Identification of quantitative trait loci for Cd and Zn concentrations of brown rice grown in Cd-polluted soils

Low grain cadmium (Cd) and high grain zinc (Zn) rice cultivars have become the current rice breeding objectives. However, the genetic control of Cd and Zn concentrations in brown rice remains poorly understood, especially when grown in Cd-contaminated soil. In this study, quantitative trait loci (QTLs) associated with grain Cd and Zn concentrations and Cd/Zn ratio were identified using a doubled haploid population derived from a cross between japonica JX17 and indica ZYQ8 rice cultivars. Three and two QTLs were detected for Cd and Zn concentration in brown rice, respectively. Two QTLs associated with grain Cd/Zn ratio on chromosomes 3 and 6 were initially mapped. These QTLs accounted for 10.83–41.66% of the total variance of the three traits measured. Only one common locus on chromosome 6 was found for Cd concentration and Cd/Zn ratio. The lack of co-location of the QTLs for Cd and Zn concentrations in this mapping population suggests different genetic mechanisms. In summary, our results provide insight into the genetic basis of rice grain Cd and Zn accumulation; the isolated QTLs may be useful for marker-assisted selection and identification of genes associated with Cd and Zn accumulation in rice.     

磷石膏改良基质中Cd、Zn在蔬菜内的富集和迁移特征

为查明改良磷石膏是否可以用作耕地,选择白菜、上海青、叶用芥菜和菠菜在磷石膏改良基质上种植,分析Cd、Zn在4种蔬菜不同部位的富集和迁移特征。结果表明：4种蔬菜中Cd、Zn的含量范围分别为0.004~0.039、45.56~361.89 mg/kg,Cd可满足《农产品安全质量无公害蔬菜安全要求》,而Zn超过《农产品安全质量无公害蔬菜安全要求》。Cd、Zn在蔬菜中的总体分布规律均为：根＞茎＞叶,其富集系数分别为0.23~0.47、0.90~3.19,且Zn＞Cd,富集较强,表明Zn较Cd在蔬菜中的富集能力强,易被蔬菜吸收。Cd、Zn在蔬菜中的迁移率总体呈现为：地下部位＞地上部位。     

粤北矿区污染农田土壤中重金属分布特征及相关性研究

为了了解调查区域的土壤污染现状和为粤北矿区土壤修复提供科学依据,采用网格法进行布点采样,采集了144个表层土壤样,通过单因子污染指数法、综合污染指数法以及相关性等对测试数据进行分析。结果表明,重金属Cd、Zn、Ni、Pb超标率分别达100%、96.53%、6.25%、3.00%;土壤重金属Cd、Zn单项污染指数分别为3.59、1.90,表明地块已受到这2种重金属的复合污染,其中Cd污染最严重,Pb、Ni、Cu的Pi均小于0.7,属于安全范围。其中,土壤中Pb(0.9851)、Zn(0.9197)、Cd(0.8994)有效态含量与全量的相关性均达到极强相关水平,表明其在土壤中极易发生迁移,潜在的生态污染风险较大;Cu、Ni有效态含量与全量的相关性也达强相关水平,在土壤中的迁移能力也不可忽视。     

镉、锌对紫花苜蓿种子萌发及幼苗的影响

在我国水资源危机日趋严重,土壤重金属镉污染面积不断扩大的情况下,针对抗旱、抗寒能力强,生物量大、经济实用价值高的紫花苜蓿,进行了重金属镉、锌的抗性试验研究。研究重点是重金属Cd^2 ,Zn^2 对紫花苜蓿种子萌发及幼苗生长的影响,结果表明：低浓度的Cd^2 ,Zn^2 处理液对种子的萌发和幼苗的生长具有激活效应,高浓度的Cd^2 ,Zn^2 处理液抑制种子的萌发和幼苗的生长;且对根的作用大于对芽的作用;而混和处理液对种子的影响大于单一离子的影响。     

5个工业大麻品种对5种重金属污染土壤的修复潜力

Uptake and translocation of lead (Pb), zinc (Zn), copper (Cu), cadmium (Cd), and arsenic (As) in industrial hemp genotypes were investigated at seedling and physiological maturity, in order to provide an insight for phytoremediation of mining soils in Yunnan. The experiment was conducted using five main varieties of industrial hemp viz., Yunma (ym)1, ym2, ym3, ym4, and ym5 under mining areas of Yunnan. Results showed that uptake and translocation of Pb, Zn, Cu, Cd, and As in all hemp genotypes were high at the seedling stage. Accumulation of Pb, Zn, Cu, Cd, and As contents in hemp roots were higher at physiological maturity as compared to seedling stage. However, comparing to seedling stage, Pb, As, and Cd contents in stems and leaves were higher at physiological maturity stage. Translocation factor coefficients of hemp stem and leaf to all heavy metals were more than 1.0 at seedling stage. At physiological maturity stage, translocation of Pb, As and Cd in stems and leaves of all hemp varieties were higher compared with Cu and Zn. The accumulated contents of Pb, As, Cu, Cd, and Zn in plants were 31.65-644.29, 365.14-624.25, 180.65-194.06, 15.13-24.40, and 540.07-684.27 g hm ^-2, respectively. However, highest contents of Pb, As, Cd, and Zn were observed in hemp variety Yunma 1 and Yunma 5, which suggested that these two varieties had significantly higher metal accumulation and translocation compared to other varieties. In conclusion, the bioconcentration ratios, translocation factor and phytoremediation ability of hemp variety Yunma 1 and Yunma 5 were higher than those of Yunma 2, Yunma 3, and Yunma 4. These results showed that both Yunma 1 and Yunma 5 were potential candidates for remediation of heavy metal polluted areas in Yunnan.     

株洲霞湾港典型植物重金属分布状况研究

为了给重金属污染区域的植物恢复提供参考依据,采集了株洲市霞湾港14种典型植物及其土壤,研究了植物中重金属的分布、污染、迁移和积累规律,发现不同典型植物在重金属污染区域的生存特点,并采用潜在生态风险指数法,评价土壤重金属污染状况,根据富集系数和转移系数研究了植物中重金属的分布和转移规律。结果表明,多数土壤重金属元素含量都明显偏高,潜在生态危害依次为Eir(Cd)>Eir(Pb)>Eir(Cu)>Eir(Zn),其中以Cd污染最严重。植物根茎叶中的重金属含量因重金属元素的不同而不同,在根茎叶3个部位中,均是Zn的含量最高,其次是Pb。商陆、苦楝和葛藤对Cu、Cd、Pb、Zn的富集能力很强,可以作为治理此4种重金属污染土壤的富集植物;牛皮消和藜对Cu、Pb、Zn的治理能有一定效果;马兜铃和臭牡丹则能够作为Cd、Pb、Zn重金属污染生态治理的参考植物。     

大庆城郊湿地沉积物重金属污染及聚类分析

本文通过对大庆城郊北二十里泡沉积物沉积物重金属含量的分析测定,结果表明主要重金属在各点位含量均超过清洁对照点,将全区域土壤重金属元素背景值作标准,北二十里泡湿地的沉积物中Hg、Zn、Cu、Cd、Pb等元素超标较多。只有Hg和As在个别点位低于标准。聚类分析表明,北二十里泡沉积物重金属中Zn、Pb、Cu可归为一类型,Hg 、Cr、Ni归为一类型,Cd、As归为一类型。在北二十里泡沉积物各采样点中,B5、B11～B18可归为一类型,B6归为单独类型。     

不同杂交水稻品种糙米中重金属Cd、Zn、As含量的差异研究

为了研究不同品种及类型杂交水稻对重金属Cd、Zn和As吸收累积差异,在湘南某矿区重金属和As复合污染稻田中种植30种不同品种的杂交水稻。研究结果表明：30个杂交水稻中糙米Cd含量为0.28~0.83 mg/kg,Zn含量为24.13~34.16 mg/kg,无机As含量为0.45~0.77 mg/kg。不同基因型杂交水稻品种吸收累积重金属Cd、Zn和无机As有一定的差异性,Cd在不同水稻品种糙米中的积累存在显著差异性,而Zn和无机As在水稻糙米中的累积差异性不显著。不同类型的杂交水稻之间对于重金属的累积也存在差异性,两系杂交水稻和三系杂交水稻糙米中Cd含量存在显著差异(P<0.05),而糙米中Zn和无机As的含量差异性不显著。因此,根据不同基因型杂交水稻对重金属累积的差异性,筛选出重金属低累积水稻品种的方法是可行的。     

滇中高山丘陵区土壤重金属来源及影响因素——以武定县为例

以武定县为例,探明土壤重金属的来源及影响因素,以期为高山丘陵区土壤重金属污染防治提供理论依据。笔者分析了武定县重金属含量和空间分布特征,运用多元统计分析方法,结合地质特征综合分析土壤重金属来源和影响因素。结果表明,表层土壤重金属的空间分布特征与深层土壤具一致性。除Cd、Pb、Zn外,表层与深层土壤重金属含量无显著差异。受区内断裂带控制,重金属主要富集在铁铜、铅锌多金属成矿带上。在垂向分布上,Cd受人为因素影响较大,Cr、Ni受自身理化性质的控制,As、Cu、Hg、Pb、Zn可能由地质背景控制。8种重金属均来源于成土母质,Cd、Pb、Zn受矿产开采的影响较大,Cr、Ni主要来源于成土母质,As、Cd、Cu、Hg、Pb、Zn来源于多金属成矿带高背景值成土母质与矿产开采的共同影响。不同土壤类型和土地利用类型中重金属含量不同,土壤重金属含量也与有机碳、铁锰氧化物、粘土矿物、养分元素、pH具有较显著的相关关系。     

长期污水灌溉条件下土壤重金属形态及生物活性的研究

摘 要: 通过野外调查和实验分析,对孝义市污灌区土壤中Ni、Cr、Pb、Cu、Zn、Cd 6种重金属的含量、形态分布和生物活性进行了研究。结果表明,孝义市污灌区土壤中重金属都未超过国家二级标准,但Ni、Cr、Pb比当地背景值都有所增加。土壤中重金属各形态的分布存在很大差异。Ni、Cr、Zn主要以残渣态的形式存在。Pb主要以残渣态和铁猛氧化态存在。Cu主要以残渣态和有机结合态的形式存在。Cd在残留态中比例最小,碳酸盐结合态和交换态含量比例很高。与对照相比,污灌降低了重金属残留态所占比例,改变了土壤中重金属存在形态,提高了重金属的生物有效性和迁移能力。污灌区土壤中重金属活性系数的大小顺序为：Cd＞Pb＞ Cu ＞Cr ＞Zn ＞Ni;迁移系数的大小顺序是：Pb ＞Cd＞ Cu ＞Cr ＞Zn＞Ni,土壤中Cd 、Pb的生物活性最高, 生态污染风险最大,应引起足够重视。     

水稻根际酶活性对土壤重金属污染的响应

为了解水稻根际土壤酶活性的变化及其与根际重金属有效性的关系,选取酸性矿山废水污灌形成的多重金属污染水稻土,采用根际袋模拟水稻根际环境,研究水稻根际土壤脲酶、磷酸酶、蔗糖酶、过氧化氢酶活性的变化特征及其与土壤有效态Cd、Pb、Cu和Zn含量的关系。结果表明,根际土壤pH和脲酶活性均低于非根际土壤,根际土壤微生物量碳和磷酸酶活性均高于非根际土壤。根际土壤有效态Cd和Zn含量低于非根际土壤,有效态Pb 和Cu含量高于非根际土壤。土壤pH与有效态Pb和有效态Zn均呈显著负相关,有效态Cd、有效态Pb 和有效态Cu含量与微生物量碳均呈显著正相关,有效态Cd、有效态Pb、有效态Cu和有效态Zn含量与土壤脲酶活性呈显著负相关,有效态Cd、有效态Pb 和有效态Cu含量与蔗糖酶活性呈显著正相关。可见,在多重金属污染土壤,土壤酶活性受不同重金属有效态含量影响;该结果可为水稻重金属污染治理研究提供理论依据。     

大宝山矿区地下水重金属污染季节特征与环境风险

为了研究矿山开采区地下水季节变化特征及这种特征引起的环境风险,以广东大宝山矿区地下水为例,应运环境健康风险评估模型计算环境风险。结果表明,丰水期地下水重金属含量较枯水期增加。运用环境健康风险评价模型对环境风险进行计算表明,Cu、Pb和Zn通过饮水途径的环境风险范围在10^-10~10^-12之间,通过皮肤接触的风险范围在10^-11~10^-17之间;Cu、Pb、Zn和Cd通过皮肤接触环境风险：值枯水期＞丰水期;Pb和Zn通过饮水途径的环境风险：丰水期＞枯水期,Cd环境风险水平与距污染源距离相关,而离尾矿库区距离越远,则重金属Cd的健康风险水平影响越小。枯丰水期Cd的环境风险值超过ICRP推荐的最大可接受风险水平,因此Cd应为该矿区地下水优先控制的污染物。     

The river Elbe: Processes affecting the behaviour of metals and organochlorines during estuarine mixing

Attempts were made to determine the relative importance of chemical or physico-chemical processes and sedimentation and resuspension processes on the behaviour of metals (Cd, Zn, Cu, Pb, Cr, Mn, Fe, Ca, Al, Si, Ti, Mg), organic C and N and organochlorine compounds (α- and γ-hexachlorocyclohexane) in the estuarine region of the river Elbe in summer 1976. The latter processes seemed to be relatively less important than in some other estuaries. This may result from a much less pronounced mud shoal in the Elbe estuary. Such a mud shoal may act as a continuous source for tidal resuspension of bottom sediment particles. Alternating sedimentation and erosion resulted in systematic variations in the composition of suspended matter in terms of the relative contributions of two fractions. One fraction consisting of permanently suspended small and low-density particles having higher contents (weight to weight) of Cd, Zn, Cu, Pb, Cr, Mg and organic C and N. The other fraction consisting of resuspending larger and denser (mud) particles having higher contents of Mn, Fe, Al, Si and Ti.In addition to Al silicates, organic matter and Fe and Mn oxides may be important sites for trace elements (like Cd and Zn) in both fractions, but particularly so in the permanently suspended fraction.Evidence was found for the removal of Cd, Zn, Cu, Mn and Fe from solution into suspended particles during the initial phases of estuarine mixing. Estuarine mud, acting as sink for particulate pollutants, may thus accumulate originally dissolved components.A wide range of PCB components with high and low degrees of chlorination was present in solution as well as in suspension. Water was the most important carrier for components with low (and seston for those with high) degree of chlorination. Concentrations of individual PCB components ranged from picograms to nanograms per litre. The only compounds present in the estuary and the Wadden Sea above the detection limit in 1-litre samples were α- and γ-HCH, in the order of ng · 1⁻¹.     

降尘和酸雨对芹菜中重金属分布特征的影响

在温室条件下模拟酸雨、降尘对芹菜进行不同的受试处理,并对茎、叶中重金属元素的含量进行了测试。结果表明,对于芹菜茎,酸雨使Zn,Cu,Ni,Pb含量增加,Fe的含量减少,Mn,Cd含量几乎不受影响;降尘使Zn,Mn,Ni,Fe,Cd含量增加,使Cu,Pb含量减少;酸雨和降尘联合作用使7种元素含量都增加。对于芹菜叶,酸雨使Cu,Zn,Mn含量增加,Fe的含量减少,Pb,Ni,Cd的含量对不同pH有增有减;降尘使Zn,Mn,Cd,Fe的含量增加,使Cu,Pb,Ni含量减少;联合作用使叶的Zn,Cu,Mn,Cd,Fe含量增加,Pb,Ni含量减少。7种元素在茎、叶中的聚类分析表明,茎中Cu-Ni协同作用显著,Fe-Cu拮抗作用显著;叶中Cu-Pb协同作用显著,Fe-Mn拮抗作用显著。     

闽西中堡银多金属矿区周边农田土壤剖面重金属分布及其评价

为了探究银多金属矿区周边农田土壤剖面重金属的分布情况,以闽西中堡银多金属矿区周边农田土壤为研究对象,分析了土壤剖面中重金属Cu、Cd、Hg、Zn、Pb、Ni、As、Cr 的含量和垂直分布规律,并讨论了污染元素的来源。结果表明：该区土壤Cu、Cd、Hg、Zn、Pb的含量垂直向下规律呈下降趋势,其中Cu、Cd和Hg主要在表层富集,Pb 和Zn的表聚现象较弱。As和Cr 未呈现表层富集现象,其含量随深度增加呈增大趋势。Ni 含量在剖面中无太大变化。只有表层土壤Cu、Cd、Hg超标,其平均综合污染指数大于1,属于轻度Cu-Cd-Hg复合污染型。土壤Cu、Cd污染源主要来自于银多金属矿区活动,而Hg污染源与民间冶金有关。     

鲁西北高产粮田土壤重金属环境质量评价

对聊城市十五里元镇高产粮田100个土壤样品中铜、锌、铅、镉含量进行分析测定,参考国家土壤环境质量标准（GB 15618-1995）,采用单因子污染指数法和内梅罗综合污染指数法对土壤环境质量进行了评价。研究结果表明,十五里元镇高产粮田土壤综合污染指数为1.161,处于轻度污染状态;4种重金属元素的单项污染指数均未超标,但镉污染达到警戒级。     

Effect of tire rubber ash and zinc sulfate on yield and grain zinc and cadmium concentrations of different zinc-deficiency tolerance wheat cultivars under field conditions

The aims of these field experiments were to investigate the effectiveness of soil application of rubber tire ash in comparison with soil and foliar applications of zinc (Zn) sulfate to increase Zn and decrease cadmium (Cd) concentrations in wheat grain. A two-year field experiment was conducted during the 2007–2008 and 2007–2008 growing seasons at Isfahan research field, Iran. Ten different Zn-efficiency bread wheat cultivars (Triticum aestivum L.) commonly cultivated in different parts of Iran were subjected to no Zn fertilizer addition (control), soil application of 40 kg ha⁻¹ ZnSO₄, soil application of 100 (for the first year) and 250 (for the second year) kg ha⁻¹ waste rubber tire ash, foliar application of Zn at the mid tillering stage, and foliar application of Zn at the early anthesis stage. In the foliar application, ZnSO₄ was sprayed at a rate of 0.66 kg Zn/ha. Foliar spray of zinc sulfate at early anthesis, in general, had no significant effect on the yield and grain Cd while significantly increased grain Zn concentrations of most cultivars. On average, the foliar Zn treatment at the mid tillering stage (0.66 kg Zn/ha), decreased the mean grain Cd concentration from 0.032 mg kg⁻¹ in the control treatment to 0.024 mg kg⁻¹. While the grain Zn concentrations of some cultivars increased with soil application of Zn sulfate, they were not affected or even decreased in other cultivars. For most studied wheat cultivars, pre-planting application of rubber tire ash in soil resulted in a significant decrease of grain Cd concentrations. The results show that the effectiveness of soil and foliar application of Zn on yield and grain Zn and Cd concentrations greatly depends on the cultivar. The currently recommended rates of soil applications of Zn to ameliorate Zn deficiency are sufficient to increase grain Zn and decrease grain Cd concentrations in some wheat cultivars, while they do not in the others. In this study, soil application of 250 kg rubber tire ash/ha and foliar spray of 0.66 kg Zn/ha at tillering stage were the most effective treatments to ameliorate Zn deficiency and to increase Zn and decrease Cd concentration in grains of most wheat cultivars.     

重金属富集植物黑麦草对锌、镉复合污染的响应

采用盆栽试验研究了锌、镉单一及复合污染对重金属蓄集植物黑麦草生长、叶绿素、抗氧化酶活性、锌及镉吸收的影响。结果表明,锌、镉及复合污染对黑麦草生物量存在不同程度的抑制作用。锌、镉及复合污染均明显降低了黑麦草叶绿素含量,提高了叶片POD、SOD的活性。黑麦草吸收的锌、镉主要集中在植株地上部。以锌、镉复合污染的处理植株抗氧化酶POD、SOD活性最强,对锌、镉的吸收量最大,其地上部锌、镉含量分别达到（3108.72、73.97 mg/kg）。黑麦草存在作为土壤重金属锌、镉复合污染植物修复材料的潜力。     

不同钝化材料对重金属污染土壤的钝化效果研究

土壤重金属污染已成为不容忽视的突出环境问题,筛选高效低成本的钝化材料十分迫切。选择有机肥、泥炭、沸石、硅藻土、石灰及不同材料的生物炭等钝化材料,采用室内模拟试验的方法,研究了不同材料不同添加用量的钝化剂对土壤中重金属Cu、Zn、Pb、Cd的钝化效果。结果表明：(1)石灰和沸石均能有效地降低地土壤中Cu、Pb和Zn浸提态含量,其中当石灰用量达到50g/kg时,Cu、Pb、Zn浸提态含量分别降低了61.75 %、25.57 %、38.45%;当沸石用量达到50g/kg时,土壤中Cu、Zn、Pb浸出态含量较对照处理分别降低了34.00 %、16.29 %和31.20%。(2)有机肥和泥炭能有效降低Pb 和Cu的浸出态含量,用量为50g/kg时,有机肥和泥炭对土壤中Pb和Cu的浸出量较对照分别减少了27.64%和33.58%。(3)锯木屑-生物炭和商品-生物炭用量达到50g/kg时,土壤中Cd浸出态含量较对照处理分别降低了21.46%和19.12%。     

Comparative Study on the Zinc and Cadmium Tolerance Potential of Twelve Prominent Rice Cultivars

Heavy metal pollution being a potential threat to agriculture raising rice cultivars with heavy metal tolerance is a promising strategy for remediation of heavy metal polluted agricultural lands. We present here a comprehensive study describing the differences in physiological and biochemical responses of 12 prominent high-yielding rice cultivars to increasing ZnSO₄ concentrations (0, 2, 6, and 10 mM) and CdCl₂ concentrations (0, 1, 2, and 3 mM). Even though Zinc (Zn) is an essential element required for the normal growth and development process of plants, a higher concentration of Zn has an antagonistic effect. Cadmium (Cd) is detrimental to plants and is found in soils contaminated with heavy metals. The effects of Zn and Cd on rice seedlings were a reduction in shoot length, greater chlorophyll and carotenoid loss, higher malondialdehyde content, proline accumulation, and an increased level of sugar and amino acids when treated with CdCl₂ and ZnSO₄. The CdCl₂ and ZnSO₄ stress-induced biochemical changes displayed major differences in the 12 rice cultivars in terms of tolerance to Zn and Cd toxicity. Our data provides evidence that the cultivar Varsha showed the highest tolerance and cultivar JY showed the least tolerance towards Cd and Zn toxicity.