锰污染对酸模叶蓼生长、锰吸收及抗氧化物活性的影响

采用土培方法,研究了广西某锰矿区未开采区、探矿区、恢复区、开采区和尾矿坝的土壤对酸模叶蓼(Polygonum lapathifolium Linn.)的生长、Mn吸收及抗氧化酶系统的影响。结果表明,酸模叶蓼的根、茎、叶中Mn含量随着土壤Mn浓度的增加而增加,Mn含量依次为根茎叶;尾矿坝土壤中(T6处理),叶片Mn含量达到最大值5566.9 mg/kg。锰污染显著提高了酸模叶蓼叶片中H_2O_2和MDA的含量,但锰污染对酸模叶蓼的生物量无显著影响。锰污染土壤显著降低了酸模叶蓼叶片中SOD、POD、APX和As A等抗氧化物的活性,而CAT的活性则呈先上升后下降的趋势,表明Mn污染促使酸模叶蓼启动了抗氧化酶系统;Mn污染同时显著提高了酸模叶蓼叶片中-SH、GSH和PCs的含量,表明-SH、GSH和PCs在解毒酸模叶蓼Mn毒害的过程中起重要作用。     

青葙对土壤锰的耐性和富集特征

通过盆栽试验,研究了青葙(Celosia argentea Linn.)对不同浓度(0、50、100、200、300、500 mg/kg)锰(Mn)污染土壤的吸收和积累特性。结果表明,青葙的锰含量、生物富集系数和生物量均随着土壤锰浓度的增加而增加。当土壤锰含量为300 mg/kg时,青葙生长良好。在锰浓度500 mg/kg时,青葙叶片边缘出现轻微褪绿现象,但是植株的生长未受到抑制,并且叶片生物量显著增加(P0.05)。此时,叶片中锰含量达到最大值42927 mg/kg,生物富集系数为69.20。青葙吸收的锰有95%—97%被转移到地上部分,表明该植物对锰具有很强转运能力。本研究的结果为利用青葙修复锰污染土壤提供了有力证据。     

杂草对土壤重金属的富集与含量特征研究

对冶炼厂周围的土壤和杂草中的4种重金属元素含量进行测定和统计。结果表明,杂草不同器官重金属的平均含量由高到低分别为根>叶>茎,重金属在植物体内含量的分布Cu>Zn>Ni>Pb,富集系数由大到小为Zn>Cu>Pb>Ni。看麦娘(Alopecurusaequalis)、菰(Zizania latifolia)、鬼针草(Bidens pilosa)、丁香蓼(Ludwigiaprostrata)、双穗雀稗(Paspalumdistichum)、芦苇(Phragmites australis)等植物的根对Cu有较强的富集能力,其富集系数分别为2.54、2.69、4.82、10.74、7.33和4.60。看麦娘、双穗雀稗、丁香蓼、芦苇、鬼针草的根以及井口边草(Pteris multifida)地下部分和小飞蓬(Conyza canadensis)叶中的Cu含量分别高达813.4、1338、1959.65、840.1、1066.6、2030和334.5 mg·kg-1。水蓼(Ploygonumhydropiper)叶对Pb有较强的富集能力,其富集系数是2.15。丁香蓼、蛇床(Cnidium monnieri)和婆婆纳(Veronica didyma)叶以及野艾蒿(Artemisialavandulaefolia)的茎和叶对Zn有较强的富集能力,富集系数分别是2.28、2.45、3.02、2.25和2.54。杂草重金属含量与土壤中重金属含量的相关性不大。丁香蓼较适合作为重金属Cu、Zn污染地区的恢复植物     

一种新发现的镉超积累植物--钻叶紫菀(Aster subulatus Michx.)

通过野外调查和温室营养液砂培试验,发现并鉴定出钻叶紫菀（Aster subulatus Michx.）是一种新的镉（Cd）超积累植物。调查结果发现,钻叶紫菀对土壤中高含量的Cd有很强的忍耐、吸收和积累能力,其地上部茎、叶Cd含量分别为90.0-150.7mg/kg和119.8-172.6mg/kg,平均值分别为132.8mg/kg和139.2mg/kg。砂基营养液培养试验证明,钻叶紫菀对生长介质中的Cd有很强的忍耐能力,当生长介质中Cd浓度高达150mg/L时,植株仍生长正常,其株高与对照相比无显著差异;地上部Cd含量及其积累量均随生长介质中Cd浓度的增加而增加,当生长介质中Cd浓度为120mg/L时,地上部茎Cd含量和积累量达到最高值,分别为5672.50mg/kg、4.93mg/株。结果表明,钻叶紫菀是一种新的Cd超积累植物,为今后探明植物超积累Cd的机理和Cd污染土壤的植物修复提供一种新的种质资源。     

商陆对锰污染土壤的修复实验研究

商陆是在中国境内发现的多年生、草本型锰超积累植物。通过室内土培试验,评价商陆对土壤中锰的去除潜力,确定最佳收获时间,以期达到最佳的重金属污染土壤植物修复效果。结果表明:商陆能将土壤中的锰转运到地上部位,叶片中Mn含量最高,平均值为17 043 mg/kg DW,远远大于茎和根的锰含量均值;单株的平均富集量在浓度为500 mg/kg DW时达最高,一棵商陆可富集平均13 mg的Mn;动态修复中确定的最佳收获时间为60 d,不同时间收获的商陆地下部分生物量差异不明显(P0.05),地上部分则差异较大。连续收获不改变其锰生物富集能力。这表明商陆对锰有较强的富集能力,是一种优良的修复锰污染土壤的物种,对土壤重金属污染的治理及植物修复领域数据库的完善具有重要意义。     

重金属镉在番茄及其害虫西花蓟马中的积累与传递

重金属镉（Cd）是农田土壤中的重要污染源,可在植物和植食性昆虫中积累与传递。本文采用水培法,研究了不同浓度的Cd在番茄Solanum lycopersicum不同组织和在其重要害虫西花蓟马Frankliniella occidentalis体内的积累量。结果表明,随着水培营养液中Cd浓度的增加,番茄植株的根、茎和叶中Cd含量呈增长趋势。根中Cd的积累量远高于茎和叶,当水培溶液中Cd含量为20 mg/L时,根、茎和叶中的积累量分别达19 333.67±233.38、122.67±6.84和147.33±2.96 mg/Kg（干重）。随着Cd浓度的增加,番茄根、茎和叶的鲜重和干重均显著下降。西花蓟马取食Cd处理的番茄叶片后,体内Cd显著积累,最高达1.95±0.36 mg/Kg。同时,Cd积累量的提高进一步影响了以番茄叶片为食的西花蓟马的适合度,降低了其存活率。除对照外,番茄茎-叶的转移系数和叶片对Cd的富集系数均大于1,叶片表现出较强的富集能力。而在所有的试验浓度处理中,西花蓟马对Cd的富集系数和转移系数均小于1,表明Cd未在其体内产生生物放大作用。研究结果明确了Cd在番茄各组织及其害虫中的积累和传递水平,为揭示重金属在农业生态系统食物链中的富集效应提供了基础数据。     

湘潭锰矿区植物资源调查及超富集植物筛选

通过设置样地,对湘潭锰矿区的植物资源进行了全面调查。结果表明:锰矿区植物丰富,共有28科,53种,植物以自然定居种为主,少见人工栽培种;生活史以多年生植物为主,少见1年生植物。群落结构上,以草灌丛为主,少见乔木种;当前锰矿区形成的以多年生草灌丛为主的局部群落,是原锰矿区植被在开采中被彻底破坏后,处在逐步向亚热带常绿阔叶林演替的一种初级阶段;其次,对矿区植物锰富集能力进行的分析表明,植物各组织(根、茎、叶)之间锰富集量差异明显,大部分物种地下部分锰含量大于地上部分,表现出一般植物的共性,只有少部分植物地上部分锰含量大于地下部分,表现出其特殊性;此外,植物种之间富集锰能力差异显著;莎草地上与地下部分锰含量均大于超富集植物10000mg.kg-1的临界浓度且富集系数与转移系数均大于1的超富集植物评价标准,表明其具有超强的富集锰能力。调查还发现,位于中-高锰矿区莎草生物量高达507.06g.m-2,符合超富集植物应具有较高生物量的标准。可见,莎草可作为中-高锰污染区生态修复的首先超富集植物种。     

沣河沿岸土壤和优势植物重金属富集特征和潜在生态风险

测定陕西省沣河沿岸32个土壤样品和16个优势植物样品中Cr、Cu、Mn、Pb、Zn和Ni 6种重金属元素的含量,并结合数据统计与GIS制图,对土壤和植物中重金属的空间分布、富集特征及潜在风险进行分析。结果表明沣河中下游沿岸土壤和植物中Cr、Mn、Pb、Zn和Ni含量空间分布呈明显富集。土壤中Cr、Mn和Pb的几何均值分别为92.1、611.1和32.9 mg/kg,均高于陕西省土壤元素背景值;植物中Mn、Zn含量在正常范围内,Cr、Cu、Ni含量部分超标,Pb含量整体较高,地上部分对Pb的积累量达到15.5 mg/kg,约为正常情况下的7.8倍。本研究中马齿苋、艾蒿、芦苇和水蓼四种植物生物量大,对这六种重金属富集能力均较强,可作为该地区耐重金属植物。沣河沿岸土壤和植物中重金属污染值得关注。     

垂序商陆繁殖期各器官锰富集规律及其对种子萌发的影响

通过室内盆栽实验,以锰超累积植物垂序商陆植株为材料,比较了不同供锰水平(0.005、0.1、1.0mmol/L)下种子成熟过程中各器官锰含量的动态变化及所产种子的萌发率,旨在了解高锰条件下垂序商陆在繁殖期体内锰富集规律及其对繁殖能力的影响。结果发现:(1)在垂序商陆种子成熟过程中,各处理组植株的根、茎、叶、果实中锰含量均随时间推移呈逐渐增加趋势,且植物器官中锰含量随环境中锰浓度升高而提高;种子内的锰含量变化规律在对照组和处理组之间不同,对照组(0.005mmol/L)先小幅下降后持续增加,而处理组(0.1与1.0mmol/L)则先持续增加,至末期出现不同程度的降低。(2)相同锰浓度环境条件下,种子成熟后期各器官锰含量均表现为种子茎根果实(包括种子)叶。(3)GC-MS分析表明果汁中有机酸主要成分为草酸与少量的2-羟基丙酸,有机酸的成分与含量在各组间无明显不同。(4)随锰浓度增加,种子中锰含量增加,而萌发率则逐渐降低,且各组间差异极显著。研究结果提示,垂序商陆植株各器官内锰积累量与环境中锰浓度密切相关,其在种子成熟过程中会对体内多余的锰在各器官进行合理分配,以减小锰富集带来的有害效应从而完成自身生命周期,并可能在种子成熟末期采取降低种子中锰的分配量来提高萌发率从而保证高繁殖能力,果浆的可溶性水环境及所含有机酸在繁殖期植株解锰毒中发挥了重要作用。     

喜钙和嫌钙植物对外源Ca2+的生长生理响应

以喜钙植物伞花木和嫌钙植物大白杜鹃为实验材料,以Hoagland营养液并设置其Ca2+浓度分别为0、5、10、25、50mmol/L培养试验,比较不同浓度外源Ca2+对其生长、叶绿素含量、渗透调节和矿质元素积累的影响,探索喜钙植物生长的适应特征,为喀斯特地区喜钙植物嗜钙机制研究提供基础资料。结果显示:(1)随着外源Ca2+浓度的增加,伞花木植株高度、茎粗以及叶干重、叶长、叶宽和叶形指数均得到不同程度提高,叶绿素和可溶性蛋白质含量增加,脯氨酸和可溶性糖含量无显著变化;而嫌钙植物大白杜鹃的生长却受到抑制,叶绿素和蛋白质含量降低,脯氨酸和可溶性糖含量增加;当Ca2+浓度为50mmol/L时,伞花木叶绿素和蛋白质含量分别为2.99mg/g和17.10mg/g,大白杜鹃叶绿素和蛋白质含量分别为1.39mg/g和14.30mg/g。(2)在实验设置的钙范围内,Ca2+可促进伞花木对P、N吸收并稳定体内Ca、K动态;而低浓度的Ca2+(<10mmol/L)促进大白杜鹃对Ca累积,抑制N、P吸收。     

Use of synchrotron- and plasma-based spectroscopic techniques to determine the uptake and biotransformation of chromium(III) and chromium(VI) by Parkinsonia aculeata

In this study, a combination of inductively coupled plasma optical emission spectroscopy and X-ray absorption spectroscopy (XAS) was used to study the uptake and speciation of chromium in Parkinsonia aculeata, commonly known as Mexican Palo Verde. Plants were treated for 14 days in a modified Hoagland solution containing chromium(III) or chromium(VI) at several concentrations. The results showed that plants treated with 70 mg Cr(III) L(-1) and 30 mg Cr(VI) L(-1) had similar Cr concentrations in leaves (～200 mg kg(-1) dry weight, DW). The results also showed that neither Cr(III) nor Cr(VI) affected the uptake of phosphorus and sulfur. However, the concentration of calcium in the stems of plants treated with Cr(VI) at 40 mg L(-1) (about 6000 mg Ca kg(-1) DW) was significantly higher compared to the Ca concentration (about 3000 mg kg(-1) DW) found in the stems of plants treated with 150 mg Cr(III) L(-1). However, no differences were observed in potassium and magnesium concentrations. The iron concentration (about 1000 mg kg(-1) DW) in roots treated with 40 mg Cr(VI) L(-1) was similar to the iron concentration found in the roots of plants treated with 110 mg Cr(III) L(-1). The XAS data showed that Cr(VI) was reduced to Cr(III) in/on the plant roots and transported as Cr(III) to the stems and leaves. The XAS studies also showed that Cr(III) within plants was present as an octahedral complex.     

Phytoremediation of lead (Pb) and Arsenic (As) by Melastoma malabathricum L. from Contaminated Soil in Separate Exposure

This study was conducted to investigate the uptake of lead (Pb) and arsenic (As) from contaminated soil using Melastoma malabathricum L. species. The cultivated plants were exposed to As and Pb in separate soils for an observation period of 70 days. From the results of the analysis, M. malabathricum accumulated relatively high range of As concentration in its roots, up to a maximum of 2800 mg/kg. The highest accumulation of As in stems and leaves was 570 mg/kg of plant. For Pb treatment, the highest concentration (13,800 mg/kg) was accumulated in the roots of plants. The maximum accumulation in stems was 880 mg/kg while maximum accumulation in leaves was 2,200 mg/kg. Only small amounts of Pb were translocated from roots to above ground plant parts (TF < 1). However, a wider range of TF values (0.01–23) for As treated plants proved that the translocation of As from root to above ground parts was greater. However, the high capacity of roots to take up Pb and As (BF > 1) is indicative this plants is a good bioaccumulator for these metals. Therefore, phytostabilisation is the mechanism at work in M. malabathricum's uptake of Pb, while phytoextraction is the dominant mechanism with As.     

Toxicity of arsenic (III) and (V) on plant growth, element uptake, and total amylolytic activity of mesquite (Prosopis juliflora x P. velutina)

The effects of arsenite [As(III)] and arsenate [As(V)] on the growth of roots, stems, and leaves and the uptake of arsenic (As), micro- and macronutrients, and total amylolytic activity were investigated to elucidate the phytotoxicity of As to the mesquite plant (Prosopis juliflora x P. velutina). The plant growth was evaluated by measuring the root and shoot length, and the element uptake was determined using inductively coupled plasma optical emission spectroscopy. The root and leaf elongation decreased significantly with increasing As(III) and As(V) concentrations; whereas, stem elongation remained unchanged. The As uptake increased with increasing As(III) or As(V) concentrations in the medium. Plants treated with 50 mg/L As(III) accumulated up to 920 mg/kg dry weight (d wt) in roots and 522 mg/kg d wt in leaves, while plants exposed to 50 mg/L As(V) accumulated 1980 and 210 mg/kg d wt in roots and leaves, respectively. Increasing the As(V) concentration up to 20 mg/L resulted in a decrease in the total amylolytic activity. On the contrary, total amylolytic activity in As(III)-treated plants increased with increasing As concentration up to 20 mg/L. The macro- and micronutrient concentrations changed in As-treated plants. In shoots, Mo and K were reduced but Ca was increased, while in roots Fe and Ca were increased but K was reduced. These changes reduced the size of the plants, mainly in the As(III)-treated plants; however, there were no visible sign of As toxicity.     

A newly found manganese hyperaccumulator—Polygonum lapathifolium Linn.

In the present work, both field investigation and laboratory experiment were carried out to testify whether Polygonum lapathifolium L. is a potential manganese (Mn) hyperaccumulator. Results from field investigation showed that P. lapathifolium had great tolerance and accumulation to Mn. Mn concentrations in leaves were the highest, varied from 6889.2 mg kg-1 dry weight (DW) to18841.7 mg kg^?1 DW with the average of 12180.6 mg kg^?1. The values of translocation factor (the concentrations of Mn in leaf to that in root) ranged from 5.72 to 9.53. Results from laboratory experiment illuminated that P. lapathifolium could grow well and show no toxic symptoms even under high Mn stress (16 mmol L^?1). Although the changes of antioxidant enzymes activities were triggered under Mn stress, the alterations of pigments were not significant (P > 0.05) as compared with control. Total plant biomass and plant height increased with increasing Mn supply. Mn concentrations in leaves and stems were constantly greater than those in roots, the ratio of concentrations in leaves to that in roots were 2.58–6.72 and the corresponding values in stems to that in roots were 1.45–3.18. The results showed that P. lapathifolium is a Mn-hyperaccumulator.     

Arsenic tolerance in mesquite (Prosopis sp.): Low molecular weight thiols synthesis and glutathione activity in response to arsenic

The effects of arsenic stress on the production of low molecular weight thiols (LMWT), glutathione S-transferase activity (GST) and sulfur metabolism of mesquite plant (Prosopis sp.) were examined in hydroponic culture at different arsenic [As(III) and (V)] concentrations. The production of LMWT was dependent on As speciation and concentration in the growth medium. The roots of As(III) treated plants produced significantly higher LMWT levels than As(V) treated roots at the same concentration of As applied. In leaves, the thiols content increased with increasing As(III) and (V) concentrations in the medium. Hypersensitivity of the plant to high As concentrations was observed by a significant decrease of LMWT produced in the roots at 50 mg/L treatment in both As(III) and (V) treatments. Sulfur was translocated from roots and accumulated mainly in the shoots. In response to As-induced phytotoxicity, the plants slightly increased the sulfur content in the roots at the highest As treatment. Compared with As(V)-treated plants, As(III)-treated roots and leaves showed significantly higher GST activity. The roots of both As(III) and (V) treated plants showed an initial increase in GST at low As concentration (5 mg/L), followed by significant inhibition up to 50 mg/L. The leaves had the highest GST activity, an indication of the ability of the plant to detoxify As in the leaves than in the roots. The correlation between LMWT content, S content and GST activity may be an indication these parameters may be used as biomarkers of As stress in mesquite.     

鼎湖山南亚热带常绿阔叶林植物和土壤微量元素含量

报道了鼎湖山南亚热带常绿阔叶林各层次植物和表层土壤(0～20 cm)四个微量元素(Cu、Fe、Mn和 Zn)的含量和分配格局。结果表明:(1)土壤有效Cu、Fe、Mn和Zn含量(mg／kg)平均值依次为0．72、140．85、 1．42和1．92;(2)所有植物叶片Cu、Fe、Mn和Zn元素含量(mg／kg)分别介于6．1～100．6、6．5～1027．5、46．3 ～1196．7和27．0～338．6,其中乔木层植物叶片微量元素含量(mg／kg)平均值表现为Mn(305．3)>Fe (259．3)>Zn(109．9)>Cu(19．3),而其它植物表现为Fe(586．4)>Mn(336．9)>Zn(141．4)>Cu(36．6);(3) 植物微量元素在各器官的分配格局随元素和植物所在的层次不同而异:乔木层植物Cu含量高低排序为干> 根>枝>叶>皮,Fe为根>皮>叶>枝>干;Mn为叶>皮>枝>根>干;Zn为叶>根>枝>皮>干;(4)在 群落垂直结构上,Fe元素含量表现为自上而下递增的趋势,而Cu、Mn和Zn含量规律不明显;(5)植物和土壤 的微量元素与微量元素间相关性均较差;(6)与亚热带其它森林相比,鼎湖山季风常绿阔叶林土壤Cu、Mn和 Zn含量较低,但乔木层植物因具有很强的吸收或富集能力而含量较高。     

纳米硒对紫色马铃薯生长及其矿质元素含量和品质特性的影响

以紫色马铃薯品种‘黑美人’为试材,采用水培法,分别用不同浓度(0、0.38、0.19和0.095 mmol/L)纳米硒溶液对紫色马铃薯进行叶面喷施处理,研究纳米硒对紫色马铃薯生长、矿质元素含量及品质特性的影响。结果表明:(1)与对照相比,各硒处理马铃薯的生物量与单株结薯数均显著增加,其中喷施0.095 mmol/L硒处理的生物量最高且增幅达1.5倍,喷施0.19 mmol/L硒处理的单株结薯数显著增加2.2倍。(2)纳米硒能够显著提高紫色马铃薯叶片、根系、块茎硒含量,各器官硒含量大小呈现:根系>叶片>块茎的特点,且喷施0.095 mmol/L硒处理块茎总硒含量达0.106 mg/kg,较对照显著提高0.65倍,达到了马铃薯块茎的富硒标准;同时纳米硒可在不同程度上调控K、Ca、Mg、Mn、Zn在马铃薯各器官中的分配。(3)随施硒浓度的增加,紫色马铃薯块茎中淀粉、可溶性蛋白及游离氨基酸含量呈先增加后降低的变化趋势,均在喷施0.19 mmol/L硒处理下达到最大值,且较对照分别显著增加56.33%、26.91%和27.89%;块茎中花青素、可溶性糖含量呈下降趋势,均在喷施0.095 mmol/L硒处理下达到最大值,且较对照分别显著提高24.73%、25.33%;而块茎中硝态氮含量呈上升趋势,在喷施0.095 mmol/L硒处理下最低并较对照显著降低34.82%。研究表明,叶面喷施0.095~0.19 mmol/L纳米硒溶液能够显著促进紫色马铃薯生长和单株结薯数,提高硒元素含量,调控矿质元素含量在器官中分配,有效改善其块茎品质特性。     

Zinc hyperaccumulation and uptake by Potentilla griffithii Hook

The ability of Potentilla griffithii Hook var. velutina Cardot to hypaeraccumulate zinc (Zn) was identified through field survey and hydroponic experiments. Our results showed that P. griffithii could be classified as a new Zn hyperaccumulator. Zn concentrations in the shoots of P. griffithii averaged 6250 mg kg(-1) (3870-8530 mg kg(-1)) growing in Zn-rich soils. The highest Zn concentration was observed in the leaves of P. griffithii at 22,990 mg kg(-1). The fact that P. griffithii was able to grow in a mining soil with a Zn concentration of 193,000 mg kg(-1) without showing a major sign of phytotoxicity demonstrated its high tolerance to Zn. When growing in hydroponic systems, P. griffithii accumulated a maximum 26700 mg kg(-1) zinc concentration in the shoots, indicating the ability of this species to effectively take up and translocate Zn. Translocation factors (the ratio of Zn concentration in shoot to root) of 1.1 to 1.6 were obtained. Compared to the control, dry biomass of P. griffithii in 160 mg L(-1) Zn treatment increased 66.6% (P < 0.05). The time-course experiment showed that the maximum Zn concentration at 100 mg L(-1) Zn treatment was found at 16 d, much later than that of the 10 mg L(-1) Zn treatment, which might be an attribution of a accumulating mechanism or detoxification of a plant. The report of a new Zn hyperaccumulator provides a new plant species for the phytoremediation of contaminated soil and for the research on mechanisms of Zn hyperaccumulation in plants.