卡拉麦里南部工业区梭梭和琵琶柴重金属空间分布及污染评价

对五彩湾工业区周边21个采样点的梭梭(Hadoxylon)和琵琶柴(Reaummuria soongorica)的Zn、Cu、Cr、Pb、As、Hg 6种重金属元素含量测定,运用统计学方法和地统计插值法分析其茎叶和根部重金属含量变化情况和空间分布特征,并综合评价其污染程度和潜在生态危害性。结果表明:梭梭和琵琶柴植株Hg含量的最大值和均值都超出新疆土壤背景值0.017 mg/kg,除梭梭根部的均值0.060 mg/kg未超出国家土壤背景值0.065 mg/kg,在二者其他部位的最大值和均值都已超出;琵琶柴整株中Cr最大值72.62 mg/kg和Zn最大值97.61 mg/kg均超出新疆土壤背景值49.3 mg/kg和国家土壤背景值61 mg/kg,Pb元素未被检出。插值精度方面,Hg、As的RMSE较小,分别为0.263和0.443,预测模型中Hg的R~2为0.72,Cu的R~2为0.67,能较好地估计预测样点的重金属含量,Zn的R~2为0.31,精度较低;插值结果,琵琶柴中的Zn、Cr、As、Hg含量较高的区域均在工业园区内部及周围,受人为扰动程度较大。梭梭和琵琶柴中Hg元素分别为中度污染和重度污染;Hg元素为中等潜在危害程度高于其他4种元素。     

Heavy metal accumulation in rice (Oryza sativa) near electronic waste dumps and related human health risk assessment

This research was conducted to assess heavy metal contamination in the environment and within Oryza sativa. The translocation factors (TFs) and bioaccumulation factors (BAFs) for heavy metals in O. sativa and estimated daily intake (EDI) and health risk index (HRI) were measured. The samples were analyzed for heavy metals using inductively coupled plasma optical emission spectrometry (ICP-OES). Pb and Cr concentrations in water samples within and near the electronic-waste dumping area exceeded water quality standards for surface water sources from the Pollution Control Department in the Ministry of Natural Resources and Environment of Thailand (PCD). The Pb concentration in soil samples within the area also exceeded soil quality standards for habitat and agriculture from PCD. Most of the metals were highly concentrated in roots, except for Mn which has the highest concentration in leaves. Pb concentrations in rice grains exceeded the FAO/WHO standard (0.2 mg/kg). The average TF values for heavy metals from the soil to roots, roots to stems, stems to leaves, and stems to grains were Mn > Pb > Ni > Cr, Mn > Cr > Ni > Pb, Ni > Pb > Mn > Cr, and Pb > Ni > Cr > Mn, respectively. The average BAF values in O. sativa were Mn > Ni > Pb > Cr. The EDI for Cr, Pb, Mn, and Ni via O. sativa consumption were 6.19, 6.02, 370.57, and 3.80 µg/kg/day, respectively. The HRI for Cr, Pb, Mn, and Ni via O. sativa consumption were 0.30, 1.50, 2.60, and 0.002, respectively.     

Contents of Heavy Metals in Chinese Edible Herbs: Evidence from a Case Study of Epimedii Folium

Toxic heavy metal contamination in Chinese edible herbs has raised a worldwide concern. In this study, heavy metals in Epimedii Folium, an edible medicinal plant in China, were quantitatively analyzed. Variations of heavy metals in different species, in various organs (i.e., leaves, stems, and roots), in wild-growing and cultivated plants, and in 35 market samples of Epimedii Folium, were systematically investigated. In all of Epimedium samples, Hg (mercury) was not detectable (0.00 μg/g). Four species, Epimedium pubescens, Epimedium sagittatum, Epimedium brevicornu, and Epimedium wushanense, were found to contain Cu (copper) and Pb (lead). And contents of Cu and Pb in E. brevicornu were significantly higher than those in other species (P < 0.01). In wild-growing and cultivated Epimedium plants, Cd (cadmium) and As (arsenic) were not detectable, and concentrations of Cu and Pb in wild-growing plants were significantly higher than those in cultivated plants (P < 0.01). Cd was not detectable in leaves, roots, and stems, while organ specificity was apparent in the distribution of Cu, As, and Pb. And the highest levels of Cu and Pb were observed in roots and leaves, respectively. In Chinese markets, several samples of Epimedii Folium contained excessive Cu, Cd, As, and Pb beyond the national permissible limits. In summary, there was a large variation of heavy metals among Epimedii Folium samples, and Cu and Pb were the most important heavy metals contaminating the edible medicinal plant. Application of Epimedii Folium to drug and food industries will need to focus more on toxic heavy metal contamination.     

Effects of Cadmium and Mixed Heavy Metals on Rice Growth in Liaoning,China

Joint effects of Cd and other heavy metals (Pb, Cu, Zn and As) on the growth and development of rice plants and the uptake of these heavy metals by rice were studied using the pot-culture method combined with chemical and statistical analyses. The results showed that the growth and development of rice plants were strongly influenced by the double-element combined pollution. There was an average decrease in the height of rice plants of 4.0–5.0 cm, and grain yield was decreased by 20.0–30.0%, compared with the control. The uptake of Cd by rice plants was promoted due to the interactions between Cd and the other heavy metals added to the soil. The Cd concentration in roots, stems/leaves and seeds increased 31.6–47.7, 16.7–61.5 and 19.6–78.6%, respectively. Due to interactions, uptake of Pb, Cu and Zn by roots and stems/leaves was inhibited, accumulation of Pb, Cu and Zn in seeds was increased, uptake of As by roots was promoted and uptake of As by stems/leaves was inhibited. In particular, the upward transporting ability of the heavy metals absorbed by rice plants was significantly increased.     

高盐生境中乌拉尔甘草盐离子分泌与积存格局的研究

采用植物水培方法,以乌拉尔甘草为研究材料,用不同浓度(0、80、160、320mmol·L~(-1))NaCl溶液胁迫处理乌拉尔甘草幼苗3周后,分析其叶片表面盐离子(K~+、Ca~(2+)、Na+)分泌速率的差异,并采集盐化低地草甸重盐土生境中2年生乌拉尔甘草植株,应用ICP-AES测定其不同部位(根、根状茎、茎、老叶和幼叶)中的盐离子(K~+、Na~+、Ga~(2+)、Mg~(2+))含量,探究盐离子在乌拉尔甘草叶片上的分泌格局以及盐离子在植株体内的积存格局,为完善甘草耐盐机理的研究提供依据。结果显示:(1)随着盐胁迫浓度的升高,乌拉尔甘草叶片上K~+、Ca~(2+)、Na+的分泌速率均呈增加趋势,且Na~+的分泌速率远远大于Ca~(2+)和K+的分泌速率。(2)在乌拉尔甘草各部位中,K+的积存量从大到小依次为:幼叶根根状茎茎老叶;Na~+在各个部位的积存量都十分有限,且无论地下部分还是地上部分,差异均不大;Ca~(2+)积存量由大到小依次为:老叶幼叶茎根状茎根,且老叶中Ca~(2+)的积存量显著高于其它部位。研究认为,在重盐碱地生境中,K+主要积存在幼叶中,Ga~(2+)主要积存在老叶中,植株体内各个部位Na~+的积存量很低,乌拉尔甘草表现出明显的拒Na现象;叶片分泌的主要盐离子为Na~+;乌拉尔甘草通过泌盐的方式将Na+排出体外,从而有效降低Na~+在体内的积存,这是其能够在重盐碱地生存生长的重要原因。     

Effect of EDTA and Tannic Acid on the Removal of Cd,Ni, Pb and Cu from Artificially Contaminated Soil by Althaea rosea Cavan

In this study an ornamental plant of Althaea rosea Cavan was investigated for its potential use in the removal of Cd, Ni, Pb and Cu from an artificially contaminated soil. Effect of two different chelating agents on the removal has also been studied by using EDTA (ethylenediaminetetracetic acid) and TA (tannic acid). Both EDTA and TA have led to higher heavy metal concentration in shoots and leaves compared to control plants. However EDTA is generally known as an effective agent in metal solubilisation of soil, in this study, TA was found more effective to induce metal accumulation in Althaea rosea Cavan under the studied conditions. In addition to this, EDTA is toxic to some species and restraining the growth of the plants. The higher BCF (Bio Concentration Factor) and TF (Translocation Factor) values obtained from stems and leaves by the effects of the chemical enhancers (EDTA and TA) show that Althaea rosea Cavan is a hyper accumulator for the studied metals and may be cultivated to clean the contaminated soils.     

Heavy metal bioaccumulation by the organs of Phragmites australis (common reed) and their potential use as contamination indicators

The concentrations of heavy metals in the roots, rhizomes, stems and leaves of the aquatic macrophyte Phragmites australis (common reed), and in the corresponding water and sediment samples from the mouth area of the Imera Meridionale River (Sicily, Italy), were investigated to ascertain whether plant organs are characterized by differential accumulation, and to test the suitability of the various organs for heavy metal biomonitoring of water and soil. Heavy metals considered were Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn. Results showed that belowground organs were the primary areas of metal accumulation. In particular, metal concentrations in plant organs decreased in the order of root > rhizome ≥ leaf > stem. All four organs showed significant differences in concentration for Cr, Hg, Mn, Zn, thus suggesting low mobility from roots to rhizomes and to aboveground organs. Although the organs followed different decreasing trends of metal concentration, the trend Mn > Zn > Pb > Cu was found in each plant organ. Mn showed the highest concentrations in all organs whereas the lowest concentrations regarded Cd and Cr in the belowground and aboveground organs, respectively. The toxic threshold was exceeded by Cr in roots, rhizomes and leaves, Mn in roots and leaves, Ni in roots. The highest average concentrations were found as follows: Cd, Hg, Pb, Zn in root, Cr, Mn, Ni in sediment, Cu in water. Positive linear relationships were found between heavy metal concentrations in all plant organs and those in water and sediment, thus indicating the potential use of such organs for pollution monitoring of water and sediment. Advantages of using plant species as biomonitors, especially Phragmites australis, were also discussed.     

Trace metal content in the seagrass Cymodocea nodosa: Differential accumulation in plant organs

Differences in the accumulation of seven metallic elements, including micronutrients (Cu, Fe, Mn, Ni and Zn) and non-essential elements (Cd and Pb) among plant organs (leaves, roots and rhizomes) were examined in the seagrass Cymodocea nodosa. Samples were taken from two coastal bays (Catalonia, Western Mediterranean), with a total of nine sampling sites encompassing different levels of metal availability. Metal content was generally higher in uptake organs (leaves and roots) than in rhizomes. However, accumulation in leaves and roots varied between elements. While Cd, Mn and Zn preferentially accumulate in leaves, Fe and Pb accumulate in roots and Cu and Ni in both. There were common spatial (between sites) trends in Cd, Mn, Cu and Zn accumulation in the three organs. However, these spatial trends varied according to the organ considered in the case of Fe, Pb, and Ni. Therefore, assessment of within-plant variability is strongly recommended prior to the use of C. nodosa for biomonitoring purposes, at least for Fe, Pb, and Ni.     

Effects of Cu,Pb and Zn on two Potamogeton species grown under field conditions

Two common macrophyte species, Potamogeton perfoliatus L. and Potamogeton pectinatus L. were grown for 12 weeks at shallow depths in sediments contaminated with 1250 or 2500 g Pb or Cu and/or Zn (gDW sediment)^-1. Control experiments were run at background levels of 4, 13, and 38 g Pb, Cu and Zn (gDW sediment)^-1, respectively. Effects of heavy metals on biomass production and metal uptake and distribution in plants are presented in relation to total amount and plant-available fraction of metals in the sediment.All three studied metals gave reduced biomass production, and the toxicity of the metals decreased in the order Zn>Cu>Pb. The root/shoot biomass ratio increased for P. pectinatus, but decreased for P. perfoliatus with metal treatment. The content of any single metal was higher in shoots than in roots of plants grown on sediments not contaminated with that specific metal, but addition of that metal increased the proportion in roots. The uptake by plants of any of the heavy metals increased with increased metal addition. The magnitude of the plant-available fraction of metals of untreated sediment was Zn>Cu>Pb, and increased in contaminated sediments. Addition of Cu decreased both the plant-available fraction and the total concentration of Zn in the sediment, while increased the uptake of Zn by the plants. The opposite was found for Cu when Zn was added. P. pectinatus accumulated about twice as much Cu as P. perfoliatus. On the other hand, the concentration of Pb was higher in P. perfoliatus than in P. pectinatus, and was negligible in P. pectinatus when cultivated in untreated sediments.     

镉污染条件下水稻对假单胞菌TCd-1微生物修复的生理响应

微生物在修复重金属污染土壤中发挥重要作用。为阐明假单胞菌TCd-1降低水稻镉吸收的机理,通过加镉土培盆栽试验,在10 mg/kg镉处理下,对比研究了接种菌株对2种镉耐性不同水稻品种(特优671、百香139)镉含量、根系活力、光合作用、抗氧化酶活性及抗氧化物质含量的影响。结果表明：与10 mg/kg镉处理相比,接种假单胞菌TCd-1后水稻“特优671”和“百香139”的根、茎、叶、糙米的镉含量分别依次降低了30.4%、39.1%、40.7%、29.2%和52.2%、51.7%、18.4%、38.8%;提高了2种水稻的根系活力、光合作用,促进了水稻的生长;“特优671”、“百香139”叶片的超氧化物歧化酶(Superoxide dismutase, SOD)活性分别提高了7.3%、138.5%,过氧化物酶(Peroxidase, POD)活性提高了82.0%、106.2%,过氧化氢酶(Catalase, CAT)活性提高了58.8%、172.7%;叶片的类黄酮含量提高了139.4%、73.6%,总酚含量提高了27.2%、23.1%;超氧阴离子含量降低了44.2%、29.0%,丙二醛(Mal...     

Zinc and Copper Bioaccumulation in Brassica napus at Flowering and Maturation

The aim of this research was to investigate the capability of Brassica napus to bioaccumulate zinc and copper from artificially contaminated soil at the flowering and maturation phenological stage. The trial was set up in a greenhouse and the plants were cultivated in pots. The agricultural soil utilized was contaminated with zinc and copper sulfate (300 and 600 mg/kg, respectively). The soil and plant samples were simultaneously collected during the flowering (8 weeks after seeding) and maturation (harvest time, 13 weeks after seeding) stages, and the heavy metal concentrations were then analyzed. The production of vegetable biomass and the length of the roots were measured. The results showed that B. napus accumulated zinc and copper and translocated these elements in different ways in the harvestable parts of the plants. The zinc bioaccumulation was higher than that of copper. At flowering, zinc was mainly accumulated in the shoots (stems + leaves). Copper was particularly accumulated in the roots, during the entire life cycle. Taking into account the biomass production, the highest heavy metal removal by the shoots (above‐ground parts) occurred at the flowering stage for both zinc and copper. The high bioavailability of zinc and copper in the soil did not severely affect the root length and the biomass production.     

Localization and quantification of Pb and nutrients in Typha latifolia by micro-PIXE

Typha latifolia is a plant species widely used for phytoremediation. Accumulation, localization and distribution of Pb and mineral nutrients were investigated in roots, rhizomes and leaves of Typha latifolia grown at 0, 50, 100 and 250 μM Pb concentrations in a pot experiment under controlled conditions. Bulk elemental concentrations were determined by X-ray fluorescence (XRF) spectroscopy whereas micro-proton-induced X-ray emission (micro-PIXE) was used for element localization in root and rhizome tissues. Gradual increase in bulk Pb concentrations was observed in Typha latifolia roots and rhizomes treated with increasing Pb concentrations, however in rhizomes Pb concentrations were an order of magnitude lower than in roots. In leaves Pb concentrations were around the limit of detection for XRF (~20 μg g(-1)). An increase in concentration of K and Ca in roots, rhizomes and leaves, of iron and zinc in roots and leaves, and of Mn in rhizomes was observed either at 50 and/or 100 μM Pb treatments, whereas for K and Ca in roots, rhizomes and leaves, Fe and Zn in roots and leaves and Mn in rhizomes, or at 250 μM Pb treatment the increase was seen for concentrations of Fe and Zn in rhizomes and Cu in roots. Mn concentrations decreased with Pb treatments in roots and leaves. Element localization using micro-PIXE analysis demonstrated Pb accumulation in epidermal and cortical tissues of treated roots and rhizomes, while in endodermis and vascular tissues Pb was not detected. A displacement of Ca from epidermal to cortical tissues was observed in Pb treated roots and rhizomes, pointing to cell wall immobilization of Pb as one of the tolerance mechanisms in Typha latifolia. High level of colocalization of Pb with P (r = 0.60), S (r = 0.37) and Zn (r = 0.70) was observed in Pb treated roots, while in rhizomes colocalization with the mentioned elements was still positive, but not that prominent. These results indicate that Pb may form complexes with phosphorus and sulfur compounds in roots and rhizomes, which may also represent attraction sites for binding Zn. Because of its large root and rhizome surface area acting as main sites for Pb adsorption, Typha latifolia may represent potentially efficient plant species for phytoremediation of Pb contaminated soils and waters.     

刺楸年轮中重金属含量动态变化及富集特性

为探索刺楸对受污染土壤重金属的富集和修复效应, 以南京栖霞山的乡土树种刺楸及其根际周边土壤为研究对象, 截取其根基部年轮盘及根际土壤样本, 采用ICP-AES法测定年轮及土壤样本中重金属(Cu、Cd、Cr、Mn、Ni、Pb、Zn)元素含量。结果表明: 栖霞山样地中的土壤受Mn、Pb和Zn污染最为严重, 存在Cu、Cd、Mn、Pb、Zn元素的高度复合污染, Cd、Cr、Cu、Ni、Zn在土壤和年轮中存在相关性, Mn和Pb则没有表现出明显的相关性; 刺楸修复受Cd、Mn、Pb、Zn污染的土壤效果并不显著, 更适用于Cr、Cu、Ni污染的土壤修复; 鉴于Cu元素含量变化特征, 刺楸也可以作为反映当地污染历史的记录载体; 刺楸年轮中的重金属元素之间存在交互作用, 其中Cd与Zn元素含量高度相关(r=0.984, p<0.01), 在刺楸年轮吸收重金属元素的过程中, Cu与Cd、Cr、Mn、Zn元素具有协同作用, Mn元素对其他元素有一定的拮抗作用。     

Studies onCabomba aquatica (Cabombaceae)

Cabomba aquatica has been found for the first time in India. Both, submerged and floating leaves are epistomatic. The stomata are anomocytic and perigenous in their development. The metaxylem vessel elements have simple perforation plates and spiral side wall thickening. Vessel elements are found in roots, rhizomes and aerial stems. The venation pattern is of two types like the dimorphic leaves. On the basis of these and other featuresCabomba deserves family rank.     

Factors affecting the distribution of cadmium,copper and lead and their effect upon yield and zinc content in bush beans (Phaseolus vulgaris L.)

Summary Concentrations of Cd, Pb and Cu in the roots, stems and leaves of bulgarian bush beans (Phaseolus vulgaris L.) were determined for plants grown in various soils of increasing levels of contamination of these metals. Most of each heavy metal absorbed by plants was retained in roots. Concentrations of Cd, Pb and Cu in roots increased in response to soil concentrations, whereas, in stems, only Cd and Pb concentrations increased and Cu concentration was relatively constant. It is thought that Cu transport to the stele was metabolically controlled, whereas Cd and Pb reached the stem by leakage across non suberised areas of the endodermis. Uptake of heavy metals was associated with a decrease in zinc content in plants and a decrease in yield. By regression analysis decrease in both zinc content and plant yield could be best related to Cd content in stems. Possible reasons for these effects are discussed.     

Contribution of Ectomycorrhizal Fungi to Cadmium Uptake of Poplars and Willows from a Heavily Polluted Soil

Phytoextraction has been proposed in recent years as an environmentally and cost-efficient treatment technique for the remediation of heavy-metal contaminated sites. In particular, plants that are fast growing, metal accumulating, and economically interesting, such as sunflowers or trees, recently became more important in research on phytoextraction. Heavy metal uptake of trees can be strongly influenced by ectomycorrhizal fungi. We investigated the possibility of enhancing phytoextraction of Cd by willows (Salix viminalis) and poplars (Populus canadensis) in association with three well known ectomycorrhizal fungi (Hebeloma crustuliniforme, Paxillus involutus and Pisolithus tinctorius). A pot experiment was conducted using Cd polluted soil from a contaminated site. Four replicates of each combination of fungus and tree species, and controls without fungal inoculum, were set up. After a growth period of 11 weeks, yields and Cd concentrations in roots, stems, and leaves were measured. In addition, the total Cd uptake, the transfer to roots, and the translocation to stems and leaves were calculated. The association of P. canadensis with P. involutus led to a highly significant increase of Cd concentrations, in particular in the leaves, which contained 2.74 ± 0.34 mg Cd per kg dry matter. Compared to the control this is an enhancement of nearly 100%. The fungi also significantly enhanced the translocation from the roots to the leaves, leading to a concentration ratio (leaves/roots) of 0.32 ± 0.06 compared to 0.20 ± 0.02 of the control plants. Additionally, P. involutus significantly enhanced the total Cd extraction by P. canadensis. Similar effects were not observed by other fungi or in association with S. viminalis.     

菰和菖蒲对重金属的胁迫反应及其富集能力

通过盆栽实验研究了Cu—Zn—Ph-Cd复合污染条件下,菰和菖蒲的生长状况、生理特性及吸收和富集重金属的能力。结果表明,高浓度污染下菰和菖蒲不能存活;低、中浓度中菖蒲的生长受到抑制,菰各生长指标与对照相比差异不显著,表明菰对低、中浓度重金属的耐性强于菖蒲。随着污染浓度的增加,菰和菖蒲叶片叶绿索含量显著降低;菰叶绿素a／b值略有降低,菖蒲叶绿素a／b值显著降低;菰和菖蒲叶片脯氨酸含量、相对电导率显著升高,超氧化物歧化酶（SOD）、过氧化物酶（POD）活性在低浓度时升高,中浓度时降低。菰体内重金属含量为Zn〉Cu〉Pb〉Cd,菖蒲体内的含量为Cu〉Zn〉Pb〉Cd,且二者体内的重金属含量都随着污染浓度的增加而升高。菰和菖蒲对Cd的富集系数较大,地上部分（茎与叶）和地下部分（根与根状茎）均大于1;对Pb的富集系数较小,地上部分和地下部分均小于1。菰和菖蒲地下部分重金属含量均高于地上部分含量,二者根系对4种重金属都有较强的滞留效应,平均滞留率均大于50％。各处理中菰对重金属的吸收量均高于菖蒲。综合分析菰和菖蒲的生长、生理及富集重金属的能力,菰比菖蒲更适用于低、中浓度重金属污染水体的生态修复。     

Enhancing phytoremediative ability of Pisum sativum by EDTA application

The aim of our research was to demonstrate how the presence of EDTA affects resistance of pea plants to Pb and Pb-EDTA presence, and to show the effectivity of lead ions accumulation and translocation. It was determined that EDTA not only increased the amount of Pb taken up by plants but also Pb ion transport through the xylem and metal translocation from roots to stems and leaves. It can be seen in the presented research results that addition of the chelator with Pb limited metal phytotoxicity. We also demonstrated a significant effect of EDTA not only on Pb accumulation and metal transport to the aboveground parts but also on the profile and amount of thiol compounds: glutathione (GSH), homoglutathione (hGSH) or phytochelatins (PCs), synthesized by the plants. We observed a significant effect of the synthetic chelator on increasing the level of Pb accumulation in roots of plants treated with Pb including EDTA (0.5 and 1 mM). Pisum sativum plants treated only with 1 mM Pb(NO3)2 accumulated over 50 mg Pb x g(-1) dry wt during 4 days of cultivation. Whereas in roots of pea plants exposed to Pb+0.5 mM EDTA 35% more Pb was observed. When 1 mM EDTA was applied roots of pea accumulated over 67% more metal. The presence of EDTA also increased metal uptake and transport to the aboveground parts. In pea plants treated only with 1 mM lead nitrate less than 3 mg Pb x g(-1) dry wt was transported, whereas in P. sativum treated with Pb-EDTA doubled amount of Pb was observed in stems and leaves.     

Differentiation of metallicolous and non‐metallicolous Salix caprea populations based on phenotypic characteristics and nuclear microsatellite (SSR) markers

The Salicaceae family comprises a large number of high‐biomass species with remarkable genetic variability and adaptation to ecological niches. Salix caprea survives in heavy metal contaminated areas, translocates and accumulates Zn/Cd in leaves. To reveal potential selective effects of long‐term heavy metal contaminations on the genetic structure and Zn/Cd accumulation capacity, 170 S. caprea isolates of four metal‐contaminated and three non‐contaminated middle European sites were analysed with microsatellite markers using Wright's F statistics. The differentiation of populations North of the Alps are more pronounced compared to the Southern ones. By grouping the isolates based on their contamination status, a weak but significant differentiation was calculated between Northern metallicolous and non‐metallicolous populations. To quantify if the contamination and genetic status of the populations correlate with Zn/Cd tolerance and the accumulation capacity, the S. caprea isolates were exposed to elevated Cd/Zn concentrations in perlite‐based cultures. Consistent with the genetic data nested anova analyses for the physiological traits find a significant difference in the Cd accumulation capacity between the Northern and Southern populations. Our data suggest that natural populations are a profitable source to uncover genetic mechanisms of heavy metal accumulation and biomass production, traits that are essential for improving phytoextraction strategies.     

Population specific fitness response of Drosophila subobscura to lead pollution

Abstract Differences in heavy metal tolerance among separate populations of the same species have often been interpreted as local adaptation. Persistence of differences after removing the stressor indicates that mechanisms responsible for the increased tolerance were genetically determined. Drosophila subobscura Collin (Diptera: Drosophilidae) populations were sampled from two localities with different history of heavy metal pollution, and reared for eight generations in the laboratory on a standard medium and on media with different concentrations of lead (Pb). To determine whether flies from different natural populations exposed to the Pb‐contaminated media in the laboratory show population specific variability in fitness components over generations, experimental groups with different concentrations of lead were assayed in three generations (F₂, F₅, and F₈) for fecundity, developmental time, and egg‐to‐adult viability. On the contaminated medium, fecundity was reduced in later generations and viability was increased, irrespective of the environmental origin of populations. For both populations, developmental time showed a tendency of slowing down on media with lead. Faster development was observed in later generations. Preadaptation to contamination, meaning higher fecundity, higher viability, and faster egg to adult development in all studied generations, was found in D. subobscura originating from the locality with a higher level of heavy metal pollution.