野茼蒿对镉的富集及其镉耐性

通过盆栽试验研究了不同镉（Cd）浓度（0、30、60、90、120、150、180mg.kg-1）胁迫下野茼蒿（Crassocephalum crepidioides（Benth.）S.Moore）的生长及其对Cd的富集特征。结果表明,随着Cd添加水平的增大,处理组野茼蒿的主根长、株高、叶绿素含量、根和地上部生物量均呈降低趋势,且主根长、株高、根和地上部生物量均显著低于对照植株;当Cd添加水平不断提高,处理组野茼蒿根和地上部Cd浓度呈显著增加趋势,而累积总量呈先增加后下降的趋势,但仍显著高于对照植株。处理Cd浓度为180mg.kg-1时,野茼蒿地上部Cd浓度最高,为1288.12mg.kg-1;处理Cd浓度为60mg.kg-1时,野茼蒿地上部Cd累积量最高,为每盆4.28mg。当Cd浓度≤90mg.kg-1时,野茼蒿生长正常,未出现Cd中毒症状。野茼蒿地上部Cd富集系数和转移系数分别为3.48～21.71和1.12～2.31。因此,野茼蒿对Cd具有较强的耐受性和转运能力以及其地上部对Cd的累积能力,适合于Cd污染土壤的植物修复。     

水稻镉安全材料分蘖期根部镉积累分布特征

【目的】镉 (Cd) 低积累作物的培育和应用是减少土壤中Cd通过食物链危害人体健康的重要途径。通过研究Cd处理下水稻分蘖期根部Cd的积累分布特征,揭示水稻Cd安全材料根部Cd的固持机理,为水稻Cd安全品种的培育提供理论依据。【方法】以水稻Cd安全材料D62B为供试材料,普通材料Luhui17为对照,进行水培试验。水稻秧苗于三叶一心时移栽至盆中 (40 cm × 60 cm × 15 cm),以CdCl₂·2.5H₂O加入营养液,设0 (CK)、0.5 (Cd0.5)、1.0 (Cd1)、2.0 (Cd2) mg/L 4个Cd浓度处理,30天后收获,分为根和地上部测定其Cd全量。采用化学试剂逐步提取法和差速离心法分别测定根部Cd化学形态和亚细胞分布特征,并进一步结合细胞壁多糖,研究其对Cd的响应特征。【结果】1) Cd处理下D62B各部位Cd含量显著低于Luhui17,转移系数较小,其根部Cd向地上部转移较少。2) 随Cd处理浓度升高D62B根部水提取态Cd分配比例降低,盐酸提取态Cd、残渣态Cd分配比例升高,Cd移动性减弱。D62B根部Cd以氯化钠提取态为主 (48.9%～52.1%),高浓度Cd处理 (2.0 mg/L) 下其分配比例是Luhui17的1.11倍,水提取态是Luhui17的82.3%,其根中Cd的移动性弱于普通材料。3) D62B根部Cd主要分布于可溶部分和细胞壁,其中细胞壁Cd分配比例为38.6%～41.8%,高于Luhui17。随Cd处理浓度升高,D62B根细胞壁Cd分配比例降幅小于Luhui17,其细胞壁对Cd的固持作用有限但强于普通材料。4) D62B根细胞壁半纤维素1的Cd含量是果胶的7.74～8.40倍,Cd主要与细胞壁中半纤维素1结合。半纤维素1 Cd含量随Cd处理浓度升高而显著增加,2.0 mg/L Cd处理下D62B和Luhui17半纤维素1单位总糖Cd结合量较1.0 mg/L Cd处理分别增加32.6%、11.2%,D62B根细胞壁半纤维素1的Cd结合能力强于Luhui17。【结论】水稻Cd安全材料D62B各部位Cd含量低于Luhui17,其转移系数较小。D62B根中Cd主要为氯化钠提取态,随Cd处理浓度升高,根部Cd向移动性较弱的化学形态转化。D62B根细胞壁中Cd主要与半纤维素1结合,由于其Cd结合能力较强,D62B根细胞壁对Cd的固持作用强于普通材料。因此,D62B对Cd的转移能力弱于普通材料,是其籽粒Cd安全的重要原因。     

中度含镉鸡粪源有机肥对土壤镉积累及小白菜吸镉量的影响

为探讨施用鸡粪源有机肥对土壤-作物系统累积重金属镉的影响,实现鸡粪源有机肥的安全利用,以种植一季小白菜盆栽试验方式,选择镉含量适中(Cd 1.58 mg·kg~(-1))的鸡粪源有机肥,以不施肥空白(CK)和化肥常规施肥处理(F)为对照,在与常规肥施加等量化肥的基础上,设置4种不同施肥量有机肥处理,分析施用鸡粪源有机肥对土壤基本理化性质和土壤镉累积量及小白菜镉吸收量的影响。结果表明:鸡粪源有机肥施用量为0.5～2 g·kg~(-1)时土壤全氮、碱解氮、速效钾及有效磷含量较高,分别为0.725～0.760 g·kg~(-1)、111.50～141.48mg·kg~(-1)、205.86～230.44 mg·kg~(-1)、19.13～28.54 mg·kg~(-1),土壤有机碳为10.27～11.84 g·kg~(-1),但种植一季对土壤机械组成和阳离子交换量无明显影响。总体来看,随着鸡粪源有机肥施用量的增加,土壤pH值呈现缓慢降低趋势,对土壤累积镉影响不明显,土壤中镉的可交换态和可还原态含量呈增加趋势,可氧化态和残渣态含量呈减少趋势,而小白菜地上可食用部分镉的累积量有降低趋势。综上,鸡粪源有机肥的施加有助于改善土壤基本理化性质,影响镉在土壤中的形态分布,在种植一季小白菜时对土壤累积镉影响不明显,但有助于降低小白菜地上可食用部分的镉累积量。     

锌镉交互作用对伴矿景天锌镉吸收性的影响

采用水培试验、不同Zn、Cd污染程度农田土壤结合外加Zn、Cd基础上的土培盆栽法,研究了不同Zn、Cd浓度交互作用对伴矿景天生长及Zn、Cd吸收和分布的影响.水培试验结果表明,增加溶液中Zn和Cd浓度,伴矿景天各组织中Zn和Cd浓度显著增加,但两个高浓度处理间没有显著差异;Zn在伴矿景天体内呈不均匀分布且与水培溶液中Zn和Cd浓度有关,当溶液中Zn浓度＞Cd浓度时,表现为新叶＞成熟叶＞其他部位＞＞根,反之则为成熟叶＞其他部位＞新叶＞＞根;而Cd在伴矿景天不同部位的分布没有一致的规律性;Zn、Cd交互作用主要体现在伴矿景天新叶上:在溶液中外加Cd时,Zn对伴矿景天新叶中Cd浓度具有“低促高抑”效应,而Cd处理对新叶中Zn浓度具有拮抗效应.土培试验也表明,添加Zn显著促进伴矿景天对土壤中Cd的吸收,外加Cd对伴矿景天Zn吸收具有拮抗效应;但无论Zn或Cd,外加量过大均会显著抑制伴矿景天的生长,降低修复效率.     

大豆对镉胁迫的生理反应及耐镉机理探讨

为探讨大豆对镉（Cd）胁迫的生理反应及忍耐机理,以8157为供试材料,采用Hoagland营养液培养和土壤盆栽培养试验,研究了添加不同浓度外源Cd对大豆的生理效应及Cd吸收分布的影响。结果表明,大豆吸收的Cd向地上部转运的比率较高,根系对Cd的阻滞作用较弱;植株体内的Cd主要以NaCl提取形态存在（占89.61%）,降低了Cd的生物毒害性。土壤添加低浓度Cd（0.25～0.50mg·kg-1）,大豆籽粒中Cd-P表现为协同作用,Cd浓度升高则转为拮抗作用;不同浓度Cd处理,籽粒中Cd-Zn表现为协同作用,叶片中Cd-Zn则表现为拮抗作用。Cd胁迫促进大豆体内脯氨酸（PRO）的合成,提高了过氧化物酶（POD）的活性,增强了大豆对Cd胁迫的防御和抵抗能力。     

镉胁迫对菊芋生理变化及镉富集的影响

通过用耐镉性较好的徐州菊芋和耐镉性较弱的潍坊菊芋进行对比试验,设置土培CK(Cd~(2+) 0 mmol/L,即对照组)、T1(Cd~(2+) 0.1 mmol/L)、T2(Cd~(2+) 0.5 mmol/L)和T3(Cd~(2+) 1.0 mmol/L)4个处理组,探讨菊芋镉胁迫下各项生理指标和根际土壤指标以及富集能力的影响。结果表明:经过不同镉浓度胁迫21天后,2个菊芋品种的根长、株高、叶长、叶宽均受到相应程度的抑制,抗氧化酶活性随镉浓度的增加而减弱;但丙二醛(MDA)含量变化有所不同,潍坊菊芋的MDA含量伴着镉胁迫加深而增加,徐州菊芋只在T3镉浓度下才出现明显的上升变化,并在21天时达到峰值,为对照组的3.52倍。根际土壤pH大致呈现出持续下降趋势,镉处理20天时潍坊菊芋和徐州菊芋根际土壤pH均在T3处理下达到最低,降幅分别为3.85%和3.41%;有机质含量却表现出不断增加的状态,T3镉处理至第20天时,潍坊菊芋最大增幅为38.60%,徐州菊芋为36.01%;随着施加镉浓度的变大,抑制了菊芋对土壤碱解氮的吸收,总体上潍坊菊芋受抑制程度大于徐州菊芋。2个菊芋品种对镉的富集效果也不同,徐州菊芋各器官镉富集量均高于潍坊菊芋;在转运镉方面,潍坊菊芋根部的镉均等地转移到了叶、茎上,徐州菊芋则将大部分从根部转移到茎上。综上所述,菊芋在镉胁迫下体现出一定的抗性,具有较强镉富集能力,徐州菊芋镉富集能力更为明显。因此,将能源植物菊芋应用于镉污染土壤兼具经济和生态意义。     

低镉水稻研究进展

稻米镉污染已成为全球粮食安全的一个重大问题.系统了解水稻体内镉响应基因调控机制及镉代谢的影响因素有助于推动低镉优质水稻新品种的培育.本文重点阐述了镉进入根细胞、镉从根转移至茎、从茎转移至籽粒的三种机制及主要影响因素,同时对目前已知的水稻镉代谢调控相关基因进行了综述,以期为利用分子育种技术选育低镉积累水稻品种提供参考.     

镉胁迫对黄麻光合作用及镉积累的影响

为揭示镉(Cd)胁迫下黄麻的光合耐性及其对Cd的富集特征,通过土壤盆栽试验分析了Cd胁迫下黄麻的生长、光合色素、气体交换参数及对Cd富集能力的变化。结果表明,当Cd浓度≤10 mg·kg~(-1)时,黄麻根长、株高和各器官生物量降幅较小;而当Cd浓度≥20 mg·kg~(-1)时,根长、株高和各器官生物量降幅进一步增大。随着Cd浓度的升高,黄麻叶片光合色素含量显著降低,但却能维持较高的Chla/b值,这可能有助于黄麻对Cd的耐性。Cd胁迫使净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)显著降低,但胞间二氧化碳浓度(Ci)随Cd浓度的升高而逐渐增大,表明黄麻光合速率的下降是由非气孔限制因素引起的。随着Cd浓度的升高,黄麻各器官Cd含量和累积量逐渐增大,在浓为100 mg·kg~(-1)Cd处理下,地上部和地下部Cd含量均达到最大值,分别为232.46 mg·kg~(-1)和186.98 mg·kg~(-1)。Cd胁迫下,黄麻地上部和地下部富集系数均大于1,各处理迁移系数在0.85~1.65之间,表明黄麻对Cd有较强的富集和转运能力。Cd浓度为5~10 mg·kg~(-1)时,Cd提取率超过1.9%。因此,黄麻是一种潜在的修复轻、中度土壤Cd污染的植物材料。本研究结果为挖掘新的植物修复材料提供了理论依据。     

Effect of soil application of cadmium contaminated lime on soil cadmium distribution and cadmium concentration in strawberry leaves and fruit

Heavy metal environmental pollution which occurs as a result of lime contaminated with cadmium (Cd) poses a potential health hazard. This investigation was undertaken to study uptake of Cd by strawberry plants grown in soil amended with three different sources and two different rates of industry waste lime containing 3.4, 14.3, and 60.0 mg Cd/kg, respectively. The effects of Cd applied to the soil were investigated, including its distribution in the soil and effect on Cd concentration in strawberry cv. Senga Sengana (Fragaria anassa) leaves and fruit in response to soil organic matter content and lime rates. Cadmium accumulated mainly in the plough layer, increasing from 0.170 mg Cd/kg (background level) to a maximum of 1.2 mg Cd/kg. Fruit had very high, hazardous Cd concentrations regardless of its content in the soil. This indicates that Cd was easily taken up by strawberry plants and accumulated in upper plant parts, including the fruit. Soil Cd content had no effect on concentration of this element in strawberry fruit. However, plant Cd uptake and fruit concentration was increased in acid soils even when soil Cd concentration was low.     

Crop uptake of cadmium from phosphorus fertilizers: I. Yield and cadmium content

We investigated the effects of different P fertilizers on the yields and Cd contents of oat (Avena sativa L.), ryegrass (Lolium multiflorum L.), carrot (Daucus carota L.), and spinach (Spinacia oleracea L.). These crops were grown in the greenhouse using soils treated with lime to achieve three pHs ranging from 4.77 to 5.94 for a sandy soil and 4.97 to 6.80 for a loam soil. The crop yields were generally not affected by liming or application of different kinds of P fertilizers, with a few exceptions. Application of Cd-containing NPK fertilizers in all cases tended to increase the Cd concentrations in crops, and the highest Cd concentrations in crops were obtained when the high-Cd NPK fertilizer was applied (adding 12.5 μg Cd kg^?1 soil). Cadmium concentrations in crops in most cases decreased with increasing soil pH. The highest percent recovery of the added Cd by plant species in the sandy soil was found for inorganic Cd-salt and in the loam soil for low-Cd NPK fertilizer. Phosphate rock resulted in the lowest recovery of the added Cd by all the plant species in both soils, but was also an insufficient P-source of its low solubility.     

外源Cd在不同品种水稻组织中的细胞分布和化学形态特征研究

采用水培试验,以低镉(Cd)积累水稻品种‘D83A/R527’和高Cd积累水稻品种‘辐优838’为供试材料,设置3个Cd浓度(5μmol·L~(-1)、10μmol·L~(-1)、25μmol·L~(-1))处理,从Cd亚细胞及化学形态分布角度研究了不同基因型水稻品种的Cd积累特性,为探讨水稻对Cd的吸收积累生理机制提供科学依据。结果表明:(1)水稻‘D83A/R527’的根系和茎叶Cd含量及根系-茎叶转移系数均显著低于‘辐优838’(P0.05)。(2)两水稻根系各亚细胞组分中Cd含量表现为可溶部分(F3)细胞壁(F1)细胞器(F2),茎叶表现为细胞壁(F1)可溶部分(F3)细胞器(F2);‘D83A/R527’根系和茎叶细胞壁Cd的质量分数(36.76%~51.75%)高于‘辐优838’(31.29%~49.07%)。(3)两水稻品种Cd化学形态含量均表现为氯化钠提取态(F_(NaCl)-Cd)醋酸提取态(F_(HAc)-Cd)去离子水提取态(F_W-Cd)乙醇提取态(F_E-Cd)盐酸提取态(F_(HCl)-Cd);随Cd处理浓度的增加,‘D83A/R527’根系F_E-Cd和F_W-Cd(活性态Cd)质量分数逐渐下降(24.75%~18.34%),‘辐优838’活性态Cd逐渐上升(27.18%~28.68%),茎叶F_(HAc)-Cd和F_(HCl)-Cd(惰性态Cd)质量分数(32.41%~38.98%)逐渐上升且高于‘辐优838’(28.44%~31.22%),‘D83A/R527’根系和茎叶F_(NaCl)-Cd质量分数(32.71%~51.17%)均高于‘辐优838’(32.14%~47.63%)。综上,‘D83A/R527’水稻幼苗Cd积累量低;与‘辐优838’相比,‘D83A/R527’水稻幼苗根系和茎叶细胞壁质量分数较高,"活性态"Cd质量分数较低,"惰性态"Cd则更高,表明‘D83A/R527’水稻对Cd有更强的固持能力。     

Effect of cadmium on growth and the uptake of cadmium and other elements by durum wheat

A solution culture study was conducted to determine the effects of cadmium (Cd) application on the uptake of Cd, potassium (K), zinc (Zn), manganese (Mn), copper (Cu), iron (Fe) and on the growth of seedlings of three wheat (Triticum turgidum L. var Durum) cultivars, Kyle, Nile, and SC84–994. Cadmium application decreased shoot and root biomass, root length, and leaf area. Cadmium application did not produce any differences among cultivars in these growth parameters. There were differential cultivar responses in the uptake of Cd and K but not for Zn, Mn, Cu, and Fe uptake. A solution Cd concentration of 0.1 μM did not affect the concentration of Cd and K compared to zero Cd but at and above 0.5 μM Cd, Nile had a higher concentration and contents of Cd and K in root and shoot than SC84–994 and Kyle. Kyle and SC84–994 were not different in any of the elements tested except K concentration in shoot where the order was SC84–994<Kyle<Nile. Cadmium application increased the Cd concentration but decreased the concentration of K, Zn, and Mn in root and shoot, while the Fe and Cu concentrations in shoot and root were not affected. Cultivar differences were observed in the translocation of Cd from root to shoot. In SC84–994 and Kyle, 0.5 μmole Cd/L decreased the total Cd translocated to shoot, Further addition of Cd did not affect Cd translocation, whereas in Nile, increased Cd concentration in solution did not affect Cd translocation to the shoot. A modified version of Weibull frequency distribution [y = a exp.(b.Cd^c)] was applied to explain the effect of Cd on plant growth parameters and on the uptake of K, Mn, Zn, and Cu in plants.     

表油菜素内酯对镉胁迫下番茄幼苗生长及镉累积的影响

采用盆栽试验研究不同浓度(0、0.02、0.1、0.5、2.5 mg/L)的表油菜素内酯(EBR)对镉胁迫下番茄幼苗生长及镉累积的影响。结果表明,镉处理后番茄幼苗的生物量、叶绿素含量、抗氧化酶(POD和CAT)活性均下降,丙二醛(MDA)含量、相对电导率和渗透调节物质含量均升高;喷施一定浓度的EBR(0.5 mg/L)后,番茄幼苗的生物量、叶绿素含量、抗氧化酶(POD和CAT)活性及脯氨酸含量均显著增加,可溶性蛋白、MDA含量和相对电导率有所下降,番茄幼苗根系和地上部分的镉含量分别上升了50.0%和93.4%,镉转运系数最低,为0.45。综上,喷施EBR能够增强番茄幼苗对镉胁迫的耐受性,促进幼苗生长,降低镉的转运系数,其中,EBR浓度为0.5 mg/L时效果最好。     

土壤镉污染对卷丹百合生长和镉分布的影响

为探究卷丹百合对镉污染的响应,开展不同镉浓度梯度(2.5、3、3.5、4 mg·kg^-1)的盆栽试验,研究了不同浓度镉污染卷丹百合种球萌发、生长速率、生物量积累、生理响应和各器官镉含量的影响,分析了镉分布规律及各器官镉含量与土壤镉浓度的关系。结果表明：(1)C4(4 mg·kg^-1)镉浓度显著降低卷丹百合发芽率、发芽势、生长速率,C2(3 mg·kg^-1)、C3(3.5 mg·kg^-1)镉浓度分别增加了百合鳞茎生物量的13.84%和38.96%。(2)随土壤镉浓度增加,丙二醛(MDA)的含量和超氧化物歧化酶(SOD)活性呈先升后降再升趋势,过氧化氢酶(CAT)和过氧化物酶(POD)活性随镉浓度的增加呈先增后降趋势,C4浓度对SOD、CAT和POD具有抑制作用,对MDA的含量有促进作用。(3)各器官镉含量随土壤镉浓度的增加而增加,同一镉污染下,镉分布规律为地上茎>叶>花>根>鳞茎;与对照相比,各器官镉富集系数均显著下降,地下部转运系数显著上升,而地上部各器官转运系数呈下降趋势。...     

米渣蛋白对镉的吸附效果及其对土壤中镉的钝化作用研究

为探究米渣蛋白对水溶液中镉的吸附效果及米渣对土壤中镉活性的钝化效果,该研究首先用米渣蛋白在水溶液中对镉进行吸附、用盐酸解吸,并用Langmuir、Freundlich等温吸附方程来拟合米渣蛋白在水溶液中对镉的吸附过程,用动力学方程研究米渣蛋白与镉结合的机理,并根据线性关系从准一级、准二级吸附动力学方程中筛选更接近吸附动力的拟合方程。其次,通过周期取样,用Tessier分步连续提取法测定并探究米渣对土壤中镉的钝化能力。研究结果表明:在不同初始质量分数的镉溶液中米渣对镉的最大吸附量13.28mg/g,用盐酸解吸各初始质量分数下结合的镉,解吸率均达到90%以上。同时,Langmuir和Freundlich等温方程均能拟合米渣蛋白在水溶液中对镉的吸附过程,且R2达到0.99以上;准一级动力学、准二级动力学方程拟合结果是,拟合出的准二级动力学方程线性更好,米渣蛋白对镉的吸附动力更符合准二级动力学方程。土壤中镉钝化试验表明:加入米渣后,28d内土壤中镉的钝化效果较好,可能是由于米渣中的蛋白改变了土壤中镉的存在状态并降低镉的活性所致。该研究结果为米渣的应用提供新的思路,可为其在废水除镉、镉污染土壤的修复等方面应用提供理论依据。     

Silicon influences cadmium translocation by altering subcellular distribution and chemical forms of cadmium in peanut roots

Effects of silicon (Si) on subcellular distribution and chemical forms of Cd in two contrasting peanut cultivars, Qishan 208 (low seed Cd cultivar) and Haihua 1 (high seed Cd cultivar), were investigated by a hydroponics experiment at low Cd level (0.2 μM CdCl₂). Two cultivars differ in Cd translocation, subcellular distribution and chemical forms. In comparison to Qishan 208, Haihua 1 shows higher translocation factors (TFs); this may be resulted from higher Cd in the soluble fraction, and a larger proportion of inorganic Cd (extracted by 80% ethanol) and water-soluble Cd (extracted by d-H₂O) in roots. Pretreatment with Si decreased Cd in the cell wall, and enhanced Cd in the soluble fraction for both cultivars. However, effects of Si on chemical forms and TFs are cultivar dependent. Si enhances Cd translocation and the d-H₂O extractable Cd in Haihua 1. Positive correlations were observed between TF and Cd in the soluble fraction (r = 0.71, P < 0.05), and between TF and d-H₂O extractable Cd in root (r = 0.89, P < 0.001). Therefore, larger proportion of d-H₂O extractable Cd may be responsible for high TF in Si pretreated plants of Haihua 1.     

高镉累积水稻对镉污染农田的修复潜力

为探究高镉累积水稻品种扬稻6号和玉珍香对镉污染农田土壤的修复潜力,通过大田小区试验,测定6个不同生育期(返青、分蘖、孕穗、齐穗、蜡熟、完熟)5个部位(根、茎0～10 cm、茎10～20 cm、茎20 cm以上和谷)稻草的镉含量,开展高镉累积水稻镉累积规律、移除时间和移除高度研究。结果表明,水稻扬稻6号和玉珍香各部位镉含量随生育期的延长而增加,孕穗期增幅最大,完熟期达到最大值,在同一时期不同部位镉含量分布随株高呈递减趋势;完熟期,水稻品种扬稻6号和玉珍香的根、茎0～10 cm、茎10～20 cm、茎20 cm以上部分和谷中镉含量分别为19.3、11.8、9.4、8.1和3.9mg/kg与19.5、16.3、14.3、9.7和3.7 mg/kg,其对应的镉富集系数均大于1,对镉表现出高积累特性;稻草镉的移除含量在全育期均表现从大到小依次为整株收割、地上部全收割、离地10 cm收割、离地20 cm收割,完熟期整株移除情况下,扬稻6号稻草镉累积移除含量达1 652.11μg/株,玉珍香稻草镉累积移除含量达1 547.70μg/株;一年种植一季水稻扬稻6号和玉珍香,整株移除情况下土壤镉移除效率分别为9.1%和8.5%,地上部全移除情况下土壤镉移除效率分别为7.2%和7.1%。因此为兼顾水稻移除修复效果和可操作性,建议稻草在完熟后按地上部全收割的方式移除。研究结果可为镉污染稻田的植物修复治理提供新的思路。     

Soil pH influence on cadmium uptake by tobacco in high cadmium exposure

Cadmium (Cd) is a non‐essential toxic element, which is highly accumulated by tobacco leaves and is transferred to tobacco smoke thus contributing substantially to the permitted level of Cd intake by humans. Therefore, measures to reduce Cd accumulation by tobacco are of significant importance. The purpose of the present study was to investigate the influence of soil liming on Cd uptake by tobacco plants in high Cd exposure. A pot experiment was conducted with Nicotiana tabacum L. Samsun 53 on an acid Typic Haploxeralf amended with refuse sugarbeet lime to obtain a pH range from 5.3 to 7.0 and contaminated with 20 mg kg^‐1 Cd applied as CdCl₂. Tobacco was grown in pots for three months under natural conditions, harvested in four cuts and Cd uptake by leaves was estimated. In soil samples selected, pH, Cd extracted by DTPA method, and Cd fractions such as exchangeable, organically bound, carbonate and residual were determined. The results showed that Cd uptake influenced negatively tobacco yield. Soil liming decreased Cd uptake by tobacco plants. The DTPA method was not a good indicator for Cd availability in tobacco. A very strong relationship was recorded between exchangeable Cd and total Cd uptake showing that this Cd fraction is available to tobacco plants. Soil pH was correlated strongly in a negative way with this Cd fraction suggesting that this soil factor is very important in controlling Cd accumulation by tobacco.