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IntroductionWater limitation is one of the most important abiotic factors that can limit plant growth and yield due to production of reactive oxygen species (ROS) like H2O2 and the reduction of chlorophyll content. To protect against oxidative stress, plant cells produce both antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX), and non-enzymatic antioxidants such as low weight molecules like proline, sugars and ascorbate. Also water limitation disturbs the mineral-nutrient relations in plants through their effects on nutrient availability and numerous of physiological and biochemical destruction in the vegetative and reproductive periods of plant development. Several strategies have been suggested in order to improve yield under abiotic and biotic stresses in plants, among them application of Plant Growth Promoting Rhizobacteria (PGPR) and nano particles such as nano iron-silicon oxide play a key role in yield improvement. A better understanding of physiological responses under water limitation may help in programs which the objective is to improve the drouht resistance of crop. During the course of these stresses, active solute accumulation of compatible solutes such as proline and the activities CAT, POD and PPO enzymes are claimed to be an effective stress tolerance mechanism. Therefore, the aim of this study was to evaluate the effects of bio-fertilizers and nano iron oxide and nano oxide on some physiological and biochemical (i.e., antioxidant enzyme activity, chlorophyll, protein, soluble sugars and proline) responses of triticale under water limitation conditions.Materials and methodsAn experiment was conducted as factorial based on randomized complete block design with three replicates at the research farm of faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili in 2021. The experimental factors were included of irrigation in three levels (full irrigation as control, irrigation withholding at 50% of booting and heading stages as severe and moderate water limitation respectively (BBCH 43 and 55 respectively), application of bio fertilizers in four levels (no application as control, application of Azospirilum, Pseudomonas, both application Azospirilum and Pseudomonas) and nanoparticles foliar application at four levels (foliar application with water as control, nano iron oxide foliar application (1 g.L-1), nano silicon oxide (50 mg.L-1), both application nano iron-silicon oxide). Psedomunas and Azospirilum were isolated from the rhizospheres of wheat by Research Institute of Soil and Water, Tehran, Iran. For inoculation seeds were coated with gum Arabic as an adhesive and rolled into the suspension of bacteria until uniformly coated. The strains and cell densities of microorganisms used as PGPR in this experiment were 1×108 colony forming units (CFU). In each plot there were 5 rows with 2 m long. In each experimental plot, two marginal rows and 0.5 m from beginning and ending of planting lines were removed data were measured from the middle lines. The used nano silicon-iron oxide had the average particle size less than 30 nm and special surface of particles was more than 30 m2.g-1. They were product of Nanomaterial US Research which was provided by Pishgaman Nanomaterials Company of Iran. Nano iron oxide and nano silicon powder added to deionized water and was placed on ultra sonic equipment (100 W and 40 kHz) on a shaker for better solution. Foliar application of nano silicon oxide and putrecine were done in two stages of period growth BBCH 21 and 30.Results and discussionThe results showed that total chlorophyll content (48.16%), quantum yield (36.05%), relative water content (35.83%) and grain yield (43.28%) increased in dual application of bio fertilizers and nano particles foliar application under full irrigation conditions compared to no application of bio fertilizers and nano particles under irrigation cut off at booting stage. But under such conditions, electrical conductivity, hydrogen peroxide and malondialdehyde content decreased 35.67, 53.16 and 56.32% respectively compared to no application of PGPR and nanoparticles under irrigation withholding in booting stage. Also, the application of PGPR and nanoparticles under irrigation cut off in booting stage increased the activity of catalase, peroxidase and polyphenol oxidase enzymes (47.06, 55.69 and 36.53% respectively), proline and soluble sugars content (45.41 and 46.93% respectively) compared to no application of PGPR and nanoparticles under full irrigation conditions.ConclusionBased on the results of this study, the application of plant growth promoting rhizobacteria and nonoparticle can increase grain yield of triticale under water limitation conditions due to improving biochemical and physiological traits.

IntroductionWater limitation is one of the most important environmental factors in reducing the growth and yield of wheat due to producing reactive oxygen species and reducing membrane stability (El-Tayeb, 2006). Several strategies have been suggested in order to improve grain yield of wheat under water limitation condition, among them use of bio fertilizers and putrescine play a key role in yield improvement. PGPR and Mycorrhiza fungi have the potential to modulate and regulate the physiological and biochemical responses of plants against drought stress, and for this reason, they increase plant survival under environmental conditions (Marasco et al., 2012). Polyamines are another compound that play a significant protective role in plants when environmental stress occurs (Hadi et al., 2016). Foliar of putrescine is able to improve the resistance of plants in oxidative stress and by increasing the activity of antioxidant enzymes, it increases the resistance of plants against oxidative stress (Groppa et al., 2001). A better understanding of physiological responses under water limitation condition may help in programs which the objective is to improve yield of wheat. During the course of these stresses, active solute accumulation of compatible solutes such as proline and the activities CAT, POD and PPO enzymes are claimed to be an effective stress tolerance mechanism. Therefore, the aim of this study was to evaluate the effects of bio fertilizers and putrescine on some the physiological and biochemical responses (i.e., antioxidant enzyme activity, soluble sugars, proline, malondialdehyde (MDA) and hydrogen peroxide (H2O2) content) of wheat under water limitation.Materials and methodsA factorial experiment was conducted based on randomized complete block design with three replications at the research farm, faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili during 2018-2019. Factors experiment were included irrigation at three levels (full irrigation as control, irrigation withholding in 50% of heading stage and irrigation withholding in 50% booting stage as moderate and severe water limitation respectively) and bio fertilizers at four levels [no bio fertilizer, both application of Psedomunas Putida Strain 186 and Flavobacterim Spp, both application of Mycorrhiza with Psedomunas and Flavobacterim, application of Mycorrhiza], and putrescine foliar application in three levels (foliar application with water as control and foliar application 0.5 and 1 mM of putrescine). Psedomunas putida strain 186 and Flavobacterim spp were isolated from the rhizospheres of wheat by Research Institute of Soil and Water, Tehran, Iran. For inoculation seeds were coated with gum Arabic as an adhesive and rolled into the suspension of bacteria until uniformly coated. The strains and cell densities of microorganisms used as PGPR in this experiment were 1×107 colony forming units (CFU). Mycorrhiza fungi (Glomus intraradices) was purchased from the Zist Fanavar Turan institute. The activity of antioxidant enzymes (catalase, peroxidase and polyphenol oxidase) was measured by Sudhakar et al. (2001) method, soluble sugar content by Dubios et al. (1956) method, measurement of malondialdehyde (MDA) by Stewart and Bewley, (1980) and method of Alexieva et al, (2001) was used to measure the hydrogen peroxide. Proline content was measured by Bates et al. (1973) method. Analysis of variance and mean comparisons were performed using SAS9.1 computer software packages. The main effects and interactions were tested using the least significant difference (LSD) test at the 0.05 probability level.Results and discussionApplication of both Mycorrhiza with Pseudomonas and Flavobacterium and putrescine foliar application under severe water limitation conditions (irrigation withholding in booting) increased the activity of polyphenol oxidase, peroxidase and catalase enzymes. The highest activity of these enzymes were obtained in irrigation withholding in booting stage with application of both Mycorrhiza with Pseudomonas and Flavobacterium and foliar application of 1 mM putrescine and the lowest of values were obtained in full irrigation and no application of bio fertilizers and no putrescine foliar application. The highest rates of proline and soluble sugar were observed under irrigation withholding in heading with the both application of biofertilizers and putrescine and the lowest of them were observed in full irrigation, no application of biofertilizers and no foliar putrescine. Water limitation increased electrical conductivity (EC), malondialdehyde (MDA) and hydrogen peroxide (H2O2) content, while application of bio fertilizers and putrescine under water limitation conditions decreased electrical conductivity, malondialdehyde and hydrogen peroxide content. Application of Mycorrhiza with Pseudomonas and Flavobacterium and foliar of 1 mM putrescine under severe water limitation decreased malondialdehyde and hydrogen peroxide content about 51 and 31.72% respectively compared to no application biofertilizers and putrescine under same water limitation level. In general, water limitation (irrigation withholding in booting and heading) decreased grain yield compared to full irrigation. application Pseudomonas and Flavobacterium (23.1%) and both application of Mycorrhiza with Pseudomonas and Flavobacterium (16.6%) increased grain yield in comparison with no application of biofertilizers under conditions of irrigation withholding in booting. Foliar application 1 mM of putrescine increased grain yield about 8.5% in comparison with no application putrescine.ConclusionIt seems that application of bio fertilizers and putrescine can increase grain yield of wheat under water limitation conditions due to improving physiological and biochemical trait.

IntroductionDrought is assumed as one of the most severe abiotic stress factors limiting plant growth and crop production. Drought stress hurts plant growth and productivity which can affect biochemical and physiological responses such as changes in contribution of stem assimilates to grain, current photosynthesis, yield and yield components. Using rhizosphere microorganisms (such as beneficial bacteria and mycorrhiza) (Dimkpa et al. 2009) and application of silicon are an alternative strategy that can improve plant performance under stress environments and, consequently, enhance plant growth through different mechanisms. Thererfore, it seems that application of nano silicon and bio-fertilizers can improve wheat yield under water limitation conditions.Materials and methodsIn order to study the effect of bio-fertilizers and foliar application of nano-silicon on the contribution of dry matter remobilization and current photosynthesis in grain yield of wheat under irrigation withholding conditions, a factorial experiment was carried out with three replications at the research farm faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili during 2018-2019. The area is 38° 15′ N latitude, 48° 15′ E longitude, and 1350 m above mean sea level. Climatically, the area is situated in the semi-arid temperate zone with a cold winter and moderate summer. Factors were included irrigation in three levels (full irrigation as control; moderate water limitation or withholding irrigation at 50% of the heading stage; severe water limitation or withholding irrigation at 50% of the booting stage) based on codes 55 and 43 of the BBCH scale; foliar application of nano silicon (foliar application with water as control, 30 and 60 mg.l-1) and bio-fertilizer (no application as control, mycorrhiza application, both application of flavobacterium and pseudomonas, both application of flavobacterium and pseudomonas with mycorrhiza). Mycorrhiza fungi (mosseae) was purchased from the Zist Fanavar Turan Corporation and soils were treated based on method of Gianinazzi et al. (2001). Psedomunas and flovobacterium were isolated from the rhizospheres of wheat by Research Institute of Soil and Water, Tehran, Iran. For inoculation, seeds were coated with gum Arabic as an adhesive and rolled into the suspension of bacteria until uniformly coated. The strains and cell densities of microorganisms used as PGPR in this experiment were 1×108 colony forming units (CFU). In this study, morphological traits, leaf area index, total biomass, dry matter remobilization from shoot and stem, contribution of stem assimilates to grain, contribution current photosynthesis in grain, yield and grain yield components of wheat were investigated. Analysis of variance and mean comparisons were performed using SAS version 9.1 computer software packages. The main effects and interactions were tested using the least significant difference (LSD) test at the 0.05 probability level.Results and discussionThe results showed that both application of mycorrhiza with flavobacterium and pseudomonas under full irrigation conditions decreased the contribution of dry matter remobilization from shoot (27.33%) and stem (17.70%) in grain yield, but increased the current photosynthesis (305.10 g.m-2) and Contribution Current photosynthesis in grain (72.66%). Also, maximum of grain yield (4593 kg.ha-1) and harvest index (38.4%) were obtained with the application of both bio-fertilizers and foliar application of 30 mg.l-1 nano-silicon under normal irrigation. Maximum leaf area index, total biomass, and yield components were obtained with the combined application of bio-fertilizers and 60 mg.L-1 nano-silicon under full irrigation conditions.ConclusionBased on the results of this study, it seems that the application of bio-fertilizers and nano-silicon can be a suitable management factor to increase grain yield of wheat under water limitation.

IntroductionDrought is assumed as one of the most severe abiotic stress factors limiting plant growth and crop production. Since in arid and semi-arid regions, some part of growth period of wheat is confronted with water limitation condition which can affect biochemical and physiological responses such as changes in photosynthetic efficiency of PSII, chlorophyll content, and stomatal conductance. Application of bio fertilizers and silicon is one of the most important strategies for alleviation of drought stress effects. Bio fertilizers (plant growth promoting rhizobacteria or PGPR and mycorrhiza) can improve plant performance under non-stress and stress conditions. Thererfore, it seems that application of nano silicon and bio-fertilizer can improve wheat yield under water limitation conditions.Materials and methodsIn order to study the effects of biofertilizers and nanosilicon on phosphorus uptake, grain yield, and some physiological traits of wheat (Triticum aestivum L.) under withholding irrigation conditions, a factorial experiment was carried out at the research farm faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, with three replications during 2018-2019. The area is 38° 15′ N latitude, 48° 15′ E longitude, and 1350 m above mean sea level. Climatically, the area is situated in the semi-arid temperate zone with a cold winter and moderate summer. Factors were included irrigation in three levels (full irrigation as control; moderate water limitation or withholding irrigation at 50% of the heading stage; severe water limitation or withholding irrigation at 50% of the booting stage) based on codes 55 and 43 of the BBCH scale; foliar application of nano silicon (foliar application with water as control, 30 and 60 mg.L-1) and bio-fertilizer (no application as control, mycorrhiza application, both application of flavobacterium and pseudomonas, both application of flavobacterium and pseudomonas with mycorrhiza). Mycorrhiza fungi (mosseae) was purchased from the Zist Fanavar Turan Corporation and soils were treated based on method of Gianinazzi et al. (2001). Psedomunas and flovobacterium were isolated from the rhizospheres of wheat by Research Institute of Soil and Water, Tehran, Iran. For inoculation, seeds were coated with gum Arabic as an adhesive and rolled into the suspension of bacteria until uniformly coated. The strains and cell densities of microorganisms used as PGPR in this experiment were 1×108 colony forming units (CFU). In this study, electrical conductivity, stomatal conductance, leaf fluorescence parameters, phosphorus of root and grain, relative water content, electrolyte leakage, anthocyanins and grain yield of wheat were investigated. Analysis of variance and mean comparisons were performed using SAS ver 9.1 computer software packages. The main effects and interactions were tested using the least significant difference (LSD) test at the 0.05 probability level.Results and discussionThe results showed that application of both flavobacterium and pseudomonas with mycorrhiza and foliar application of 60 mg.L-1 nano silicon under severe water limitation increased 84.32%, 49% and 49.52% of electrolyte leakage, electrical conductivity and minimum fluorescence (F0) respectively, and decreased root and grain phosphorus by 30.67 and 36.05% compared to full irrigation. The highest RWC (92.26%), stomatal conductance (58.86 mmol.m-2.s), anthocyanin (0.0274 µmol.g-1FW), Fm (860), and Fv/Fm (0.909) were obtained at foliar application of 60 mg.L-1 nano silicon, both applications of flavobacterium and pseudomonas with mycorrhiza under normal irrigation. Also, the highest grain yield was obtained with both flavobacterium and pseudomonas with mycorrhiza and foliar application of 30 mg.l-1 nano silicon under normal irrigation. According to the results of this study both the application of biofertilizers and nanosilicon can improve wheat grain yield under water limitation conditions by improving the physiological traits and also the uptake of phosphorus from the soil.ConclusionGenerally, it seems that application of bio fertilizers and nano silicon can be recommended as the proper method for increasing the physiological trait grain yield of wheat under water limitation conditions.

IntroductionDrought stress is one of the most important abiotic factors that can limit plant growth and yield. The response of plants to water limitation has been evaluated based on genetic, biochemical and morpho-physiological traits. Several strategies have been developed in order to decrease the toxic effects caused by severe water limitation on plant growth. Among them the use of bio-fertilizers (such as mycorrhizae and vermicompost) and nano-silicon play a key role in yield improvement. The aim of this study was to investigate the effects of irrigation withholding in reproductive stages and nano-silicon and bio-fertilizers application on grain filling period, chlorophyll content and grain yield of triticale.Materials and methodsIn order to study the effect of vermicompost, mycorrhizae and nano-silicon on yield and chlorophyll content of triticale under water limitation conditions, an experiment was conducted as factorial based on randomized complete block design with three replications in greenhouse research of faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili in 2020. Experimental factors were included irrigation limitation at three levels (full irrigation as control, irrigation withholding in 50 percent of heading and booting stages as moderate and severe water limitation, respectively), bio-fertilizers application at four levels (no application of bio-fertilizers as control, application of vermicompost, mycorrhizae, and both application of vermicompost and mycorrhizae) and foliar application of nano-silicon (2 g.L-1 of nano-silicon and water-sprayed as control). Sanabad cultivar was used in the experiment with plant density of 400 seed m-2. Chlorophyll and carotenoids content were obtained according to Arnon (1949).To study the grain filling parameters in each sampling, two plants in each pot were taken. The first sampling was taken on day 8 after heading, and other samplings were taken in 4-days intervals to determine the accumulation of grain weight. At each sampling, grains were removed from spikes manually and were dried at 75°C for 48 h. A two-part linear model was used to quantifying the grain filling parameters. Total duration of grain filling was determined for each treatment combination by fitting a bilinear model:GW = [a + gfr(daa), ... ... if ... daa

IntroductionIn arid and semi-arid regions, drought stress as the main factor and salinity stress as a secondary factor reduces plant growth and yield. Water limitation can damage pigments and plastids, reduce chlorophyll a, b, rate and grain filling period. One of the important strategies for increasing carbon dioxide concentration in plants is using chemicals such as methanol that can increase the concentration of CO2 in a plant and improves photosynthesis rate and growth under water deficit conditions. Methanol is considered as quasi-essential for plant growth and development, and alleviates toxic effects caused by various environmental stresses in plants. The aim of this study was to investigate the effects of methanol on the agro –physiological traits (i.e., chlorophyll content and grain filling period) and yield of wheat under water limitation conditionMaterial and method A factorial experiment was conducted based on randomized complete block design with three replications at the research farm of Faculty of Agriculture and Natural Resources of University of Mohaghegh Ardabili, during 2015-2016. Factors experiment were included irrigation levels (full irrigation as control, irrigation withholding in 50% of booting and heading stages as severe and moderate water limitation respectively, according with 43 and 55 BBCH code) and methanol foliar application at four levels (foliar application with water as control and foliar application 10, 20 and 30% volume of methanol). Foliar application with methanol was done in two stage of period growth (Stem elongation and Flag leaf development).Results and discussionResults showed that the maximum contribution of dry matter remobilization from air parts (20.52%) and contribution of stem reserves in grain yield (16.42%) were obtained with irrigation withholding at booting stage and no foliar application. The maximum grain filling period and effective grain filling period (33.62 and 29.33 days respectively) were obtained in full irrigation and foliar application of 30% volume of methanol and its minimum was obtained at no foliar application under irrigation withholding in booting stage. Also, results showed that there were an increase about 46.98%, 194.17%, 37.54%, 69.82% and 15.96% in grain yield, leaf area index, chlorophyll index, current photosynthesis and contribution of current photosynthesis in grain yield respectively in full irrigation and foliar application of 30% volume of methanol in comparison with no foliar application of methanol under irrigation withholding in booting stage. Based on the results this study, foliar application of 30% volume of methanol can be applied as a proper method to increase grain yield under water limitation conditions.

Drought stress is a critical environmental stress that limits the productivity and sustainability of agriculture in arid and semi-arid regions by reducing the germination rate and delaying the start of germination and seedling establishment. There are various methods to increase the yield of agricultural plants, each of which somehow improves the yield of seeds in terms of germination indicators and seedling establishment. One of the most common methods to increase poor seed germination is priming before planting. To investigate the effects of priming on aspects of germination of aged pumpkin seeds under drought stress, a factorial experiment was conducted based on a completely randomized design with four replications in the laboratory. Treatments that include seed aging (control, 85% and 75% of control germination), drought stress (0, -0.75 and -1.5 MPa), and priming (control, hydro, gibberellin, GR24, benzyl aminopurine and spermidine). The results of a mean comparison between drought stress, seed ageing and priming showed that the lowest germination percentage (GP) of pumpkin (43.6%), protein (0.82 mg.g-1Fw), radical length (RL, 9.24 mm), plumule length (PL, 1.19 mm), relative water content (RWC, 35.5%), carotenoid (1.253 mg.g-1Fw), catalase (CAT, 7.03 µmol.gmin-1.mgprotein-1), peroxidase (POX, 47.72 µmol.gmin-1.mgprotein-1) and superoxide dismutase activity (SOD, 53.48 mmol.gmin-1.mgprotein-1) were associated with drought treatment at -1.5 MPa and with 75% aging in the absence of priming. In addition, the lowest content of malone dialdehyde (MDA, 3.75 mmol.g-1Fw) and proline (1.573 µg.g-1Fw) were obtained from the absence of drought and aging with priming using spermidine. The highest GP (98.03%) and protein (9.54 mg.g-1Fw) were obtained from gibberellin treatment, RL (15.73 mm) and PL (4.26 mm) in priming using GR24 hormone, RWC (83.64%), carotenoid (6.277 mg.g-1Fw), CAT (40.44 µmol.gmin-1.mg protein-1), POX (95.71 µmol.gmin-1.mgprotein-1) and SOD activity (131.68 µmol.gmin-1.mg protein-1) in priming with spermidine with non-drought stress and aging conditions. The highest MDA (32.42 mmol.g-1Fw) and proline (0.55 µg.g-1Fw) were observed in drought conditions with an intensity of -1.5 MPa and 75% aging in the absence of priming.

In order to study the effects of mycorrhizae and foliar application of nano Fe and Zn oxides on nodulation and quantitative and qualitative yield of lentil under rain fed conditions, a factorial experiment was conducted based on randomized complete block design with three replications in a farm at Zardalo village, Ardabil province during 2017-2018. Treatments included foliar application of nano Fe and Zn oxides at four levels (foliar application with water as control, foliar application of nano iron oxide (0.6 gL-1), nano zinc oxide (0.6 gL-1), combined foliar application of nano Fe and Zn oxides (0.3 g L-1 each), and application of mycorrhiza at four levels (no application of mycorrhiza as control, application of Mycorrhizae mosseae, Mycorrhiza intraradices, and combined application of Mycorrhiza intraradices with mycorrhiza mosseae). Means comparison showed that foliar application of nano Fe-Zn oxides as well as combined application of mycorrhizal mosseae and intraradices increased number of active nodules per plant, percentage of active nodules per plant, 100 grain weight, and grain yield by 173.2, 93.08, 36.58, and 58.34% respectively in comparison with no foliar application of nano Fe-Zn oxide and no application of mycorrhiza. Also, combined foliar application of nano Fe-Zn oxide along with mycorrhiza mosseae and intraradices increased respectively the number of grains per pod, number of pods per plant, dry weight of root, zinc content of grains, and protein contentof grains increased by 42.14, 95.17, 12o, 58.2, and 47.55%, respectively in comparison with no application of mycorrhiza and nano Fe-Zn oxide. It seems that foliar application of nano Fe-Zn oxide and mycorrhiza application owing to improving some morphophysiological traits can be considered as a proper method for increasing quantitative and qualitative yield and mitigating the effects of water deficit in rain fed conditions.

Abstract The effect of triad application of the phytohormone 24-epibrassinolide (EBL), the polyamine spermine (Spm), and the element silicon (Si) has not yet been considered on plant growth and behavior in water-stressed conditions. We aimed to evaluate the impact of single/dual/triad application of 24-epibrassinolide (EBL), spermine (Spm), and silicon (Si) on the growth, photosynthetic metabolites, and antioxidant enzymes in the maize plant exposed to water stress. This study was conducted as a potential drought resistance system and plants' maintenance against oxidative damage. In this regard, one maize hybrid (Paya) was grown under well-watered and water-deficit conditions (interrupted irrigation at the flowering and the filling seed stages) with and without foliar spraying of EBL, Spm, and/or Si. Drought conditions remarkably reduced growth, productivity, water-related content (RWC), and chlorophyll content. However, the dual and triad applications of EBL (0.1 mg L−1), Spm (25 mg L−1), and Si (7 mg L−1) significantly improved the above parameters. Water stress considerably augmented the levels of H2O2 and MDA. Their content in stress-subjected plants was significantly reduced by triad application. In water-stressed circumstances and after foliar treatments, the activities of superoxide dismutase, catalase, and peroxidase as well as the amounts of total soluble proteins, phenolic compounds, proline, and glycine betaine all improved. Overall, triad application increased the plant's drought resistance and diminished ROS accumulation by raising the scavenging via the enhanced activity of the antioxidant enzymes.

Water limitation is the most severe stress factor limiting plant growth and crop production in arid and semi-arid regions. Several strategies have been developed in order to decrease water limitation effects caused by the rainfed condition on plant growth. Among them, the use of putrescine and bio-fertilizers such as plant growth promoting rhizobacteria (PGPR) and Mycorrhiza play a significant role in yield improvement. Therefore, to study biofertilizers and putrescine’s effect on biomass and some physiological and biochemical traits of vetch (Vicia villosa) under rainfed conditions, a factorial experiment was conducted based on a randomized complete block design with three replications in a research farm at the University of Mohaghegh Ardabili in 2019. Experimental factors included biofertilizers (no biofertilizer as control, application of Rhizobium, Mycorrhiza, combined application of Mycorrhiza and Rhizobium, Rhizobium and Azotobacter, Mycorrhiza and Azotobacter, Rhizobium with Mycorrhiza and Azotobacter) and foliar application of putrescine in three levels (water as control, 0.5 and 1mM putrescine). The results showed that both application of Azotobacter with Mycorrhiza and Rhizobium and foliar application of 1 mM putrescine increased catalase, peroxidase and polyphenol oxidase enzymes activity )37.08, 37.54 and 34.41% respectively (, maximum fluorescence and anthocyanin content )56.94 and 4.57% respectively( compared to no application of biofertilizers and foliar application of putrescine. Also, both application of Azotobacter with Mycorrhiza and Rhizobium and foliar application of 1 mM putrescine increased total biomass by about 56.9% compared to no application of biofertilizer and putrescine. It seems that the application of biofertilizers and putrescine can increase the total biomass of Vica villosa under rainfed conditions due to improving the physiological and biochemical traits.

Abstract Background and Objective: Salinity is one of the most important environmental stresses that reduce the growth and yield of crops. The use of bio and organic fertilizers increases growth and yield of plants to various environmental stresses such as salinity. The purpose of this study was to investigate the role of vermicompost, humic acid and inoculation of seeds with Flavobacterium in improvment grain filling components and yield triticale. Materials & Methods: An experiment was conducted as factorial based on randomized complete block design with three replications in greenhouse research of the Faculty of Agriculture and Natural Resources, the University of Mohaghegh Ardabili during 2020. Factors experiment were included salinity levels (non-application of salinity as control, application of 50 and 100 mM salinity by NaCl), and bio-fertilizers application (no application of bio-fertilizers as control, application of vermicompost, seed inoculation with Flavobacterim,both application vermicompost and Flavobacterim) and foliar application humic acid (foliar application with water as control and foliar application of 2 g.L-1 humic acid). Results: The results showed that both application of vermicompost, Flavobacterim and foliar application of 2 g.L-1 humic acid under no salinity condition, increased chlorophyll a (83.38%), total chlorophyll (76.61%) and carotenoid (89.26%), maximum of grain weight (53.56%), grain filling period and effective grain filling period (19.39 and 55.11% respectively) in comparison with no application of bio-fertilizers and humic acid under the highest soil salinity level. Also, both application of vermicompost with Flavobacterim and foliar application of 2 g.L-1 humic acid under no salinity condition increased plant height, ear length, the number of grain per spike, 100 grains weight and grain yield of per plant of triticale. Conclusion: Application of bio-fertilizers and humic acid can increase grain yield of triticale under soil salinity conditions due to improve of chlorophyll content and grain filling components.

In order to study the effects of supplementary irrigation and application of mycorrhiza and azetobacter on grain filling components, chlorophyll content, and grain yield of rain fed barley (Var. Sahand), a factorial experiment was conducted based on a randomized complete block design with three replications in the village of Khalkhoran Viand, Ardabil province during 2017. Factors of the experiment included irrigation levels (no irrigation as rain fed, supplementary irrigation at 50% heading, and booting stages) and biofertilizers application at four levels (without biofertilizers as control, application of mycorrhizal fungi, application of azetobacter, and combined application of mycorrhiza and azetobacter). Results showed that the highest chlorophyll a (1.76 mg/g FW), chlorophyll b (0.88 mg/g FW), carotenoid (0.83 mg/g FW), chlorophyll total contents (2.64 mg/g FW), maximum fluorescence (1433.2), variable fluorescence (1281.3), quantum yield (0.847), grain filling period (32.06 days), and maximum grain weight (58.3 mg) were obtained under supplementary irrigation treatment at boot stage with both application of mycorrhiza and azetobacter while the minimum levels of these traits were obtained under rain fed condition without application of biofertilizers. Moreover, the highest grain filling rate (1.9 mg/day) was obtained under rain fed condition and no application of biofertilizers while the lowest rate was obtained under supplementary irrigation at boot stage with application of mycorrhiza. Supplementary irrigation at boot stage and combined application of mycorrhiza and azetobacter increased grain yield by 29.87% in comparison with no application of biofertilizers under rain fed condition. Based on the results, it seems that application of biofertilizers and supplementary irrigation can increase grain yield of rain fed barley through improving chlorophyll content and grain filling components.

In order to study the effect of uniconazole and bio fertilizers on activity of some antioxidant enzymes and compatible osmolites of wheat (Triticum aestivum L var Zagros.) in soil salinity conditions, a factorial experiment was conducted based on randomized complete block design with three replications in a research greenhouse of the Faculty of Agriculture and Natural Resources of Mohaghegh Ardebili University in 2018. Treatments were included soil salinity in four levels (no application of salinity as control and application of 40, 80 and 120 mM soil salinity), by NaCl and application of uniconazole, mycorrhiza fungi (Glomus intraradicese) and pseudomonas putida strain 186 in seven levels. Means comparision showed that both application of mycorrhiza with uniconazole and pseudomonas under 120 mM salinity increased soluble sugars and proline contents, antioxidant enzymes activity such as catalase, peroxidase polyphenol oxidase (93.98, 47.33, 63.88, 75.67, 69.35% respectively) in comparison with no application of bio fertilizers under without salinity. Also, both application of mycorrhiza with uniconazole and pseudomonas under without salinity increased leaf proteine, plant height and grain yield (72.36, 41.85 and 108.84% respectively) and decreased electrolyte leakage (39.02%) in comparison with application of bio fertilizers under at the highest soil salinity level. It seems that the mentioned bio-fertilizers and uniconazole application can increase grain yield of wheat due to improve biochemical and physiological traits of wheat under soil salinity condition.

Abstract In this research, effects iron nano‐oxide and biofertilizers and chemical was investigated on the yield and some traits of Maize under normal and drought stress conditions in two years (2018 and 2019). The experiment was performed in the form of split–spilt plot in a complete random block design with three replications. The studied irrigation treatment included three levels (normal, 85% and 65% optimum water requirement) in the main plots and iron nano‐oxide at four levels (0, 0.5, 1, and 1.5 g/L) in subplots, and biofertilizers at four levels (noninoculation, inoculation with mycorrhiza, inoculation with pseudomonas and combined inoculation of mycorrhiza and pseudomonas) in sub‐plots. The results showed that grain yield, 1000‐grain weight, and leaf chlorophyll contents decreased by drought stress. Use of pseudomonas and mycorrhiza increased these traits in normal and stress conditions, but iron nano‐oxide had no significant effect on the measured traits. Also, drought stress increased malondialdehyde, ion leakage, catalase, peroxidase, proline, and polyphenol oxidase in both light and severe stress regimes. The amount of antioxidant enzymes increased under drought stress conditions in corn. The results indicated that all the characteristics measured by double inoculation with Pseudomonas and Microoriza had the best performance in conditions of water shortage and the use of these biofertilizers increases yield, 1000‐seed weight, and chlorophyll content of maize. Also, the use of biofertilizers modulates the effect of drought stress and reduces its negative effects.

Abstract Microbial endophytes are considered as one of the most important soil microorganisms which increase their yield per unit area by generating genetic, physiological, and ecological changes in their host plants. We conducted an experiment as factorial in a completely randomized manner with three replications at the Ghasre Shirin greenhouse of Kermanshah province in order to evaluate the interaction of Piriformospora indica (inoculation–noninoculation) with manure (25% of the flowerpot volume—without using manure as a control) and NPK chemical fertilizer (10 g per flowerpot—without the use of fertilizer as a control), the quantitative and qualitative yield and absorption of elements in sunflower. The results showed that the interaction of P. indica, manure, and chemical fertilizer on the colonization percentage, seed oil percentage, nitrogen concentration, phosphorus concentration, and the 1000‐seed weight was significant at 1% probability level, and on yield index, growth, plant height, and concentration of potassium element it was at 5% probability level. Bilateral effects of P. indica with chemical fertilizer and the manure treated with chemical fertilizer on the budding time were significant at the probability level of 1% and 5%, respectively. It seems that the coexistence between sunflower root and P. indica increases the growth of the root system of the plant; thereby it increases the height of plant because of the absorption of essential elements such as nitrogen, phosphorus, and potassium by the root, and increases the quantitative and qualitative yield of sunflower.

In order to evaluate the effects of nano Zn oxide, nano Fe oxide and bio fertilizer on variation of some physiological traits and grain filling parameters of wheat (Triticum aestivum L.) under soil salinity, a factorial experiment was conducted based on randomized complete block design with three replications in research greenhouse of faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili in 2015. Treatments were included soil salinity in three levels, no-salt or control, salinity 25 and 50 mM respectively, by NaCl, seed inoculation by plant growth promoting rhizobacteria at four levels, no bio fertilizer (F1), seed inoculation by Azotobacter chroococcum strain 5 (F2), Azospirillum lipoferum strain OF (F3), Pseudomonas putida strain 186 (F4) and foliar application at four levels, without nano or foliar application by water as control, application of nano Zn oxide, nano Fe oxide and nano Fe-Zn oxide 1.5 g.lit-1). The results showed that the maximum grain filling components such as maximum of grain weight (0.049 g), grain filling rate (0.00172 g.day-1), grain filling period (52.85 days) and effective grain filling period (39.18 days) were obtained in no salinity, application of nano Zn-Fe oxide and seed inoculation by Pseudomonas. Similar results were obtained for chlorophyll index and quantum yield. Application of nano Zn-Fe oxide increased about 17.40% from grain yield in comparison with no application of nano oxide in the highest salinity level. Generally, it seems that bio fertilizer and nano Zn-Fe oxide can be used as a proper tool for increasing wheat yield under salinity condition.

In order to study the effects of nano iron oxide on yield, chlorophyll fluorescence indices and some physiological traits of wheat (Triticum aestivum L.) under rain fed and supplementary irrigation conditions, a factorial experiment was conducted based on randomized complete block design with three replications in Agricultural Research Station of Ardabil in 2016. Factors experiment were included irrigation levels (no irrigation as rain fed, supplementary irrigation at heading and booting stages), foliar application nano iron oxide in four levels (without nano iron oxide as control, application of 0.3, 0.6 and 0.9 g L -1 ). Means comparison showed that 0.9 g L -1 nano iron oxide application and supplementary irrigation at booting stage increased maximum fluorescence (F m ), variable fluorescence (F v ), chlorophyll content, nitrogen percentage, relative water content and grain yield compared to non-application of nano iron oxide under rain fed condition. Rain fed condition increased minimum fluorescence (F 0 ) and electrical conductivity. Foliar application of 0.9 g L -1 nano iron oxide and supplementary irrigation at booting stage increased grain yield 38.43% compared to no foliar application under rain fed condition.

The poisoning of heavy metals and their accumulation in food chains are major environmental and health risks. There have been several reports that determined that pumpkins tend to collect small amounts of nitrate or heavy metals. Therefore, the aim of the present study is to investigate the effect of organic matter (humic acid) on the germination and activity of antioxidant enzymes, glycosylate cycle enzymes, and utilization of lipid and protein reserves of pumpkin seeds under cadmium stress conditions. An experiment was conducted to quantify the germination response and biochemical change of pumpkin seeds to the use of humic acid under cadmium stress conditions. The treatments were cadmium at three levels (0 (control), 100, and 200 mg.L−1) and humic acid at five levels (0 (control), 100, 200, 300, and 400 mg.L−1). Linear and sigmoidal models were used to investigate the trend of trait changes. The results show that changes in the germination percentage and seed vigor were affected by applying humic acid and cadmium stress. The highest germination percentage for pumpkins was observed without stress and cadmium stress at a concentration of 200 mg.L−1. The results of quantification for the germination and seed vigor also showed that the model of germination changes by the use of humic acid was sigmoidal in non-stress and cadmium stress conditions of 100 mg.L−1, but it was linear for seed vigor in the stress conditions of 200 mg.L−1. The activity of superoxide dismutase, catalase, peroxidase, isocitrate lyase, and malate synthase was also affected by the simultaneous use of humic acid and cadmium stress, and the trend of their changes was linear.

In order to study the effects of different levels of salinity on germination components of wheat cultivars, a factorial experiment was conducted based on a completely randomized design with three replications. Experimental factors were wheat cultivars at eight levels (Saysons, Gaspard, Finkan, MV-17, Chamran, Sardari, Atila-4 and Azar-2) and six levels of salinity (0, 25, 50, 100, 150 and 200 mM NaCl). The results indicated that salinity had significant effects on all of the traits studied (i.e., radicle length and dry weight, plumule length and dry weight, remaining seed weight after germination, seedling weight, the longest radicle and plumule, number of radicle per seed, ratio of radicle weight to plumule weight and rate, and uniformity and percentage of germination). All of these traits declined with an increase in the salinity (except the ratio of radicle weight to plumule weight, remaining seed weight after germination and seedling weight). The highest ratio of radicle weight to plumule weight, remaining seed weight after germination and seedling weight were recorded in the salinity of 200 mM NaCl. The cultivars showed significant effects on all of the traits studied (except remaining seed weight after germination and seedling weight). Chamran cultivar showed the highest number of radicle per seed, the ratio of radicle weight to plumule weight, rate and percentage of germination. The highest radicle length and the longest radicle were obtained from the Sardari cultivar while in Azar-2 cultivar it was vice versa in plumule. Atila-4 cultivar showed the highest radicle and plumule weight. It seems that compared with other cultivars, out of the cultivars studied, Chamran, Azar-2, Sardari and Atila-4 were more resistant to salinity stress. Highlights: Introduction of wheat cultivars with more tolerance to salinity conditions at germination stage. Study of eight different wheat cultivars in terms of germination indices under salinity stress conditions.

Plants are always subjected to various environmental adverse factors such as salinity, drought, high/low temperatures, heavy metal toxicity, waterlogging, UV-B radiation, and ozone. Abiotic stresses cause hampering in the growth, physiology, and yield of crops and thus, are an important challenge for crop production and food security. Various strategies have been proposed to improve crop production under stress conditions, but attempts to enhance yield under these conditions have been largely unsuccessful. However, in recent years, exogenous application of phytoprotectants such as osmoprotectants (like proline and Glycinebetaine), phytohormones (for instance Abscisic acid, Salicylic acid, Gibberellic acid, Jasmonic acid, Brassinosteroids, and polyamines), antioxidants (including Ascorbic acid, Glutathione, and Tocopherol), micro nutrients (like Iron and Zinc), and trace elements (including Selenium and Silicon) have been found effective in mitigating the stress-induced damage in plant. This strategy has gained considerable attention because of its high efficiency, feasibility, and cost and labor effectiveness. Moreover, exogenous phytoprotectants show acceptable capacity to enhance plants’ growth, yield, as well as stress tolerance under adverse environmental factors. Regarding the importance of the application of exogenous phytoprotectants under stress condition, this article provides a review of the major responses of plants to these components in the presence of growth restriction factors.

Abstract: The objective of this work was to evaluate the effects of the integrated application of nitrogen fertilizer and biofertilizers on the yield, grain filling period, and composition of fatty acids of safflower (Carthamus tinctorius). Split-plot experiments were carried out during the 2011 and 2012 crop seasons. The treatments consisted of seed inoculation with plant growth-promoting rhizobacteria (Azotobacter chroococcum strain 5, Azospirillum lipoferum strain F, and Pseudomonas putida strain 186) in the subplots, including a control without seed inoculation; and of the application of N fertilizer at different rates (60, 120, and 180 kg ha-1 urea) in the main plots, including a control without N. The highest grain yield, grain filling period, and effective grain filling period were obtained by the application of 180 kg ha-1 urea and by seed inoculation with P. putida. The application of high N rates and P. putida inoculation resulted in 25.66% increase of the potential rate of grain filling. Biofertilizer inoculation in seed reduced the contents of saturated fatty acids (palmetic and stearic acids) and increased the contents of unsaturated fatty acids (linoleic, linolenic, and oleic acids). The suitable amount of N fertilizer (between 120 and 180 kg ha-1 urea) can improve plant growth, and the quantity and quality of oil in seeds treated with P. putida in safflower plants.

In order to evaluate the effects of nano Zn-Fe oxide and bio fertilizer on physiological traits, antioxidant activity and yield of wheat under salinity stress, a factorial experiment was conducted based on RCBD with three replications.Treatments were included salinity in three levels (no-salt, salinity 25 and 50 mM NaCl), four bio fertilizers levels (no bio fertilizer, seed inoculation by Azotobacter, Azosperilium, Pseudomonas) and nano oxide (without nano, application of nano Zn oxide, nano Fe oxide and nano Fe-Zn oxide 1.5 g/lit). Salinty stress decreased the chlorophyll-a, chlorophyll-b, total chlorophyll, photochemical efficiency of PSII and yield of wheat, whearas electrical conductivity, soluble sugars, proline content, and the activities of Catalase (CAT), Peroxidase (POD) and Polyphenol Oxidase (PPO) enzymes increased. Similar results were observed in CAT, POD and PPO activities due to inoculation by bio fertilizers and nano oxide. Maximum of soluble sugars and proline content were observed in the highest salinity level and application of Pseudomonas. Application of nano Zn-Fe oxide increased about 17.40% from grain yield in comparision with no application of nano oxide in the highest salinity level. Generally, it was conducted that bio fertilizer and nano oxide can be used as a proper tool for increasing wheat yield under salinity condition.

In order to study the effects of bio fertilizers and zinc fertilizer on antioxidant enzymes activity, chlorophyll content, soluble sugars and proline in triticale under salinity condition, a factorial experiment was conducted based on randomized complete block design with three replications under greenhouse condition. Experiment factors were included salinity in four levels [no-salt (control or S0), salinity 20 (S1), 40 (S2) and 60 (S3) mM NaCl) equivalent of 1.85, 3.7 and 5.55 dS m−1 respectively], four bio fertilizers levels (no bio fertilizer (F0), application of mycorrhiza (F1), PGPR (F2), both application PGPR and mycorrhiza (F3) and three nano zinc oxide levels (without nano zinc oxide as control (Zn0), application of 0.4 (Zn1) and 0.8 (Zn2) g lit-1). Results showed that salinity severe stress (60 mM) decreased chlorophyll a, chlorophyll b, total chlorophyll, carotenoid and grain yield of triticale, whereas soluble sugars and proline content, the activities of Catalase (CAT), Peroxidase (POD) Polyphenol Oxidase (PPO) enzymes increased. Results showed that both application of bio fertilizer and 0.8 g lit-1 nano zinc oxide (F3Zn2) increased about 39% from grain yield in comparison with F0Zn0 under the highest salinity level. Based on the results, it was concluded that bio fertilizers and nano zinc oxide application can be recommended for profitable triticale production under salinity condition.

Marigold (Calendula officinalis) is a medicinal plant belonging to the Asteraceae family, which seems necessary the review of its various features especially the improvement of reproduction in order to the development of vegetation and extraction of raw pharmaceutics materials. In order to study the effects of seed hardening on the quality of seeds harvested from different positions of inflorescence on the storability of pot marigold, an experiment conducted at the University of Mohaghegh Ardabili in 2011. Seeds hardened before planting with CaCl2 2% and distilled water. At harvest, the seeds collected from both inner and outer regions of the inflorescence from storage experiments in the laboratory. Harvested seeds stored for six months at 40°C. Then an experiment conducted as factorial based on a completely randomizes design with four replications at the laboratory. Results showed that the highest germination percentage (96%), rate (3.91 day-1), radicle length (5.71 cm) and seed residual dry weight (0.061 g) were related to outer positioned seeds. The highest plumule length (4.79 cm) and seedling dry weight (0.016 g) obtained from outer seeds hardened with distilled water. In conclusion, for best stability results of pot marigold seeds, it is recommended to harden seeds before planting with water and harvest outer seeds from the inflorescence. <<

Application of zinc can improve the tolerance and resistance of plants especially sunflower to environmental stresses and be effective on kernel set and yield. To investigate the effects of zinc oxide nanoparticles on the length, effective period, the rate of kernel filling and kernel weight in sunflower cultivars, a factorial experiment based on randomized complete block design with three replications was conducted at the University of Mohaghegh Ardabili, Ardabil, Iran. Treatments were three sunflower cultivars as Aline 191, Aline 122 and Farrokh and three concentrations of nano zinc oxide including 0, 0.5 and 1 g lit-1 which sprayed at three stages. Results showed that interaction of cultivar and nano zinc oxide was significant on kernel filling rate, the effective period of kernel filling, maximum kernel weight and duration of kernel filling. The rate of filling and maximum kernel weight increased with 0.5 g lit-1 spraying of Nano zinc oxide in Aline 191 and 122, but in Farrokh cultivar was significantly reduced in comparison to the control. Also, no significant difference was found between 0, 0.5 and 1 g lit-1 of nano zinc oxide on kernel filling rate, effective kernel-filling period and duration in Farrokh cultivar. In conclusion, foliar application of zinc oxide nanoparticles led to the improvement of kernel weight and their filling parameters and the more appropriate response was observed in foreign cultivars for this treatment, while final kernel weight decreased in Farrokh cultivar. Therefore, it can be used 0.5 g lit-1 of nano zinc oxide for increasing grain yield in foreign cultivars of Aline.

The study tackled the effect of humic acid and cadmium concentrations on the pumpkin seed germination characteristics throughout were studied. Treatments were cadmium concentrations on three levels: 0, 100 and 200 ppm and humic acid concentration of 0, 100, 200, 300 and 400 mg lit-1. Results showed that interaction of humic acid and cadmium was not significant on germination traits, but there was a significant effect on seedling growth indexes. Radicle and plumule length increased by 86 and 192% in comparison with control, of the mixture of 200 ppm cadmium and 300 mg lit-1 of humic acid. Cadmium had stimulatory effect on radicle and cotyledon dry weight and the highest values obtained with 200 ppm in mixture with 200 mg lit-1 of humic acid. Also, maximum plumule dry weight was recorded in 200 ppm cadmium and 300 mg lit-1 of humic acid. The highest of indexes were observed of 200 ppm cadmium and 400 mg lit-1 humic acid. In conclusion, the humic acid had detoxifying effect on cadmium stress in the culture and responded antagonistically against cadmium, but it seems that these concentrations of cadmium are low for the pumpkin seed and can be increased in order to reach the toxicity level.

Combined application of organic and inorganic fertilizers can play an important role for increasing yield and quality of soybean (Glycine max L.). In order to study of effects of biofertilizers and nitrogen rates on yield, nodulation state and fatty acids composition of soybean, a factorial experiment was conducted based on randomized complete block design with three replications in 2012 and 2013. Factors were different rates of nitrogen fertilizer in four levels (without nitrogen and application 25, 50 and 75 kg urea/ ha) and seed inoculation with as biofertilizers in five levels (without inoculation, seed inoculation with Pseudomonas putida strain 41, P. putida strain 186, Azotobacter chroococcum strain 5 and Bradyrhizobium japonicum). The results showed that maximum of grain yield, plant height, number of filled pods and number of grains per plant were obtained from the highest level of nitrogen fertilizer (75 kg urea/ha) and Rh. inoculation. Furthermore, the highest rate of nitrogen usage (75 kg urea/ha) adversely inhibited nodulation of soybean. Number and dry weight of nodules/plant increased significantly with increasing nitrogen application rates up to 50 kg urea/ha. Seed inoculation with biofertilizers increased oil and protein contents. The maximum oil content was obtained by applying 50 kg urea/ha and seed inoculation with Bradyrhizobium. The saturated fatty acids (palmitic and stearic acids) declined in seed inoculation with Bradyrhizobium than the control, while it was vice versa in unsaturated fatty acids (linoleic, linoneic and oleic acids). Based on the results, it was concluded that application of suitable amounts of nitrogen fertilizer (i.e. between 50 and 75 kg urea/ha) as starter in seed inoculation with Bradyrhizobium japonicum can be recommended for profitable soybean production in the study area.

Grain yield of wheat (Triticum aestivum L.) under Mediterranean conditions is frequently limited by both high temperature and drought during grain growth. In this region, most rain falls during autumn and winter and water deficit emerges in the spring, resulting in a moderate stress for rainfed wheat around anthesis, which increases in severity throughout grain filling. Hence, selection of genotypes with high grain yield is the principal aim of wheat production in this region. In order to evaluation of yield and dry matter accumulation in wheat genotypes as affected by terminal drought stress, a factorial experiment based on randomized complete block design was conducted in Research Farm Islamic Azad University, Ardabil branch in 2009. Factors were: terminal drought stress by changing in planting date at three levels (12 October, 1 November and 21 November) with wheat (Triticu aestivum L.) genotypes at four levels (�Azar-2�, �Sardari�, �Frankia� and �Trakia�). The results showed that various levels of terminal drought stress affected yield, dry matter accumulation and leaf area index in wheat genotypes. Means comparisons showed that maximum grain yield (183.18 gr/m2) was obtained at the first of planting date or the least duration of confronting with thermal drought stress in �Azar-2� genotype and minimum of it was obtained in the third planting date with �Trakia� genotype due to the highest duration of confronting with thermal drought stress. Investigation of variances trend of dry matter accumulation indicated that in all of treatment compounds, it increased slowly until 190-200 days after sowing and then increased rapidly till 270-280 days after sowing. From 280 days after sowing till harvest time, it decreased due to increasing aging of leaves and decreasing of leaf area index. In the other hand, wheat genotypes had difference response to dry matter accumulation in confronting with thermal drought stress. Decrease in duration of terminal drought stress also significantly increased the leaf area index and the maximum of it was observed by the plots that were applied in the first planting date with �Azar-2� genotype. In all of treatment compounds, LAI increased slowly until 190-200 days after sowing and then decreased slowly till 240-250 days after sowing. From 240-250 days after sowing till harvest time, it decreased rapidly due to hasten leaf senescence in confronting with terminal drought stress. Thus, it can be suggested that in order to increasing of grain yield, dry matter accumulation and leaf area index should be applied �Azar-2� genotype with the first planting date(12 October ) in conditions of Ardabil Plain in Iran.

The objective of this work was to determine the effects of seed priming and sulfur application on cell membrane characteristics, seedling emergence, chlorophyll content and grain yield of soybean (Glycine max) in saline soil. A complete-block design in 4x3 factorial arrangement with three replicates was used to test four types of seed priming (water, auxin, gibberellin and non-priming) and three levels of sulfate availability (0, 70 and 140 kg ha-1 K2SO4). The soil had a silty loam texture with an electrical conductivity of 3.61 ds m-1, a pH of 8.2 and a saturation percentage of about 46%. Seed priming had significant effects on mean emergence rate (MER), emergence percentage, relative water content (RWC) of leaves, relative chlorophyll content, time of maturity, shoot length and grain yield. The highest values for these variables were observed in the priming treatments, except for the time of maturity. Sulfur application had significant effects on MER, shoot length, RWC, membrane injury index and grain yield. Priming treatments provide greater emergence rates and grain yields and interact sinergicaly with sulfur rates.O objetivo deste trabalho foi determinar os efeitos do condicionamento osmótico das sementes e da disponibilidade de enxofre sobre características da membrana celular, emergência de plântulas, conteúdo relativo de clorofila e produtividade de soja (Glycine max) em solo salino. O experimento foi conduzido em delineamento de blocos ao acaso, em arranjo fatorial 4x3, com três repetições, para avaliar quatro tipos de condicionamento osmótico das sementes (água, auxina, giberelina e ausência de condicionamento) e três níveis de disponibilidade de enxofre para as plantas (aplicação ao solo de 0, 70 e 140 kg ha-1 de K2SO4). O solo utilizado apresentava textura média, com condutividade elétrica de aproximadamente 3,61 ds m-1, pH de 8,2 e percentagem de saturação em torno de 46%. O condicionamento osmótico das sementes teve efeito significativo sobre a taxa média de emergência (MER), percentagem de emergência, conteúdo relativo de água das folhas (RWC), conteúdo relativo de clorofila, época de maturação, comprimento da parte aérea e produtividade de grãos. Os maiores valores para essas variáveis, exceto época de maturação, foram observados nos tratamentos com condicionamento osmótico. A aplicação de enxofre teve efeito significativo sobre MER, comprimento da parte aérea, RWC, índice de dano à membrana celular, e produtividade de grãos. O condicionamento osmótico proporciona maiores taxas de emergência e produtividade de grãos e interage significativamente com a aplicação de enxofre.