnesium and phosphorus had a significant effect at 1% level. Correlation results revealed that the highest correlation between grain yield and biological yield.

In general, the results of this experiment showed that reduction of irrigation levels (percent plant requirement) leads to reduction of growth and yield characteristics of wheat. Irrigation water salinity was significant decrease at 5.4 dS.m-1 level on plant height, leaf area and 1000-seed weight. Interaction between irrigation and salinity levels of irrigation water showed a non-significant effect on the leaf area, spike length, and grain yield. The results of this study revealed that the highest and lowest value for different traits was observed at 125% plant water requirement and rain fed with one supplementary, respectively. According to high soil salinity (Table 2), observation of the highest amount of biological yield and grain yield in 125% water requirement is acceptable due to prepare the full or partial water need for salt leaching.

Salinity stress negatively impacts agricultural yield throughout the world affecting production whether it is for subsistence or economic gain. The plant response to salinity consists of numerous processes that must function in coordination to alleviate both cellular hyperosmolarity and ion disequilibrium. In addition, crop plants must be capable of satisfactory biomass production in a saline environment (yield stability).Soil salinity is a major constraint to food production because it limits crop yield and restricts use of land previously uncultivated. The United Nation Environment Program estimates that approximately 20% of agricultural land and 50% of cropland in the world is salt-stressed Natural boundaries imposed by soil salinity also limit the caloric and the nutritional potential of agricultural production. These constraints are most acute in areas of the world where food distribution is problematic because of insufficient infrastructure or political instability. Water and soil management practices have facilitated agricultural production on soils marginalized by salinity, but additional gain by these approaches seems problematic. Salinity is one of the most brutal environmental factors limiting the productivity of crop plants because most of the crop plants are sensitive to salinity caused by high concentrations of salts in the soil, and the area of land affected by it is increasing day by day. For all important crops, average yields are only a fraction – somewhere between 20% and 50% of record yields; these losses are mostly due to drought and high soil salinity, environmental conditions which will worsen in many regions because of global climate change. A wide range of adaptations and mitigation strategies are required to cope with such impacts. Efficient resource management and crop/livestock improvement for evolving better breeds can help to overcome salinity stress. However, such strategies being long drawn and cost intensive, there is a need to develop simple and low cost biological methods for salinity stress management, which can be used on short term basis. Microorganisms could play a significant role in this respect, if we exploit their unique properties such as tolerance to saline conditions, genetic diversity, synthesis of compatible solutes, production of plant growth promoting hormones, bio-control potential, and their interaction with crop plants.

Salinity is a major abiotic stress limiting growth and productivity of plants. Hence, the aim of this study was to investigate the effect of the plant growth promoting bacteria (isolated from alfalfa plant nodules) on reducing the effects of salinity stress in the alfalfa plant. For this purpose, 63 bacterial isolates were isolated from the nodules of 13 samples of alfalfa plants grown in the agricultural fields of Qom province. These bacterial isolates were characterized in terms of the resistance to salinity and some the plant growth promoting traits. Finally, three superior isolates including two non-rhizobial isolates A36 and A37 and one rhizobial isolate ARh29 were selected for greenhouse testing. Based on the 16S rRNA gene sequences, the isolates A36, A37, and ARh29 were closely related to Klebsiella sp., Kosakonia cowanii and Sinorhizobium meliloti, respectively. Greenhouse experiment was conducted in a completely randomized design with factorial arrangement in three replications. Salinity levels and bacterial levels included 0, 50, 100, 150, and 200 mM sodium chloride (NaCl), the isolates A36 + A37, ARh29, A36 + A37 + ARh29, negative controls (plants non-inoculated with bacterial isolates and fertilized with N-free Hoagland's solution), and positive control (plants non-inoculated with bacterial isolates and fertilized with N- containing Hoagland's solution plants), respectively.

The results showed that bacterial strains could increase plant dry weight and proline content in all salinity levels compared to non-inoculated plants. In addition, bacterial strains increased the uptake of potassium ions and decreased the absorption of sodium ions in alfalfa plants under salinity stress. At salinity level of 200 mM NaCl, plant dry weight and proline content in the plants inoculated with every three bacterial isolates were respectively 29 and 35% more than those in the positive control plants and the ratio of potassium to sodium was 36% higher than this control. In general, the results of this study showed that alfalfa plant root nodules harbor salinity tolerant-and plant growth promoting non-rhizobial bacteria and that their use along with rhizobial bacteria can improve alfalfa plant growth under salinity stress.

Salinity stress is one of the limiting factors in crop production especially in agricultural lands of arid and semi-arid regions. Under salinity stress, the availability of nutrients is reduced due to poor soil conditions. In contrast, the use of these elements by foliar spray is an appropriate method to increase the efficiency of nutrients absorption. Application of some elements by foliar spray reduces the negative effects of salinity. According to the reports regarding the positive effects of nitrogen, calcium and potassium as inducers of salt tolerance, this study was designed to investigate the response of cumin plant in hydroponic conditions to salinity stress and foliar spray of the above mentioned elements.

This research was conducted in 1395 in a research greenhouse in Fasa, Iran. A factorial experiment was conducted in a completely randomized design with three replications. The first factor was salinity stress in three levels including control (semi Hoagland solution), semi Hoagland solution + 75 mM sodium chloride and semi Hoagland solution + 150 mM sodium chloride. The second factor was foliar spray treatments consisted of control (distilled water), calcium nitrate, potassium nitrate, ammonium nitrate and calcium nitrate + potassium nitrate which were prepared with concentrations of 5/857, 7.214 and 2.857 kg per 1000 liters of water, respectively. These concentrations were selected in such a way that the nitrogen concentration used in all of them was equal. Salinity treatments were applied to Hoagland solution. Spraying of the desired compounds was carried out every two weeks until the end of the flowering stage.

The results showed that increasing in salinity stress reduced plant dry weight and leaves chlorophyll content in cumin. Foliar spray of calcium nitrate + potassium nitrate and calcium nitrate alone could somehow prevent the adverse effects of salinity on cumin. Compared to control, salinity level of 75 mM did not reduce the leaf relative water content in cumin. But increasing the salt stress to 150 mM reduced the relative water content of the leaves. While increase in salinity stress increased ion leakage, compared to control foliar spray of calcium nitrate, potassium nitrate, ammonium nitrate and calcium nitrate + potassium nitrate could reduce ion leakage in cumin. At salinity level of 75 mM sodium chloride, foliar spray of calcium, potassium and ammonium and at 150 mM sodium chloride, calcium spray could somewhat neutralize the adverse effects of salinity stress on chlorophyll a. The results showed that salt stress increased the sodium content of the cumin shoot. In fact, salinity stress disturbs the cationic balance of cumin and prevents the absorption nutrient elements and provides the possibility of more sodium absorption by cumin. In all salinity treatments, compared to control, foliar spray of the utilized compounds increased the number of umbel per plant. Calcium and potassium sprays with a competitive effect reduced the sodium absorption and to some extent could play a role in improving the yield components of cumin.

Overall, the results of this study showed that increase in salt stress caused disturbance in leaf relative water content, ion leakage and chlorophyll content of cumin. However, foliar spray of calcium nitrate and potassium nitrate increased leaf relative water content and reduced ion leakage in cumin. Also, increase in salt stress caused a disturbance in cationic balance and prevented other cations such as calcium, potassium and magnesium to be absorbed while allowed cumin to absorb more sodium. Finally, the use of various spray combinations could improve the number of umbrellas per plant, the number of seeds per umbrella and the weight of 1,000 seeds of cumin in 75 mM salt stress conditions.

salinity stress is one of the most important abiotic stresses limiting plant cultivation. Evaluation of germination characteristics under salinity stress conditions is one of the fastest methods for selecting resistant plants to this stress.

Ocimum basilicum L. (Basil), Thymus daenensis Celak. (Denaee thyme), Hyssopus officinalis L (Hyssop). And Dracocephalum moldavica L. (Moldavian balm) seeds were subjected under six salinity treatments (0, 3, 7, 10, 15 and 20 ds/m) in growth chamber with daily mean temperature 25 °C, night mean temperature 18 °C, day length 14 hours and night length 10 hours. After germination (emergance of 2mm root),were evaluated germination characteristics such as seedling fresh weight, fresh weight of radicle and shoot, ratio of shoot/ radicle weight, seedling length, length of radicle and shoot, ratio of shoot/ radicle weight, germination percentage, seed vigor index, germination rate, mean of germination time and tolerance index. Experiment was conducted as factorial based on completely randomized design with three replicates at research center of medicinal plants breeding and development, university of Kurdistan in 2018.

seeds of these plants were unable to germinate at salinity level of 10 ds/m or more. Mean of germination time, seedling weight and shoot weight in all of plants were significantly affected by salinity, but in other characteristics, effect of salinity was different depend on plant species. Germination rate decreased in all plants with increasing level of salinity. Basil and Moldavian balm seeds required the lowest and the highest time for germination, respectively. Seed vigor index similar to germination rate decreased with increasing level of salinity. The highest of seedling weight, shoot weight and radicle weight in all studied plants was observed in salinity level of 3 ds/m. It seems that increasing in weight at low level of salinity can be due to existence and efficacy of Na and Cl ions on membrane penetrability and also enzyme activity relevant to germination that finally will be led to increase in growth rate and seedling weight, but in continue with increasing salinity level and further decreasing of osmotic potential, division, turgescence and cell volume decrease and eventually weight loss in the seedling will be seen. Seedling weight of Basil, Hyssop and Moldavian balm decreased with increasing level of salinity, but seedling weight in Denaee thyme increased at first and then decreased with increasing in salinity level from salinity level of 3 to 7 ds/m. Seeds germination percentage of Denaee thyme, Moldavian balm and Hyssop decreased significantly with increasing level of salinity and in all of three mentioned plants, germination stopped in salinity level of 10 ds/m. But in Basil against to other plants, germination percentage increased with increasing level of salinity up to salinity level of 7 ds/m and then germination reach to zero with increasing in salinity level from 7 to 10 ds/m. The highest tolerance to salinity level of 3 ds/m was observed in Basil, Moldavian balm, Hyssop and Denaee thyme seedling respectively and the highest tolerance in salinity level of 7 ds/m was observed in Basil, Moldavian balm, Denaee thyme and Hyssop seedling, respectively. Whereas with increasing in salinity level, osmotic potential of water will be decreased, therefore water absorption by seed will be decreased and subsequently rate of metabolic activates in seed such as carbohydrates hydrolysis and breaking will be decreased and therefore germination characteristics such as percentage and rate of germination and also length of root and length of shoot will be reduced.

Generally, based on results of this research, it has been suggested that salinity had not unfavorable effects on germination until special level and even same to basil can be improved germination characteristics. But, if salinity be upper than tolerance threshold of plant, can lead to undesirable effects on germination characteristics. Tolerance threshold to salinity stress is varying in different plants and as the results showed, the highest and the lowest of tolerance threshold was related to basil and Hyssop, respectively.

Short periods of heat stress in spring under Mediterranean climate (e.g. southern vast areas of Iran) are common and cereal crops often exposed to short periods of elevated temperatures which can have large effects on crop yields. Stem water-soluble carbohydrate (WSC) could be an important carbon bank for supporting grain filling in wheat especially when carbon assimilation is hampered by heat stress. In Iran, a large number of studies have been done on the effects of heat stress on grain yield of wheat and its components, based mainly on the change in planting date, and data from the effect of short-term heat wave on yield and grain growth and the role of WSC in developing grains do not exist under field conditions. The aim of this study was to determine the effects of short-term heat stress before flowering and the beginning of grain filling on peduncle WSC and grain filling pattern as well as determination of the contribution of peduncle WSC in genotypes with different amounts of carbohydrates in grain growth under short-term stress conditions.

This research was carried out at Research Farm of Khuzestan Agricultural Sciences and Natural Resources University, located 35 km northeast of Ahwaz, in 2014. Four wheat genotypes (Chamran. Maroon, Arvand and Atrak) were exposed to heat stress (maximum 35 °C) for a three-day in the field with a portable heat chamber at two different stages, near flowering (H1) and early grain set (H2). to investigate the changes in individual grain weight (IGW) during grain development, the total WSC changes in the peduncle of the main stem after exposure to short-term heat stress during the development of grain, three plants marked from day zero after flowering. The grains were harvested at intervals of seven days until the time of maturity. The total WSC were measured by anthrone method. When the dry weight of peduncles was maximized in each genotype, the concentration of peduncle carbohydrates (WSC-C) was considered as the maximum WSC-C. To calculate the maximum peduncle WSC content, the maximum WSC-C was multiplied by the maximum peduncle weight. The difference between peduncle WSC-C at maximum time and at maturity time was considered as the mobilized WSC from peduncle to grain. The ratio (%) of peduncle mobilized WSC to maximum peduncle WSC-C was calculated as the efficiency of peduncle in mobilized WSC. The analysis of variance of the measured traits in this study was performed using SAS 9.4 software. Duncan's test was done for means comparison.

The results of analysis of variance showed that there were significant differences between heat stress levels and the traits of genotypes. Short term heat stress (H1 or H2) caused a significant reduction in individual grain weight (IGW) and grain number of main spike. There was no detectable change in IGW until 14 days post-anthesis, after which time grain growth in the heat-stressed plants was reduced from 4.5% to 17%. Based on number of grain per spike and IGW, Atrak, Chamran and Arvand genotypes were recognized as tolerant gynotypes. Heat stress (average of H1 and H2) reduced maximum peduncle water soluble carbohydrate (WSC) content by 26% and mobilized WSC by 15%. The reduction of peduncle WSC content by the heat stress treatments appeared to start at 21 days post-anthesis Reductions in IGW and among genotypes were negatively correlated to the maximum peduncle WSC content.

Wheat (Triticum aestivum L.) is one of the most important sources of plant food for human among the main crops globally. High temperature resulting from delay in planting is one major environmental factor limiting growth and production of wheat, especially in tropical regions. Terminal heat stress during the last phases of wheat development especially in booting, heading, anthesis and grain filling stages of the spring wheat cultivars is considered as one of the major environmental constraints that drastically reduces grain yield and yield components of wheat in Khuzestan province and other warm and dry regions of Iran. Most of the Iranian soils have a high pH and calcareous nature, so absorption of nutrients is limited in these soils. Mineral nutrition of plants plays a critical role in increasing plant resistance to environmental stresses. Zinc is a ubiquitous micronutrient. It is required as a structural and functional component of many enzymes and proteins, and increases the yield and yield components of wheat. Boron is essential for pollen viability, flowering, fruiting and seed production. As a micronutrient, it plays a vital role in nitrogen metabolism, hormonal action, and cell division.

To evaluate the remobilization of photosynthetic materials and their contribution in the formation of grain yield of two bread wheat cultivars affected by terminal heat stress and zinc and boron foliar application, an experiment was conducted as split-split plot based on randomized complete blocks design with 3 replications in Ramhormoz city. The experimental factors were included planting date in two levels optimum (November 21) and late (January 5) to coincide growth terminal stages with high temperatures as the main factor, foliar application in four levels with water (control), zinc, boron and zinc + boron as the sub factor and two cultivars of bread wheat Pishtaz and Chamran 2 as the sub-sub factor.

The results showed that terminal heat stress caused by delay in planting increased significantly traits of stored photosynthetic materials remobilization from stem and spike to seed and relative contribution of stem and spike reserves in grain yield, but decreased significantly traits of current photosynthesis and its relative contribution in yield, and grain yield of two bread wheat cultivars of Pishtaz and Chamran. Zinc and boron foliar application reduced significantly all of the above traits in both optimum and late planting dates except for the traits of current photosynthesis and its relative contribution in yield, and grain yield. Among the wheat cultivars cultivated, Chamran 2 cultivar had a significant advantage in traits of current photosynthesis and current photosynthesis relative contribution in yield and grain yield compared to Pishtaz cultivar, but in other traits this superiority was evident in Pishtaz cultivar.

In general, it can be attributed the main factor increasing grain yield of two bread wheat cultivars of Pishtaz and Chamran to improve current photosynthesis. As well as, it can be used from timely planting date, zinc and boron foliar application and suitable wheat cultivar such as Chamran 2 as three management strategies to reduce the harmful effects of terminal heat stress caused by late planting date in Ramhormoz city.

Wheat (Triticum aestivum L.) is considered as the major cereal crop in the world in respect of the cultivated area and total production. High temperature resulting from delay in planting is one major environmental factor limiting growth and production of wheat, especially in tropical regions. Most of the Iranian soils, have a high pH and calcareous nature, and micronutrients solubility in these soils is low. Micronutrients plays a critical role in increasing plant resistance to environmental stresses. Iron as a micronutrient, is critical for chlorophyll formation and photosynthesis and is important in the enzyme systems and respiration of plants. Zinc is a ubiquitous micronutrient. It is required as a structural and functional component of many enzymes and proteins, and increases the yield and yield components of wheat. Manganese as a micronutrient, is necessary in photosynthesis, nitrogen metabolism and to form other compounds required for plant metabolism.

To study the effect of iron, zinc and manganese foliar application on the physiological, agronomic traits and protein of wheat under late season heat stress, an experiment was conducted as split-plot based on randomized complete blocks design with four replications in Ramhormoz city located in south-western Iran. The experimental factors were included planting date in two levels (5 November and 20 December) as the main factor and micronutrients foliar application in six levels of non-foliar application (control), foliar application by water, iron, zinc, manganese and iron+zinc+manganese (each 3 lit.h-1) as the sub factor. Solutions for foliar application were prepared by using Iron chelate (6%), Zinc chelate (7.5%) and Manganese chelate (7%). The measured traits included leaf chlorophyll index, leaf proline content, cell membrane stability index, grain yield, biological yield, harvest index and grain protein content. To determine the leaf chlorophyll index used of chlorophyll meter digital. To determine the leaf proline content, method of Bates et al. (1973) was used. To determine the cell membrane stability index used of method Lutts et al. (1996). The grain yield was determined at maturity stage and through the harvest of all spikes from the level of 1 m-2 per plot and after removing 0.5 m from the beginning and end respective planting rows (rows 5 and 6). To measure the biological yield at maturity stage, after removing 0.5 m from the beginning and end respective planting rows (rows 5 and 6) from the level of 1 m-2 per plot all the plants were harvested and weighted for each plot separately. The harvest index was determined by the equation GY / BY × 100. The grain protein content was calculated as N% × 5.7 on a dry weight basis. N% in grain was determined by the Kjeldahl method according to A.A.C.C. (2000). Analysis of variance was performed using general linear model (GLM) procedure of statistical analysis system (SAS version: 9.3). The means were analyzed using the least significant difference (LSD) method at P=0.05 (LSD 0.05).

Results showed that the delay in planting due to terminal heat stress decreased significantly traits of leaf chlorophyll index, cell membrane stability index, grain yield, biological yield and harvest index except for leaf proline content and grain protein. However, iron, zinc and manganese foliar application could increase significantly the measured traits in optimum and late planting date. Meanwhile, application of zinc spray showed the greatest effect in reducing the damage caused by terminal heat stress on measured traits.

In general, planting on 5 November and the use of micronutrients, especially zinc, as foliar application, can reduce the harmful effects caused by terminal heat stress and improve the physiological, agronomic traits and grain protein content of bread wheat in the region.

Basil (Ocimum basilicum), a member of Lamiaceae family, is used in traditional Iranian medicine. Essential oils of basil leaves are composed of phenylpropanoids which are important in treatment of headaches, diarrhea, coughs, warts, worms and kidney malfunctions. The most important phenylpropanoid compounds contain eugenol, chavicol, methyl eugenol, methyl chavicol, myristicin, methyl cinnamat and elemicin. Heavy metals pollution is a major problem of crops and medicinal plants production inthe large parts of the world which has a negative impact on all aspects of plant growth and production. Heavy metal toxicity is one of the major current environmental health problems and potential dangerous due to bioaccumulation through the food chain and in plant products for human consumption. Arsenic is a heavy metal with high toxicity that absorbed by plants mainly through the root system and in minor amounts through the leaves. After entering the cells, lead inhibits activities of many enzymes, and affects membrane structure and permeability. Today, phenolic compounds and plant growth regulator has been proposed, to reduce the negative effects of stress. Salicylic acid is a substance that causes plant resistance to biotic and abiotic stresses. Salicylic aside inhibit the production of reactive oxygen species and protect plants against ROS damages. This study was to evaluate the effect of Salicylic aside spray on some morphological characteristics, photosynthetic pigments activities of antioxidant enzymes basil was conducted under arsenic stress.

This study was conducted at the Faculty of Agriculture, University of Zabol a factorial in a completely randomized design with three replications. The experimental treatments was included arsenic stress 0 (control), 10, 45 and 80 mg per kg of soil and application of salicylic acid at 3 levels of 0, 1 and 2 mM. T. Physiological traits (Chlorophyll a, b and T. chlorophyll, Carbohydrate, Carotenoid), morphological characteristics (fresh and dry weight, leaf area) and activities of antioxidant enzymes (Peroxidase and Catalase) were estimated in this experiment. The statistical analyses were carried out using the SAS version 9. The treatment means separated using Duncan's multiple-range test (DMRT) taking P < 0.05 as significant.

Based on the results, increasing of stress severity reduced some traits, So that addition of 80 mg per kg of soil arsenic significantly reduced amount of fresh and dry weight, leaf area , chloroohyll a, b and total, carotenoid and increased concentrations of carbohydrate and anti-oxidant enzyme (catalase and peroxidase ). Also, the results of simple effects of foliar application levels showed that by increasing the concentration of foliar application, the traits were increased, so that The highest fresh and dry weight, leaf area , chloroohyll a, b and total, carotenoid and carbohydrate was obtained in plants spraying with 2 mM SA, But reduced the activity of the antioxidant compounds. on the other hand, In this study the interaction between salicylic acid and arsenic on chloroohyll a, b, total and anti-oxidant enzyme catalase and peroxidase were significant, so that the highest of amount of chloroohyll a, b and total, were obtained in plants subtended in sprayed with 2 mM SA and without stress, But the highest the activity of the antioxidant enzyme catalase and peroxidase were obtained in plants Under in stress 80 mg per kg of soil arsenic and without sprayed.

Our observations indicated that ascorbic acid spraying at lower concentration might be favorable to improve growth and defense ability against arsenic toxicity in basil though field testing would be required to verify this and Based on the findings of this study, as well as supplemental studies, salicylic acid spraying can be proposed to improve the growth and reduce the arsenic toxicity of Basil plant under arsenic stress.

Salinity stress is known as a worldwide plant growth limiting factors (Alavimatin et al., 2015: Atlasipak 2018). In addition, it is estimated that around 50 percent of arable lands are affected by salinity stress by 2050 (Butcher et al., 2016: Qadir et al., 2014). The use of chemical fertilizers is a common practice in arid soils for improving plant performance grown under non-fertile soils. While there is little evidence of yield benefits due to application of fertilizers in salt affected soils at rates beyond optimal in non-saline conditions, there is enough evidence indicating that soil salinity does not affect or decrease plant fertilizer requirements (Hanson, 2006). Accordingly, the objectives of this field study were to (a) evaluate the interactions between phosphorous nutrition and the salinity of irrigation water and their effects on wheat growth and (b) test the possibility of wheat improvement at saline conditions by applying higher levels of phosphorous fertilizer.

A field experiment was conducted on wheat at Sadooq Salinity Research Station, Ashkezar, Yazd, Iran. The soil at the experimental site was calcareous with 30.92% total nutrient value, sandy loam texture, pH 8.06 and 0.22 % organic carbon. Mean annual temperatue is 18°C and precipitation is 70 mm. The treatments, four triple superphosphate application rates (0, 100, 200 and 300 kg ha-1) and three irrigation water qualities (1.88, 7.22 , 14.16 dS/m), arranged in a randomized block with three replications. Consisting 12 rows of wheat, each field plot was 3*5 m. All plots received common agricultural practices including tillage and fertilizer application. Rgarding typical recommendations and guidelines for this region and soil type (Balali et al., 2000: Moshiri et al., 2015), all fertilizers, except urea that applied in 4 splits, were soil-applied before planting and included 40 kg ha-1 ZnSO4, 40 kg ha-1 MnSO4 and 20 kg ha-1 CuSO4. To model the relationship between plant properties and irrigation water salinity, the data were subjected to different regression models at the probability level of 0.01 and 0.05 with the help of the Sigmaplot software. The analysis of variance for different parameters was done following ANOVA technique. When F was significant at p ≤ 0.05 level, treatment means were separated using LSD.

The results showed that increasing irrigation water salinity to 7.22 dS/m did not significantly affect wheat grain yield. This is due to the positive effect of salinity on 1000 seed weight and harvesting index. At the same time, the results showed 50% decrease in wheat grain and straw yield due to the increase in the salinity of irrigation water from 1.88 to 14.16 dS/m. The heighest graine yield for treatments irrigated with irrigation water salinity of 1.88, 7.22 and 14.16 dS/m was obtained from application of 40, 20 and 0 kgha-1 FeSO4, respectively.

Overall, it was concluded that application of triple superphosphate at a rate of 150 kgha-1 is recommended for wheat yield improvement at irrigation water salinity of 1.88 and 7.22 dS/m. As wheat performance irrigated with irrigation water salinity of 16.14 ds/m was not affected by different rates of phosphorous fertilizer, it can be concluded that wheat phosphorous requirement decreased at irrigation water salinity beyond salt tolerance.