番茄吸收和积累Cd能力的品种间差异

旨在筛选和利用在受污染土壤中可食部位污染物积累水平在食品卫生标准允许范围内的农作物品种(pollution-safecultivar,简称为PSC),以降低水土环境污染物经食物链危害人类健康的风险。研究对象为番茄,探讨了在一定Cd污染土壤中其果实Cd含量低于国际食品法典委员会(CAC)Cd最高限值的品种(Cd-PSC)存在的可能性。通过盆栽试验研究了36个番茄品种(包括普通番茄和樱桃番茄两个变种)不同器官在受不同程度镉污染的土壤中吸收和积累Cd能力的差异。结果表明:(1)在土壤Cd重度胁迫(13.3mg.kg-1)和轻度Cd胁迫(1.1mg.kg-1)下,番茄所有器官Cd含量的变异在统计学上均存在极显著意义(p<0.01),其中果实Cd含量的范围分别为0.08~0.33mg.kg-1和0.00~0.09mg.kg-1,变异系数分别达到28.5%和77.9%;(2)在重度胁迫下,所有供试品种的果实Cd含量均超出CAC标准,而轻度胁迫下的Cd含量超标率达到19.4%,说明番茄是易受Cd污染的农作物种类,其中樱桃番茄的受污染风险特别高,在轻度胁迫下6个供试品种中有5个超标,而30个普通番茄品种仅1个超标。因此,仅在轻度胁迫条件下,存在着番茄的Cd-PSC,其中有5个普通番茄品种的果实中未检出Cd,属于比较安全的PSC,包括品种No.121、6、24、35和No.36,可以推荐在土壤Cd污染程度略超国家三级标准或具有潜在受污染风险的区域应用;(3)尽管大多数情况下各营养器官的Cd含量间均呈显著的正相关,但营养器官与果实Cd含量间均无明显的相关性,推测Cd在番茄营养器官间和营养器官与果实间的转运途径是不一样的。组织中Cd含量的显著相关性说明该特性可以作为农作物品种的种性特征;(4)与轻度胁迫相比,重度胁迫下的所有供试品种平均果实生物量上升了7.5%,一半以上的品种表现出较强的耐Cd能力,这一特性可能导致因不易察觉土壤的Cd污染状况而增加番茄产品受Cd污染风险。     

玉米与番茄间作对土壤镉吸收的影响

为探究间作对作物吸收重金属镉(Cadmium,Cd)的影响,以Cd相对高积累番茄(中蔬4号)和相对低积累玉米(金珠蜜甜玉米)为试验材料,在Cd 3.70 mg/kg的污染水平下以单作、限制性间作、间作3种种植方式进行了盆栽试验,研究间作后作物各部位Cd积累差异及其形成原因。结果表明,番茄和玉米间作和限制性间作所产番茄根、茎、叶中Cd含量均有所提高(叶中Cd含量从13.52mg/kg分别升高至24.94mg/kg和27.30mg/kg);与未种植作物的对照组相比,非单作条件下番茄根围土壤的pH有所下降,酸性磷酸酶活性上升,而脲酶活性下降,且间作组变化幅度较大;间作还能改变作物根围微生物种群结构,提高对重金属吸收有促进作用的微生物种群的丰度,最终实现Cd高积累番茄对Cd的吸收能力提高。研究结果可为利用间作模式修复土壤重金属污染和保障食品安全提供参考。     

盐分胁迫下两个苋菜品种对镉及主要渗透调节物质累积的差异

采用重金属Cd平均含量为2.28 mg·kg-1的污灌菜园土,在外源Na Cl处理下进行盆栽试验,研究花红圆叶苋菜(BRLA)和红柳叶苋菜(ARW)对Cd及主要渗透调节物质吸收和积累的品种间差异。结果显示:随盐胁迫增强,两品种根、叶Cd和Na+含量较对照显著增加(P0.05),且品种ARW的Cd累积量高于品种BRLA。与ARW相比,BRLA根可贮存更多的Na+以减少向叶转运,在0.4%盐处理时BRLA叶K+/Na+比值降幅为39.2%,而ARW达56.9%。盐分促进BRLA根、叶Mg2+含量增加,而ARW根Mg2+则低于对照。盐胁迫后,两品种根、叶脯氨酸含量显著高于对照(P0.05),且BRLA表现较强的脯氨酸合成能力。两品种根、叶总游离氨基酸与可溶性蛋白含量随盐胁迫强度增大呈相反的变化。盐分促进了两品种根部可溶性糖积累。综上,BRLA比ARW具有较低Cd累积性,表现较好的耐盐性,具备较强的渗透响应能力,可为筛选和培育既耐盐又低累积Cd的农作物提供科学参考。     

不同品种菜心对镉抗性的研究

以对镉（Cd)抗性不同的两个菜心品种特青60天和迟心2号为试验材料,用盆栽土培试验的方法研究了在不同浓度Cd处理下（0mg/kg,1.0mg/kg,3.0mg/kg,10.0mg/kg)Cd在菜心体内及迁移的差异,并探讨了造成差异的机理。研究结果表明：Cd处理下,特有60天茎叶中积累的Cd比迟心2号的少,在高Cd浓度（10.0mg/kg)下,与对照相比,特青60天的干重明显增加,而迟心2号的干重则显著降低。进一步分析研究发现,在相同的Cd上,特青60天中Cd的迁移率较小,特别是在30mg/kg Cd处理下比迟心2号的低5．62％;根系细胞壁中的Cd所占的比例比迟心2号的高;特青60天根系中全硫（S）的含量比迟心2号的高,而且随着Cd处理浓度的增加,全S含量提高,但迟心2号中S含量的变化趋势与之不同;持青60天根系汁液的pH值比迟心2号的高,且汁液中Cd的含量比迟心2号的低;相关分析的结果显示;根系汁液中的Cd含量与茎叶汁液中Cd的含量呈显著的正相关关系。以上的结果可能造成了特青60天中Cd在根系内的活性和迁移能力较低,减少了Cd由根系向茎叶的迁移,从而使特青60天对Cd的抗性高于迟心2号。     

镉超积累植物及植物镉积累特性转基因改良研究进展

植物提取修复技术是一项既经济又环保的土壤镉(Cd)污染修复技术,该技术的关键是筛选Cd超积累植物或利用基因工程手段改良植物以提高其Cd积累能力。人们已发现遏兰菜等7种Cd超积累植物及美人蕉等潜在的Cd超积累植物。还发现了许多与Cd耐受和积累能力有关的基因:(1)编码与Cd积累、耐受有关酶的基因,如细菌中的ACC(1-aminocyclopropane-1-carboxylic acid),植物中的PCS(Phytochelatin Synthase)基因;(2)编码金属结合蛋白的基因:MT(Metallothionein)、转运蛋白(P-type ATPase、ABC型转运器)基因;(3)其它相关基因:Hvhsp17、PvSR2(Phaseolus vulgaris stress-related gene number 2)等。并将其中的一些基因转入到其它生物中,提高了其对Cd的耐受性和积累量,为实现Cd污染土壤修复的目标奠定基础。     

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。     

玉米与番茄间作对土壤镉吸收的影响（英文）

为探究间作对作物吸收重金属镉(Cadmium,Cd)的影响,以Cd相对高积累番茄(中蔬4号)和相对低积累玉米(金珠蜜甜玉米)为试验材料,在Cd 3.70 mg/kg的污染水平下以单作、限制性间作、间作3种种植方式进行了盆栽试验,研究间作后作物各部位Cd积累差异及其形成原因。结果表明,番茄和玉米间作和限制性间作所产番茄根、茎、叶中Cd含量均有所提高(叶中Cd含量从13.52mg/kg分别升高至24.94mg/kg和27.30mg/kg);与未种植作物的对照组相比,非单作条件下番茄根围土壤的pH有所下降,酸性磷酸酶活性上升,而脲酶活性下降,且间作组变化幅度较大;间作还能改变作物根围微生物种群结构,提高对重金属吸收有促进作用的微生物种群的丰度,最终实现Cd高积累番茄对Cd的吸收能力提高。研究结果可为利用间作模式修复土壤重金属污染和保障食品安全提供参考。     

蕹菜典型品种中Cd、Pb、Cr、Ni 等重金属含量及其相关性

目的:蕹菜(Ipomoea aquatica Forsk.)Cd(镉)积累典型品种对Cd、Pb(铅)、C(r铬)、N(i镍)等多种重金属的吸收积累及相互关系。方法:采用盆栽试验,分析4个蕹菜Cd积累典型品种在6种土壤上的两茬茎叶及根Cd、Pb、Cr、Ni含量及相关性。结果:①品种和土壤对供试蕹菜典型品种Cd含量的效应均达显著水平(P<0.05),对Pb、Cr和Ni含量的效应因重金属、收获时期及部位而不同,二者对Cd、Pb含量具一定的交互效应。②两茬茎叶Cd含量平均值均为T308>GDB>QLB>QLQ,根Cd平均含量高于茎叶Cd平均含量;除Cr外,根Pb和Ni平均含量均高于茎叶。③Cd、Pb、Cr、Ni含量呈现复杂的相关关系。茎叶Cd含量与Pb含量正相关,且第一茬相关性极显著(P<0.01);Pb含量与Ni含量相关关系明显,第一茬茎叶、根Pb含量与Ni含量的正相关达到显著(P<0.05)或极显著水平(P<0.01),但第二茬茎叶Pb含量与Ni含量却显著负相关(P<0.05);Pb含量与Cr含量的相关性仅第一茬茎叶显著(P<0.05);Cr含量与Ni含量的相关性仅第二茬茎叶达极显著水平(P<0.01)。结论:蕹菜典型品种对Cd、Pb、Cr、Ni的吸收积累存在协同和拮抗两种作用。     

基于定量评价方法研究不同水稻品种的镉积累差异

为筛选出高产且适用于粮食安全生产的镉低积累水稻品种，本研究以18个早、中、晚熟稻品种为供试材料，比较了不同品种水稻在中轻度镉污染农田的生长情况以及对镉吸收、积累差异，并通过综合定量评价方法进行评估。结果表明：根据综合定量筛选评价方法将糙米镉浓度、稻谷产量、转运系数和秸秆积累量作为评价指标并赋予不同权重，通过计算综合得分筛选出的高产且镉低积累水稻品种有JR-9(沪香粳106)、JR-2(沪早香软1号)、JR-7(8333)、JR-15(宝农34)和JR-8(南梗9108);品种JR-8水稻产量最高，品种JR-9、JR-7和JR-15水稻产量均显著高于其他品种；不同水稻品种的稻米镉含量差异较大，JR-9、JR-15、JR-7稻米镉含量显著低于其他水稻品种；品种JR-2转运系数最低，更多的镉保留在秸秆中，表现出最高的秸秆积累量，最终成为候选品种。本研究采用的综合定量评价方法可对高产、低Cd的水稻品种进行科学评价，并初步筛选了5个适用于中轻度Cd污染农田推广的Cd低积累水稻品种，其稻米Cd含量达到国家粮食安全限量标准。     

不同镉水平下大麦幼苗生长和镉及养分吸收的品种间差异

利用水培试验研究了不同Cd水平下大麦幼苗的Cd和几种矿质元素吸收、积累、生长和生物学产量的品种间差异 .结果表明 ,1μmol·L-1Cd处理显著降低麦苗株高、绿叶数、叶绿素计读数、地上部和根系干重 ,显著抑制植株对Zn、Mn、Cu的吸收和累积 ;品种之间存在着显著差异 ,无芒六棱受抑制最为严重 ,米麦 114和浙农 1号表现出相对较强的抗性 .麦苗Cd含量和累积量品种之间也有显著差异 ,浙农 1号的Cd含量最高 ,米麦 114最低 .相关分析表明 ,麦苗生物学产量与地上部Cd含量、累积量及根系Cd含量呈显著负相关 ,其中与地上部Cd含量的相关性最强 ,与根系Cd累积量无显著相关 .     

Cs phytoremediation by Sorghum bicolor cultivated in soil and in hydroponic system

Cs accumulation characteristics by Sorghum bicolor were investigated in hydroponic system (Cs level at 50–1000 μmol/L) and in soil (Cs-spiked concentration was 100 and 400 mg/kg soil). Two varieties of S. bicolor Cowly and Nengsi 2# grown on pot soil during the entire growth period (100 days) did not show significant differences on the height, dry weight (DW), and Cs accumulation. S. bicolor showed the potential phytoextraction ability for Cs-contaminated soil with the bioaccumulation factor (BCF) and the translocation factor (TF) values usually higher than 1 in soil system and in hydroponic system. The aerial parts of S. bicolor contributed to 86–92% of the total removed amounts of Cs from soil. Cs level in solution at 100 μmol/L gave the highest BCF and TF values of S. bicolor. Cs at low level tended to transfer to the aerial parts, whereas Cs at high level decreased the transfer ratio from root to shoot. In soil, the plant grew well when Cs spiked level was 100 mg/kg soil, but was inhibited by Cs at 400 mg/kg soil with Cs content in sorghum reaching 1147 mg/kg (roots), 2473 mg/kg (stems), and 2939 mg/kg (leaves). In hydroponic system, average Cs level in sorghum reached 5270 mg/kg (roots) and 4513 mg/kg (aerial parts), without significant damages to its biomass at 30 days after starting Cs treatment. Cs accumulation in sorghum tissues was positively correlated with the metal concentration in medium.     

Toxic Effects of Cadmium on Morus alba L. and Bombyx moril L.

A 3-year micro-plot experiment of mulberry cultivation with Cd-polluted soil and silkworm breeding experiments by feeding with exogenous or endogenous –Cd-polluted mulberry leaves were conducted to evaluate the toxic effects of Cd on mulberry and silkworms. There was no apparent harmful effect on mulberry plant growth at a soil Cd content of 8.49 mg/kg. At a soil Cd content of 75.8 mg/kg, a yield reduction in the leaves became apparent, whereas at 145 mg Cd/kg soil, the plants exhibited marginal growth. There was a significant decrease of the ingestive rate of leaves at an exogenous Cd content of 1.98 mg Cd/kg leaf, whereas the digestive rate decreased significantly at an exogenous Cd content of 0.50 mg/kg. The endogenous Cd content that significantly affected the ingestive and digestive rates was 1.66 mg/kg. The influence of exogenous and endogenous Cd on the biomass of the silkworms decreased with increase of the instar stage. The weight of cocoons and rate of silk reeling was significantly reduced at exogenous and endogenous Cd contents of 5.17 mg/kg and 1.66 mg/kg, respectively.     

一种新发现的铜积累植物——密毛蕨

对铜尾矿上生长的密毛蕨(Petridium revolutum)进行了野外调查分析和温室营养液砂培实验.结果表明,密毛蕨所生长的废铜矿土壤中Cu含量平均为2 432 mg·kg^-1 DW,最高达7 554 mg·kg^-1 DW;地上部生物量平均为18.33 g·plant^-1 DW,最高达40.05 g·plant^-1 DW;地上部Cu含量平均为201 mg·kg^-1 DW,最高达567 mg·kg^-1 DW;地下部Cu含量平均为346 mg·kg^-1 DW,最高达1 723 mg kg^-1 DW;密毛蕨对Cu的转移系数平均为0.81,最高达3.88.在营养液砂培的条件下,Cu 7 mg·L^-1处理没有抑制密毛蕨地上部的生长;密毛蕨体内的Cu含量随着介质中Cu浓度的增加而显著增加,但是大部分的Cu积累在地下部.密毛蕨对Cu具有较强的忍耐和较高的积累能力,可作为修复Cu污染土壤的新材料.     

德国鸢尾对Cd胁迫的生理生态响应及积累特性

通过盆栽研究了Cd胁迫下德国鸢尾的生长状况、生态效应、生理特性及吸收和富集Cd的能力.结果表明:德国鸢尾对小于5 mg/kg的Cd有较强的耐性,适用于城区土壤修复;Cd浓度大于5 mg/kg时抑制德国鸢尾生长,降低了其生态效应.随着Cd浓度的增大,德国鸢尾根系活力、叶绿素含量和含水量逐渐降低,游离脯氨酸和可溶性糖含量先升高后降低,细胞膜透性逐渐升高.Cd在德国鸢尾体内分布为根系＞地上部分,随着Cd浓度的增大,德国鸢尾根系和地上部分Cd积累浓度逐渐升高、富集系数和转运系数逐渐降低;Cd浓度为20 mg/kg时德国鸢尾对Cd的积累量最大,为2.122 mg/plant.     

不同品种小白菜对镉的吸收积累差异

通过盆栽试验,研究了60个小白菜品种在不同程度镉污染土壤中吸收和积累镉能力的差异.结果表明：在土壤镉浓度为0.6 mg·kg^-1时,小白菜镉含量超过国家标准的为8.33％;而在土壤镉浓度为1.2 mg·kg^-1时其超标率达66.67%,表明小白菜容易受到镉污染.2种镉浓度下白菜地上部分镉含量均低于国家食用标准,且其生物量不受影响的小白菜品种为：长梗白菜、上海青、矮箕苏州青、青优四号、矮脚葵翩黑叶白菜、皱叶黑油冬儿、高华青梗白菜、早生华京、金冠清江白、夏王青梗菜、利丰青梗白菜和杭州油冬儿.这12个品种可作为在镉轻度污染土壤中种植的安全系数较高的小白菜品种.     

Cadmium phytoextraction from loam soil in tropical southern China by Sorghum bicolor

The cadmium (Cd) uptake characteristics by Sorghum bicolor cv. Nengsi 2# and Cowley from the acidic sandy loam soil (pH = 6.1) during the entire growth period (100 days) were investigated in pot outdoors in a tropical district of southern China, Hainan Island. The Cd-spiked levels in soil were set as 3 and 15 mg/kg. Correspondingly, the available Cd levels in soil extracted by Mehlich III solution were 2.71 and 9.41 mg/kg, respectively. Basically, two varieties in a full growth period (100 days) did not show a significant difference in their growth and Cd uptake. Under high Cd stress, the plant growth was inhibited and its biomass weight and height decreased by 38.7–51.5% and 27.6–28.5%, respectively. However, S. bicolor showed higher bioaccumulation capability of Cd from soil to plant [bioconcentration factor (BCF)>4], and higher transfer capability of Cd from roots to shoots [translocation factor (TF)>1] under high Cd stress; Cd contents in the roots, stems, and leaves of S. bicolor reached 43.79–46.07, 63.28–70.60, and 63.10–66.06 mg/kg, respectively. S. bicolor exhibited the potential phytoextraction capability for low or moderate Cd-contamination in acidic sandy loam soil.     

Screening of As-Accumulating Plants Using a Foliar Application and A Native Accumulation of As

The discovery of novel accumulating plants is useful for efficient phytoremediation due to the demands of various conditions of impacted sites such as land use, soil properties, concentration of pollutants, and climate. In the present study, we investigated foliar application or a field with highly bioavailable arsenic (As) to screen As-accumulating plants. Plants grown in the downstream of a hot springs area were analyzed for native As accumulation and As foliar application, and the rhizosphere soils were collected. The water-soluble As in the rhizosphere soils had a high average, 144 μg/kg, whereas total As was similar to normal soil in Japan. Among 34 herbaceous plants and 17 woody plants, Chelidonium majus var. asiaticum accumulated a relatively high As level, 8.07 mg/kg DW (93.6% of As added), that was not revealed by native accumulation. In a further pot experiment, C. majus accumulated a moderately high As level (314 mg/kg DW) in the roots but not in the shoot (30.1 mg/kg DW), and exhibited a low transfer factor (TF = 0.096). Thus, a foliar application would be a simple and high-throughput method to screen plants that accumulate and tolerate As. C. majus would be useful as a tool for phytostabilization of As.     

Increased activity of ATP-sulfurylase and increased contents of cysteine and glutathione reduce high cadmium-induced oxidative stress in mustard cultivar with high photosynthetic potential

Cadmium is known to reduce photosynthesis and overall growth of plants. Plants adopt several mechanisms of Cd detoxification, such as accumulation of sulfur-rich compounds, like glutathione (GSH) and its precursor cysteine. The accumulation of GSH is regulated by the activity of ATP-sulfurylase, a rate-limiting enzyme in sulfur assimilation. The carbon of Cys is provided through photosynthesis. Thus, a plant with the higher photosynthetic potential and ATP-sulfurylase activity may have the higher contents of Cys and GSH and therefore may provide for a greater tolerance to Cd stress. Mustard (Brassica juncea L. Czern and Coss.) cvs. Varuna (high photosynthetic potential) and RH30 (low photosynthetic potential) were subjected to 0 and 200 mg Cd/kg soil, and the activity of ATP-sulfurylase, the contents of Cys and GSH, oxidative stress, and activities of antioxidant enzymes were studied. Under 200 mg Cd/kg soil, cv. Varuna showed an increased ATP-sulfurylase activity, the higher contents of Cys and GSH, and the net photosynthetic rate than cv. RH30. In contrast, the activity of superoxide dismutase, the contents of thiobarbituric acid-reactive substances, and H₂O₂, and electrolyte leakage were found to be greater in cv. RH30 showing an increased oxidative stress than cv. Varuna. However, the activities of ascorbate peroxidase and glutathione reductase were greater in cv. Varuna than cv. RH30. The results show that a greater ATP-sulfurylase activity, an enhanced production of Cys and GSH, and an efficient antioxidant enzyme system in the high photosynthetic mustard cv. Varuna helped to the reduce the oxidative stress maintaing high photosynthesis.