镉胁迫对不同砧穗组合葡萄植株镉吸收规律和果实品质的影响

以3年生盆栽不同砧穗组合葡萄植株为供试材料,加入氯化镉（CdCl2）以模拟成15mg·kg-1Cd2＋的Cd污染土壤,研究镉在不同砧穗组合葡萄植株内的吸收和分配规律以及对果实品质的影响。结果表明：Cd在不同组合葡萄植株的积累浓度由高到低顺序均为：根系〉茎〉叶片〉果实,不同组合葡萄植株镉含量和果实品质存在显著的差异。所有葡萄植株的果实Cd积累质量分数均低于我国绿色食品Cd限量标准（0.03mg·kg-1,FW）,然而自根苗果实Cd质量分数（0.028mg·kg-1,FW）非常接近0.03mg·kg-1FW,嫁接葡萄植株果实的Cd含量均显著低于自根苗,大约为自根苗的20%～86%,Y/华佳8号、Y/SO4和Y/5BB葡萄果实的Cd含量较低。嫁接降低了葡萄果实中的Cd含量,从一定程度上减轻了人类的Cd暴露风险。不同组合葡萄植株果实的品质存在差异,嫁接提高了Cd胁迫下葡萄果实的可溶性糖（Y/SO4除外）和花青苷含量,降低了可滴定酸含量,提高了果实品质。     

Heavy metal concentration in water,sediment, and tissues of fish species (Heteropneustis fossilis and Puntius ticto) from Kali River,India

The river Kali has been one of the major recipients of industrial effluents in the Muzaffarnagar district of western Uttar Pradesh. The present studies revealed the occurrence and bioaccumulation of heavy metals (Cd, Cr, Pb, Zn, Mn) in riverine water, sediment, and muscles of two fish species, Heteropneustis fossilis and Puntius ticto. Data showed that the order of occurrence of heavy metals was Pb > Zn > Mn > Cr > Cd in river water, Mn > Zn > Pb > Cr > Cd in sediment, Zn > Mn > Cr > Cd > Pb in Puntius ticto and Cr > Zn > Mn > Cd > Pb in Heteropneustis fossilis. Results indicate that the concentrations of Cd, Pb, and Zn in river water, Pb, Zn, and Mn in sediment, Cd, Cr, Pb, and Zn concentration in muscles of Puntius ticto and Cr, Pb, and Zn concentration in in muscles of Heteropneustis fossilis are higher than the permissible standard limits. The presence of heavy metals contributed to toxicity in different organs of fish in River Kali. The bioaccumulation of heavy metals in different biotic organisms in river ecosystem may have adverse consequences on humans and livestock.     

Effect of cadmium in the soil on growth,secondary metabolites and metal uptake in Salvia miltiorrhiza

We investigated the effect of Cd with different concentrations in soil (control, 0.5, 1.0, 1.5, and 2.0 mg kg^?1) on Salvia miltiorrhiza. The growth of S. miltiorrhiza was examined at 90 and 120 d, while active components were tested at 0, 30, 60, 90, and 120 d; Cd uptake was measured at days 0, 90, and 120. The biomass data indicated that high Cd concentration can stimulate the accumulation of biomass after a long treatment. The Cd content in the above- and below-ground parts strongly corresponds to the bioavailable Cd extracted by ethylene diamine tetraacetic acid (EDTA) and acetic acid. The Cd content in the below-ground parts of control approached the Cd standards given by World Health Organization after 120 d. The Cd content in the below-ground parts of S. miltiorrhiza at a Cd concentration of 0.5 mg kg^?1 exceeded the Cd standards after being grown for 90 and 120 days. The accumulation of hydrosoluble components in the above-ground parts appeared later than that in the below-ground parts. With longer treatment time, high Cd treatment promoted an accumulation of hydrosoluble and liposoluble components. The Cd content in the below-ground plant parts indicated that there was still a risk of exceeding the Cd limit for S. miltiorrhiza grown in the soil contaminated by low-concentration Cd after a long time.     

Use of the digestive gland of the oyster Crassostrea rhizophorae (Guilding, 1828) as a bioindicator of Zn,Cd and Cu contamination in estuarine sediments (south-east Brazil)

This study demonstrates the accumulation of Zn, Cd and Cu in the digestive gland of the oyster Crassostrea rhizophorae in response to the contamination of sediments and discusses the potential use of this specific organ in monitoring metal contamination in tropical areas. Sediment and oyster samples were collected from coastal Rio de Janeiro sites with different levels of human impact: Sepetiba Bay, Guanabara Bay and the Paraty coast. Metal concentrations were measured using inductively coupled plasma optical emission spectrometry (ICP OES). Significant statistical differences (p<0.001; p<0.05) were observed for Zn and Cd concentrations in the digestive gland; the highest Zn concentrations were found at Sepetiba, followed by Guanabara and Paraty. The highest digestive gland Cd concentrations were found at Paraty, followed by Sepetiba and Guanabara. These concentrations were proportional to those found in the sediments. There was no significant difference (p>0.05) in Cu among the sampling sites. The highest digestive-gland Cu concentration was also found at Sepetiba, followed by Guanabara. The biosediment accumulation factor indicated a gradient of sediment contamination for Zn and Cd. The digestive gland of C. rhizophorae can be a potential indicator of trace metal contamination in sediments from tropical estuarine environments.     

Levels of heavy metals in blue whiting caught from the eastern Black Sea area of Turkey

This paper presents data on the concentrations of 5 metals, copper (Cu), cadmium (Cd), iron (Fe), zinc (Zn) and lead (Pb) in Blue Whiting sampled from the Eastern Black Sea coast of Turkey. The highest metal concentrations of Cu, Cd, Fe, Zn and Pb were recorded in Blue Whiting with the values of 2.71, 0.601, 14.137, 15.322 and 1.078 μg g^‐1 dry weight, respectively. On average the metal concentrations in Blue Whiting followed the order of Zn > Fe > Cu > Pb > Cd. Temporal differences of concentrations of these metals were significant (p < 0.05). Spatial fluctuations of Cu, Cd, Fe, Zn and Pb concentrations in Blue Whiting were also significant (p < 0.01). It was found that the concentrations of Cu, Cd, Fe, Zn and Pb in the muscle in Blue Whiting were below the limit of Public Health Regulation in Turkey.     

Phytoaccumulation prospects of cadmium and zinc by mycorrhizal plant species growing in industrially polluted soils

The natural vegetation growing along a wastewater channel was subjected to analyze the uptake of Cadmium (Cd) and Zinc (Zn) and their subsequent accumulation in aboveground and underground plant parts. Species which were mycorrhizal and growing in soils receiving industrially contaminated wastewater were collected along with their rhizospheric soil samples. The nearby uncontaminated control (reference) area was also subjected to sampling on similar pattern for comparison. Both Cd and Zn concentrations were significantly higher in soils of the study area as compared to the reference site. Five plant species i.e. Desmostachya bipinnata, Dichanthium annulatum, Malvastrum coromandelianum, Saccharum bengalense, and Trifolium alexandrinum were analyzed for metal uptake. The maximum phytoaccumulation of Cd was observed in Desmostachya bipinnata (20.41 μg g⁻¹) and Dichanthium annulatum (15.22 μg g⁻¹) for shoot and root tissues, respectively. However, Malvastrum coromandelianum revealed maximum Zn accumulation for both the shoot and the root tissues (134 and 140 μg g⁻¹, respectively). The examination of cleared and stained roots of the plants from both the areas studied revealed that all of them were colonized to a lesser or a greater degree by arbuscular mycorrhizal (AM) fungi. The Cd hyperaccumulating grasses i.e. Desmostachya bipinnata and Dichanthium annulatum, from study area had smaller root:shoot (R/S) ratio as compared to those growing on reference area indicating a negative pressure of soil metal contamination. The lower R/S ratio in the mycorrhizal roots observed was probably due to increased AM infection and its mediatory role in soil plant transfer of heavy metals. Furthermore, comparatively lower soil pH values in the study areas may have played a key role in making the overall phytoavailability of both the metals. Consequently variations in Cd and Zn tissue concentration among species were observed that also indicate the phytoaccumulation potential of the native species.     

Metal remediation potential of naturally occurring plants growing on barren fly ash dumps

The present study aimed to elucidate the remediation potential of visibly dominant, naturally growing plants obtained from an early colonized fly ash dump near a coal-based thermal power station. The vegetation comprised of grasses like Saccharum spontaneum L., Cynodon dactylon (L.) Pers., herbs such as Tephrosia purpurea (L.) Pers., Sida rhombifolia L., Dysphania ambrosioides (L.) Mosyakin & Clemants, Chromolaena odorata (L.) King & H.E. Robins along with tree saplings Butea monosperma (Lam.) Taub. The growth of the vegetation improved the N and P content of the ash. Average metal concentrations (mg kg^?1) in the ash samples and plants were in order Mn (345.1)?>?Zn (63.7)?>?Ni (29.3)?>?Cu (16.8)?>?Cr (9.9)?>?Pb (1.7)?>?Cd (0.41) and Cr (58.58)?>?Zn (52.74)?>?Mn (39.09)?>?Cu (10.71)?>?Ni (7.45)?>?Pb (5.52)?>?Cd (0.14), respectively. The plants showed fly ash dump phytostabilization potential and accumulated Cr (80.19–178.11 mg kg^?1) above maximum allowable concentrations for plant tissues. Positive correlations were also obtained for metal concentration in plant roots versus fly ash. Saccharum spontaneum showed highest biomass and is the most efficient plant which can be used for the restoration of ash dumps.

     

Variations between rice cultivars in root secretion of organic acids and the relationship with plant cadmium uptake

To attempt to understand certain mechanisms causing the variations between rice cultivars with regard to Cd uptake and accumulation, pot soil experiments were conducted with two rice cultivars at different levels of Cd, i.e., 0 (the control), 10, 50 mg Cd kg⁻¹ soil. The two rice cultivars differ significantly with regard to Cd uptake and accumulation. Root secretions of low-molecular-weight organic acids (LMWOA) for each treatment were measured with ion chromatography. The results showed that LMWOA concentrations in the soil planted with Shan you 63 (a high soil Cd accumulator) were all higher than those in the soil planted with Wu yun jing 7 (low soil Cd accumulator) at different soil Cd levels, although the magnitudes of the differences varied for individual LMWOA and depend on soil Cd concentrations. For all six LMWOA, there were significant differences at P < 0.05 or < 0.01 levels for soils treated with 10 and 50 mg kg⁻¹ Cd. The magnitude of the differences was greater under soil Cd treatments, especially at relatively low levels (for example, 10 mg Cd kg⁻¹ soil), than in the control. Acetic acid and formic acid constituted more than 96% of the total concentration of the six LMWOA, while citric acid constituted only about 0.1%. The rice cultivar with higher concentrations of LMWOA in soil accumulated more Cd in the plants. The results indicate that LMWOA secretion by rice root, especially in Cd-contaminated soils, is likely to be one of the mechanisms determining the plant Cd uptake properties of rice cultivars.     

Uptake of cadmium in tropical marine lamellibranchs,and effects on physiological behaviour

The effect of cadmium introduced as inorganic salts (chloride, nitrate, sulfate, carbonate, acetate and iodide) or organic chelates (with EDTA, NTA and humic acid) on the physiological behaviour of six species of tropical lamellibranchs — arcid blood clamsAnadara granosa andA. rhombea, venerid clamsMeretrix casta andKatelysia opima, and mytilid musselsPerna viridis andP. indica, collected from various intertidal areas in southern India from 1986 to 1989 — was evaluated. Inorganic salts of Cd are reported to completely ionize upon introduction to full-strength sea water and form predominantly (97%) chloride complexes. Some inorganic Cd salts, therefore, would hardly affect physiological parameters. However, bioaccumulation of Cd was greatest upon exposure to Cd introduced as sulfate, followed by iodide, acetate, chloride, nitrate and carbonate; 96-h LC₅₀'s also varied, but in a different order, being highest for chloride (3.5µg ml^–1), followed by nitrate, acetate, iodide and sulfate (1.8µg ml^–1). Furthermore, Cd levels increased linearly with time of exposure and levels in medium, and were species-specific, being highest in the arcid clams, followed by the venerid clams and mytilid mussels. The presence of other metals such as Zn reduced bioaccumulation of Cd significantly (P < 0.001), but the reverse was not true. Upon exposure to Cd in the presence of Cu, on the other hand, accumulation of both metals was reduced by 15 to 20%. In the presence of organic chelators — EDTA, NTA and reduced glutathione (GSH) — Cd accumulation was significantly inhibited, by 1/2 to 1/3. Humic acid, on the other hand, had no effect. Cd levels in soft tissues were inversely related to ambient salinity in the range of 12 to 32. However, both Zn and Cu significantly inhibited Cd accumulation irrespective of salinity. Cd increased the rate of filtration inAnadara granosa over the first 24 h by 28%, but on prolonged exposure (96 h) that rate decreased significantly, by 50%. Zn alone and in the presence of Cd, on the contrary, initially reduced filtration activity, which subsequently increased to control levels upon continued exposure. Cu alone and in combination with Cd and Zn also significantly (P < 0.001) inhibited filtration relative to controls. This combination also progressively reduced respiratory activity with time, the maximum decrease being 80% after 96 h of exposure. Furthermore, impact of all three metals on both filtration rate and oxygen consumption was initially synergistic, but changed to antagonistic upon prolonged exposure up to 96 h.Deceased. Please send all correspondence and requests for reprints to Dr. S. Patel at the same address     

Effect of Pseudomonas fluorescens on metal phytoextraction from contaminated soil by Brassica juncea

The present study deals with metal uptake by Brassica juncea in the presence of Pseudomonas fluorescens Pf 27 for Zn, Cu and Cd removal from brass and electroplating-industry effluent-contaminated soil. Inoculation of P. fluorescens significantly (p<0.05) increased water soluble (Ws) and exchangeable (Ex) metal content in contaminated soil in laboratory conditions and also enhanced plant biomass by 99% and chlorophyll content by 91% as compared to uninoculated plants in the greenhouse. The metal uptake by B. juncea followed the pattern Zn>Cu>Cd and increased with increasing plant growth duration. P. fluorescens inoculation increased root and shoot uptake of Zn by 3.05 and 2.69, Cu by 3.19 and 2.82 and Cd by 3.11- and 2.75-fold, respectively. BCF value for each metal was>1 and increased by 44%, 42% and 38% for Zn, Cu and Cd, respectively, in inoculated conditions, whereas TF remained unaffected and followed the order Zn>Cd>Cu. P. fluorescens inoculation also enhanced Ws fraction of Zn, Cu and Cd by 99%, 77% and 90% and Ex by 107%, 70% and 93%, respectively. Results depicted that association of B. juncea with P. fluorescens could be a promising strategy for enhancing soil metal bioavailability and plant growth for successful phytoremediation of heavy metal contaminated soils.     

Remediation rates and translocation of heavy metals from contaminated soil through Parthenium hysterophorus

The potential translocation of heavy metals by Parthenium hysterophorus over 30 and 90 days and its effect on biomass, chlorophyll content and photosynthetic activity were studied on 0, 10, 25, 50 and 100% fly-ash-amended soil (FAS). The results showed a decrease in chlorophyll content and photosynthetic area on exposure to 50–100% FAS. Heavy metal reduction was in the order Pb>Cd>Zn>Fe>according to accumulation trends. The plant exhibited good biomass growth on exposure to 25–50% FAS, but this decreased at>100% FAS. Heavy metal concentrations in P. hysterophorus after 90 days of the experiment were in the order Fe>Zn>Cu>Pb>Cd>Ni. Parthenium hysterophorus was suitable for translocating Fe, Zn and Cu based on translocation factors (TF=1.5, 1.3 and 1.05), but was more efficient for Pb, Ni and Cd (TF=8.5, 4.3 and 3.3). Plant uptake of Pb, Ni and Cd was high, whereas translocation of Fe, Zn and Cu was poor. These results indicated that P. hysterophorus can efficiently reduce heavy metal pollution in soil.     

Variation in cadmium uptake by estuarine phytoplankton and transfer to the copepod Eurytemora affinis

The pathways of cadmium (Cd) uptake and transfer within an estuarine planktonic community from the Patuxent River, Maryland, USA, were investigated using an assemblage of natural phytoplankton and the copepod Eurytemora affinis Poppe. The experiment was carried out in October 1992 in replicated 500-liter, flow-through, fiberglass tanks. Growth rate, species composition, and Cd loading affected the accumulation of Cd by the phytoplankton. Uptake of Cd by phytoplankton was proportional to the amount of Cd available in the water column. Partition coefficients (K _d) for phytoplankton uptake averaged 4.4 × 10⁴. As metal loading rates and phytoplankton species composition changed during the 12-d experiment, Cd partitioning declined. Transfer of Cd to E. affinis occurred from Cd-laden phytoplankton, with levels in the copepods being approximately the same as, or somewhat less, than in the phytoplankton. Some Cd uptake occurred in copepods exposed to dissolved Cd only; however, the uptake was considerably less than that seen from food. Thus, Cd content of higher trophic levels, such as copepods, can be affected by the degree of Cd incorporation in their food source, and by ecological factors regulating phytoplankton ingestion. Received: 13 September 1995 / Accepted: 29 October 1998     

Life cycles in marine meiobenthos. Experiments at various temperatures with Monhystera disjuncta and Theristus pertenuis (Nematoda)

Monhystera disjuncta Bastian 1865 and Theristus pertenuis Bresslau and Schuubmans Stekhoven 1935 were cultured on sea-water agar in Boveri dishes at various temperatures. Generation time was measured as the period elapsing in two consecutive generations between the first egg deposit, the first hatching, or the first appearance of sexual characters. M. disjuncta has a generation time of 13 days at 17° to 22°C, 15 days at 13° to 15°C, 17 days at 9° to 12°C, 22 days at 7°C, 77 days at 0° to 2°C, and 135 days at -1° to 1°C. Low temperatures result sometimes in vivipary. T. pertenuis has a generation time of 23 days at 17° to 22°C, 41 days at 13° to 15°C, 47 days at 9° to 12°C, and 71 days at 7°C. M. disjuncta females live for up to 61 days at 17° to 22°C, T. pertenuis females up to 208 days at 7°C. Under North Sea temperature conditions, 17 generations of M. disjuncta and 7 generations of T. pertenuis could occur during the course of 1 year (calculation based upon experiments giving the shortest possible generation time). Females deposit eggs over a couple of days, therefore, the medium generation time is longer, and there will be fewer generations per year in the sea.     

Cadmium, zinc and copper accumulation in the squid Illex argentinus from the Southwest Atlantic Ocean

 The levels and burdens of Cd, Zn, Cu and Hg were measured in the dorsal mantle, digestive gland and gonads of the squid Illex argentinus, from the Southwest Atlantic Ocean. Mature and immature individuals of both sexes were analysed. Correlations of heavy metal concentrations and burdens with sex and food habits were studied. The highest metal levels were found, particularly for Cd, in the digestive gland, which attained a concentration of up to 270 μg g⁻¹ (wet weight). Dorsal mantle and gonads exhibited the same order of metal enrichment: Zn>Cu>Cd. Zinc and Cu levels were higher in ovaries than in testes and varied with the stage of maturation. The dorsal mantle exhibited the lowest heavy metal concentrations. Mercury levels were below the detection limit of the method in all the tissues analysed. Received: 7 September 1999 / Accepted: 9 March 2000     

Accumulation of cadmium and zinc in <Emphasis Type="Italic">Evodiopanax innovans</Emphasis>

The use of tree species for phytoremediation of contaminated soil offers the advantage of a large biomass in which to store contaminants. We investigated the cadmium (Cd) and zinc (Zn) accumulation ability of Evodiopanax innovans, a common deciduous tree species belonging to the Araliaceae family and widely found in secondary forests in Japan. Sampling was conducted at an old silver mine. Leaf samples were collected from nine tree species, including E. innovans. The seasonal variation of metal concentrations in the leaves and the detailed distribution of metals in the leaves and twigs of E. innovans were measured. We also analyzed the contents of organic acids in the leaves. The highest concentration of Cd in the leaves of E. innovans was 118 μg/g, which exceeds the threshold level for being considered a Cd hyperaccumulator (100 μg/g). For Zn, the highest value was 1040 μg/g in leaves, which is less than required to qualify as a Zn hyperaccumulator. Both Cd and Zn were found to accumulate in the petioles and veins of leaves and the bark of twigs. Since the oxalic acid content of leaves showed a weak correlation with Cd concentration, oxalic acid may play an important role in the accumulation of Cd. Taking both the Cd concentration level and the biomass of this woody plant into consideration, it may be possible to use E. innovans for the phytoremediation of Cd-contaminated soils.     

Metal accumulation by three Tilapia spp. from some Egyptian inland waters

Five trace metals (Cu, Zn, Fe, Mn and Cd) were determined in different tissues and organs (muscle, liver, brain, gills, gonads and intestines) of some Tilapia spp. (Oreochromis spp. and Sarotherodon galilaues) collected from two Egyptian Lakes (Edku and Mariut, exposed to different types of pollutants), El-Umum Drain, and from the fishing farm El-Nozha Hydrodrome. Our results indicate that metal accumulation in different organs vary considerably between the same and among different Tilapia spp. There is a preferential accumulation of metals by different organs. Liver is a target organ for Cu accumulation, whereas the brain and flesh tissues clearly accumulate more levels of Zn than the other studied elements. Amongst the studied elements, Cd concentrations in the different organs are the lowest. It was found that edible parts of Tilapia spp. collected from Lake Mariut accumulate the highest levels of the studied elements (Fe, Zn, Mn and Cu for S. galilaues and Cd for Oreochromis niloticus), compared with those in the other studied areas. In general, the levels of Cd (0.0–0.11?ppm), Cu (0.25–1.85?ppm) and Zn (3.58–8.46?ppm) in the edible parts of studied fish cannot be considered as hazardous levels.     

Salps in the Lazarev Sea,Southern Ocean: I. Feeding dynamics

Feeding dynamics of the Antarctic salps Ihlea racovitzai and Salpa thompsoni were studied in the Lazarev Sea in fall 2004, summer 2005–2006 and winter 2006. Pigment concentrations in the guts of both species were positively correlated with ambient surface chlorophyll a (chl a). No evidence was found for salp clogging even at dense surface concentrations of up to 7 μg chl a L⁻¹. However, gut pigment concentrations had a lower range than ambient pigment concentrations, suggesting that salps increased retention times of ingested material in low-food environments. For medium-sized I. racovitzai and S. thompsoni, estimated individual daily rations reached 7–10 and >100% of body carbon in winter and summer, respectively. Daily respiratory needs of I. racovitzai and S. thompsoni accounted for 28 and 22% of daily carbon assimilation based on pigment ingestion rates in winter, and for 2 and 1% in summer, respectively. The grazing impact of the salp populations on the phytoplankton standing stock was negligible during all seasons due to generally low salp densities. Fatty acid trophic biomarkers in the salps suggest high year-round contributions of flagellates and modest contributions of diatoms to the salp’s diet. These markers showed low seasonal variability for I. racovitzai. The more pronounced seasonality of trophic markers in S. thompsoni were likely related to their generally deeper residence depth in winter linked to a seasonal alternation of sexual and asexual generations.     

Phytoremediation potential of weed plants’ oxidative biomarker and antioxidant responses

The purpose of this study was to assess the oxidative biomarkers responses, antioxidant potential and metal accumulation tendency of weed plants collected from the control and metal-contaminated site. The metal contamination was found to be higher in soil and plant parts collected from contaminated site and the most serious problem seemed to be metal elevations above than the safe limit for Cd, Pb and Ni in the aerial parts of weed plants. There were variations in metal accumulation in different weed plants that was justified by principal component analysis. The enzymatic and non-enzymatic antioxidants were found to be higher in plant parts collected from contaminated site. Based upon metal accumulation tendency, weed plants showed a translocation ratio (>1) that reflect their potential for metal remediation. The values of metal pollution index also showed higher tendency of metal accumulation in weed plants, particularly in Solanum nigrum, Euphorbia hirta, Amaranthus hybridus and Xanthium strumarium, and they can also flourish at contaminated sites with more production of antioxidants. So, it suggests that studied weed species can be classified as phytoremediation plants and can be used as eco-friendly and economically feasible technique for restoring the land contaminated with toxic metals.     

Effects of Cadmium on Nutrient Uptake and Translocation by Indian Mustard

Plants that hyperaccumulate metals are ideal subjects for studying the mechanisms of metal and mineral nutrient uptake in the plant kingdom. Indian Mustard (Brassica juncea) has been shown to accumulate moderate levels of Cd, Pb, Cr, Ni, Zn, and Cu. In this experiment, 10 levels of Cd concentration treatments were imposed by adding 10–190 mg Cd kg^–1 to the soils as cadmium nitrate [Cd(NO₃)₂]. The effect of Cd on phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and the micronutrients iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) in B. juncea was studied. Plant growth was affected negatively by Cd, root biomass decreased significantly at 170 mg Cd kg^–1 dry weight soils treatment. Cadmium accumulation both in shoots and roots increased with increasing soil Cd treatments. The highest concentration of Cd was up to 300 mg kg^–1 d.w. in the roots and 160 mg kg^–1 d.w. in the shoots. The nutrients mainly affected by Cd were P, K, Ca, Fe, and Zn in the roots, and P, K, Ca, and Cu in the shoots. K and P concentrations in roots increased significantly when Cd was added at 170 mg kg^–1, and this was almost the same level at which root growth was inhibited. Zn concentrations in roots decreased significantly when added Cd concentration was increased from 50 to 110 mg kg^–1, then remained constant with Cd treatments from 110 to 190 mg kg^–1. However, Zn concentrations in the shoots seemed less affected by Cd. It is possible that Zn uptake was affected by the Cd but not the translocation of Zn within the plant. Ca and Mg accumulation in roots and shoots showed similar trends. This result indicates that Ca and Mg uptake is a non-specific process.     

The gastropod Osilinus atrata as a bioindicator of Cd,Cu, Pb and Zn contamination in the coastal waters of the Canary Islands

The aim of this study was to assess the use of Osilinus atrata (Gastropoda, Mollusca) as a biomonitor of heavy metals (Cd, Cu, Pb and Zn) within the coastal zone of the Canary Islands. In general, this top-shell snail showed high intraspecific variability in its tissue metal concentrations, which decreased according to the following sequence: Cu≥Zn>Cd≥Pb. In particular, Cd and Zn concentrations were higher in males than in females, whereas Cu concentrations increased slightly with weight, and Pb concentrations decreased. Cd and Cu concentrations showed notable spatial variability; Cd concentrations were higher in the eastern islands (Alegranza, La Graciosa, Lanzarote and Fuerteventura) and La Palma, whereas Cu levels were highest in some western islands (Gran Canaria, La Gomera and El Hierro). The arrival of waters from the African coastal upwelling, the pollution of coastal waters with agricultural fertilisers and the competition for uptake between metals appear to be the likely causes within these patterns of accumulation. In conclusion, O. atrata presents a great potential as a biomonitor of heavy metals, however, more information and further studies are necessary.