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1.
Heavy metal uptake, translocation and partitioning differ greatly among plant cultivars and plant parts. A pot experiment was conducted to determine the effect of cadmium (Cd) levels (0, 45 and 90 mg kg?1 soil) on dry matter yield, and concentration, uptake and translocation of Cd, Fe, Zn, Mn and Cu in seven rice cultivars. Application of 45 mg Cd kg?1 soil decreased root and shoot dry weight. On average, shoot and root Cd concentrations and uptake increased in all cultivars, but micronutrients uptake decreased following the application of 45 mg Cd kg?1. No significant differences were observed between 45 and 90 mg kg?1 Cd levels. On average, Cd treatments resulted in a decrease in Zn, Fe and Mn concentrations in shoots and Zn, Cu and Mn concentrations in roots. Differences were observed in Cd and micronutrient concentrations and uptake among rice cultivars. Translocation factor, defined as the shoot/root concentration ratio indicated that Cu and Fe contents in roots were higher than in shoots. The Mn concentration was much higher in shoots. Zinc concentrations were almost similar in the two organs of rice at 0 and 45 mg Cd kg?1. A higher Cd level, however, led to a decrease in the Zn concentration in shoots.  相似文献   

2.
ABSTRACT

Effects of application of zinc (Zn) (0, 1, 5, 10 mg kg?1 soil) and phosphorus (P) (0, 10, 50, 100 mg kg?1 soil) on growth and cadmium (Cd) accumulations in shoots and roots of winter wheat (Triticum aestivum L.) seedlings were investigated in a pot experiment. All soils were supplied with a constant concentration of Cd (6 mg kg?1 soil). Phosphorus application resulted in a pronounced increase in shoot and root biomass. Effects of Zn on plant growth were not as marked as those of P. High Zn (10 mg kg?1) decreased the biomass of both shoots and roots; this result may be ascribed to Zn toxicity. Phosphorus and Zn showed complicated interactions in uptake by plants within the ranges of P and Zn levels used. Cadmium in shoots decreased significantly with increasing Zn (P < 0.001) except at P addition of 10 mg kg?1. In contrast, root Cd concentrations increased significantly except at Zn addition of 5 mg kg?1 (P < 0.001). These results indicated that Zn might inhibit Cd translocation from roots to shoots. Cadmium concentrations increased in shoots (P < 0.001) but decreased in roots (P < 0.001) with increasing P supply. The interactions between Zn and P had a significant effect on Cd accumulation in both shoots (p = 0.002) and roots (P < 0.001).  相似文献   

3.
The effects of calcium and humic acid on seed germination, growth and macro- and micro-nutrient contents of tomato (Lycopersicon esculentum L.) seedlings in saline soil conditions were evaluated. Different levels of humic acid (0, 500, 1000 and 2000 mg kg?1) and calcium (0, 100, 200 and 400 mg kg?1) were applied to growth media treated with 50 mg NaCl kg?1 before sowing seeds. Seed germination, hypocotyl length, cotyledon width and length, root size, shoot length, leaf number, shoot and root fresh weights, and shoot and root dry weights of the plant seedlings were determined. Macro- and micro-nutrient (N, P, K, Ca, Mg, S, Cu, Fe, Mn and Zn) contents of shoot and root of seedlings were also measured. Humic acid applied to the plant growth medium at 1000 mg kg?1 concentration increased seedling growth and nutrient contents of plants. Humic acid not only increased macro-nutrient contents, but also enhanced micro-nutrient contents of plant organs. However, high levels of humic acid arrested plant growth or decreased nutrient contents. Levels of 100 and 200 mg kg?1 Ca2+ application significantly increased N, Ca and S contents of shoot, and N and K contents of root.  相似文献   

4.
ABSTRACT

The response of potted pear trees grafted on quince (Cydonia oblonga Mill.) Sydo stock to increasing concentrations (0, 50, 100, 200, 400, 600, 800, and 1000 mg kg?1) of copper (Cu) in sandy and clay-loam soils were evaluated and crop toxicity thresholds and symptoms were determined. Reductions of shoot growth and leaf area were observed only for pear grown in sandy soil with more than 400 mg Cu/kg. During the growing season, carbon assimilation and soil microbial biomass were reduced as concentration of soil Cu increased. However, the effect was always stronger in sandy than clay-loam soil. Copper accumulated in roots, with response to soil Cu additions described by a linear and a quadratic function for sandy and clay-loam soil, respectively. A possible antagonism was observed between Cu and zinc (Zn) in the roots. Root Zn concentration decreased as soil Cu concentration increased.  相似文献   

5.
Selection of appropriate plant species and rhizosphere manipulation to enhance metal uptake are considered key factors in the development of phytoextraction technologies. A pot trial was conducted with two contaminated soils to investigate the effect of EDTA and ammonium sulfate on the accumulation of heavy metals into shoots of the low‐biomass hyperaccumlator Thlaspi goesingense Hálácsy (Brassicaceae) and the high‐biomass non‐hyperaccumulating plant Amaranthus hybridus (Amaranthaceae). Upon application of 1 g EDTA (kg soil)—1 metal extractability with 1 M NH4NO3 increased substantially, whereas the application of (NH4)2SO4 was less effective. The EDTA treatment increased the heavy metal concentrations in both plant species, however, the difference to the control was larger for A. hybridus. EDTA enhanced shoot concentrations in A. hybridus grown on soil Arnoldstein from 32.7 mg kg—1 to 1140 mg kg—1 for Pb and from 3.80 mg kg—1 to 10.3 mg kg—1 for Cd. Cd concentrations in shoots of T. goesingense were also increased by EDTA application, however, a slight decrease was observed for Pb. T. goesingense accumulated 2840 mg Pb kg—1 without any treatment. This is the first report of Pb hyperacumulation by T. goesingense. A decrease of shoot Pb concentration was observed in T. goesingense upon treatment with ammonium sulfate. Although metal concentrations in the shoots were rather large and significantly increased upon application of EDTA, plant growth and heavy metal removal were still too small to obtain reasonable extraction rates in soils heavily polluted by metals. It should be also noted that metal lability largely increased in EDTA‐treated soils and this lability persisted for several weeks after the application of the chelating agent, which is likely to be associated with the risk of groundwater contamination.  相似文献   

6.
Cadmium (Cd) accumulation and distribution was studied in sunflower (Helianthus annuus L., public line HA‐89) plant. From an uncontaminated sandy loam brown forest soil with 162 μg kg‐1 HNO3/H2O2 extractable Cd the HA‐89 sunflower public line accumulated 114 ug kg‐1 Cd in its kernels under open field conditions. This value is rather low as compared to data found by others. Sandy loam brown forest soil was treated with 0, 1 or 10 mg kg‐1 of Cd to study the interaction of this heavy metal with young sunflower plants in a greenhouse pot experiment. The fresh weight and dry matter accumulation of sunflower plant organs (roots, shoots, leaves or heads) was unaffected by cadmium treatment of soil. The nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), or zinc (Zn) uptake of sunflower plant organs was not influenced by lower or higher Cd‐doses, except sunflower heads where 10 mg kg‐1 of Cd treatment of soil significantly reduced the uptake of Ca, Fe, and Mn. Although Cd reduced the Zn uptake of roots, its rate was statistically not significant. Cadmium was accumulated prevalently in roots (1.21 mg kg‐1,4.97 mg kg‐1, or 13.69 mg kg‐1 depending on Cd‐dose), and its concentration increased also in shoots or leaves. In spite of the short interaction time, elevated concentrations of cadmium (0.78 mg kg‐1, 1.34 mg kg‐1, or 3.02 mg kg‐1 depending on Cd‐dose) were detected in just emerged generative organs (heads) of young sunflower plants.  相似文献   

7.
Assessment of zinc (Zn) phytoavailability by the newly developed technique of diffusive gradients in thin films (DGT) has started gaining more importance because of some advantages over routine soil extractants. A greenhouse study was conducted to determine Zn phytotoxicity thresholds and the phytoavailability of Zn to sorghum sudan (Sorghum vulgare var. sudanese) grass by DGT, compared with calcium chloride (CaCl2) extraction. Treatments were five Zn levels and two soil pH (6.5 and 6). To obtain various amounts of Zn phytoavailability, soils having two different pH values were amended with zinc sulfate (ZnSO4) at rates of 0, 150, 300, 600, and 1200 mg Zn kg?1. Control soil (pH = 6.5) was treated with predetermined elemental sulfur to create different soil pH values (6). Shoot and root Zn concentrations ranged from 27 to 827 mg kg?1 and 101 to 2858 mg kg?1, respectively. In general, the Zn concentrations in shoots and roots were increased by increasing Zn concentrations and soil pH. Increasing applied Zn to soil decreased the plant biomass yield and increased adsorption of Zn by DGT. Calcium (Ca) to Zn ratios for all treatments except controls were <26 for shoots and <13 for roots. The CaCl2‐extractable Zn and effective concentration (CE) correlated well with plant Zn concentration. A critical shoot Zn concentration for 90% of the control yield was chosen as an indicator of Zn toxicity. The performance of DGT, CaCl2 extraction, Ca/Zn ratio and plant Zn concentrations were similar for assessing Zn phytoavailability.  相似文献   

8.
Rice cutgrass (Leersia oryzoides Sw.) and tall fescue (Festuca arundinacea Schreb.) were assessed for potential for phytoremediation of arsenic (As) in a soil-based medium amended with phosphorus (P) in a greenhouse experiment. Arsenic was added at 30 mg kg?1, and P concentrations ranged from 0 to 120 mg kg?1. Plants were grown for 8 weeks. Rice cutgrass accumulated greater concentration and total amount of As in shoots or roots than fescue. Only the first increment of P fertilization increased As in shoots above that which accumulated without P fertilization. Phosphorus fertilization did not stimulate growth of either species. Most of the As remained in the roots of either species. Plant–soil accumulation ratios suggest that rice cutgrass has more potential in phytoremediation than fescue. Above a minimal amount, P fertilization did not enhance As accumulation in shoots and may not be useful in increasing the potential of either species to remediate soils.  相似文献   

9.
A greenhouse experiment was designed to determine the cadmium (Cd) and lead (Pb) distribution and accumulation in parsley plants grown on soil amended with Cd and Pb. The soil was amended with 0, 5, 10 20, 40, 60, 80, and 100 mg Cd kg?1 in the form of cadmium nitrate [Cd(NO3)2] and 0, 5, 10, 50 and 100 mg Pb kg?1 in the form of lead nitrate [Pb(NO3)2]. The main soil properties; concentrations of the diethylenetriaminepentaacetic acid (DTPA)–extractable metals lead (Pb), Cd, copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn) in soil; plant growth; and total contents of metals in shoots and roots were measured. The DTPA-extractable Cd was increased significantly by the addition of Cd. Despite the fact that Pb was not applied, its availability was significantly greater in treatments 40–100 mg Cd kg?1 compared with the control. Fresh biomass was increased significantly in treatments of 5 and 10 mg Cd kg?1 as compared to the control. Further addition of Cd reduced fresh weight but not significantly, although Cd concentration in shoots reached 26.5 mg kg?1. Although Pb was not applied with Cd, its concentration in parsley increased significantly in treatments with 60, 80, and 100 mg Cd g?1 compared with the others. Available soil Pb was increased significantly with Pb levels; nevertheless, the increase was small compared to the additions of Pb to soil. There were no significant differences in shoot and root fresh weights between treatments, although metal contents reached 20.0 mg Pb kg?1 and 16.4 mg Pb kg?1 respectively. Lead accumulation was enhanced by Pb treatments, but the positive effect on its uptake was not relative to the increase of Pb rates. Cadmium was not applied, and yet considerable uptake of Cd by control plants was evident. The interactive effects of Pb and Cd on their availability in soil and plants and their relation to other metals are also discussed.  相似文献   

10.
We assessed the response of the tomato variety “Tiny Tom” to the application of copper (Cu) and zinc (Zn) fertilizers in three tropical peat soils of Sarawak: mixed swamp forest, Alan forest and Padang Alan forest. Limed soils were used because peat soils in their natural condition are unsuitable to sustain healthy growth of most crops. Yield responses were correlated with added Cu and Zn using Mitscherlich model. Adequate levels of applied Cu and Zn were calculated as those which resulted in 90% of the maximum obtainable shoot dry weight. Application of Cu and Zn significantly (P ≤ 0.05) increased the shoot dry weight and the shoot Cu and Zn concentrations of tomato. Application of the equivalent of 8.3 kg Cu and 5.2 kg Zn per ha was required to achieve 90% of the maximum shoot dry weight. In tomato shoots, the critical concentration for Cu was 18 mg/kg and for Zn, 92 mg/kg. The corresponding concentrations for diethylenetriaminepentaaceticacid (DTPA) extractable Cu and Zn in the soils were 2.3 mg Cu kg ?1 and 3.6 mg Zn kg ?1 . However, the addition of Cu fertilizer also increased Zn uptake by tomato plant, probably by displacing native Zn that was weakly sorbed to the soil solid phase.  相似文献   

11.
To investigate the effects of different levels of lead (Pb) on the concentration of iron (Fe), manganese (Mn), and zinc (Zn) in Zea mays, an experiment was conducted in a completely randomized design and 4 × 8 factorial arrangement with three replicates on a calcareous soil in a greenhouse. Factors included four levels of Pb (0 as control, 100, 200, and 400 mg Pb kg?1 soil) from PbCl2 source and eight varieties of maize (single cross 260, 301, 302, 500, 604, and 647 and double cross 370). Results showed that the accumulation of Pb was greater in roots than shoots in the maize varieties studied. Increased Pb concentration in soil decreased Mn and Fe in shoot and elevated Fe concentration in roots. The Mn concentration of roots on different levels of Pb was not affected. Zinc concentration of almost all varieties increased in shoots and decreased in roots with the increase of Pb in soil.  相似文献   

12.
A hydroponic trial was conducted to assess interaction of molybdenum (Mo) and phosphorus (P) on uptake and translocation of P and Mo by Brassica napus. Molybdenum was applied at four rates (0, 0.01, 0.1 and 1 mg L?1) and P at three rates (1, 30, and 90 mg L?1) in nutrient solution. The results indicated that P increased shoot growth and 0.01 mg L?1 Mo improved the growth of shoots and roots. Molybdenum increased shoot P uptake and root P concentration and uptake when higher P was provided, and had a stimulating effect on P translocation from shoots to roots. P increased shoot Mo concentration and uptake, decreased those in roots, and enhanced Mo transport from roots to shoots. These results implied that both Mo and P had beneficial effects on Mo and P absorption and translocation and co-application of them were necessary to promote growth and utilization of Mo and P for Brassica napus.  相似文献   

13.
We compared acetic, ascorbic, and oxalic acids with ethylenediaminetetraacetic acid (EDTA) to enhance phytoextraction of nickel (Ni), manganese (Mn), zinc (Zn), copper (Cu), cadmium (Cd), and lead (Pb) by maize. Except ascorbic acid, acids significantly (P < 0.05) decreased shoot dry weight with maximum (5.60 g pot?1) recorded with ascorbic acid and minimum with oxalic acid (4.06 g pot?1). Maximum ammonium bicarbonate–diethylenetriaminepenta acetic acid (AB-DTPA)–extractable nickel (19.94 mg kg?1) was recorded with EDTA and it was minimum (10.57 mg kg?1) with oxalic acid. The EDTA significantly (P < 0.05) increased AB-DTPA-extractable lead while other acids decreased it. Except acetic acid, other acids significantly (P < 0.05) increased Ni and Zn concentration in shoots with maximum Ni (9.22 mg kg?1) and Zn (37.40 mg kg?1) with EDTA.  相似文献   

14.
The boron (B) sufficiency range for plant growth is narrow and its management is problematic under brackish irrigation water. This study was conducted to evaluate the B requirement of mungbean at different sodium adsorption ratios of irrigation waters (SARiw) [control, 8 and 16 (mmolc L?1)1/2]. The boron adsorption characteristics of a loamy soil were first determined in the laboratory by equilibrating 2.5 g soil with 0.01 M CaCl2 solution containing different B levels. Boron rates for a pot study were computed against different soil solution levels by fitting sorption data in a modified Freundlich model [x/m = K f (EBC)1/n ]. The maximum increase in shoot dry matter was 11.9% when B was applied at 1.29 mg kg?1 soil at control SARiw. Visual leaf B toxicity symptoms appeared at higher B rates and became severe at higher SARiw. By contrast to Ca, shoot concentrations of B and Na increased significantly with B application and SARiw. For optimum shoot growth, internal and external B requirements were 25 mg B kg?1 shoot dry matter and 0.39 mg B L?1 soil solution, respectively, at control SARiw. At higher SARiw, a lower concentration of B in plant shoots and soil solution had an inhibitory effect on plant growth.  相似文献   

15.
This study reports distribution of uranium (U) and thorium (Th) in soil samples and the roots and shoots of some plants grown around an abandoned lead (Pb)–zinc (Zn)–copper (Cu) mining area. The plants Euphorbia macroclada, Verbascum cheiranthifolium Boiss, and Astragalus gummifer were examined. The determinations of U and Th were carried out by inductively coupled plasma‐mass spectrometry (ICP‐MS). Uranium and Th levels of the studied soil samples were found to be in the range of 1.1–70.3 mg kg?1 and 2.1–62.1 mg kg?1, respectively. Some results obtained from this study were higher than the mean U and Th concentrations of soils reported around the world. Uranium and thorium concentrations in studied plant roots were in the range of 0.04–16 and 0.08–14.57 mg kg?1, whereas in plant shoots they were 0.02–2.76 and 0.07–12.3 mg kg?1, respectively. It was concluded that the shoots of Astragalus and roots of Euphorbia and Verbascum can be used as both a biomonitor for environmental pollution and biogeochemical indicator because of their higher U and Th concentrations.  相似文献   

16.
The zinc (Zn) requirement of a maize (Zea mays L.) hybrid (‘FHY-396’) and an indigenous variety (‘EV-7004’) was measured at low (22.4 ± 5°C) and high (28.8 ± 5°C) root-zone temperatures (RZT). Four Zn rates (0, 3, 9 and 27 mg kg?1 soil) were applied to a calcareous loam soil in pots for the glasshouse study. Shoot and root dry matter yields were significantly more at the higher RZT. Regardless the RZT, maximum relative shoot dry matter yield in hybrid and variety was produced, respectively, at 9 and 3 mg Zn kg?1 soil. Zinc concentration in roots and shoots of both the cultivars increased with Zn rates and it was significantly more at the higher RZT. Cultivars differed in critical Zn concentration (CZnC) required for maximum shoot dry matter yield. The CZnC ranged from 25 to 39 μg Zn g?1 plant tissue for optimum growth of both the cultivars at low and high RZT.  相似文献   

17.
A greenhouse experiment with 11 soil series and two zinc (Zn) rates (0 and 15 mg Zn kg?1 as zinc sulfate) was performed to determine critical deficiency level of Zn for corn (Zea mays L.) on calcareous salt-affected soils in central Iran. In addition, the most important soil properties affecting Zn phytoavailability were determined. Critical Zn deficiency levels were determined using the Cate-Nelson and Mitscherlich procedures. In most soils, application of Zn increased the dry matter yield, and Zn concentration and content in the shoot and root of corn. A positive correlation was observed between the soil electrical conductivity (EC) with Zn concentration in shoots, roots and whole plant while shoot Zn content was negatively correlated with buffer capacity of Zn in soil. Critical deficiency levels of Zn in soil for corn based on the Cate-Nelson and Mitscherlich method were 1.35 and 1.23 mg kg?1 for diethylenetriaminepentaacetic acid (DTPA)-extracted soil Zn, respectively.  相似文献   

18.
In the present study, the growth and the Cu2+accumulation by roots, shoots and leaves of Zea mays were examined using copper sulphate in the range of 10?4 to 10?2 M. Plants of Z. mays did not show inhibition of growth in the presence of 10?4 to 10?2 M Cu2+; however, it was observed growth effects on root when different Cu2+ solution concentrations were used. Only the seedlings exposed to 10?2 M exhibited substantial root growth reduction, yielding only 56% of length with respect to the control. Seedlings exposed to 10?4 M Cu2+ exhibited 16% and 42% growth increase in shoots and leaves, respectively, when compared with the controls. The seedlings treated with 10?3 and 10?2 M Cu2+ were inhibited in shoot and leaf growth. The fresh weights in roots, shoots and leaves significantly decreased at 10?2 M Cu2+. The tolerance index, based on root length, was not significantly different for the three different treatments with copper. However, the total accumulation rate was very low at 10?4 and 10?3 M compared to 10?2 Cu treatments. The capacity of copper accumulation by roots, shoots and leaves of Z. mays plants increased concomitant to the copper concentration, arriving to 382 times more in roots, 157 in shoots and only 16 in leaves, all compared to the controls. Cu could be accumulated by roots, shoots and leaves when the initial concentrations were 10?3 and 10?4 M. However, when it was 10?2 M, the metal could not be accumulated by leaf and shoot levels; the roots could increase their copper accumulation capacity three times compared to the control. Z. mays has potential ability to accumulate Cu without being overly sensitive to Cu toxicity.  相似文献   

19.
The aim of this work was to investigate the possibility of using plants for mercury (Hg) removal from a contaminated industrial soil, increasing the metal's bioaccessibility by using mobilizing agents: ammonium thiosulphate [(NH4)2S2O3] and potassium iodide (KI). The selected plant species were Brassica juncea and Poa annua. The addition of the mobilizing agents promoted Hg uptake by plants, with respect to controls. Treatments promoted Hg translocation to aerial parts. In the case of Poa annua, greater Hg uptake was found in plants after the 100 mM KI treatment, reaching values that were nearly 400 mg kg?1 in the aerial part. In contrast, Brassica juncea plants accumulated in their aerial part the greatest Hg quantities, about 100 mg kg?1, after treatment with 0.27 M (NH4)2S2O3. The ratio between the concentration of Hg in the shoots and the initial concentration in the soil support the potential for successfully applying Hg phytoextraction on this soil.  相似文献   

20.
ABSTRACT

A greenhouse experiment was conducted to determine the bioavailability of copper (Cu) in clay loam and sandy clay loam soil. Lettuce (Lactuca sativa) and spinach (Spinacia oleracea) were grown in pots for 45 d. When mature, plants were treated for 15 additional days with 0, 100, 250, 500, or 1000 mg Cu kg?1 as CuSO4·5H2O. After harvest, Cu in soils and plant tissues was determined. In soils, applied Cu raised total and EDTA-extractible Cu. Results also revealed that the amounts of Cu extracted from sandy clay loam soil (80%) were higher than those extracted from clay loam soil (70%). In plants, increasing soil Cu concentration increased plant concentration of the metal. Plant species vary in their capacity for Cu accumulation: Lettuce has a relatively higher potential for Cu uptake and translocation than does spinach. Cu accumulation also differs among plant organs. In lettuce, metal accumulation is higher in roots than in shoots, where 60% to 80% of the total Cu of the plant is located in the roots. However, in spinach, there is no significant difference in Cu content between roots and shoots. The transfer of the metal from soil to plant is higher for plants grown on sandy clay loam soil. For a given rate of applied Cu, metal content in plant tissues is higher on sandy clay loam soil due to its higher transfer coefficient (CT) from soil to plant. Nevertheless, all crops studied showed a positive linear relationship between extractible soil Cu and plant Cu.  相似文献   

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