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1.
Cd、Cr、Pb复合胁迫下小麦植株重金属的积累与分布   总被引:1,自引:0,他引:1  
为了预测重金属复合胁迫对小麦的危害,采用溶液培养、田间土柱栽培等毒理试验方法,分析了小麦幼苗期及成熟期Cd、Cr、Pb在植株不同器官的富集,并对小麦受重金属胁迫的安全限量值进行了研究。结果表明,①Cd、Cr、Pb二元或三元胁迫条件下,小麦幼苗期植株各器官对重金属的富集浓度均极显著高于单一胁迫处理,说明复合胁迫加剧了重金属向小麦体内的迁移累积。成熟期小麦对Cd、Cr、Pb的富集比较依赖于土壤中相应Cd、Cr、Pb的浓度水平,其他两种重金属的协同作用在根系所占比例大约为5.09%~21.66%。②各器官中重金属的富集表现:幼苗期为根系>叶鞘>叶片,成熟期为根系>茎叶>籽粒。但幼苗期复合胁迫促进了重金属向地上部分的转移。③幼苗期植株各器官对重金属富集系数的大小为Cr>>Pb>Cd,表明幼苗期小麦根系对Cr的富集能力最强;植株地上部分的重金属平均富集量Cd为68.68%、Cr为51.63%、Pb为70.83%,说明Cd、Pb运输到地上部的能力较强。成熟期Cd在小麦地下、地上各器官的转移速率最快,Cr次之,而Pb转移到籽粒中去的量很少。  相似文献   

2.
为了解重金属胁迫下甘蔗地上部和地下部重金属的累积特征,用高、中、低浓度的镉、铅和铬处理土壤进行甘蔗盆栽试验,用原子吸收石墨炉法测定其含量。结果表明甘蔗地下部重金属富集的量比地上富集的量大,此差异随处理浓度增加而增加。在最高浓度时,8月份,镉(Cd)地上部为44.750mg/kg,地下部的为299.250 mg/kg;铅(Pb)地上部为96.250 mg/kg,地下部339.250 mg/kg;铬(Cr)地上部为94.325 mg/kg,地下部为4 148.750 mg/kg;9月份,Cd地上部为94.000 mg/kg,地下部为803.500mg/kg;Pb地上部为199.500 mg/kg,地下部为686.500 mg/kg;Cr地上部为138.625 mg/kg,地下部为10 282.750 mg/kg。由此可看出甘蔗的Cd、Pb、Cr在地下部富集量大,地上部富集量小,它们的转运系数都小于1 (转运系数=地上部重金属含量/地下部重金属含量),故甘蔗可在中轻度污染的土壤中种植,这样能够提高重金属污染土壤的利用率,还能对这些重金属土壤慢慢进行生物修复。另外,这样的土壤种植出的甘蔗可用于绿色能源——乙醇的生产,减少环境污染,节省自然资源。  相似文献   

3.
玉米植株对重金属的富集与分布   总被引:21,自引:0,他引:21  
从湛江市赤坎区文章村的玉米园中采集玉米植株及其生长的土壤样品,采用原子吸收光谱法测定铬(Cr)、铅(Pb)、镍(Ni)、铜(Cu)、锌(Zn)5种重金属元素的含量,对玉米不同器官积累重金属的特性进行了初步研究。结果表明,①玉米园土壤受重金属Cr的中度污染;②玉米对土壤中5种重金属的平均富集系数大小顺序为Ni>Pb>Zn>Cr>Cu,其中,Ni、Pb、Zn的富集系数分别为2.411、1.892和1.139;③玉米地上部重金属含量大于根部该种重金属含量。各种重金属在器官中的分布规律不一致,玉米茎中的重金属含量偏高,玉米根中的含量较低;④玉米对土壤Cr元素有较强的避性。  相似文献   

4.
广藿香重金属污染及潜在生态风险评价   总被引:1,自引:0,他引:1  
采用国标法测定10个产区广藿香Pogostemon cablin(Blanco)Benth.药材及其生境土壤中Cu、Pb、Cd、Cr、As、Hg的含量,以非参数检验分析6种重金属元素在广藿香药材、生境土壤中的分布规律,并结合富集系数确定广藿香对重金属的富集情况。以单因子污染指数(P_i)、Nemerow污染指数(P综合)和潜在生态风险指数(RI)对土壤样品进行污染等级评价。结果表明,生境土壤全部达标;广藿香药材中重金属含量总体合格,4个产区药材中Hg有不同程度的超标。重金属Pb、Cu、Cd在不同生境土壤中的分布、土壤Pb、Cr、As与药材中的含量、不同产地广藿香对Pb的富集均有显著性差异。P综合和P_i分别显示四会广藿香种植区域土壤、长丰土样Cd、莲塘Pb以及四会Pb、Cd均达警戒限,其他生境土壤都属清洁级别;RI值方面,各产区均属于轻微污染级别。不同产地的广藿香植株都会富集土壤的Cd、Hg。因此,从药材安全性考虑,在种植广藿香时,应该选择重金属含量较低的土壤进行种植,确保药材安全性。  相似文献   

5.
几种重金属(Cd、Cr、As)在玉米植株中的分布研究   总被引:2,自引:0,他引:2  
从株洲市某社区玉米园中采集玉米植株及其生长的土壤样品,利用ICP等离子法测定铬(Cr)、砷(As)、镉(Cd)3种重金属元素的含量,对玉米不同器官积累重金属的特性进行初步研究。结果表明:(1)玉米园土壤受重金属As中度污染,重金属Cd重度污染;(2)3种重金属在玉米植株中的分布规律大致为根叶茎;(3)玉米对土壤中3种重金属的平均富集系数大小排列顺序为CdCrAs;(4)玉米对土壤As元素有较强的耐性;(5)玉米茎中Cr元素含量与根中Cr达到了显著负相关,而茎、叶中Cd含量与根部Cd呈正相关。  相似文献   

6.
不同花生品种重金属Cu、Zn、Pb、Cd、Cr富集与转运规律   总被引:4,自引:0,他引:4  
以青岛市8个主栽花生品种为试材,通过相同土壤条件下大田种植和室内检测分析,对花生植株不同器官中Cu、Zn、Pb、Cd和Cr重金属元素的吸收、富集与转运规律进行了研究。结果表明,供试的8个花生品种植株根系中Cu、Zn、Pb和Cd含量存在显著性差异,茎叶中Cu、Zn、Pb和Cr含量存在显著性差异,籽仁中Cu、Zn、Pb、Cd和Cr含量均存在显著性差异,果壳中Cu、Zn和Cd含量存在显著性差异;供试的8个花生品种籽仁中Cd含量均超过了农业部无公害花生Cd≤0.05 mg.kg-1的卫生限量标准。花生植株各器官对重金属的平均生物富集量顺序:根系和果壳为Zn〉Cu〉Cr〉Pb〉Cd,茎叶和籽仁为Zn〉Cu〉Pb〉Cr〉Cd。花生植株各器官的平均转运量系数顺序:茎叶为Pb〉Zn〉Cd〉Cr〉Cu,籽仁为Zn〉Cu〉Cd〉Pb〉Cr,果壳为Cr〉Cu〉Zn〉Pb〉Cd。A4为花生籽仁低Pb吸收富集型品种,A3为花生籽仁低Cd吸收富集型品种。  相似文献   

7.
对217份稻谷样品重金属含量的测定分析表明,谷壳中重金属含量大于精米,精米中Cr、Cd含量相对较高,谷壳中Cr含量相对较高;相关性分析结果表明,土壤中的Cd、Pb与稻谷中的Cd、Pb含量显著相关,谷壳与精米中的Cd、As、Hg含量显著相关而与品种类型无关;对重金属富集系数的分析表明,稻米对重金属的富集能力强弱为Cd>Hg>As>Cr>Pb,不同品系稻米对5种重金属的富集能力差异均达到显著,银占系列稻米的重金属富集能力与其它8个品系差异显著且显著高于其它品系。结论对研究稻米中重金属污染问题具有一定的参考价值。  相似文献   

8.
《中国马铃薯》2016,(5):277-281
利用火焰原子吸收法测定了种植于磷矿复垦地马铃薯植株不同器官中镉(Cd)、铅(Pb)重金属的含量。结果表明,在磷矿复垦地土壤Cd、Pb含量高于土壤无机污染物的二级标准条件下,马铃薯块茎中Cd、Pb含量都超过安全食用标准;马铃薯植株中不同器官Cd、Pb的分布具有明显规律,块茎、根、茎、叶的含量差异显著,呈逐渐增加趋势,叶片是积累2种重金属含量最多的器官,块茎含量最低;随生育期延长,成熟期马铃薯根、茎、叶中的Cd含量较现蕾期略有增加。马铃薯各器官对2种重金属元素的富集系数不同,对Cd的富集作用明显大于对Pb的富集作用,因此即使在低Cd土壤中种植马铃薯也需要谨慎选择。  相似文献   

9.
小麦富集重金属的品种差异及其潜在健康风险评价   总被引:2,自引:0,他引:2  
为了筛选出适合黄淮冬麦区种植的具有重金属低累积潜力且食用安全的小麦品种,在黄河故道丰县境内选取代表性农田,采用田间小区试验,研究了12个小麦品种籽粒对Pb、As、Cr、Hg、Cd和Ni富集的差异,并用目标危害系数(THQ)法对其食用后的潜在健康风险进行了评价。结果表明,试验区144个采样点表层土壤中As、Cr、Cd和Ni的平均含量较中国土壤元素背景值分别超标0.14倍、0.20倍、1.32倍和0.20倍,Pb和Hg均低于背景值,仅Pb未见超标点位,但所测6种重金属的含量均低于《土壤环境质量标准》中的Ⅱ级标准值和《绿色食品产地环境质量》规定的土壤中污染物含量限值。供试的12个小麦品种籽粒中的6种被测重金属含量均符合国家食品安全标准限制值,但对Pb、Ni、As、Cr的吸收累积差异较Cd、Hg明显,以Pb最为明显。聚类分析可将12个品种划分为较低累积类群(保麦2号、烟农19、百农207、保麦5号、荔高6号和迁麦1号)、中等累积类群(新麦288、淮麦20、百农AK58和豫农035)和高累积类群(徐麦30和徐麦33)。12个小麦品种的籽粒对6种重金属的平均富集系数由大到小依次为Hg、Cd、As、Pb、Ni和Cr,富集程度在不同品种间差异程度不同。其THQ值和总危害系数(TTHQ)值均小于1.0,表明居民消费供试品种小麦籽粒无被测重金属引起的潜在健康风险。但徐麦30、豫农035和徐麦33籽粒中重金属的TTHQ值均介于0.9~1.0,对此应引起重视。综合评价,保麦2号、百农207、保麦5号、荔高6号和新麦288可作为黄淮冬麦区种植的重金属低累积小麦品种。  相似文献   

10.
为探索适合镉(Cd)污染农田的种植模式,在浏阳市蕉溪镇某中度污染农田(pH为5.73,Cd总含量为0.86 mg/kg)开展大田试验,分析亚麻—水稻水旱轮作模式对Cd的累积能力和对农田土壤Cd污染的修复效率。结果表明,亚麻对Cd具有较强的富集能力,其叶片Cd含量最高,为7.77 mg/kg,富集系数(BCF)达9.83;果壳与籽粒的镉含量均在3.00 mg/kg以上,对应的BCF值分别为4.18和3.86。一季亚麻的总生物量为16 950.50 kg/hm2,可提取Cd 74.28 g/hm2,修复效率为3.84%。与前茬未种亚麻的对照相比,轮作模式下水稻各部位尤其是糙米对Cd的累积呈现明显下降的趋势。后茬水稻收获后,稻草离田,亚麻—水稻轮作模式每年可从土壤中提取Cd达128.26 g/hm2,修复效率可达到6.63%。  相似文献   

11.
12.
Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.  相似文献   

13.
Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.  相似文献   

14.
15.
Novel food and non-food uses for sorghum and millets   总被引:4,自引:3,他引:4  
Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.  相似文献   

16.
Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.  相似文献   

17.
Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X1 (also called RXact).  相似文献   

18.
The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O2•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O2•− scavenging, (IC50 = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC25 = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC50 = 863 µg/mL; elastase, IC50 = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O2•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.  相似文献   

19.
The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.  相似文献   

20.
Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).  相似文献   

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