جستجوی مقالات مرتبط با کلیدواژه "root volume" در نشریات گروه "زراعت"

 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.

Chickpea is the third most important grain legume and its seeds contain protein that is an important energy source for human. Drought diminishes crop yields and carries the potential to result in total crop failure. However, chickpeas are renowned for their superior drought tolerance compared to many other cool-season legumes. Given that water availability is the primary constraint on growth in arid conditions, optimal yields and crop production occur when plants efficiently absorb the limited soil moisture available. This feature will only be achieved through the compatibility mechanisms associated with the root system. Chickpea have a direct and deep root system that helps the plant absorb moisture from the lower layers of the soil. Therefore it has led to the prosperity of its cultivation in rainfed areas. Water absorption by the plant depends on the size of the root, its activity and distribution in the soil. Therefore, it seems that the understanding of plant root traits is necessary to further understand the mechanisms of drought resistance. In general, few studies have been done on the diversity of legume roots. Therefore, this research was carried out with the aim of investigating the diversity of root morphological traits of chickpea lines in order to use these traits to select drought-tolerant chickpea lines.
 

The plant materials of this experiment included 39 chickpea lines of Icarda origin, which were taken from the Kurdistan Research Center. The experiment was conducted as a completely randomized design with four replications in the research greenhouse of Ilam University. Seeds were implanted in PVC tubes with a diameter of 10 cm and a length of 60 cm. A drip irrigation system was designed in such a way that an emitter was located inside each tube. With this method, the test tubes were in favorable conditions. In the greenhouse the temperature was under control and had a temperature of 25 degrees Celsius and an average humidity of 70% and the plants used natural light without any additional light. After 35 days of seed germination traits were measured. For this purpose, first the aerial parts of the plant were separated by scissors. After separating the roots from the PVC tubes, they were placed in ethanol with a concentration of 98% and after being transferred to the laboratory, they were stored in the refrigerator, then the traits were measured. Variance analysis of traits and average comparison of data was done with Duncans multi-range test using SAS software version 9.1.
 

All the measured traits had a good variation range among the studied chickpea lines that these results are consistent with previous studies. None of the lines showed superiority for all root traits. Line FLIP07-20C having the longest root length, can benefit from the water available in a larger volume of the soil profile. In the examination of rooting depth in grain legumes, such as chickpeas, it was observed that root length remains relatively stable across a broad spectrum of soil moisture levels. Root length is considered a crucial parameter in plant growth, as researchers posit that the length of roots per unit of soil volume is the most effective characteristic for assessing water and nutrient absorption by plants. In our current investigation, a significant disparity was noted between the highest and lowest root volumes. Root volume stands out as one of the plant's key attributes for absorbing water and nutrients. In this research, line FLIP 82-150C had the highest and line FLIP97-706C had the lowest specific root length. The specific root length is one of the important traits in showing the efficiency of the root in absorbing water and resistance to drought. When faced with drought stress, the plant assigns more dry matter to the root system in order to increase the absorption ability of the roots; as a result, there are changes in the morphological characteristics of the roots, such as an increase in the specific length of the root. The highest root density was observed in line FLIP09-149C. root density is a trait that is affected by root weight and volume. In the condition of drought stress, the decrease in root volume caused an increase in root density and at the end of the growth period, the decrease in root dry weight was more than the decrease in its volume, which ultimately led to a decrease in root density. Studies have indicated that as humidity decreases and soil depth increases, there is a notable decrease in root density. Overall, the findings from this research offer foundational insights for advancing efforts to enhance root characteristics, thereby mitigating drought and enhancing the resilience of chickpea varieties to drought stress.
 

The results showed that Line FLIP07-20C had the highest root length, root length density and root water content compared to other lines, but none of the lines were superior in terms of all root traits. The obtained information about the characteristics of the roots of the studied lines can be used to improve drought-resistant chickpea lines.

This experiment was conducted to investigate the effects of nanoparticles (Zn and Si) and putrescine on grain-filling components of wheat under salinity stress.

An experimental factorial based on a randomized complete block design with three replications was conducted at the research greenhouse of the University of Mohaghegh Ardabili in 2022. The experimental factors included salinity at four levels (without salinity application as control, application of 40, 80, and 120 mM salinity with NaCl) and nanoparticle and putrescine foliar application at eight levels (foliar application with water as control, foliar application of 50 mg.L-1 of Si, foliar application of 1 g.L-1 of Zn, foliar application of 1 mM putrescine, foliar application of Si-Zn, foliar application of Si and putrescine, foliar application of Zn and putrescine, foliar application of Si-Zn and putrescine).

 The results showed that the highest grain-filling period and effective grain-filling period were obtained under nanoparticles and putrescine foliar application. This treatment combination under non-saline condition increased the root weight and volume (48.1 and 53.03% respectively), chlorophyll index (45.75%), and grain-filling rate (20%). There was an increase of 45.34, 62.72, 40.5, 36.21 and 37.37% in plant height, spike length, number of grains per spike, 100 grains weight and grain yield, respectively, under non-saline condition and foliar application with nanoparticle and putrescine in compared with no foliar application under 120 mM salinity.

It seems that the foliar application of nanoparticles and putrescine under salinity can increase the yield of wheat by improving root characteristics and grain-filling components.

Covering a staggering 215 million hectares, wheat stands as the world's most extensively cultivated crop plant. Just like its botanical counterparts, wheat operates as an obligate aerobic organism, implying its reliance on absorbing oxygen from the surrounding environment to facilitate growth, proliferation, and the successful completion of its life cycle. Annual instances of waterlogging stress inflict harm upon wheat crops, attributed to inadequate irrigation practices, subpar drainage systems, uneven field leveling, elevated groundwater levels, the presence of unyielding impermeable layers, and bouts of intense, abrupt rainfall. This adverse impact is progressively escalating, potentially influenced by the ongoing shifts in climate patterns. Consequently, the adoption of resilient cultivars and the genetic enhancement of bread wheat assume critical importance. These strategies are aimed at augmenting the wheat's capacity to effectively cope with waterlogging stress, aligning it with the mounting demands of a burgeoning global population.To achieve these goals, it is necessary to understand the factors causing waterlogging stress damage in wheat and to know the mechanisms of tolerance in this plant. The survival of root terminal meristem cells under waterlogging stress conditions is very limited, and their ability to grow again after removing the stress is also restricted. Waterlogging stress leads to the death of primary roots and reduced growth of lateral roots in wheat. However, there is variation among wheat cultivars concerning these traits. Reduced access to oxygen hampers root growth and nutrient absorption, including nitrogen. Consequently, photosynthesis and carbohydrate availability decrease, further restricting root growth.

An outdoor pot experiment was conducted to investigate the effect of waterlogging stress on shoot and root dry matter, as well as some physiological characteristics. The experiment followed a split-plot design based on randomized complete blocks with three replications. The stress was applied at the three-leaf stage, and three control levels were used: no waterlogging stress, mild stress (48 hours of waterlogging stress), and severe stress (120 hours of waterlogging stress) as the main factors. Cultivars and genotypes were also included as secondary factors.During the stress period, the water level was maintained at approximately 5 cm above the soil level. The cultivation took place outdoors in plastic pots. Data analysis was performed using SAS software, and graphs were generated using Excel software. Comparisons between treatments were based on the standard error. After testing different models, the linear regression model was ultimately employed.

Mild and severe waterlogging stress resulted in a significant decrease in shoot dry matter of 14.06% and 38.37%, respectively, across all cultivars and genotypes. Different cultivars and genotypes exhibited varying responses to waterlogging stress. To further understand the reasons for these differences, among the 21 cultivars and genotypes, Mehrgan and Sarang cultivars, as well as ms 93-16 and ms 93-6 genotypes, were selected due to their contrasting tolerance levels and yield potential. These selected cultivars and genotypes were studied to analyze specific root traits.Amidst severe waterlogging stress, a significant 38% reduction in root dry matter and a corresponding 29% decrease in root volume were recorded when compared to stress-free conditions. This closely mirrored the decline evident in shoot dry matter. Evaluation of the susceptibility index during the three-leaf stage unveiled that sole resilience was exhibited by the Aflak cultivar. In contrast, the remaining cultivars and genotypes were stratified into semi-tolerant and semi-susceptible categories.Notably, regression analysis underscored that even brief periods of waterlogging stress ushered in a reduction in dry matter. Furthermore, the elongation of the waterlogging duration magnified this decrease in dry matter, thereby mitigating the disparities across various cultivars and genotypes.

In general, cultivars that were able to sustain higher levels of photosynthetic activity during waterlogging stress demonstrated a lower percentage decrease in dry matter. Although the Mehrgan cultivar experienced a significant reduction in dry matter yield and fell into the semi-sensitive group, it consistently exhibited significantly higher dry matter yield compared to other cultivars and genotypes across all treatments.

In order to investigate the effect of seed priming (pretreatment) and coating on seedling characteristics, root morphology and phenological stages of rice, a two-year experiment has been conducted in the Rice Research Institute of Iran (Rasht) between 2020 and 2021. The experiment is performed as a factorial in a randomized complete block design with three replications. Experimental factors include two rice cultivars (Hashemi and Gohar) and the seed pretreatment of rice cultivars in seven levels, including (1) priming with calcium chloride (-1.25 MPa in 24 hours), (2) priming with potassium chloride (1.25 MPa in 24 hours), (3) priming with zinc sulfate (concentration of 0.5 mM in 12 hours), (4) hydro-priming (48 hours) + coating the seeds with calcium chloride, (5) hydro-priming (48 hours) + coating with potassium chloride, (6) hydro-priming (48 hours) + coating with zinc sulfate, and (7) hydro-priming (48 hours as control). The results show that the highest percentage and germination rate has been observed with 99.5% and 0.23 seeds per day under seed priming with potassium chloride in the Gohar cultivar, respectively. The lowest time required to achieve 90% emergence has belonged to Hasehmi and Gohar cultivars through priming with potassium chloride and calcium chloride. The highest root length (with 24.6 cm) has been observed in priming with potassium chloride in the Gohar cultivar. The highest root dry weight in Hashemi and the Gohar cultivars has been 2.14 and 4.9 g, respectively, in priming with potassium chloride. The results also show that the maximum root volume and area are obtained with 43 cm3 and 155.28 cm2 in priming with potassium chloride in Gohar cultivar, respectively. The least time required to achieve maximum tillering, 50% flowering, and physiological maturation takes place in priming treatment with calcium chloride and potassium chloride. Seed priming with potassium chloride and coating with calcium chloride have increased grain yield by 22% and 13%, respectively, compared to the control. The highest biological yield is observed in potassium chloride priming and coating with calcium chloride treatments with 5552 and 5414 kg. ha-1 in Gohar cultivar, respectively. In general, rice seed priming with calcium chloride and potassium chloride promoted plant yield by improving seedling characteristics, root system, and phenological stages.

canola (Brassica napus L.) is one of the most important oilseed plants that has been ranked third in the oil production after soybeans and oil palm. Drought is seriously the most important factor limiting the growth and production of canola in Iran. By foliar application of micronutrients, plant growth condition can be improved under stress. Salicylic(SA) acid plays an important role in abiotic stress tolerance, and more interests have been focused on SA due to its ability to induce a protective effect on plants under adverse environmental conditions. It is necessary to know the traits related to drought tolerance and their relationship with seed yield. due to the important role of roots in the absorption and conduction of water and nutrients, recognition the root system and how it is distributed in the soil is special importance. therefore, the purpose of the present study was to investigate the Effect of foliar application of some micronutrients and salicylic acid on root characteristics and seed yield of canola (Brassica napus L.) under water deficit stress.

the experiment was conducted as split factorial in a randomized complete block design with three replications in Lorestan University, Iran, in two cropping seasons (2016-2018). water deficit was considered as the main factor in levels irrigation at 80 (control) and 30% of field capacity, and the combination of foliar application of micronutrient fertilizer (non-consumption and spraying at a concentration of 0.2%) and salicylic acid concentration of 0, 0.5, 1 and 1.5 mM were considered in sub-plots. the time of water deficit stress coincided with the stage of the beginning of regrowth (BBCH32). foliar application of micronutrient fertilizer in rosette stage (BBCH29) and foliar application of salicylic acid in two stage of flowering beginning (BBCH60) and pod filling (BBCH72). the measured traits included root dry weight, root volume, root area, seed yield, oil percentage, and water use efficiency. the data was analyzed by statistical analysis system (SAS version: 9.1). the means were analyzed using the Duncan test at P=0.05.

the results of analysis of variance showed the effect of year on seed yield, effect of salicylic acid on seed yield and oil percentage, double interaction of micronutrient fertilizer in salicylic acid on root volume and triple interaction of stress in micronutrient fertilizer and salicylic acid on root weight, root volume and water use efficiency were significant. the results of comparative analysis of the mean data showed that the highest percentage of oil was obtained from concentration of 1 to 1.5 mM of salicylic acid.the highest root volume (49.90 cm3) was obtained from the treatment composition (foliar application of 1.5 mM salicylic acid and concentration of 2 per thousand micronutrient fertilizers). the highest root dry weight (28.95 gr), root area (4360 cm2) and water use efficiency (1.26 kg m-3) from the treatment composition (no stress + 1.5 mM salicylic acid spraying and concentration of 2 per thousand fertilizers Micronutrients) was obtained. the highest seed yield (4955.7 kg ha-1) was obtained from foliar application 1.5 mM of salicylic acid, In the first year, the highest seed yield (4427.7 kg ha-1) from the combination (no stress + foliar spraying of 1.5 mM salicylic acid and a concentration of 2 per thousand micronutrient fertilizers) and in the second year of the combination (no stress + foliar spraying of 1 mM salicylic acid) and a concentration of 2 per thousand micronutrient fertilizers with an average (4955.7 kg ha-1) was obtained.

therefore, a triple micronutrient fertilizer (iron+zinc+ manganese) with a concentration of 0.2% is recommended along with a concentration of 1.5 mM of salicylic acid to reduce the negative effects of water deficit stress and achieving acceptable seed yield.

The first factor limiting plant yield in many crop ecosystems is drought stress, and plant productivity under these conditions depends on the distribution of dry matter between plant organs and the spatial distribution of roots in the soil. Knowledge of root length conditions and its distribution in soil profile, which is an indicator of the ability of plants to absorb water from deeper layers and better root permeability in the soil, as well as understanding the shape of the root system, is important (Wasson et al., 2012). In general, the size, morphology, and architecture of the root system determine the plant's ability to absorb water and nutrients, as well as the relative size and growth rate of the shoot (Vamerali et al., 2003). Root growth is determined by the genetic characteristics of the plant as well as the physical and chemical characteristics of the soil. Even in wet areas in response to drought stress, root growth is limited to the topsoil, and when the soil dries, its infiltration resistance increases rapidly, resulting in a combination of drought stresses. Soil and its infiltration resistance (He et al., 2017). Reduction of root dry weight in rice (Nasiri et al., 2015), fresh weight of root in rapeseed (Razaviezadeh and Amoubeigi, 2013) indicate the negative effect of drought stress on root characteristics in Different plants. Tillage is the only crop method by which humans can directly affect soil properties. Moisture storage and aeration to the roots, depending on the desired or unfavorable application of tillage, affects the growth and development of plant roots and ultimately its yield (Bronick and Lal, 2005).

This experiment was conducted in split -split plots based on randomized complete block design with three replications. Tillage systems as the main -plot in two factors was including no tillage and conventional tillage, Water stress as the subplot in three levels by 30, 60 and 90 Percent of moisture requirement and nitrogen urea as the sub-sub plot at three levels by 0, 50 and 100 percent of the recommended rate.

The combined variance analyses indicated that the maximum root length (4147 cm per plant), root volume (158.13 cm3 per plant), root area (3055.7 cm2 per plant), root length density (0.44 cm2. cm-3), root dry weight (24.32 gr pl-1) and plant fresh weight (6732.6 gr. m-2) was obtained from the interaction of conventional tillage in mild drought stress (90% of the plant's water requirement) in 100% of the plant's nitrogen fertilizer requirement. Also, the interaction effect of severe drought stress (30% of plant water requirement) in 100% of plant nitrogen fertilizer requirement led to a sharp decrease in studied traits in both studied tillage systems. Although the conventional tillage system in this study ultimately increased the root growth characteristics and fresh weight of the forage maize plant, but because no significant difference in wet forage yield was observed in both studied tillage systems, the system no tillage is recommended because it can improve the physical and chemical properties of the soil in the long turn.

In order to investigate the effect of salinity on some root characteristics and ion distribution, a research was carried out in a split factorial on three replications with two salinity levels (2 dS.m-1) and 16 dS.m1 (salinity) on six wheat cultivars (Atrak, Pishtaz, Chamran, Roshan, Qods, and Shiraz) and in two levels of harvest (two weeks and three weeks after planting) in greenhouse. The traits of root dry weight, shoot dry weight, shoot dry weight/root dry weight ratio, root length, total volume, sodium ion concentration, potassium ion concentration, potassium/sodium ratio in root and shoot, number of axial root, number of first and second- order lateral roots were measured. The results showed that salinity in the second and third week reduced the dry weight of root, shoot, length, root volume, axial, and first-order lateral root number in all cultivars. In the control treatment Chamran and Roshan had the highest ability to produce root and shoot dry weight respectively. Under salinity the highest root dry weight (14 and 18 mg/plant) and total root volume (78 and 93 mm3 /plant) were related to Roshan in both weeks. Qods had the lowest root dry weight with the highest drop (54% and 50%, respectively) in second and third week. The lowest total root volume in salinity of second and third week respectively was related to Qods and Shiraz (40 and 59 mm3 /plant).Qods with high root producing potential in control showed a significant decrease in the production of lateral roots and total root length in salinity. Also, Roshan cultivar, despite having the highest sodium concentration of shoots in salinity treatment, it was able to produce the highest amount of shoots due to maintaining potassium ions in roots and shoots. Based on the traits evaluated and the response of the studied cultivars to salinity, tolerance of the Roshan cultivar and susceptibility of Qods cultivar to salinity arecompatible with previous study at this stage of growth.

Optimizing the effectiveness of herbicides by additives is one of the ecological and economical approaches for weed management. The aim of this study was to investigate the effect of vegetable oils on the efficacy of clethodim herbicide in control of foxtail as a factorial based on a completely randomized design including clethodim concentration in six levels (0, 7.5, 15, 30, 60 and 120 g ai per ha) and additives in eight levels (without vegetable oil and vegetable oils of sesame, bitter almonds, sweet almonds, cottonseed, canola, rapeseed and soybean) with four replications in 2014 in Research Greenhouse of Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran. The results of this study showed that clethodim concentration, vegetable oil types and interaction effect of concentrations in vegetable oils had a significant effect on measured traits of foxtail including height, fresh and dry weight of shoot and root and root volume. Increasing relative potency for all traits measured based on 50% effective dosage was observed, which indicates an increase in the efficiency of clethodim in foxtail control. The results of this study also showed a 90% effective dose reduction for fresh and dry weight of green foxtail in the presence of all vegetable oils. The higher relative potency for fresh and dry weight of roots compared with fresh and dry weight of the shoot showed greater root susceptibility to the application of vegetable oils by increasing the transfer of clethodim to the root. The application of sesame, bitter almonds, sweet almonds, cottonseed, canola, rapeseed and soybean oil led to 1.20, 1.26, 1.42, 1.39, 1.41, 1.43, and 1.41 times increases, respectively, in clethodim performance. Finally, application of vegetable oils as additives to clethodim herbicide can be considered as an ecological and environmental approach for controlling green foxtail.

This study was performed for the evaluation of the effect of Azotobacter and nitrogen levels on morphological traits, plant nitrogen uptake rate, seed oil and yield and nitrogen use efficiency of six safflower (Carthamus tinctorius L.) genotypes under rainfed conditions, as a factorial experiment based on a randomized complete block design with three replications, during 2015-2016 and 2016-2017 growing seasons. Experimental factors were seed inoculation with Azotobacter and urea chemical fertilizer application (Non-inoculated with Azotobacter and urea as control, seed inoculation with Azotobacter, inoculation with Azotobacter + 50% N and inoculation with Azotobacter + 100% N) and six genotypes of safflower (312-S6-692, PI-401478, PI-253895, PI-306974, padide and sina). The combined analysis of variance for two years showed that the main effects of fertilizer and genotype had significant effect on all of the traits. The interaction of nitrogen × genotype was significant on root volume, leaf are index, number of lateral branches, grain nitrogen, straw nitrogen and total nitrogen uptake. Result showed that inoculation with aztobacter + 50% use of nitrogen had higher nitrogen use efficiency than aztobacter + 100% use of nitrogen. However, there was no significant difference in the grain yield between those fertilizer treatments. Sina with the highest values of grain yield (1203 kg.ha-1) and nitrogen use efficiency (17.49 kg.kg) was considered as superior variety. Therefore, with the aim of reducing environmental pollution by excessive use of N chemical fertilizer, application of Azotobacter is suitable for safflower production under daryland conditions.

Water is an important economic resource in many parts of the world, especially in arid and semi-arid reigns. Also, drought stress is a major constraint for crop production in arid and semiarid regions, such as Iran. Drought stress affects different aspect of plant growth, through a series of morphological and physiological changes. Application of some soil conditioners, like superabsorbent polymers, could be effective for absorbing seasonal rain and suitable source of water for plant growth during dry seasons. These polymers can reserve different amounts of water in itself and so increases the soil ability of water storing and preserving and approve plant growth under water deficiency. Also, they can improve plant growth indices and increase its growth by changing the soil structure and improving the environmental conditions of plant growth. This experiment was conducted in order to study the effects of superabsorbent and irrigation period on root characteristics and yield of mung bean.
 

The field experiment was conducted at two locations during summer in 2015. First location was Khorramabad which located at 33.46° N, 48.33° E and has moderate and semi-humid climate with average annual rainfall of 504.3 mm. The second location was Kuhdasht that located at 33.52° N, 47.61° E and has semi-dry climate with average annual rainfall of 390.4 mm. The field experiment was carried out as a split-plot base on randomized complete block design with four replications. The treatments included irrigation period at three levels (5, 10, and 15 day) as main plots and four levels of superabsorbent polymer Aquasorb (control, 100, 200 and 300 Kg ha-1) as subplot. Finally, at the end of growth period, 5 plants was used to measure mung bean traits included root volume, root dry matter, the weight ratio of shoot to root stem dry weight, total root area, total root length and grain yield. The volume and length of root was measured using the method of Atkinson (Atkinson, 2000). ANOVA and Duncan's Multiple Range Test were performed to determine and analyze the significant difference and means comparison respectively at P<0.05. SAS-9.1 software was used to do statistical analysis. Also, OriginPro 9.1 software was applied to draw figures.
 

The results of variance analysis showed that location and irrigation had a significant effect on all the evaluated properties. Also, superabsorbent had a significant effect on all the evaluated properties (except the weight ratio of shoot to root). In addition, interaction effects of superabsorbent and irrigation and superabsorbent and location were just significant on grain yield (p<0.05). Interaction effects of superabsorbent and irrigation was also significant on water use efficiency (WUE) (p<0.05). Interaction effects of location and irrigation were significant on attributes such as the weight ratio of shoot to root, grain yield (p<0.01) and total root area (p<0.05). Results indicated that drought stress reduced root volume and root dry weight and increased total root length traits and root dry weight, increasing the total length of the roots so that the lowest root volume (3.11 cm3 Plant-1) and root dry weight (0.93 g. Plant-1) and the highest total root length (9.1 cm Plant-1) was recorded at 5-day irrigation period. However, all these traits and grain yield were increased by applying the super superabsorbent polymer. The highest root volume (3.62 cm3 Plant-1), root dry weight (1.1 g Plant-1) and total root length (9.8 cm Plant-1) were obtained at 200 kg superabsorbent per ha. The highest WUE (1.12 Kg grain yield m-3) was obtained at 200 Kg superabsorbent per ha and 15-day irrigation period and the lowest (0.31 Kg grain yield m-3) was recorded at control and 5-day irrigation. Also, across irrigation periods and locations, the difference between the highest (200 Kg superabsorbent per ha and 10-day irrigation period) and lowest (300 Kg superabsorbent per ha and 15-day irrigation period) grain yield was 800 Kg per ha. Actually by increasing superabsorbent per ha, grain yield was increased but it improved until a certain level of superabsorbent and after that grain yield was reduced. Result showed that although the interaction of irrigation period and superabsorbent was not significant on root morphological characteristics, effects of superabsorbent was significant on root morphological characteristics and these traits of mung bean were improved by applying superabsorbent.
 

Generally, results revealed that the Aqasorb superabsorbent hydrogel can improve the morphological characteristics of mung bean root and can reduce the negative impact of the high periods of irrigation on grain yield and WUE of mung bean. Thus, applying superabsorbent that has the ability of absorbing considerable amount of water, caused improving in physical conditions of soil and affected the plants response to water stress indirectly and can help plants in water shortage conditions. Also, the amount of optimal application of Aqasorb superabsorbent is 200 Kg ha-1 and using more than 200 Kg superabsorbent per ha (especially in the high periods of irrigation) will reduce grain yield, WUE and the morphological characteristics of mung bean root and will increase the cost of production.

In order to study the effects of mung bean seed priming with salicylic acid (0, 0.2, 0.5 and 1 mM) and inoculation with different plant growth promoting bacteria (control, inoculation with Pseudomonas, Azotobacter chroococcum and Azospirillum lipoferum) a factorial experiment was conducted based on randomized complete block design with three replications. Based on results, the interaction effect of salicylic acid priming and inoculation with growth-promoting bacteria on leaf chlorophyll index, protein percentage, grain yield and harvest index were significant. However, root dry weight, root volume and biological yield were only affected by the simple effects of salicylic acid priming and inoculation with growth-promoting bacteria. The highest amounts of biological yield, root volume and dry weight observed in 0.5 mM salicylic acid priming. In all levels of salicylic acid, inoculation with Azotobacter resulted in highest percentage of seed protein content. The positive effects of plant growth promoting bacteria on seed yield, leaf chlorophyll index and harvest index was related to concentration of salicylic acid and in the concentration of 0.2 and 0.5 mM the highest seed yield observed after inoculation with Pseudomonas treatment.

Current estimates indicate that 25% of the world agricultural lands are affected by water stress. Iran, with an annual 228 mm of rainfall, is classified as a dry region in the word. Wheat is one of the main cereal crops, cultivated for human feeding. In order to increase crop yield per unit area, largely chemical fertilizers are used. The result of these activities in recent years has been the crisis of environmental pollution, especially water and soil pollution that threatens human society. Phosphorus is one of the limiting elements for crop production. It is essential for energy transfer, photosynthesis and other biochemical and genetic activities of plant. Biofertilizers have been used as source to improve plant nutrients in sustainable agriculture. Phosphorus Solubilizing Bacteria (PSB) plays an important role in phosphorus nutrition by enhancing its availability to plants through release from inorganic and organic soils phosphorus pools by solubilizing and mineralization. Mycorrhizal crops often have greater tolerance to drought than nonmycorrhizal crops. The use of arbuscular mycorrhizal fungi capable of forming symbiotic associations with most agricultural crops and has potential under such systems due to its higher binding capabilities and mineral nutrition. Therefore, the main of this study was to study the effect of phosphate solubilizing bacteria and mycorrhizal fungi on root characteristics and grain yield in dryland wheat cultivars. This experiment was carried out as factorial arrangement based on a randomized complete block design with three replications at the Agricultural Research Station of Ilam University (46*28' N, 33*37 E; elevation 1174 m) and Sarableh Agricultural Research, Recources Center (34*46 N, 33*45 E; elevation 975 m) during growing season 2013-2014. Experiment factors consisted of two dry land cultivars (Keras Sablan and Saji) and fertilizer sources including of 1: without application of phosphorious chemical fertilizer, 2: 50 kg.ha-1 phosphorous chemical fertilizer, 3: pseudomonas putida (PSB), 4: Glomus mosseae (GM), 5: PSB+GM, 6:PSB+GM+25 kg.ha-1phosphorous chemical fertilizer, 7: PSB+ 25 kg.ha-1 phosphorous chemical fertilizer and 8: GM+25 kg.ha-1phosphorous chemical fertilizer. At flowering stage root traits such as root volume, root area, root diameter, root length density and root surface area density were studied and measured. At full maturity, agronomic traits such as spikes.m-2, grains.spike-1, 1000-grain weight, grain yield and biomass yield were recorded using a sample of ten random guarded plants from the middle ridges of each plot. The data were analyzed statistically by SAS program and the data means were compared by Duncan's multiple range test (DMRT). Results indicated that interaction effect between cultivar× fertilizer sources had significant effect on root length total, root volume, root area, root diameter, root length density, root surface area density, spike.m-2, grains.spike-1, 1000-grain weight, grain yield and biomass yield. Using fertilizer sources had  positive and significant effect on root traits and grain yield in two dryland wheat under dry land condition, so that Saji cultivar ×GM+25 kg.ha-1 had the highest root volume (4.6 cm3), root area (70.9 cm-2), root length density (0.158 cm root length.cm-3 soil), root surface area density (84.3 cm2.cm-3), spike.m-2 (257.5 spikes), grains.spike-1 (42.7 grains), 1000-grain weight (39.7 g), grain yield (3571.6 kg.ha-1) and biomass yield (7840.6 kg.ha-1) and the lowest root traits and grain yield belonged to Keras Sabalan×check treatment. There was significant different between cultivars to response of Using of phosphate solubilizing bacteria and mycorrhizal fungi, so that Saji cultivars had the best response to mycorrhizal fungi. Therefore with regard to cultivation of wheat is facing to drought and heat stress indicated that Saji cultivar and using of mycorrhizal fungi can be the best result under dry land conditions. The results indicated phosphate solubilizing bacteria (PSB) and mycorrhizal fungi (GM) had positive effect on root system and grain yield, so that root traits and grain yield had the better status in presence of inoculation with GM. In fact PSB and GM could alleviate the partial of grain yield in presence of dry land farming. Recent studies indicated that symbiosis bio-fertilizers also improved soil physical and chemical traits and increaced organic matters content, root system and P available to coexistent plant.

In order to evaluate the effect of bacterial isolates on growth parameters and nutrient uptake in two varieties of maize (such as SC704 & TWC645), two experiments were separately conducted based on a completely randomized design with four replication in greenhouse of University of Vali-e-Asr in 2014. The experimental treatments consist of four isolates of fluorescent Pseudomonads (P7, P15, P24 and P29) and control (without bacteria inoculation). The results showed that the inoculation with isolates P29, P15, P7, P15, P29 and p24 respectively increased shoot dry weight (42.9 percent), shoot length (23.7 percent), leaf area (43.6 percent), chlorophyll content (15.9 percent), root dry weight (49.8 percent) and root mass in variety of SC704 compared to the control (no inoculation). of SC704 significantly compared to the control. The examined isolates increased the uptake of Fe, Zn, Cu and Mn in root and shoot in variety of TWC645 significantly compared to the control. The highest uptake of Zn was observed in treatment P29 which raised the uptake of Zn in root and shoot 66.2 and 41.8 respectively in variety of TWC645 in comparison with control. All isolates had significant effect on SC704 root zinc uptake and largest increase in shoot Zn uptake was related to isolate P29 with 60.2% increase compared to the control. Overall, our observations revealed that the inoculation of maize with selected isolates had effective role on the growth and uptake of nutrients in maize.

Seed priming is a method which is effective in improving germination and seedling establishment under stress conditions. To investigate the effects of seed priming on emergence and morphological characteristics of root of three canola cultivars, an experiment was arranged in a randomized complete block design in split plot with three replications. Main factors including five sowing dates with an interval of ten days and three canola cultivars and priming treatments including priming with water, zinc sulfate and control as sub plots were arranged in a factorial experiment. Results showed the highest emergence rate was achieved in Okapi by zinc sulfate priming with an average increase of 32 percent in all sowing dates. The most of the fresh and dry weight of three cultivars resulted from the first sowing date, 6 September. Sowing date October 16 under the hydropriming and primed with zinc sulfate increased root length by 7 and 10 percent in the Okapi, 18 and 23 percent in Zarfam and 32 and 35 percent in Talayeh compared with their controls, respectively. Root volume of Okapi on September 26, October 6 and 16, increased respectively 38, 61 and 71 percent in hydropriming and 51, 67 and 47 percent by priming with zinc sulfate compared with their control treatments. The highest root area on 6 and 16 September in all three cultivars was achieved by priming with zinc sulfate. Despite the decrease in root diameter of delay sowing date, priming treatments could increase root diameters compared with controls in each sowing date.

To study the root structure and its morphological characteristics of winter and durum wheat cultivars, an experiment was carried out based on randomized completely design with four replications at faculty of Agriculture, Ilam University during 2013-2014. Experimental treatments consisted of six bread wheat cultivars (Sardari, Keras Sabalan, Nestor, Pistaz, Bahar and S83-3), four durum wheat cultivars (Karkheh, Dena, Sora and Saji). Traits under study were seminal roots, nodal roots, sub-nodal roots, number of total roots, seminal roots length, nodal and sub-nodal roots, total root lengths, root dry weight, root volume and root to shoot ratio. The results showed significant differences for root structure of bread wheat cultivars (Sardari, Keras Sabalan and Nestor). They had stronger root system than the other bread wheat cultivars.It was also found that Saji from durum and Sabalan cross from bread wheat cultivars had the highest number of total roots (seminal, nodal and sub-nodal roots), root length total (seminal, nodal and sub-nodal roots), root volume and root/shoot ratio as compared with the other cultivars under study. Orthogonal contrast for three groups of genotypes indicated that in terms of number and length of nodal roots, bread wheat cultivars showed higher values as compared to durum wheat cultivars.

Maize (Zea mays) is a cereal crop that is grown widely throughout the world in a range of agroecological environments. .Its value as a cost-effective ruminant feed is one of the main reasons that farmers grow it. However, lack of nutrients such as N and P, are the principal obstacles - to crop production under low input agricultural systems leading to dependency on chemical fertilizers. Long-term use of chemical fertilizers destroy soil physicochemical properties and it reduced permeability which restricts root growth, nutrient uptake and plant production. Therefore, the use of organic fertilizers can help to enrich the soil root zone As a result growth and yield will improve.
In order to study the effects of different levels of vermicompost and foliar application of tea compost on growth characteristics of the hybrid maize genotype 713, a greenhouse experiment was conducted as a factorial experiment in randomized complete block design with three replications at the Vali-e-Asr University of Rafsanjan, during 2013. Treatments were included vermicompost (0, 5%, 10%, 15%, 20%, 25% and 30% pot weight) and tea composts (foliar application, non-foliar application). Measured traits were included root dry weight, root volume, leaf dry weight, stem dry weight, macro nutrient concentration (N and P) and micro nutrient concentration (Zn, Mn, Fe and Cu). All the data were subjected to the statistical analysis (two-way ANOVA) using SAS software (SAS 9.1.3). Differences between the treatments were performed by Duncan’s multiple range test (DMRT) at 1% confidence interval.
Results indicated that leaf and stem dry weight affected by the application of vermicompost and tea compost. However, the interaction effects had no significant effects on the leaf and stem dry weight. Application of tea compost increased 20% and 50% leaf dry weight and stem dry weight of corn compared to non- foliar application, respectively. The highest leaf dry weight and stem dry weight observed at 25% pot weight vermi compost, and lowest leaf and stem dry weight observed in control. Root volume and root dry weight affected by the interaction effects of vermi compost and tea composts. The highest root dry weight and root volume observed in 30% weight in non-foliar application condition. The highest root dry weight and root volume observed in 15% pot weight in tea compost application condition. It is also resulted that Fe concentration of shoot had affected by the application of tea compost, and using vermi compost affected the concentration of Zn, Fe and N in shoot. Application of tea compost increased 15% Fe concentration of shoot compared to non- foliar application. Using vermi compost of 30, 30 and 15% per pot weight increased concentration of Fe, N and Zn of corn shoot, respectively.
Result indicated that Mn, Cu and P concentration of corn shoot affected by interaction effects of vermicompost tea compost. It is also resulted that the highest concentration of Mn, and Cu observed in 15% pot weight in tea compost application condition and the highest concentration of P observed in 5% pot weight in tea compost application.
Nutrient contents of vermicompost and tea compost are comparable with other organic fertilizers. Totally, it seems that using tea compost foliar application due to bioavailability nutrient could decrease the amount of vermicompost application.

Background and According to FAO's report, lentil yield in iran is much lower than average yield in the world. This is due to low quality seedling production, low germination and emergence capacity, biotic and abiotic stresses and poor seedling establishment which was forced to looking for a way to enhance these components. Seed priming is one of the strategy for increasing the rate and percentage of the germination, increasing in quality of the prodeuctivity seedling and plant suitable establishment. So this method can cause the fast growth of plants, the increase of rate and percentage of germination, the quality and quantity of yield and the absorption of nutrients as well as early flowering and plant resistance to drought through roots under variable environmental conditions. therefore, in order to study the effects of mycorrhizal inoculation and seed priming with application of the some plant growth regulators on the roots and the features of aerial parts of lentil, the present experiment was conducted. In order to study response of lentil to seed priming (non-primed seeds, hydro-priming, 100 ppm GA3, 100 ppm salicylic acid and 100 ppm GA3 + 100 ppm salicylic acid) and soil mycorrhizal inoculation (non-inoculation as control, Glomus mosseae and G. intraradices), a factorial experiment based on a completely randomized design was conducted in the farm research and green house of Gonbad Kavous University in four replications during 2013-2014. Measured traits included rate and percentage of emergence, seed vigor, root length, root area, root volume, the number of secondary roots, the number of nitrogen-fixing nodules, the percentage of active nodes, fresh and dry weight of nitrogen fixation nodules, shoot length, the number of primary branches, leaf area, shoot dry weight and leaf dry weight which were measured. The results showed that different treatments of mycorrhizal inoculation, priming and their interaction had a significant effect on some of the studied traits. Various priming treatments along with mycorrhizal fungi had more increase and significant effect on the most measured traits in comparison with without application of studied fungi. Mycorrhizal inoculation using G. mosseae fungal + 100 ppm of salicylic acid significantly increased root volume) 12.10 mm3), fresh (0.178 mg) and dry weight of nitrogen fixation nodules (9.58 mg), while traits of leaf area (96.42 cm2), leaf dry weight (29.97 mg/seedling) and root length (15.27 cm) significantly was increased by the mixed treatments of G. intradices and salicylic acid. In this study, the highest nitrogen fixing nodules, shoot length, seed vigor and the number of secondary roots were obtained using a mixed treatment of G. intraradices + 100 ppm gibberellic acid which had a significant difference with other treatments and control. The treatment of hydro priming + G. mosseae increased root volume and seed yield over control and separate treatments when were applied. The present findings showed that combined effects of priming treatments + mycorrhizal inoculation treatments had more positive effects on the measured traits over control and other treatments.