r. seyed sharifi

Water deficit is one of the most important factors limiting crop production under rainfed condition. Several methods have been proposed to increase the resistance of crops against water deficit. In this regard, foliar application of methanol and nano zinc oxide can improve the performance of crop plants under water limitation conditions. Zinc deficiency is recognized as a critical problem in plants, especially when grown on soils with high pH values. But, recent researches have shown that application of micronutrients, including Zn, in the form of nano-fertilizers is a viable criterion for growing plants under water deficit condition, as it increases resource use efficiency and reduces environmental pollution. Also, foliar-applied methanol can increase the concentration of CO2 inside the plant tissue and promote photosynthesis rate and growth under water deficit conditions. On the other hand, water deficit is mitigated by stress modulators such as methanol and nano zinc oxide through a variety of mechanisms, including increased photosynthetic efficiency and nutrient acquisition in plants, and enhancement of the antioxidant system towards preventing damage from reactive oxygen species. Considering the above fact, the present study was undertaken to evaluate the effects of nano zinc oxide and methanol foliar application on grain yield and some physiological traits (i.e, relative water content, electrical conductivity of flag leaf, dry matter remobilization from plant’s above-ground parts and hence contribution of photoassimilates remobilization in grain yield) of wheat under rainfed conditions.

A factorial experiment was conducted based on a randomized complete block design with three replications in Sarab in north-west of Iran, in 2018-2019. Experimental factors included nano zinc oxide foliar application at four levels (foliar application with water as control, 0.3, 0.6, and 0.9 g L-1) and methanol application at four levels (foliar application with water as control, 10, 20, and 30% v/v). Methanol was prepared from Mojallal Co. and  nano zinc oxide from Pishgaman Nanomaterials Co. Nano zinc oxide consisted of particles of  less than 30 nm. Foliar application of nano zinc oxide and methanol were done in stages of tillering and boot stage. Relative water content (RWC) and electrical conductance (EC) of flag leaves was calculated based on the given formula Kheirizadeh Arough et al (2015):RWC (%) = [(FW-DW)/(TW-DW)] × 100  (1)where FW is the fresh weight; DW is the dry weight; and TW is the turgid weight. From each plot, the samples of  developed flag leaf were randomly selected and after placing them in aluminum foils, they were transferred to the laboratory very quickly, then the flag leaf samples were kept in flasks containing 25 ml of distilled water. It was then placed at room temperature for 24 hours and then the electrical conductivity was measured by an EC meter (Mi 180 Bench Meter).Dry matter and remobilization of stem reserves to grain yield were evaluated as follows:Dry matter remobilization from shoot (g plant-1) = maximum of  dry matter of shoot after anthesis (g plant-1) - shoot dry matter (grains excluded) in maturity (g plant-1)Contribution of dry matter remobilization to grain (%) = [dry matter remobilization from shoot (g plant-1) /grain yield (g plant-1)] × 100.Contribution of dry matter remobilization from stem to grain yield (g plant-1) = [maximum  of stem dry matter after anthesis (g plant-1) - stem dry matter in maturity (g plant-1) ] × 100.Analysis of variance was done by SASv9.12. The main effects and interactions were compared by LSD test at the 0.05 probability level.

Mean comparison showed that the least of dry matter remobilization from above-ground parts (0.21 g plant-1) and contribution of remobilization to grain yield (23.6%), dry matter remobilization from stem (0.17 g plant-1) and contribution of stem reserves to grain yield (10.3%) were obtained at the highest level of nano zinc oxide application. Similar results were obtained in these traits at the highest level of methanol application. Foliar spraying of high rates of nano zinc oxide and methanol increased the relative water content of flag leaf in ear emergence (17%) and grain filling stages (11%), zinc content (62%), protein content (14%) and grain yield (33%) in comparison to control.

Results of this study taken together, it seems that application of 0.9 g L-1 nano zinc oxide with 30% v/v of methanol can be suggested for improvement of physiological traits and thereby increase in grain yield of wheat under rainfed conditions.

Drought stress is one of the most common limiting factors for crop production. Due to its detrimental effects on numerous physiological and biochemical processes, this stress restricts the growth and development of plants. In this regard, the application of stress modulators (methanol, silicon and humic acid) has been found to enhance plant growth and grain yield while also increasing its resistance to abiotic stresses. On the other hand, stress modulators can lessen the effects of stress toxic by reducing malondialdehyde and hydrogen ‎peroxide accumulation and keeping the effectiveness of the photosynthetic apparatus‎. Therefore, measurement of traits of such as antioxidant enzymes activity, chlorophyll content, proline and soluble sugars content, malondialdehyde content, electrical conductivity are as indicators of plant response to environmental stress. Although, several strategies have been developed to decrease the effects caused by drought stress on plant growth. But, among them, the application of stress modulators (methanol, nano silicon, and humic acid) plays a very important role in yield improvement. The aim of this study was to evaluate the effects of foliar application of stress modulators (methanol, nano silicon and humic acid) on the activity of antioxidant enzymes, compatible osmolytes, photosynthetic pigments content and grain yield of wheat in different irrigation regimes.

an experiment as factorial was conducted based on randomized complete block design with three replications in Agricultural and Natural Resources Research Station of Ardabil, Ardabil, Iran, in 2022-2023 growth season. The treatments were different irrigation regimes (normal irrigation as control; irrigation withholding at 50% of booting and heading stages) and foliar spraying of stress modulators (foliar spraying with water, foliar spraying of methanol (25% volume), nano silicon (50 mg.L-1), humic acid (300 mg.L-1), foliar spraying of methanol and silicon, methanol and humic acid, nano silicon and humic, methanol with nano silicon and humic acid). In each plot, there were six rows with two m long. In this experiment, the wheat cultivar ‘Hiran’ was employed. For this cultivar, 400 seeds.m-2 is the optimum density. The used nano silicon had an average particle size of less than 30 nm and the 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. For a better solution, deionized water was mixed with nano Si powder and placed on a shaker with ultrasonic equipment (100 W and 40 kHz). Two phases of period growth, BBCH 21 and 30 were used for the foliar application of nano silicon.  In this study, the activity of antioxidant enzymes (Catalase, peroxidase, and Polyphenol oxidase), compatible osmolytes (Proline and soluble sugars), photosynthetic pigments content (Chlorophyll a, Chlorophyll b, total chlorophyll, and carotenoid), H2O2, MDA, protein content and grain yield of wheat were investigated.

The result indicated that both application stress modulators (methanol, silicon and humic acid) at irrigation withholding in booting stage decreased malondialdehyde content (39.79%) and electrical conductivity (31.25%), but increased activity of peroxidase (4.89%), polyphenol oxidase (7.73%) enzymes, soluble sugars (22.15%), chlorophyll a (33.48%), chlorophyll b (24.96%), leaf protein content (25.09%) and grain yield (36.21%) in compared to the no application of stress modulators under irrigation withholding in booting stage.

According to our findings, applying stress modulators (methanol, silicon and humic acid) under water limitation often reduced this damage by strengthening the defensive mechanisms, particularly antioxidant enzymes and compatible osmolytes (Proline and soluble sugars). In summary, our results indicated that application of stress modulators upgrade plant physiology and trigger the cellular defense of wheat plants against severe water limitation. Therefore, in can be suggested that applying stress modulators as individual and integrated could enhance grain yield of wheat under water limitation conditions due to improving of physiological and biochemical characteristics.

 Among abiotic stress factors, drought is one of the most detrimental factors in arid and semiarid regions, causing a significant decrease in plant growth and yield in most species, including crops. Under drought conditions, morphological, physiological, and biochemical characteristics are negatively affected. The detrimental impact of water scarcity may be mitigated through the utilization of plant growth-promoting rhizobacteria (PGPR) and nanoparticles (NPs) like nano iron-silicon oxide. PGPR species such as Azospirillum and Pseudomonas have been found to enhance hormonal balance, maintain nutrient levels, improve plant growth characteristics, and ultimately boost yield. Additionally, the application of NPs aids in enhancing plant growth under stressful conditions by facilitating water retention, fortifying membrane integrity, and enhancing nutrient and water uptake. Consequently, it is plausible that the combined application of PGPR and NPs could enhance triticale yield even in conditions of water limitation.

An experiment as factorial split-plot was conducted based on randomized complete block design with three replications at the research farm of the Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili in 2021. Different irrigation regimes 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 codes respectively) were assigned to the main plots and the combination of bio fertilizers application 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) were assigned to the subplots. Psedomunas and Azospirilum were isolated from the rhizospheres of wheat by the 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 five rows with two m long. In each experimental plot, two beside rows and 0.5 m from the beginning and end of planting lines were removed as margin, and measurements were done on three rows in the middle lines. The used nano silicon-iron oxide had an average particle size of less than 30 nm and the 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 silicon oxide and nano silicon oxide powder added to deionized water and was placed on ultrasonic equipment (100 W and 40 kHz) on a shaker for better solution. Foliar application of nano silicon-iron oxide was done in two stages of period growth BBCH 21 and 30 codes respectively. In this study, dry matter remobilization, volume and root dry weight, leaf area index (LAI), and grain yield of triticale were investigated. Analysis of variance and mean comparisons were performed using SAS ver 9.1. The main effects and interactions were tested using the least significant difference (LSD) test at the 0.05 probability level.

 The results showed that remobilization from the stem (22.75%) and total dry matter remobilization (21.36%) and contribution of these processes in grain yield (58.29 and 56.24% respectively) decreased in both application of PGPR and nano iron-silicon oxide foliar application under irrigation withholding at booting stage in compared to no application of bio-fertilizers and nanoparticles. Also, the application of PGPR and nanoparticles under irrigation withholding in the booting stage increased the root volume (44.68%), current photosynthesis (48.63), the contribution of photosynthesis contribution in grain yield (15.63%), LAI (32.82%), and grain yield in compared to no application of PGPR and nanoparticles under irrigation withholding at booting stage.

Based on the results of this study, it seems that the application of both PGPR and nanoparticles can be a suitable management factor to increase the grain yield of triticale under water-limited conditions.

In order to evaluate the effect of putrescine, vermicompost and mycorrhiza on yield, activity of antioxidant enzymes and some physiological traits of triticale in different irrigation regimes, an experiment was conducted as factorial based on randomized complete block design with three replications at the Research Farm of University of Mohaghegh Ardabil, northwest of Iran in 2020. The experimental factors included irrigation in three levels (full irrigation as control; irrigation withholding at 50% of heading, and irrigation withholding at booting stage), application of bio-organic fertilizers in four levels (no application as control, application of vermicompost, mycorrhiza, and simultaneous application of vermicompost and mycorrhiza), foliar application of putrescine in three levels (foliar application with water as control, foliar application of 0.4 and 0.8 mM). The results showed that the irrigation withholding in booting stage with application of mycorrhiza, vermicompost and foliar application of 0.8 mM putrescine increased activity of catalase, peroxidase and polyphenol oxidase enzymes compared with no application of bio-organic fertilizers and putrescine at the same irrigation level. Evaluation of some physiological traits showed that at 242 days after planting, the simultaneous application of vermicompost and mycorrhiza and foliar application of 0.8 mM putrescine under irrigation withholding in booting stage conditions increased the relative water content (39.1%), chlorophyll a content (49.3%), chlorophyll index (37.2%), stomatal conductance (32.1%), variable fluorescence (84.9%), maximum fluorescence (45.1%), and quantum efficiency of photosystem II (27.6%) in comparison with no application of biofertilizers and putrescine at the same irrigation level. Moreover, application of vermicompost and mycorrhiza and foliar application of 0.8 mM putrescine at full irrigation conditions decreased hydrogen peroxide (29.2%), while increased grain yield (39.6%) in comparison with no application of biofertilizers and putrescine under irrigation withholding in booting stage. It seems that the simultaneous application of mycorrhiza and vermicompost and foliar application of putrescine can increase the grain yield of triticale under water limitation conditions due to improvement of antioxidant enzymes activity and some physiological traits.

Salinity stands as a significant environmental stressor that profoundly curtails the growth and yield of crop plants. This adversity also extends to the impairment of pigments and plastids, leading to diminished chlorophyll indices, rates, and grain-filling durations. To counteract the deleterious impact of such stressors on plant growth, a spectrum of strategies has been devised. Prominent among these strategies are plant growth-promoting rhizobacteria, exemplified by azospirillum, and the utilization of nanoparticles like zinc and silicon. These factors play a pivotal role in elevating yield outcomes. Zinc's pivotal involvement spans protein metabolism, photosynthetic activities, and diverse physiological traits within plants. Particularly noteworthy is its contribution to rectifying zinc deficiency, a particularly critical concern in plants cultivated in high-pH soils. Notably, recent research has illuminated the potential of applying minute quantities of micronutrients, notably zinc via foliar spraying, in bolstering plant resilience against salt stress. Likewise, silicon emerges as a supplemental micronutrient that imparts heightened resistance to environmental stresses, fostering increased resilience within biological systems. Therefore, this study aimed to evaluate the effects of application of plant growth-promoting rhizobacteria and nanoparticles (zinc and silicon) on the yield, photosynthetic pigments, and filling components of triticale grain under salt stress.

This experiment was conducted as factorial based on a randomized complete block design with three replications in greenhouse research of the Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili in 2022. Factors experimental included salinity at three levels (no salinity as control, application of 60, 120 mM salinity) by NaCl, application of PGPR at two levels (no inoculation as control and seed inoculation with Azospirillium), and foliar application of nanoparticles at four levels (foliar application with water as control, foliar application of 0.8 g.L-1 nano zinc oxide, foliar application 50 mg.L-1 nano silicon, foliar application both of nano zinc oxide (0.4 g.L-1) and nano silicon (25 mg.L-1). The strains and cell densities of microorganisms used as PGPR in this experiment were 1×107 bacteria per milliliter (107 cfu.ml−1). A two-part linear model was used to quantify the grain-filling parameters. In this study, grain dry weight and number were used to calculate the average grain weight for each sample. Total duration of grain filling was determined for each treatment combination by fitting a bilinear model:    GW =where GW is the grain dry weight; a, the GW-intercept; b, the slope of grain weight indicating grain filling rate; t, the days after earring; and t0, physiological maturity. The effective grain filling period (EGFD) was calculated from the following equation:EGFD = the highest grain weight (g)/rate of grain filling (g day-1).

The results showed that application of Azospirillium and foliar application of nano zinc-silicon oxide under no salinity increased chlorophyll a (38.42%), chlorophyll b (41.76%), total chlorophyll (39.39%), carotenoids (53.99%), root weight (62.61%), grain filling rate (16.37%), grain filling period and effective grain filling period (21.28 and 29.78%) and grain yield (47.23%) in compared to no application of Azospirillium and nanoparticles under 120 mM salinity. Application of Azospirillium and foliar application nano zinc-silicon oxide under 60 mM salinity also increased chlorophyll a (31.4%), chlorophyll b (34.35%), total chlorophyll (32%), carotenoids (45.68%), root weight (57.14%), grain filling rate (15.21%), grain filling period and effective grain filling period (21.29 and 28.16%) and grain yield (35.67%) in compared to the application of Azospirillium and nanoparticles under 120 mM salinity. According to this study, application of Azospirillium and nanoparticles (zinc and silicon) can increase yield of triticale grain under salinity stress such as no salinity due to the improvement of photosynthetic pigments content and grain filling components.

Salinity is one of the major constraints to wheat growth, which hampers production, causing yield loss in arid and semi-arid regions. Reductions in growth resulting from high salinity are because of both osmotic stress, inducing a water deficit, and the effects of excess Na+ and Cl– ions on critical biochemical processes. Salt stress induces a significant reduction in photosynthesis through the reduction of leaf area and photosynthetic pigments. Several strategies have been developed to decrease the toxic effects caused by high salinity on plant growth. Among them, the use of plant growth-promoting rhizobacteria (PGPR) such as Pseudomonas and Mycorrhiza play an important role in yield improvement. Many studies have been published on the beneficial effects of bacterial inoculation on plant physiology and growth under salt stress. One of the common hypotheses employed in most of the studies conducted under salinity stress was the lowering of ethylene level by the ACC-deaminase activities of PGPR and improved plant growth and yield under salinity stress.
It was reported that the application of Pseudomonas spp. improved plant growth by decreasing the uptake of Na+ and increasing the activities of antioxidant enzymes under salinity stress. The selective uptake of K+ as opposed to Na+ is considered one of the important physiological mechanisms contributing to salt tolerance in many plant species. Inoculation with PGPR significantly decreased Na+ uptake and increased K+ content and enhanced levels of K+ that could be to mitigate oxidative stress imposed by higher salinity. Some researchers have reported that PGPR species like Azotobacter and Pseudomonas increased the growth and biomass of canola (Brassica napus L.) under salinity stress.
A Better understanding of wheat physiological responses under salinity may help in programs in which the objective is to improve the grain yield under salinity stress. Therefore, this study aimed to evaluate the physiological, stomata conductance, along with root and shoot Na+/ K+ ratios) of wheat to cycocel and PGPR application under salinity stress.

A factorial experiment was conducted based on a randomized complete block design with three replications at the research greenhouse of the Faculty of Agriculture and Natural Resources, the University of Mohaghegh Ardabili in 2018. The experimental factors included salinity at four levels (no-salinity as control, salinity 40, 80, and 120 mM NaCl based salinity), application of biofertilizers at four levels (no biofertilizers as control, mycorrhiza application, application of both Pseudomonas and Flavobacterim, application of mycorrhiza with Pseudomonas and Flavobacterim) and putrescine foliar application at three levels (foliar application with water as control, foliar application of 0.5 and 1 mM putrescine). Mycorrhiza fungi were purchased from the Zist Fanavar Turan Institute and soils were treated based on the manufacturer’s protocol of 20 g of inoculums per m2 of soil. 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 107 colony-forming units (CFU). Humidity ranged from 60-65%. The wheat cultivar "Gascogne" was used in the experiment. The optimum density of cultivar "Gaskogen" is 400 seeds m-2, so forty seeds of wheat were sown in each pot at a depth of 4 cm deep. The pots were immediately irrigated after planting. Nano putrescine zinc oxide powder was added to deionized water and was placed on ultrasonic equipment (100 w and 40 kHz) on a shaker for making a better solution. Foliar application with nano putrescine oxide was done in two stages of period growth (pre and post-4 booting stage).

The results showed that with increasing salinity, potassium content, stomata conductance, and leaf area index decreased but the application of putrescine and biofertilizers increased these traits. At the highest salinity level (120 mM), there was a decrease of 24.94 and 21.57% respectively in Na+ root and shoots in the application of mycorrhiza with Pseudomonas and Flavobacterim and foliar application of 1 mM putrescine in comparison with no application biofertilizer and putrescine in same salinity level. At the highest salinity level, application of mycorrhiza with Pseudomonas and Flavobacterim and foliar application of 1 mM putrescine increased K+  root (47.76%), shoots (21.66%) and grain yield (28.57%) in comparison with no application biofertilizer and putrescine in same salinity level. It seems that the application of biofertilizers and putrescine can increase the grain yield of wheat under salinity stress due to improve stomata conductance and leaf area index.

In arid and semi-arid regions, drought stress as the main factor and salinity stress as a secondary factor decreases plant growth and yield. Water limitation can damage pigments and plastids, and reduce chlorophyll index, rate, and grain filling period. Several strategies have been developed to decrease the toxic effects caused by environmental stresses on plant growth. Among them, the use of bio-fertilizers such as plant growth-promoting rhizobacteria (PGPR) and also nanoparticles such as nano iron-silicon oxide plays a very important role in yield improvement. Inoculation of plants with native suitable microorganisms may decrease the deleterious effects of environmental stresses and increase stress tolerance of plants by a variety of mechanisms, including synthesis of phytohormones such as auxins, cytokinin, and gibberellins, solubilization of minerals like phosphorus, production of siderophores and increase in nutrient uptake, N2 fixation. It seems that application of nanoparticles and biofertilizers can improve triticale yield under water limitation conditions.

To study the effects of bio-fertilizers and nano silicon-iron oxide on the quantitative yield and grain-filling components of triticale under water limitation conditions, a factorial experiment was conducted based on randomized complete block design with three replications at the research farm of the faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili during 2021. The experimental factors included irrigation in three levels (full irrigation as control, irrigation withholding at 50% of the heading stage based on codes 43 of the BBCH scale; irrigation withholding at 50% of the booting stage based on codes 55 of the BBCH scale), as severe and moderate water limitation respectively, application of biofertilizers in four levels (no application of biofertilizers 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, nano silicon, both foliar application nano iron-silicon oxide). The strains and cell densities of microorganisms used as PGPR in this experiment were 108 bacteria per milliliter (108 cfu.ml−1). A two-part linear model was used to quantify the grain-filling parameters. In this study, anthocyanin, flag leaf protein, chlorophyll index, grain filling components, and yield of triticale were investigated. Chlorophyll Index was calculated by a chlorophyll meter (SPAD-502; Konica Minolta Sensing, Inc., Japan). Grain dry weight and number were used to calculate the average grain weight for each sample. The total duration of grain filling was determined for each treatment combination by fitting a bilinear model: 
Where GW is the grain dry weight; a, the GW-intercept; b, the slope of grain weight indicating grain filling rate; t, the days after earring; and t0, physiological maturity. The effective grain filling period (EGFD) was calculated from the following equation:EGFD = the highest grain weight (g)/rate of grain filling (g day-1).

The results showed that the both application of biofertilizers and foliar application of nano iron-silicon oxide in full irrigation, increased maximum grain weight (56.07%), grain filling period, and Effective grain filling period (22.29 and 48.43% respectively), chlorophyll index (45.11%) and flag leaf protein (64.75%), plant height (49.31%), number of grains per spike (70.58%), spike length (53.75%), 1000 grains weight (64.9%) and grain yield (43.28%) in compared to no application of biofertilizers and no foliar application under severe water limitation. Severe water limitation increased the content of anthocyanin, but the application of biofertilizers and foliar application of nano silicon-iron oxide decreased its content.

Based on the results of this study, it seems that application of both applications of Azospirilum and Pseudomonas and foliar application of nano iron-silicon oxide can be applied as a proper method for increasing grain yield of triticale under water limitation conditions.

In order to study the effects of nanoparticles and biofertilizers on chlorophyll fluorescence indices and some physiological traits of triticale (Triticosecale Wittmack) under salinity stress, a factorial experiment was conducted based on a randomized complete block design with three replications in the research greenhouse of Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardebili in 2021. Experimental factors included salinity (non-saline control, 35, and 70 mM NaCl), application of biofertilizers (PGPR) (biofertilizers-free control, application of Azospirilum, Pseudomonas, combined application Azospirilum and Pseudomonas) and nanoparticles foliar application (foliar application with water as control, nano iron oxide foliar application, nano silicon, combined foliar application of nano iron-silicon oxide). The results showed that both application of PGPR and foliar application of nanoparticles under non-saline condition increased quantum yield (64%), maximum fluorescence (69%), variable fluorescence (175%), chlorophyll index (48.1%), leaf nitrogen content (35.3%), leaf relative water content (49.7%) and stomatal conductance (81.4%) and grain yield per plant (44.5%) in comparison with biofertilizers-free and nanoparticles foliar application under 70 mM salt condition. Maximum of minimum fluorescence (178) and electrical conductivity (126) were obtained at the highest salinity level, i.e. 70 mM NaCl. Based on the results of this study, it seems that application of bio fertilizers and nanoparticles foliar application may improve the grain yield of triticale under salinity stress.

Grasspea (Lathyrus sativus L.) is one of the most important forage crops in the world. It contains 12 to 20% protein. Silicon (Si) existing in the Earth’s crust is classified as the most abundant element after oxygen. Although silicon is not considered an essential element for plant growth, but a number of studies have reported that it as an important factor in plants that plays an important role in the resistance mechanisms of plants against environmental stress. Also, it plays a crucial physiological role in photosynthetic rate and chlorophyll content. One of the most effective factors in increasing the Grasspea biomass is seed inoculation with plant growth-promoting rhizobacteria (PGPR). Some of the benefits provided by PGPR are the ability to produce gibberellic acid, cytokinins and ethylene, N2 fixation, solubilization of mineral phosphates and other nutrients. Numerous studies have shown a substantial increase in dry matter accumulation via inoculation with PGPR. Some researchers reported that seed inoculation with PGPR enhanced relative water content and photochemical efficiency of PSII lathyrus under water limitations. Therefore, the aim of this study was to evaluate the effects of nano silicon and seed inoculation with plant growth-promoting rhizobacteria on biomass, nodulation and some physiological traits of Grasspea.

In order to study the effect of nano silicon and plant growth-promoting rhizobacteria on biomass, nodulation and some physiological traits of Grasspea, a factorial experiment was conducted based on randomized complete block design with three replications in research farm of University of Mohaghegh Ardabili in 2021. Treatment were included application of plant growth-promoting rhizobacteria at four levels (no inoculation as control, seed inoculation with Azosprillum lipoferum strain OF, Psedomonas putida strain 186, both application of Azospirillium and Pseudomonas) and nano silicon foliar application at four levels (foliar application with water as control, foliar application 25, 50 and 75 mg.L-1 nano silicon). The area is located at 38° 15ʹ N latitude and 48° 20ʹ E longitude with an elevation of 1350 m above mean sea level. Climatically, the area is situated in the wet zone with cool winter and hot summer. For inoculation, seeds were coated with gum Arabic as an adhesive and rolled into the suspension of bacteria until uniformly coated. Seeds were inoculated with plant growth promoting rhizobacteria (PGPR) at the rate of approximately 1 × 107 colony forming units (CFU) mg-1 just before planting. Foliar application of nano silicon was conducted in two stages of vegetative growth. 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. At the Flowering stage, the leaves of plants were selected to measure the stem and leaf protein, chlorophyll index, RWC (relative water content), quantum yield, stomatal conductance and EC (electrical conductivity). RWC was calculated based on method of Kostopoulou et al. (2010). Chlorophyll Index was calculated by chlorophyll meter (SPAD-502; Konica Minolta Sensing, Inc., Japan). The Quantum yield of leaves was calculated with fluorometer (chlorophyll fluorometer; Optic Science-OS-30 USA). Stomata conductance was measured with a porometer system (Porometer AP4, Delta-T Devices Ltd., Cambridge, UK) according to the instructions in its manual. Leaf electrical conductivity (EC) values were measured at room temperature of 23±1°C using an electrical-conductivity meter. Analysis of variance and mean comparisons were performed using SAS 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.

The results showed that both application of Azospirillium and Pseudomonas and foliar application of 75 mg.L-1 nano silicon increased root weight and volume (40.4 and 41.9%), number of active nodules (81.2%), percentage of active nodules (33.2%), nodule dry weight (37.4%), chlorophyll index (46%), relative water content (46.3%), stomatal conductance (34.6%) and quantum yield (34.1%) in comparison with no application of PGPR and nano silicon. Also, the highest leaf and stem protein (23.37 and 12.66%) and total biomass (37.7 %) were obtained in both application of Azospirillium and Pseudomonas and foliar application of 75 mg.L-1 nano silicon in comparison with no application of PGPR and nano silicon.

It seems that application of PGPR and foliar application of nano silicon can increase biomass of Lathyrus sativus due to nodulation and  improving  physiological traits.

Inroduction & Objective:

Increasing in temperature and drying of pastures cause water and nutritional stress to animals. In this study, resistance control genes in crossbred and native sheep were examined.

In this study, ten cross of Romanov native male lambs and ten purebred male native lambs in 4 treatments and 5 replications in each group were used. They are divided into two groups with normal and water restriction condition. At the end of the experiment, liver tissue samples were collected from slaughtered animals and it was kept in liquid nitrogen, to investigation of gene expression whole RNA was extracted and purified and the cDNA was synthesis. In the end Real Time PCR reaction were performed using specific primers.  For statistical analysis we used randomized design as factorial analysis method using SAS 9.2.

By extracting the genes, it was found that the expression of GPX1, TFAM, SIRT3, PRKAA1, NRT2 genes increased under stress in native sheep compared to crossbred sheep.

The expression of GPX1, TFAM, NRF2, SIRT, PKAA1 genes in the liver of two groups of native and crossbred in normal and stress conditions indicate that Under stress, these four groups of genes act as oxidative process and store energy and prevent energy loss and protect the cell. Due to the genetic compatibility of native sheep with the drought conditions of the region, it makes the animal more resistant to heat and disease.

Drought is the most severe abiotic stress factor limiting plant growth and crop production. Many physiological processes in plants are impaired by drought stress. Also, this stress can damage the photosynthesis of plants, pigments and plastids reduce chlorophyll a, chlorophyll band other carotenoids, hydrolyze proteins and prevalent photochemical reactions in most plants. The response of plants to drought stress depends on several factors such as developmental stage, severity, duration of stress, and cultivar genetics. Several strategies have been developed in order to decrease the water limitation-induced toxic effects on plant growth, among them use of bio fertilizers and putrescine play a key role in yield improvement. The aim of this study was to investigate the effects of irrigation withholding during reproductive stage and putrescine and bio fertilizers application on grain filling period, chlorophyll content and yield of wheat.

A 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 percent of heading stage and irrigation withholding in 50 percent booting stage as moderate and severe water limitation respectively) and bio fertilizers at four levels (no bio fertilizer, application of mycorrhiza (Glomus Intraradices), both application Psedomunas(Psedomunas Putida Strain 186)and Flavobacterim Spp, application of mycorrhiza  with Psedomunas and Flavobacterim), foliar application putrescine in three levels (foliar application with water as control and foliar application 0.5 and 1 mM of putrescine). Mycorrhiza fungiwas 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. Two part linear model was used to quantifying the grain filling parameters. In this study, total chlorophyll, chlorophyll a, b, carotenoid, grain filling components and yield of wheat were investigated. Grain dry weight and number were used to calculate the average grain weight for each sample. Total duration of grain filling was determined for each treatment combination by fitting a bilinear model: 
Effective grain filling duration (EGFD) was calculated from the below equation: EGFD = the highest grain weight (g)/rate of grain filling (g.day-1).

Means comparison showed that maximum of grain weight (0.0641 g), grain filling rate (2.28 mg.day-1), grain filling period (39.7 day) and effective grain filling period (28.14 day) were obtained in full irrigation, application of mycorrhiza with Psedomunas and Flavobacterim and foliar application 1 mM of  putrescine and the least of these traits (0.0361 g, 1.6 mg. day-1, 33.15 and 22.57 days respectively) were obtained in irrigation withholding at booting stage and no application of putrescine and bio fertilizers, there were an increase about 77.56%, 42.5%, 19.76% and 24.68% in this treatment compounds in comparison with withholding at booting stage and no application of putrescine and bio fertilizers. Full irrigation, both application Psedomunas and Flavobacterim withmycorrhiza and foliar application 1 mM of putrescine increased volume and root dry weight 124.37 and 123.47% respectively. Grain yield under irrigation withholding in heading and booting stages decreased in comparison with full irrigation. The highest grain yield was obtained in full irrigation (682.68 g.m-2), both application Psedomunas and Flavobacterim(686.42 g.m-2) andfoliar application 1 mM of putrescine (618.02 g.m-2).

Based on the results of this study, it seems both application of mycorrhiza with Psedomunas and Flavobacterim and foliar application 1 mM of putrescine with full irrigation can increase grain yield of wheat due to improve biochemical and physiological traits under water limitation condition in reproductive stages.

Water limitation can damage pigments and plastids, reduce chlorophyll a, chlorophyll b, rate and grain filling period. One approach to improve the water stress problem is the use of plant growth promoting rhizobacteria (PGPR) and Mycorrhiza. The PGPR are a group of rhizosphere colonizing bacteria that produces substances to increase the growth of plants, synthesize different phytohormones, including auxin, cytokinin, and gibberellin, synthesize enzymes that can modulate plant growth and development. Arbuscular mycorrhizal fungi (AMF) symbiosis is considered a valuable component in most agricultural systems due to their role in plant nutrition and soil health. Silicon (Si) is considered as quasi-essential for plant growth and development, and alleviates toxic effects caused by various environmental stresses in plants. So, it seems that application of nano silicon and bio-fertilizer can improve wheat yield under water limitation conditions.

In order to study the effect of nano silicon and bio-fertilizer on yield and grain filling components of wheat in different irrigation levels, 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, University of Mohaghegh Ardabili in during 2018-2019. The experimental factors were included irrigation in three levels (full irrigation as control, moderate water limitation or irrigation withholding at 50% of heading stage; severe water limitation or irrigation withholding at 50% of 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). Psedomunasand flovobacterium were isolated from the rhizospheres of wheat by Research Institute of Soil and Water, Tehran, Iran. A two part linear model was used to quantifying the grain filling parameters. In this study, total chlorophyll, chlorophyll a, b, carotenoid, grain filling components and yield of wheat were investigated. Grain dry weight and number were used to calculate the average grain weight for each sample. Total duration of grain filling was determined for each treatment combination by fitting a bilinear model: Effective grain filling duration (EGFD) was calculated from the below equation: EGFD = the highest grain weight (g)/rate of grain filling (g day-1).

Means comparison showed that highest grain filling rate (3.04 mg day-1), grain filling period (37 day), effective grain filling period (30.44 day) and grain yield (4593 kg ha-1) were obtained at foliar application of 30 mg L-1 nano silicon, both application of flavobacterium and pseudomonas with mycorrhiza under normal irrigation. Also, maximum of chlorophyll a, chlorophyll b, total chlorophyll and carotenoid content (2.04, 0.93, 2.87 and 9.89 mg g-1 FW-1 respectively) were obtained at foliar application of 60 mg L-1 nano silicon in seed inoculation with flavobacterium and pseudomonas under normal irrigation. Maximum of volume and root dry weight were obtained at foliar application 60 mg L-1 nano silicon and mycorrhiza application fungi under normal irrigation. The highest leaf area index was obtained at both applications of flavobacterium and pseudomonas with mycorrhiza, foliar application 30 mg L-1 nano silicon under normal irrigation.

Generally, it seems that application of bio-fertilizers and nano silicon can be recommended as appropriate management factors for increasing grain yield and grain filling components of wheat under water limitation conditions.

In order to study the effects of supplementary irrigation and biofertilizers on grain yield, dry matter remobilization and some physiological traits of barley (Hordeum vulgare L.) under rainfed condition, a factorial experiment was conducted based on randomized complete block design with three replications at in 2017. Factors included irrigation at three levels (no irrigation as rainfed (I1), supplementary irrigation at 50% heading (I2) and booting stages(I3) and biofertilizers application at four levels (without biofertilizers as control (Q1) , application of mycorrhiza(Q2), Azetobacter(Q3), both application of mycorrhiza and Azetobacter(Q4). The results showed that supplementary irrigation at heading stage with both application of mycorrhiza and Azetobacter increased efficiency of PSII photochemistry (Fv/Fm(, chlorophyll index and relative water content of flag leaf compared to non-application of biofertilizers under rainfed condition. Rainfed condition and no application of biofertilizers increased electrical conductivity and contribution of dry matter remobolization in grain yield. The highest and the lowest grain yields (268.2 and 206.5 g m-2 respectively) were obtained at supplementary irrigation at heading stage with both application of mycorrhiza and Azetobacter, and no application of biofertilizers under rainfed condition. In conclusion, it seems that application of biofertilizers and supplementary irrigation can increase grain yield of barley under rainfed condition due to improving some physiological traits.

In order to study the effects of supplementary irrigation and nano iron oxide on  the grain yield, and  some physiological and biochemical traits of wheat (Triticum aestivum L.) under rain fed conditions, a factorial experiment was conducted based on a  randomized complete block design with three replications in Agricultural Research Station of Ardabil, Northwest of Iran, in 2016. Factors included irrigation levels (no irrigation as the rainfed, supplementary irrigation at heading and booting stages), nano iron oxide application at four levels (without nano iron oxide as the control, application of 0.3, 0.6 and 0.9 g L-1). Application of 0.9 g L-1 nano iron oxide under rainfed condition increased soluble sugars and proline content and antioxidant enzymes activity (catalase, peroxidase and polyphenol oxidase) by 129.89, 168.76, 27.64, 94.2, and 31.71%, respectively, in comparison with no application of nano iron oxide and supplementary irrigation at the booting stage. Also, there were 75.89 and 38.43 increases, respectively, in the leaf protein and grain yield with the application of 0.9 g L-1 nano iron oxide and the supplementary irrigation at the booting stage, in comparison with no application of nano iron oxide under rainfed conditions. It seems that the application of nano iron oxide and supplementary irrigation can increase the grain yield of wheat under rainfed conditions due to improving the physiological and biochemical traits.

As the progress of molecular genetics techniques, it is now possible to determine the relationship between individuals and their evolutionary process. In this study, the genetic structure and assignment test of Kurdish horses breed to its origin or Arab and Turkmen horses breed were investigated using 12 microsatellite markers recommended by the International Society for Animal Genetics (ISAG). For this purpose, blood samples from 238 Kurd, 36 Arab and 30 Turkmen horses were taken in their distribution areas. DNA was extracted from Blood samples by the salting-out method. DNA fragments were amplified by multiplex PCR reaction using fluorescently labeled primers and determined by capillary electrophoresis. The mean of observed and effective alleles for all markers was 9.9 and 4.71, respectively. The highest and lowest expected heterozygosity was obtained for ASB17 (0.83) and HTG4 (0.71) markers, respectively. Cluster analysis using the UPGMA method and the Dice coefficient differentiated each breed. The result of the Bayesian Assignment test showed that all individuals correctly assigned to its population, so it seems that these markers are useful for the assignment test. Overall, the results of this study showed that the microsatellite markers used in this study showed high genetic diversity, so the use of these markers for genetic diversity study and assignment test of the Kurdish horse is recommended. So, these markers can be used to determine the exact origin of the Kurdish horse breed and eliminated the non-purebred horses from the reproductive process.

This study was conducted to investigate the  role  of water and polyamines (PAs) as priming  agents on  improving seed vigour and chilling tolerance with  different  moisture  content (Mc)(14.0,16.0,18.0%) under chilling conditions in barley (Hordeum vulgare L.) c.v Usef. Experiments were conducted at the seed and Plant certification and Registration Research Institute in 2013 -2014. The seeds were hand harvested at three initial moisture contents including 18, 16, and 14%  wet weight basis .The seed samples then were sealed in polythene bags and stored in conditioned storage and equilibrium for 8 months. After that for seed priming, seeds were soaked in 20mg/L-1 (w/v) aerated solution of spermine (Spm), Puterscine (Put), and Spermidine (Spd) and distilled water (W) for 16h at 20±2C°. After each treatment, Seeds dried to original moisture level in forced air and sealed in polythene bags, stored in a conditioned storage again until one month. Experimental units were arranged as factorial in a completely randomized design with four replications after treat. The results indicated that Mc18% improved the germination percentage (GP) and seedling vigour compared to Mc 16 and 14%. The electrolyte leakage decreased in seeds harvested by Mc 18% when compared with Mc16 and Mc 14.0%. Also seed treatments significantly increased the seed viability. Likewise, in chilling stress condition maximum proline content and areal dry weight were obtained from Put treat, whereas the lowest electrolyte leakage was recorded for Put treat. Meanwhile, interaction between seed moisture content ×PAs treatment in cold condition significantly affected on plumule length and radicle dry weight, statistically maximum plumule length and radicle dry weight were recorded from Put ×18.0% mc. Also seed priming with water had positive effect on seedling growth after chilling stress.  Generally, the effectiveness of PAs on improving chilling tolerance and increasing seedling vigor was more pronounced in Put treatment along with sample with 18.0% mc.

In this research effect of priming types was investigated on the activity of antioxidant enzymes including Catalase (CAT), Ascorbate peroxidase (APX), Superoxide dismutase (SOD), Malone dialdehyde (MDA) and Gluthation reductase (Gred) in hybrid maize single cross 704 under drought stress. Treatments were drought at 4 levels (0, -3, -6 and -9 bar) and priming (Hormone, hydro, osmo, ascorbic and control). Germination percentage, seedling vigor and the activity of antioxidant enzymes were measured. Results showed that interaction of drought and priming was significant an all traits except of germination percentage. The highest seedling vigor (15.996) obtained from control condition. The highest CAT activity (35 μmol min-1 mg-1) observed in ascorbic acid priming at -9 bar drought stress. Also, the highest APX activity was related to hormone priming and -9 bar. While the lowest activity observed in control drought and osmo-priming. The highest amount of MDA achieved in -9 bar and control priming. The highest SOD activity observed in -9 bar. The highest Gred activity obtained by ascorbic acid priming at -9 bar.

In order to investigate the effects of seed deterioration on the activity of antioxidant enzymes and lipid peroxidation in pumpkin seedlings a factorial experiment conducted based on completely randomized design with three replications. Treatments were three deterioration levels (control, 5 and 10 days deterioration at 45◦C and 95-100% relative humidity) and three germination temperatures (15, 25 and 35°C). Results showed that activity of superoxide dismutase and catalase were the highest at 5 days aging and 25°C, and activity of peroxidase was the highest at non-aging and 25°C. Also, the highest amount of Malondialdehyde (7.1 mmol gr-1FW) observed in the seeds with 10 days deterioration and 15°C. The highest respiration index (0.018 mg) achieved in 5 days deterioration and 35°C and the lowest value (0.009 mg) was related to 10 days deterioration and 35°C. It seems that reduction in seed vigor under deterioration and high temperatures causes to oxidative stress and lipid peroxidation and leads to increase in the activity of antioxidant enzymes in order to face the related damages. Considering results obtained from germination and antioxidant enzymes activity the best temperature for germination of aged seeds of pumpkin was 15◦C.

In order to study of the effects ofnano-zinc oxide andseed inoculation with plant growth promoting rhizobacteria on phosphatase activity, zinc and protein content and related traits to grain growth of Triticale, a factorial experiment was conducted based on a randomized complete block design with three replications in research greenhouse of faculty of Agriculture Sciences, University of Mohaghegh Ardabili in 2013. Factors were seed inoculation with plant growth promoting rhizobacteria in four levels (without inoculation as control, seed inoculation with Azotobacter chrocoococum strain 5, Azosprillium lipoferum strain OF and Psedomunas putida strain 9) and foliar application of nano-zinc oxide at five levels (0 as control,0.25, 0.5, 0.75 and 1 g.lit-1). Means comparisons showed that maximum of phosphatase activity (1.35 nmol.min-1, zinc (31.4 mg.kg-1 and protein (134.2 g.kg-1) content, rate (0.10017 g.day-1) and grain filling period (40.74 days)were obtained at application of  1 g.lit-1 Nano-Zinc oxide and seed inoculation with Azosprillium and minimum of them (0.46 nmol.min-1, 23.1 mg.kg-1  ,108.6 g.kg-1, 0.0012 g.day-1 and 24.12 days respectively) were recorded at no application of nano-zinc oxide and without of seed inoculation with PGPR. Therefore, it seems that in order to improve seed quality, increasing of grain filling period, zinc and protein content, it can be suggested that be applied 1 g.lit-1 Nano-Zinc oxide ×seed inoculation with Azosprillium.

This study was conducted to investigate the role of polyamines (PAs) as priming agents on  improving seed vigour with  different  moisture  content (Mc)(14,16,18%) under storage conditions in barley (Hordeum vulgare L.) c.v Usef. Experiments were conducted at the Seed and Plant Certification and Registration Research Institute 1n 2012 -2013. The seeds were hand harvested at three initial moisture contents including 18, 16, 14% using wet weight basis. The seed samples then were sealed in polythene bags and stored in conditioned storages and for 8 months. After that for seed priming, seeds were soaked in 20mg/L-1 (w/v) aerated solution of Spermine (Spm), Puterscine (Put), and Spermidine (Spd) and distilled water (W) for 16h at 20±2C°. After each treatment, seeds were dried to original moisture level in forced air and sealed in polythene bags, stored in a conditioned storage again for one month. Experimental units were arranged as a completely randomized design with four replications after harvesting time and one month conditioned storage after treatment. The result indicated that 18% MC improved the germination percentage and seedling vigour compared to 16 and 14 % MC. Also after 8 month storage, 18% Mc had the highest germination percentage and seedling vigour. The electrolyte leakage decreased in seeds with 18% MC compared to 16 and 14% MC. Also seed treatments significantly increased the seed viability and germination percentage, whereas, mean germination time and electrical conductivity were reduced in all seed treatments. Meanwhile, maximum germination percentage was detected for seed Spm seed treatment and 18% MC. Generally by decreasing moisture content of seed and delay in harvesting time, seedling vigour decreased and the optimum moisture content and seed treatment were  18% and Spm, respectively.

In order to investigate the effects of free living nitrogen fixing bacteria application and time of nitrogen spraying on contribution of stem reserves in grain yield, rate and effective grain filling period of Triticale, a factorial experiment was conducted based on a randomized complete block design with three replications in Research farm of the Faculty of Agriculture, University of Mohaghegh Ardabili in 2012. Treatments consisted of different nitrogen spraying times in four levels (no spraying as control, spraying in boot stage, ear emergence, grain filling period) and seed inoculation with plant growth promoting rhizobacteria in four levels containing (without inoculation as control, seed inoculation with Azotobacter chroococcum strain 5, Azospirillum lipoferum strain OF, Psedomunas putida strain 9). Results indicated that spraying time of nitrogen fertilizer and seed inoculation with free living nitrogen fixing bacteria had significant effects on yield, yield components, rate and effective grain filling period of Triticale. Maximum of grain weight (0/054 gr) and effective grain filling period (34.17 days) were obtained in seed inoculation with Azotobacter× nitrogen spraying in boot stage. Maximum of contribution of stem reserves in grain yield (30.63 %) was obtained in no nitrogen spraying × no seed inoculation with PGPR and minimum of  it (8.12 and 8.13 %) were obtained in nitrogen spraying in boot stage × seed inoculation with Azotobacter and spraying in ear emergence × seed inoculation with Azotobacter. It seems that in order to increase the grain yield,rate and effective grain filling period of Triticale, it can be suggested that nitrogen spraying is applied in boot stage and seed inoculation with Azotobacter

In order to study the qualitative and quantitative yield and some agronomic characteristics of sunflower (Helianthus annus L.) in response to seed inoculation with PGPR under various levels of nitrogen fertilizer, a factorial experiment was conducted based on a randomized complete block design with three replications in field experimental University of Mohaghegh Ardabili during growing season of 2009-2010. Factors were nitrogen fertilizer in three levels (0, 80 and 160 kg N ha-1) as urea and seed inoculation with plant growth promoting rhizobacteria in four levels containing, without inoculation (as control), seed inoculation with Azotobacter chroococcum strain 5, Azospirillum lipoferum strain OF, Psedomunas strain 186. Results indicated that nitrogen levels and seed inoculation with Plant Growth Promoting Rhizobacteria (PGPR) had significant effects on all of characteristics studied (except grain 1000 weight and stem diameter). Grain yield, plant height, head diameter, seed number per head,, yield and oil percentage, yield and protein percentage increased with increasing of nitrogen fertilizer and application of seed inoculation with PGPR. Response of grain yield wasnt the same for various levels of nitrogen fertilizer and seed inoculation with PGPR. The highest grain yield belonged to application of 160 kg N ha-1 and seed inoculation with Azotobacter. Means comparison showed that treatment compounds N160 × without inoculation with PGPR and N80 × seed inoculation with PGPR Azotobacter had similar grain yields. Thus, it can be suggested that in order to increasing of grain yield seed should be inoculated with Azotobacter bacteria × 80 kg N/ha in conditions of Ardabil region.

In order to investigate the competition effect and yield of two soybean cultivars in pure stand and intercropping systems, a factorial experiment based on randomized complete block design with three replications was conducted in field, 22 kilometers from Gorgon-Sari in 2002. Factors were: soybean cultivars Pershing and Williams with three densities (40, 50 and 60 plants m-2) and six levels of planting patterns of Pershing-Williams(0:100, 20:80, 40:60, 60:40, 80:20, 100:0). The competition models of reverse productivity for Willims and Pershing in pure stand was Cayera equation and for intercropping were Shenozoki and Cayera equations. The reverse productivity of single plant in pure stand in both cultivars had a linear relationship with plant density. The results showed that productivity of Williams single plant was equal to 1.2385 of Pershing and the single plant productivity of Pershing was equal to 0.9212 of Willims. The intracultivar competition in Willims was more than intercultivar competition, while in Pershing it was vice versa. The differences between inverse productivity of single plant of Williams in pure cultivation and intercropping was very low. But in Pershing this difference was relatively high, which shows that Willims cultivar is more competitive than Pershing. The highest yield was obtained at the ratio of 40:60 with 50 plantsm-2 and land equivalent ratio of 1.21.