جستجوی مقالات مرتبط با کلیدواژه « cadmium » در نشریات گروه « زراعت »

In order to investigate the effects of different sources and selenium values on yield, stress sensitivity indices and some physiological traits of rainfed wheat cultivars under cadmium stress in the Maragheh region, an experiment was conducted in field and greenhouse states in year 2017-2018. In the field section, factor a was different sources of selenium (sodium selenite and selenite), factor b was different amounts of selenium (0, 18 and 36 g.ha-1) and factor c was three wheat cultivars (Azar 2, Pishtaz and Sardari). Results of analysis of variance showed that there was a significant difference between yield and yield components of cultivars under normal conditions and moisture stress. Average grain yield and grain weight per spike of genotypes under normal conditions was respectively (1752.83 kg.ha-1 and 0.591 g) and (1790.82 kg.ha-1 and 0.59). Pishtaz and Sardari genotypes had the highest and lowest yield under normal conditions (18 and 36 g.ha-1 sodium selenite) and moisture stress (Not using selenium), respectively. In the greenhouse section, a field experiment was chosen based on the selection of a cultivar (Pishtaz) and a two-factor factorial experiment was conducted in RB with three replications. In this section, factor A was different values of cadmium (concentrations of 0, 350 and 700 μM) and factor b was sodium selenate (concentrations of 0, 1.5 and 3 mg/l). The results indicated that stress induced by tested cadmium decreased the content of photosynthetic pigments and selenium increased chlorophyll content. This decrease was significant in the 700 μM cadmium treatment. Overall, the results of this study indicate that selenium, especially sodium selenate at a concentration of 3 mg/L, has been able to reduce the toxic effects of cadmium on wheat (especially Pishtaz cultivar) and improve plant growth and development.

Quinoa, with its high nutritional value, is highly resistant to a wide range of non-biological stresses. Despite the limited resources and the increasing demand for food products in lands with low or limited fertility, it can be cultivated well and produces a good product.

This experiment was conducted with the aim of investigating the simultaneous effect of drought stress and heavy metals on the quinoa plant, in a factorial format in a completely randomized design with 3 replications. The first component involved two levels of soil (contaminated and uncontaminated), and the second factor, three levels of drought stress (100% of field capacity 60% of field capacity, and 30% of field capacity).

Interaction effect of soil type and drought stress was significant on all traits except the fresh weight of shoot and plant height. The lowest amount of fresh and dry weight of roots, dry weight of shoot and weight of thousand seeds was observed in contaminated soil with severe drought stress. Nevertheless, the weight of 1000 quinoa seeds under the influence of moderate drought stress was not significantly different from the condition without drought stress. Examining the simple effects showed that soil contamination with heavy metals caused a decrease of 13.7% in fresh weight of shoot and 30.5% decrease in dry weight of shoot compared to plants grown in uncontaminated soil.

In general, it can be stated that the increase in drought stress has significantly reduced root fresh weight and 1000 seed weight in quinoa, but the percentage and ratio of this reduction in soil contaminated with heavy metals was much higher than that of non-contaminated soil. According to the results of this research, the cultivation of quinoa can be investigated as a promising plant in soils with similar limitations.

Industrialization and destructive human activities have led to a rapid spread of heavy elements contamination in soil. The purpose of this study was to investigate the effect of silicon and salicylic acid on yield and physiological traits of corn in Rahimi and Molavi farms (contaminated with heavy metals and located near lead and zinc factors in Zanjan) in 2020, by using a factorial design based on randomized complete blocks. Factors included spraying salicylic acid at zero, 600, 1200, and 1800 µM, and spraying nanosilicon at zero, 600, 1200 and 1800 mM. Based on the results of soil analysis, lead, zinc, and cadmium concentrations in both fields were higher than the allowable limit and this heavy metal contamination was more severe in Rahimi field. Heavy metal contamination reduced plant height, grain yield and yield components, biological yield, chlorophyll content, and proline levels. The highest grain yield and grain weight were obtained with 1800 µM salicylic acid and 1200 mM nanosilicon treatments, and the lowest with the control treatment (without salicylic acid or nanosilicon). The highest chlorophyll content was obtained from 1800 µM salicylic acid treatment on Molavi's farm and the maximum amount of chlorophyll was observed in 1800 mM nanosilicon treatment. Overall, the treatments improved the yield, chlorophyll content, and relative water content of corn leaves. It is recommended to spray 1800 µM salicylic acid and 1200 mM nanosilicon on the corn fields in this area to increase the stress tolerance under heavy metal conditions.

Soil pollution with heavy metals and its transfer to agricultural products is expanding as a global problem. Cadmium is one of the heavy metals that increase its concentration in the root environment of the plant causes metabolic disorders in the plant. Studies have shown that the use of intercropping systems while increasing diversity, increasing yield, improving resource efficiency, reducing weed damage, pests and diseases(such as Uromyces and Botrytis Vicia-Faba), increasing the stability of the system follows.This study investigates the effect of different levels of cadmium on plant pigments as one of the effective factors in the process of photosynthesis, as well as the amounts of phenol and flavonoid compounds and antioxidant activity in legumes (faba beans, peas) and potatoes in monoculture and intercropping culture.

The pot experiment was carried out as a factorial based on a completely randomized design with 4 replications at Gaemshar Agricultural Research Station, Mazandaran province during two agronomic seasons 2018-2019 examined in pot conditions. Treatments were included planting pattern at five levels of monoculture potato, faba bean, pea and Intercropping (potato+fabaBean), (potato+ pea) and five cadmium concentrations of 0 (control), 5, 10, 20 and 30 milligrams of cadmium per kilogram of soil as cadmium nitrate was added to the soil. For this purpose, methanolic extract was prepared from the dried leaves of the studied plants. Total phenols and flavonoids were assayed by spectrophotometry and the antioxidant activity of the extracts was evaluated by free radical scavenging methods (DPPH).Statistical analysis was performed using SAS software and comparison of means was performed by Duncan's multiple range test at the level of one and five percent probability and graphs were drawn using SigmaPlot and Excel software.

The results showed that different cadmium concentrations had a significant effect on the amount of photosynthetic pigments (P≤0.01). The reduction trend of chlorophyll a, chlorophyll b and carotenoids was plinomial. With the application of the highest level of cadmium (30 mg of cadmium in the soil), carotenoids, chlorophyll a and chlorophyll b were significantly reduced.In concentration of 30 mg of cadmium in soil, the amount of chlorophyll a in the faba bean reached 3.84 mg/kg soil. In other words, with increasing the concentration of cadmium in the soil, the amount of chlorophyll a decreased by 83.07%. The decrease in total chlorophyll due to cadmium may be due to the inhibitory effect on the activity of its molecules. Total chlorophyll of faba bean with increasing concentrations of cadmium (from 5 to 30 mg soil) was a significant decrease. The sensitive treatments to increasing cadmium concentration were faba beans (7.66 mg/kg soil), potatoes (9.19 mg/kg soil) and chickpeas (9.28 mg/kg soil), respectively. In this study, faba bean plant had the highest mean of phenol (0.1643 mg que/g DW) and intercropping culture (potato+bean) had the highest flavonoids (0.00814 mg que/g DW) and antioxidant (56.03 %) obtained in the treatment of 30 mg of cadmium per kg of soil.

The results of the present study indicate a significant difference between the different treatments in terms of the total amount of phenolic and flavonoid compounds that the existence of such diversity can indicate the role of plants and genetics in the production of these compounds. with increasing the concentration of cadmium, the amount of chlorophyll a and chlorophyll b pigments was significantly reduced. In general, from the findings of this study, it can be concluded that these plants, cadmium toxicity in all three plants led to the induction of phenolic compounds.

This study is conducted to evaluate the concentration of nitrate and heavy metals in soil and edible organs of lettuce in Varamin plain farms for one year during 2017-2018. For this porouse, 30 lettuce fields in Varamin plain are selected and in the lettuce harvest season, soil and crop sampling are performed and the average concentrations of nitrate and heavy metals in the soil and lettuce were compared statistically with the standard limits by one paired t-test. The average concentrations of nitrate, lead and cadmium in lettuce are 2756, 1.46, and 0.11 mg / kg in fresh weight, respectively, which are 1.8, 7.3, and 1.1 times greater than the standard limit, declared by the National Standards Organization of Iran, respectively. The mean concentrations of nitrate and total concentrations of lead, cadmium, and nickel in the soil of lettuce fields are 27, 42, 0.64, and 42.5 mg /kg, respectively, while the concentrations of nitrate and lead have been 35% and 180% higher than the allowable limits, respectively. Risk assessments for heavy metals and non-cancerous diseases are performed, using formulas provided by the US Environmental Protection Agency (USEPA, 2006). In this regard, the risk index for non-cancerous diseases (HQ) is used. The risk factor for non-cancerous diseases for all contaminants is less than one, indicating that there is no risk for consumption. Accordingly, consuming 40 grams of lettuce per day does not pose a problem for an adult consumer. The bioaccumulation index for all the studied metals has been less than one. According to this study, the highest bioaccumulation factor belongs to the heavy metal cadmium, which indicates the tendency of lettuce to absorb and accumulate cadmium compared to other heavy metals. In order to reduce the concentration of nitrate and lead in the soil and prevent contamination of lettuce soils, it is recommended to avoid excessive use of fertilizers containing nitrogen and phosphorus and fertilizer application should be based on soil test. According to the results of this study, there is no serious possibility of exposure to non-cancerous diseases caused by nitrate and heavy metals from eating lettuce, but monitoring the concentration of nitrate and heavy metals in soil and lettuce at different intervals is necessary.

Environmental stresses such as drought, temperature, heavy metals and salinity greatly reduce plant growth and development, among non-biological stresses, drought stress is one of the environmental factors which limits crop production and reduces average yield by 50% or more (Wang et al.,2 003). Heavy metals are another environmental stress that in recent years as it has become one of the biggest problems of the agricultural sector. Due to technical and economic limitations of heavy metal removal methods, the search for new methods has received a great deal of attention and in this regard biological absorption as a new method has received special attention(Maleki and Zarasvand, 2008).

In order to Evolution Ability of Remediation Heavy Metal Cadmium by Some of Plant Species and Biochar in drought stress conditions experimental in years 2017-2018 was carried out for two years in the research farm of the Faculty of Agriculture, Islamic Azad University, Karaj Branch. The experiment was factorial in a completely randomized design with 3 replications. Experimental factors included cadmium chloride salt at four levels (control, 10 mg.kg-1, 20 mg.kg-1, 30 mg.kg-1), Biochar at three levels (control, biochar at the time of first year planting, biochar after first year harvest and at the time of second year planting), 3 crop species (clover, alfalfa, canola) and drought stress (control, 40% available moisture discharge based on gypsum block, 60% available moisture discharge based on gypsum block). One month before planting the soil was contaminated with cadmium chloride at specific levels in the experiment then biochar treatment was added to the soil of the desired pots. After cultivating crops and sufficient vegetative growth shoot and root specimens were carefully removed from the soil of the pots and after washing and drying according to the protocol in this experiment extracts were taken for reading in an atomic absorption apparatus. For analyze the measured data, Mean and Bartlett comparison were performed using MSTATC, SAS and Excel software.

The results of analysis of variance showed that Triple interactions of cadmium, crop species, drought stress for all studied traits(Dry weight of shoots, dry weight of roots, amount of cadmium in shoots, amount of cadmium in roots, measurement of metal element, accumulation coefficient, extraction coefficient) It became significant with a one percent error probability. The results also showed that the triple interactions of cadmium, crop species, biochar only for traits Translocation factor, Accumulation factor, Enrichment cofficient became significant with a probability level of one percent. And for other traits, this triple interaction was not significant. The results of mean comparison showed that the highest mean amount of cadmium in the shoot(2.68 mg.kg-1) And roots(1.78 mg.kg-1) Related to canola treatment at the level of 30 ppm cadmium And under drought stress conditions, 60% of available moisture discharge was based on gypsum block. Most average Translocation factor related to the triple interactions of cadmium, crop species, biochar related to treatment Canola cadmium at the level of 20 ppm and biochar at the time of crop cultivation in the first year(a3b3c2) with average (3.73) and the lowest was related to cadmium control treatments (a1b1c1) with mean (0.1). The most common triple interactions of cadmium, crop species, drought stress are also related treatment of cadmium Canola at 20 ppm level without drought stress (a3b3d1) (3.98) and the lowest mean was related to cadmium control treatment (a1b1d1) with mean (0.1). Most average Accumulation factor corresponding to the triple interactions of cadmium, crop species, biochar related to the treatment of cadmium Canola at the level of 30 ppm and biochar at the time of crop cultivation in the first year(a4b3c2) with average (70.137) and the lowest was related to cadmium control treatments (a1b1c1) with mean (0.0044). Most of the triple interactions of cadmium, crop species, drought stress also related to cadmium Canola treatment at 20 ppm level without drought stress (a3b3d1) (148.87) and the lowest mean was related to cadmium control treatment (a1b1d1) with mean (0.0043). The highest mean of triple interactions of cadmium, crop species, biochar for Enrichment cofficient related to the treatment of cadmium Canola at the level of 30 ppm and without biochar in the first year (a4b3c1) with a mean (0.182) and the lowest was related to cadmium control treatments (a1b1c1) with mean (0.0117).

Most of the triple interactions of cadmium, crop species, drought stress are also related Treatment of cadmium Canola at 30 ppm level and drought stress 60% available moisture discharge based on gypsum block (a4b3d3) (0.180) the lowest mean was related to cadmium control treatment (a1b1d1) with mean (0.0011). The results of this study showed that Canola had a higher uptake and transport of cadmium metal than clover and alfalfa.

Cadmium is an important pollutant of heavy metals, which is very toxic to plants and animals. Rice is the most popular food among Iranians and the presence of heavy metals in trace level in rice has received special attention because they are directly related to health. In order to evaluate the tolerance of rice genotypes to cadmium, 40 rice genotypes under hydroponic conditions were used for seedling tolerance and absorption of cadmium in different levels of stress (control, 100, 200 and 300 μm cadmium) and in a split plot experiment in a completely randomized design template was examined. The results showed a significant difference between genotypes. In terms of cadmium adsorption, genotypes of Mirtarom, Sangtarom, F12L49-3، 229R and KOSHIHIKARI had the lowest cadmium adsorption. Principal components analysis based on the traits evaluated for cadmium show 70.160, 70.357, 72.641 and 66.305 percent of the changes by the first and second components, respectively, at the control levels of 100, 200 and 300 micromolar of cadmium. Cluster analysis based on the studied traits at control, 100, 200 and 300 micromolar of cadmium classified the genotypes in two, five, three and two clusters, respectively. In sum, genotypes of Sangtarom, Mirtarom, F12L49-3, 229R and KOSHIHIKARI as genotypes tolerant to cadmium and genotypes of M30, ARIAS HALUS and Kinan Dang Patong as genotypes classified as Noncompliant were determined according to biplot analysis and cluster analysis. The generations obtained from crossing between tolerant and susceptible cultivars could be used as segregating population in genetic and molecular studies.

Basil (Ocimum basilicum L.) is a plant that is cultivated for the first time due to the aroma, extra taste and healing properties. In the medical industry, it is used to treat nerve headaches, calming nerves, fever, diarrhea, and anti-nausea and vomiting. One of the serious environmental problems is soil contamination with heavy metals and has negative effects on human health and agricultural lands. Soil pollution to heavy metals is the result of many human activities such as mining, extraction and melting of metals and the using of fertilizers, pesticides and agricultural fungicides, etc. which endangers human health and ecosystems. The major problem with heavy metals is that these inorganic pollutants are not decomposable, in contrast to organic pollutants. Among heavy metals, cadmium is of particular importance due to the high mobility and dynamism in the soil and absorption by the plant. Many of the agricultural soils of the world have been contaminated due to the long-term using of phosphate fertilizers, sewage sludge, etc. with low to moderate concentrations of cadmium. Sodium nitroprusside is one of the compounds recently tested to reduce the effects of stress on plants. Sodium nitroprusside is a nitric oxide-releasing compound whose role in plants has been the subject of many research studies. This compound is red powder and is a plant growth regulator. The purpose of this study was to investigate the effect of sodium nitroprusside foliar application as a reducing agent on heavy metals stress on growth, vegetative, physiological, antioxidant enzymes and essential oil content of basil plant with different amounts of heavy metal cadmium.

This research to investigate the role of sodium nitroprusside in reducing cadmium toxicity in basil plant in a factorial form in a completely randomized design in 2017-2018 was conducted. The applied factors in this study were included cadmium at 0 (control), 10, 20 and 30 mg.kg-1 soil and sodium nitroprusside solution at 0 (control), 50 and 100 μM. The measured traits were included plant height, plant dry weight, number of leaves per plant, essential oil percent, malondialdehyde, superoxide dismutase antioxidant activity, proline and cadmium concentration.

The obtained results showed that cadmium was decreased plant height, plant dry weight, number of leaves per plant, essential oil percent and superoxide dismutase activity, and was increased Proline cadmium and malondialdehyde concentrates. The most effect of cadmium on 30 mg.kg-1 treatment was obtained. It was also observed that Sodium nitroprusside using was increased plant height, plant dry weight, number of leaves per plant, essential oil percent and superoxide dismutase activity, and was decreased Proline, cadmium and malondialdehyde concentrations, in general, the most positive effect was obtained in 100 μM sodium nitroprusside using. Based on the results, sodium nitroprusside foliar application could improve the vegetative properties and reduce malondialdehyde under heavy metal cadmium stress conditions. According to the the results, it can be founded the positive effects of sodium nitroprusside, especially in the presence of cadmium and reducing the negative effects of stress on the basil drug.

It can be concluded that sodium nitroprusside moderates much of the harmful effects of heavy metal cadmium stress in basil plant and improves plant growth under stress conditions. Therefore, in the range of this study results, foliar application of this material on a stressed basal plant can be suggested as a factor for decreasing stress intensity and subsequently increasing yield.

Cadmium is one of the soil primary pollutants which is categorized as heavy metals and brassicaceae family are able to accumulate high amounts of heavy metals such as cadmium by producing high amounts of dry matter. In order to evaluate fatty acids variation, seed oil percentage, yield and yield components of black mustard as affected by growth promoting rhizobacteria and growth regulators under cadmium stress condition, a factorial experiment based on randomized complete block design was conducted at the Research Green House of Mohaghegh Ardabili University with four replications. Experimental treatments were two cadmium levels (0 and 100 milligrams per kilograms of soil), three rhizobacteria levels (control, Azospirillum and Pseudomonas) and three growth regulator levels (control, salicylic acid and brassinosteroid). Mean comparisons indicated that cadmium treatment decreased pods number per plant, grain number per pod, root dry weight, seed oil percentage, oleic, linoleic, eicosenoic and erucic acid percentages, significantly. Growth promoting rhizobacteria increased all of above mentioned parameters significantly, where as, it decreased palmitic acid content. Plant growth regulating sprays resulted in a significant increment in plant yield, shoot and root dry weight, seed oil percentage and all kinds of unsaturated fatty acids while it reduced stearic acid content and saturated fatty acids. The interaction of cadmium×rhizobacteria indicated that both cadmium levels used, along with rhizobacteria treatment, increased plant yield, thousand seed weight, shoot dry weight, linolenic acid and unsaturated fatty acids, where as decreased stearic and saturated fatty acids, significantly. In general, the effects of cadmium on these traits were different. Interaction of cadmium×growth regulators, spray application of growth regulators, under both cadmium levels, reduced palmitic acid and induced unsaturated fatty acids significantly and cadmium application had an inverse result.

Melissa officinalis is a medicinal plant belonging to the Lamiaceae family. The essential oil of this plant is used in many fields. Although more than 100 types of chemical substances have been identified in this plant, the most important compositions of its essential oil include citral, citronella, geraniol and linalool. Heavy metals are one of the main causes of non-biotic stress for living organisms due to increased use in the field of industrial and agricultural development and its high accumulation and toxicity. Cadmium is an unnecessary heavy metal, which, due to its high mobility and low concentration, easily enters the food chain from the soil. Cadmium induces oxidative stress by stimulating the synthesis of free oxygen radicals in the plant. In this study, the effect of cadmium chloride on oxidative stress induction in lemon balm was investigated. This experiment was carried out in 2016-2017 at Shahrekord University.

This research was conducted in a completely randomized design with three replications in vitro condition. We investigated the effects of different concentrations of cadmium chloride (0, 10, 20 and 40μm) on the biochemical parameters of the lemon balm. In this study, sterile stems of lemon balm propagated on the medium (1/2 MS) were used. After 60 days, seedlings were removed from solid MS medium and the roots were cut and cultured in liquid medium of 1/2 MS with different concentrations of cadmium. The cultivation was carried out in Erlenmeyer flask (250 cc) and was kept in an incubator shaker device. Sampling for the experiment was conducted one week after the growth of the stems in the medium.

Based on the results obtained in this study, fresh weight of shoots grown in 10 and 20μM of cadmium chloride increased compared to the control. This heavy metal significantly reduced the amount of chlorophyll a, b and carotenoids, while the total chlorophyll content decreased only at 40μm concentration relative to control. Cadmium significantly increased hydrogen peroxide levels in all treatments. Also, it increased the activity of catalase and superoxide dismutase enzymes. Malondialdehyde increased in all treatment concentrations, but this increase was not significant at 40μm of cadmium chloride. Chloride cadmium reduced the absorption of molybdenum and iron, yet increased the adsorption of manganese and zinc.

The results of this study revealed that the cadmium chloride in lemon balm shoots may have the potential to accumulate compounds such as hydrogen peroxide which, as a messenger molecule, produces antioxidants and can help the plant tolerate stressed conditions. It seems that two concentrations of 10 and 20 μm of cadmium chloride have no toxic effects for the stems and the plant has managed to withstand this tension with defense mechanisms.

Selenium is a beneficial element with antioxidant and antivirus function and it can increase plant growthand tolerance to environmental stress.Inthis study, the effects of selenium in stress conditions caused by heavy metals cadmium, nickel and lead in cucumber (Cucumis sativus L. cv Super Dominus) was investigated.The research was conducted using a completely randomized design with factorial arrangement in three replications for two germination tests .The first experiment was carried out to determine the optimal effectiveness of selenium and heavy metal toxicity threshold levels, Which contains levels of selenium (0, 4, 6, 8, 10 mgL-1) from sodium selenate, cadmium (0, 10, 15, 20, 25 µM) from cadmium chloride, nickel (0, 50, 100, 150, 200 µM) from nickel chloride and lead (0, 20, 40, 60, 100 µM) from lead chloride sources. The second experiment were consisted of two levels of selenium (0, 8 mgL-1) and toxicity threshold levels of heavy metals, including cadmium (0, 25 µM), nickel (0, 200 µM) and lead (0, 100 µM) treatments.The results showed that the germination index was significantly reduced as presence of toxic concentrations of heavy metals in the medium of cucumber seed germination. However, the application of selenium was improves the rate and percentage of germination, increase the length of shoot and root and seedling wet and dry weight in stress condition.Selenium was significantly increased cell membrane stability and decrease malondialdehyde under stress condition.Selenium improved antioxidant activity and increase activity of catalase, ascorbate peroxidase and guaiacol peroxidase enzyms in heavy metal toxicity condition .In general, the results of this study showed that the optimum concentration of selenium was reduces symptoms of toxicity due to the presence of heavy metals incucumber seedgermination mediumas  improving germination, growth and antioxidant activity.

IntroductionHeavy metals, as one of the most important factors contaminating natural environments and agricultural ecosystems, are found in almost all industrial regions. Toxic effect of high concentration of heavy metals is also observed in plants. One of the specific characteristic of heavy metals which has high influence in occurrence of toxicity of heavy metals is their bioaccumulation. Heavy metals are not biologically inseparable and decomposable and remain in environment which finally threaten human health. Therefore, removing, or at least, reducing their concentration in agronomical systems is closely related to human health. Cadmium is a heavy metal which is an unnecessary element for plants and enter agronomical systems through pesticides usage. However, cadmium is easily absorbed by plant roots and its toxicity is 20 times more than that of other heavy metals. There are chemical, physical and biological methods for removal of heavy metals from agronomical soils. Phytoremediation is a low cost and environmental compatible method for heavy metal removal from soils. This research was aimed to compare the ability of wheat, clover and rapeseed for removal of cadmium from agronomical soils to achieve the goal of reduction of heavy metal for incoming crop in rotation.
Materials and methodsThe current research was conductedas3×3 factorial experiment based on randomized complete block design with three replications. The first factor was plant type including wheat, clover and rapeseed and the second factor was heavy metal concentrations including 0.0, 50 and 100 mg kg-1 soil. Soil samples were contaminated with cadmium concentrations of 0.0, 50.0 and 100 mg per kg soil. Experimental plots (with height and diameter of 40 cm) were filled with 10 kg contaminated soils. Four weeks after planting, all plants parts (including root and shoot) were harvested and oven dried at 75°C for 72 hours. Finally, cadmium concentration was determined in all plants.
Results and discussion The highest cadmium uptake was observed in wheat under the concentration of 50 and 100 mg kg-1 soil. Increasing cadmium concentration from 50 to 100 mg kg-1 soil had not significant effect on the ability of wheat, clover and rapeseed for cadmium uptake from soil. Plants with high biomass are capable for more heavy metals uptake which is line with the findings of this research where wheat with higher biomass removed more cadmium from soil in comparison with clover and rapeseed. However, nonsignificant difference between clover and rapeseed for cadmium uptake was not compatible with this opinion where rapeseed produced higher biomass. Although different physical, chemical and biological methods are used for removal of heavy metals from soils, phytoremediation has the highest effect for removal of cadmium from soils.
ConclusionThe current research confirmed the results of other experiments about the ability of phytoremediation for removal of cadmium from soil. Furthermore, the results revealed that wheat, in addition to its nutritional value, has a high ability for reduction of cadmium from contaminated soils and can be considered as a good crop in crop rotation programs.

IntroductionThroughout their life cycle, plants are subjected to various types of environmental stresses which include salinity, water deficit, temperature extremes, toxic metal ion concentration and UV radiation. These environmental factors limit the growth and productivity of plants to various degrees, depending upon severity of stress. Heavy metal toxicity is one of the major current environmental health problems and potential dangerous due to bioaccumulation through the food chain and in plant products for human consumption. Cadmium (Cd) is a high toxic trace element that enters the environment mainly from industrial processes and phosphate fertilizers. It can reach high levels in agricultural soil and is easily accumulated in plants. Cd ions are taken up readily by the plant roots and translocated to the above-ground vegetative parts. The presence of Cd at higher concentrations in the soil damages root tips, reduces nutrient and water uptake, impairs photosynthesis and inhibits growth of the plants. Furthermore, Cd directly or indirectly induces reactive oxygen species (ROS), which affect the redox status of the cell and cause oxidative damage to proteins, lipids, and other biomolecules. Cd damages the nucleoli in cells of the root tip, alters the synthesis of RNA, inhibits ribonuclease activity and inhibits the DNA repairing mechanism. Understanding the biochemical and molecular responses to Cd stress is essential for a holistic opinion of plant resistance mechanisms of heavy metal stress.
Materials and MethodsIn this study, the effect of different concentrations of cadmium on proline and phenolic contents, activity of some antioxidative enzymes such as superoxide dismutase, catalase and ascorbate peroxidase, phenylalanine ammonialyase in Lense culinaris Medik. was studied. Therefore, two-week-old plantlets were treated with different concentrations of cadmium chloride (0 as control, 0.125, 0.25, 0.5, 1, 2.5 and 5 mM) of cadmium chloride for 10 days and then the above mentioned factors were investigated. The experiments were carried out by using a complete randomized block design with three replications. The statistical analyses were carried out using the SAS version 9. Changes in biochemical parameters were tested statistically by performing one-way analysis of variance (ANOVA). The treatment means separated using Duncan's multiple-range test (DMRT) taking P Results and DiscussionSurveying the results indicated that the amount of non-enzymatic antioxidant compounds (phenol and proline) were increased in treated seedlings compared with the control. Review of the literature indicates that a stressful environment results in an overproduction of proline in plants which in turn imparts stress tolerance by maintaining cell turgor or osmotic balance; stabilizing membranes thereby preventing electrolyte leakage; and bringing concentrations of ROS within normal ranges, thus preventing oxidative burst in plants. The increase in phenolic content may be due to protective function of these compounds against heavy metal stress by metal chelation and ROS scavenging. The results obtained from measuring the activity of antioxidant enzymes showed that with increasing concentrations of cadmium, the activity of antioxidant enzymes superoxide dismutase, catalase and ascorbate peroxidase were increased in lentil seedlings. However, this increase was more evident at concentrations greater than 0.5 mM. These results suggest that lentil seedlings tend to cope with free radicals generated by Cd through coordinated, enhanced activities of the antioxidative enzymes involved in detoxification. With increasing levels of cadmium in the medium, the activity of the phenylalanine ammonialyase also increased. The trend of phenylalanine ammonialyase activity induction in response to different concentrations of cadmium, was similar to those of antioxidant enzymes. Although the induction of activity of this enzyme was higher than the antioxidant enzymes. PAL is a key enzyme in the phenolic metabolism that has been reported to protect plants against stress conditions via synthesizing various phenylpropanoid products such as simple phenols, anthocyanin, flavonoid, and lignin.
ConclusionThe present study demonstrated that antioxidative system in L. culinaris underwent biochemical changes to survive under high concentrations of cadmium. Increase in metal chelate components (free phenols and proline) in all treatment levels proves this fact. Proline and phenolic compounds produced by the Phenylpropanoid Pathway in lentil played a major role in its response to Cd stress. Also that prolonged stress induced by Cd concentrations, can result into the activation of antioxidant enzymes such as superoxide dismutase, catalase and ascorbate peroxidase.

Cadmium is a toxic unnecessary element for humans and plants which is easily absorbed by plants. Genetic variation in cadmium accumulation provides an opportunity for breeding programs to select genotypes with low cadmium. Due to the high cost of plant tissue analysis to determine the amount of cadmium, use of markers to make efficient selection of low cadmium accumulating genotypes is an effective way. Therefore, to evaluate the effectiveness of AFLP and RAPD markers for identification and determination of cadmium accumulation characteristics in wheat, an experiment was conducted with two cadmium levels including zero (control) and 0.25 mM CdCl2 on 45 wheat genotypes. AFLP analysis using six combinations of primers produced 328 bands with an average of 54.66 bands per primer combination which 207 of these bands were polymorphic. In RAPD analysis, six primers with appropriate banding patterns out of 50 primers were used to evaluate all the genotypes. These primers produced 31 polymorphic bands with 5.16 bands for each primer. Associations between molecular markers and traits were assessed by multiple regression analysis. According to the results of regression analysis, 113 and 77 informative markers were detected at control and 0.25 mM Cd levels, respectively. Some of the markers were significantly associated with more than one trait. The results of this study provide useful preliminary information for indirect selection of traits by associated markers.

Heavy metals of biosphere rise since the beginning industrial revolution and the toxicity of heavy metals cause to impair in the process of germination and growth of plants. In order to evaluate the effects of heavy metals on the germination of pinto bean (cv. Sadri) an experiment was conducted at Seed Technology Laboratory of Yasouj University in 2013. The experiment was conducted as CRD in five replications include different concentration of Cd(NO3)2, Pb(NO3)2, Ni(NO3)2 and CuSO4 (25, 50, 75 and 100 mg/l) and a control treatment. Germination characteristics include the rate and percentage of germination, seedling weight and length and seed vigor index were studied .Results showed that the highest rate and percentage of germination was belonged to control, and least in the 100 mg/l of Pb(NO3)2. With the increase in concentrations of Pb, percentage and rate of germination and root and shoot dry weight showed a downward trend. 100 mg/l concentration of Cadmium nitrate decreased the rate germination of pinto bean seeds in compare with control. Increasing the concentration of cadmium impairs the growth of seedling root; shoot and vigor index of bean. Toxic concentration of copper compared to nickel had more negative effect on germination, root and shoot length, root and shoot dry weight and seedling vigor. In general, the results of this study showed that cadmium and Pb may give to plants allows germination, but increased in their concentration impaired the some seed germination indices of pinto been seed.

Understanding of the mechanisms affecting root uptake, transport and grain deposition of cadmium can successfully improve the success of breeding programs aiming to produce low cadmium accumulating genotypes. To determine the role of potassium in cadmium uptake by roots, transport to shoot and accumulation in the grain of two durum wheat (Behrang and Yavarous), a pot experiment was carried out, using a factorial experiment based on randomized complete block design with three replications in different treatments: control, 20 mg Cd kg-1 soil (CdCl2), 20 mg Cd kg-1 soil with two levels of 300 and 450 mg K kg-1 soil as potassium sulphate, and two levels 30 and 45 mg K kg-1 soil as nano chelate potassium 27%. Cadmium decreased differentially the concentration of potassium in roots, leaves and grains in both cultivars, but cadmium concentrations were increased. The highest and lowest cadmium concentration was found in roots and grains, respectively. Potassium application in combination with cadmium through competition led to the decrease of cadmium concentrations compared to cadmium treatments in roots, leaves and grains of both cultivars, but increased potassium concentrations. According to the findings in this study, potassium plays an important role in grain quality improvement by increasing potassium concentrations and decreasing cadmium concentrations.

Cd in the soil is a serious threat to both the environmental quality and human health over the long-term. So following the availability and mobility of Cd in soil is very important. Soil microorganisms and fauna are factors which may have an influence on the mobility and bioavailability of Cd in soil-plant systems. Specifically, both earthworms and arbuscular mycorrhizal fungi (AMF) have been found to affect Cd chemistry with changes in its immobilization and mobilization in Cd-polluted soils. To examine the effects of these organisms on soil Cd fractionation, chemical forms of Cd were measured in a calcareous soil artificially spiked with Cd (0, 10 and 20 mg Cd kg-1), inoculated with earthworm (Lumbricus rubellus L.), and AMF (Glomus intraradices, and Glomus mosseae species) under sunflower (Helianthus annuus L.) crop for 90 days. Three Cd, two earthworm and three mycorrhizal treatments were applied in a 3×2×3 factorial experiment with three replicates for each treatment. Results showed that the percentage of the total Cd content in exchangeable늉湮 (0-5.7%) and organic (0-1.3%) forms were very low. But the percentage of carbonate fraction of the total Cd content was between 54-87%. Earthworm addition increased exchangeable늉湮 and organic Cd, while AMF had no influence on these Cd fractions. Both earthworm and AMF species decrease carbonate fraction of Cd but they had no influence on sulfide fraction of Cd.

To investigate the effect of Trichoderma harzianum, as a bioabsorbant to ameliorate the harmful effects of cadmium (Cd) on growth and yield of barley (Hordeum vulgare L. variety ‘Sahra’), a factorial pot experiment based on completely randomized design with three replicates was conducted. Trichoderma harzianum withtwo levels (with and without inoculation) and cadmium nitrate with four levels (0, 50, 100 and 150 mg.L-1) were the treatments. Results of ANOVA revealed that there was a significant interaction between Trichoderma and cadmium nitrate in terms of biological yield, straw yield, harvest index, spike number per plant and seed number per spike. Mean comparisons showed that Trichoderma inoculation at all Cd levels significantly improved both biological and straw yields. Trichoderma at 50 and 100 mg.L-1 of Cd also increased the spike number per plant (up to 120 and 66%, respectively) significantly. Increasing Cd levels decreased seed yield (19%), 1000 seed weight (18%), partitioning coefficient (57%) and tolerance index (23%) significantly. Inoculation of Trichoderma into growth medium had a significant effect on seed yield and tolerance index (up to 17 and 22%, respectively). In conclusion, Trichoderma harzianum inoculation at lower concentrations of Cd (50 and 100 mg.L-1) could be effective to improve growth parameters of barley plant.