Ograniczanie wyników

Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 20

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  cadmium accumulation
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
The influence of Cd concentration in growing substrate (0, 10, 20, 40 mg·dm⁻³) and AMF colonization of root system on growth, flowering, and Cd accumulation in osteospermum shoots were examined. Cd in the applied concentrations did not affect decorative value of osteospermum, no chlorosis or necrosis were observed on leaf margins frequently visible on leaves of other bedding plants. Cd at higher concentrations (20 and 40 mg·dm⁻³) lowered dry weights of shoots and roots in non-mycorrhizal plants. Mycorrhizal plants were lower and had lower dry weights of shoots and roots. Cd did not affect dry weights of shoots and roots in mycorrhizal plants. The effects of Cd and mycorrhization on flowering of osteospermum were negligible. Cd content of osteospermum shoots increased with the increasing content of Cd in growing substrate. Mycorrhizal plants grown in substrate containing 40 mg Cd·dm⁻³ accumulated more Cd in shoots than non-mycorrhizal plants. Obtained results showed that osteospermum is very tolerant to Cd toxicity and can accumulate great amount of Cd in shoots.
Our study investigated the accumulation of chromium, nickel, lead and cadmium by maize (Zea mays L.), sunflower (Helianthus annuus L.), willow (Salix x smithiana Willd.), and poplar (Populus nigra L. x P. maximowiczii), and the realtionship between the contaminants in soil and in plants. The experiment was performed in contaminated soil (former waste incineration plant) at the Hradec Králové (Czech Republic) site. Plant and soil samples were collected from three plots with different risk element contents (higher amounts of Cd, Cu, Hg, Zn, Cr, Ni, and Pb). The total and available soil metal concentrations in soil were investigated. Only a low portion of risk elements were available for plants (6% Ni, 14% Cd, 1.3 % Pb, and less than 1% of Cr). Chromium, nickel, and lead showed a similar trend to element accumulation where the highest amount was found in plant roots, higher in herbs than in trees (6.83 mg Cr·kg⁻¹, 5.04 mg Ni·kg⁻¹, and 7.76 mg Pb·kg⁻¹). The highest cadmium concentration was found in leaves of willow (1.87 mg Cd·kg⁻¹) and roots of willow (3.05 mg Cd·kg⁻¹). The correlation between the concentration of risk elements in soil and in plants was the highest in the case of lead reaching up to R= 0.89. Results also indicated that translocation of Cr, Ni, Cd, and Pb from roots to aboveground biomass of willow and poplar was low (89-98% of risk elements was retained in roots). The highest translocation from plant roots to aboveground biomass of maize and sunflower was found in the case of Cd and Pb (57 and 83% of Cd, 56 and 76% of Pb). The behaviour of these elements concerning soil and plants differed among fields with unknown history of contamination and type of contaminants.
Seedlings of wheat (Triticum aestivum L.) cultivars Jing 411, Jinmai 30 and Yangmai 10 were exposed to 0, 10, 20, 30, 40 or 50 μM of CdCl₂ in a solution culture experiment. The effects of cadmium (Cd) stress on wheat growth, leaf photon energy conversion, gas exchange, and Cd accumulation in wheat seedlings were investigated. Gas exchange was monitored at 3, 9, 24 days after treatment (DAT). Growth parameters, chlorophyll content, leaf chlorophyll fluorescence, and Cd concentration in shoot and root were measured at 24 DAT. Seedling growth, gas exchange, chlorophyll content, chlorophyll fluorescence parameters were generally depressed by Cd stress, especially under the high Cd concentrations. Cd concentration and accumulation in both shoots and roots increased with increasing external Cd concentrations. Relationships between corrected parameters of growth, photosynthesis and fluorescence and corrected Cd concentrations in shoots and roots could be explained by the regression model Y = K/(1 + exp(a + bX)). Jing 411 was found to be Cd tolerant considering parameters of chlorophyll content, photosynthesis and chlorophyll fluorescence in which less Cd translocation was from roots into shoots. The high Cd concentrations were in shoots and roots in Yangmai 10 which has been found to be a relative Cd tolerant cultivar in terms of most growth parameters.
In the spring-summer season in the years 2005 and 2006 (every year) three vegetation experiments were carried out with three species of ornamental plants: common sunflower (Helianthus annus ‘Pacino’), scarlet sage (Salvia splendens ‘Fuego’), tagetes erecta (Tagetes erecta ‘Inca Yellow’). These plants were planted in a substrate artificially contaminated by cadmium. Doses of cadmium applied in the experiment represent different degrees of contamination. The dose of 1 mg Cd ∙ dm⁻³ indicates natural contents; 5 mg Cd ∙ dm⁻³ – small contamination; 10 mg Cd ∙ dm⁻³ – large contamination. The objective of the presented studies was the determination what quantities of cadmium pass from the substrate to the organs of the studied plants and which plant organs accumulate the greatest amounts of cadmium. Cadmium was mainly accumulated in leaves and shoots, then in inflorescences. While the least amount of this metal was found in the roots with the exception of Tagetes erecta where the greatest amount of cadmium was found in roots, then in leaves and shoots, while the lest amount was in inflorescences. The greatest cadmium contents were found in the roots of Tagetes erecta, in leaves and shoots of Salvia splendens, and in the inflorescences of Helianthus annus. Among the studied ornamental plant species, the plants of Tagetes erecta were characterized by the highest cadmium uptake.
The objective of the study was genetic and breeding screening of selected varieties and hybrids of oil flax for in-seed cadmium fixing ability. Seven parental varieties as well as nineteen F1 and F2 hybrids were analyzed. The varieties were crossed in di-allelic scheme, according to the Griffing method II. Significant differences were found in the activity of fixing cadmium from the soil between analysed flax parental forms and hybrids. High variability of tested genotypes, calculated by the variance coefficient, was observed in F1 generation. The variability of tested genotypes in the F2 generation was two times lower. The analysis of general combining ability (GCA) showed that Chinese cultivar Shanxi reduced significantly the fixing cadmium from the soil in combinations of F1 generation crossing. However, the effects of the specific combining ability (SCA) of tested hybrids to reduce the cadmium content in seeds were statistically insignificant. The analysis of genetic components variance showed no significance both in domination and cumulative genes which suggests a complex inheritance pattern of the tested trait.
The total content of heavy metals in soil does not indicate bioavailability of these elements after introduction of sewage sludge to soil. Determination of the rate of heavy metal mobilization from sewage sludge after its application to soil is very important for agricultural practice since it allows us to asses the rate at which these elements pass into the soil solution, which conditions their uptake by plants. This research has been conducted to assess the effect of farmyard manure and sewage sludge fertilization on the amounts of zinc and cadmium absorbed by maize and the content of their mobile forms in soil. The research consisted of a three-year pot experiment. Farmyard manure and sewage sludge fertilization resulted in larger total yields of maize biomass (for the 3-year period of the investigations) than harvested from the treatments where only mineral compounds were used as fertilizers. Irrespectively of the fertilizer dose, the total (for 3 years) amounts of zinc and cadmium absorbed by maize were the highest in the treatments where only mineral salts were added and Zn and Cd quantities taken up by maize in the first year of the experiment contributed to this result. Fertilization with farmyard manure and sewage sludge did not cause any significant mobilization of mobile zinc and cadmium forms in soil after the first year of the research. As a result of organic matter mineralization and progressing soil acidification, in the second and third year of the research, the content of mobile forms of the elements in soil increased, although to a lesser degree than under the influence of exclusively mineral treatment.
The aim of this study was to investigate the accumulation of cadmium (Cd) in the kidneys and its excretion with urine, and possible effect of benzo(a)pyrene (B(a)P) and pyrene on these processes in rats. The studies were conducted on 60 Wistar male rats by short-term (28 d) and subchronic (90 d) experiments. Cadmium was given at doses 0.1 and 0.5 mg/kg. The samples of urine and kidneys were analysed by atomic absorption spectrophotometry. The obtained data showed that Cd in a dose of 0.5 mg/kg significantly increased its renal and urine content; however, the lower dose (0.1 mg/kg) administered during 28 d did not increase Cd urinary excretion levels. This indicates that Cd has a tendency to accumulate in the organism (in kidneys in particular), and when absorbed, is very slowly eliminated from the organism. In short term experiments both doses of Cd increased its accumulation in the kidneys. B(a)P (dose 0.00015 mg/kg) in 28 d and 90 d studies, and pyrene (dose 0.00075 mg/kg) in 90d studies had no effect on the accumulation of Cd in the kidneys and excretion with urine.
In Poland, soils contaminated with cadmium constitute about 1.6 % of arable lands whereas in the œlšskie province they make up 21.5 % of agricultural lands. Because of the fact that the metal is counted among the most dangerous environmental poisons, research was undertaken to determine soil properties most impacting plant growth and their ability of cadmium accumulation. The studies were conducted as a pot experiment on 15 soils diversified as to their properties, which might affect solubility of cadmium contained in them and its bioavailability. Oats, rape and maize were cultivated in each of the soils. Sensitivity of the tested plant species to soil requirements and ability for cadmium accumulation by plants were decreasing in the following order: rape > maize > oats. From among the tested soil properties acidification most affected the uptake and accumulation of cadmium in rape, whereas soil organic carbon concentration affected it to a lesser degree. Cadmium uptake by rape was increasing with the growth of these soil properties. Oats and rape developed mechanisms alleviating the results of soil properties affecting cadmium adsorption from the substratum.
The aim of the study was to assess the dynamics of cadmium and nickel accumulation in the carp, Cyprinius carpio L., during the rapid growth period between 3rd and 6th month of life, including seasonal changes. Chemical assays were performed on samples of gills, anterior and mid-posterior part of the alimentary tract, liver, kidneys, skin and muscles. Prior to the assay, 1-g tissue samples were digested with 3 ml of concentrated HNO3 in a CEM MDS 2000 microwave oven. The samples prepared this way were assayed for Cd and Ni. Cadmium level was determined with flameless graphite furnace atomic absorption spectrometry (GF-AAS) in a ZL 4110 Perkin Elmer. Nickel was determined inductively coupling plasma atomic emission spectrometry (ICP-AES) in a JY-24 Jobin Yvon apparatus. The results indicated that in the period of growth between 3rd and 6th month of life, cadmium and nickel concentrations in the examined carps fluctuated. Average cadmium content in examined organs ranged between 0.053 ÷ 0.004 µg g-1 wet weight. Average nickel content in examined organs ranged between 0.326 ÷ 0.023 µg g-1 wet weight. The observed fluctuations are supposed to be a result of intensive growth and accompanying accumulation of metals from water.
The bays of Skikda and Jijel present an ecosystem of great biological diversity and a significant economic interest (fishing and trading ports, industrial zones and tourism). They are threatened by the inputs of industrial effluents that are loaded with different substances, especially heavy metals. These pollutants have the distinction of being toxic and non-biodegradable, they accumulate in the different levels of the food chain which represents a danger for human health. The present work aimed to evaluate the impact of metal pollution in both bays via the study of the bioaccumulation of heavy metals namely, cadmium (Cd) and lead (Pb) in red mullet Mullus barbatus Linnaeus, 1758. Forty two (42) fish samples were obtained from 4 sites, 2 from bays of Skikda and 2 from bays of Jijel. After preparation, lyophilisation and mineralisation, samples were analysed by Atomic Absorption Spectroscopy (AAS) for detection of Cd and Pb concentrations in µg/g of dry weights. Lead has reached the values of 141.666±5.238 and 89±3.464 µg/g in Skikda sites and 20±1.527 and 10±0.577 µg/g in Jijel sites, while Cd has reached 0.76±0.023 and 0.3±0.011 µg/g in Skikda, with lowest values in Jijel 0.116±0.008 and 0.1±0.005 µg/g. The highest levels were recorded in the areas that are subject to anthropogenic pollution, namely the port areas and the oil industry (Skikda bays). While the low concentrations were found in less polluted areas like Jijel bays. The results obtained in this study are alarming and reflect a significant level of pollution especially in the bays of Skikda. Preventive and remedial measures and awareness raising are needed.
The effect of two cadmium concentrations (10-5 M and 10-4 M) on growth, Cd accumulation and within-plant distribution, proline (Pro) content, and the activity of superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST) and glutathione peroxidase (GSH-Px) was examined in leaves and roots of poplar plants. Symptoms of Cd toxicity were evident in Cd-treated plants: stunted growth (plant height and biomass), decreased root length, and chlorosis of young leaves. Stem and leaf growth was more affected than root growth. The decreased photosynthetic activity of treated plants may have been due to lowered chlorophyll synthesis. The activity of SOD, CAT, GST and GSH-Px was altered, as was Pro accumulation. The increment of pollutant concentration in the nutrient medium was associated with higher Cd accumulation in plants. Cd in roots was ~40 times higher than in leaves and stems of plants exposed to 10-5 M Cd. Although Cd accumulation in roots was high, the potential use of this hybrid poplar for remediation of Cd-contaminated sites seems low. This is because, apart from the described growth disturbances, translocation of Cd from roots to aboveground parts is low.
Intoksykacja kadmem ciężarnych samic szczurzych od 7 do 19 dnia ciąży, w dawkach w zależności od grupy doświadczalnej równych 0,2, 2,0 oraz 20,0 mg Cd/kg masy ciała, powodowała w jelicie cienkim spadek aktywności procesów fosforylacji oksydatywnej korelujący z wielkością dawki oraz zawartością metalu w ścianie badanych odcinków jelita cienkiego. Równolegle obserwowano aktywację beztlenowych szlaków uzyskiwania energii.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.