改良剂对镉及铅污染土壤中塌地乌品质的影响

采用盆栽试验,研究了施用不同改良剂—骨粉、纳米羟基磷、粉煤灰及其两两组合对镉、铅污染土壤中塌地乌叶绿素及维生素C含量及品质的影响。结果表明:施入改良剂后,塌地乌叶片叶绿素含量和植株内维生素C含量均不同程度增加,硝酸盐和可溶性糖含量降低,叶绿素a/b值降低(除单施纳米羟基磷灰石)。因此,添加改良剂可提高镉、铅污染土壤中塌地乌的品质。     

重金属镉对丝瓜种子萌发及根系活力的影响

采用水培法,研究了不同浓度的Cd2+对丝瓜种子的发芽率、发芽势、发芽指数、活力指数变化及根系活力的影响。结果表明:当Cd2+浓度为10mg/L时,发芽率和活力指数均高于对照;当Cd2+浓度为5mg/L时,根系活力高于对照;之后随着Cd2+溶液浓度的升高,发芽率、发芽势、发芽指数、活力指数、根系活力均显著降低,抑制效应逐渐增强;说明低浓度的Cd2+对丝瓜种子萌发具有促进作用,高浓度的Cd2+则具有抑制作用。     

不同改良剂对土壤-叶菜系统Cd迁移累积的调控作用

为筛选适合在中轻度镉污染土壤上有效降低叶菜吸收镉的改良剂及用量,采用镉污染菜地土壤进行盆栽试验,研究不同用量的石灰、泥炭和碱渣对小白菜（Brassica chinensis L.）生物量、镉吸收量,土壤pH及有效态镉含量的影响。结果表明,3种改良剂对小白菜生长均无显著的抑制作用;与不施改良剂的处理相比,石灰、泥炭显著抑制小白菜对镉的吸收,地上部镉含量与石灰和泥炭用量均呈显著负相关关系（R=-0.668、-0.785,P〈0.05）,碱渣对小白菜地上部镉含量的影响不显著,但显著增加根系镉含量;改良剂均显著提高土壤pH,但对DTPA-Cd影响不同,石灰显著降低DTPA-Cd,泥炭、碱渣均有增加DTPA-Cd含量的趋势;泥炭对土壤-小白菜系统Cd迁移的调控效果最佳,其最佳用量为20 g.kg-1土,石灰次之,碱渣不适合。     

Cd~(2+)处理对几种叶菜可食部分Cd含量及品质的影响

以5种叶菜为材料,采用水培和盆栽试验2种培养方式,测定不同浓度Cd2+处理下叶菜地上部(可食部分)生物量、Cd含量、硝酸盐及纤维素含量等生理与品质指标。结果表明:水培与盆栽培养条件下青菜、塌地乌、小白菜、菠菜及芥菜5种叶菜生物量随着Cd2+处理浓度增加显著降低(P0.05);可食部Cd含量显著升高(P0.05);高浓度水培与盆栽Cd2+处理(40mg.L-1和70mg.kg-1)下,5种叶菜中菠菜Cd含量相对较高,青菜Cd含量较低;随着Cd2+处理浓度增加,5种叶菜硝酸盐及纤维素含量升高,维生素C和可溶性糖含量下降,采用灰度关联综合分析表明,不同浓度Cd2+处理的5种叶菜中,青菜品质相对稳定及Cd含量较低,为Cd低积累品种。     

在积累镉油菜后茬种植白菜可否减少其对镉的吸收?

Rapeseed (Brassica campestris L.), a Cd-accumulating crop, is effective in reducing plant-available Cd from soil. A pot experiment was conducted to test the hypothesis that the Cd uptake by Chinese cabbage (Brassica pekinensis Rupr.) grown in rotation with rapeseed would be reduced due to the efficient removal of bioavailable Cd from soil solution by the rapeseed crops. The Cd removal by shoot for the rapeseed cultivar Zhucang Huazi ranged from 0.24% to 0.99% in natural Cd-contaminated soil (soil A) and from 0.63% to 1.23% in artificial Cd-contaminated soil (soil B) during the growth period of 4–7 weeks; whereas that for the rapeseed cultivar Chuanyou II-93 ranged from 0.25% to 0.66% and from 0.38% to 1.02%, respectively. Chinese cabbage grown in the pots with soil A for five weeks after harvesting rapeseed exhibited a significantly lower Cd concentration compared to that grown in the control pots (uncropped with rapeseed). However, the rotation of rapeseed did not lower the Cd concentration of Chinese cabbage on soil B. Although an increase of Cd uptake was observed in the rapeseed cultivars with growth time, and the decrease of soil NH 4 OAc-extractable Cd was found only in the natural rather than artificial Cd-contaminated soil.     

毛细管离子分析法测定茶叶中的锌、锰、铜、铅和镉

用毛细管离子分析(CIA)法测定了茶叶中的锌、锰、铜、铅和镉,在10mmol/L咪唑,10mmol/Lα-羟基乙酸,pH=4.0的电泳介质中,五种离子在10min内得到了分离,用间接紫外法检测,以外标法定量,五元素的线性关系良好,相关系数为0.9973~0.9997,平均回收率在96.4%~104.2%之间,相对平均偏差为2.1%~3.3%,检测限为0.02~0.2μg/ml。此方法快速简便、准确度高、测定成本低。     

镉污染土壤伴矿景天的萃取强化-螯合剂和植物激素的叶面调控

为提高Cd超富集植物伴矿景天(Sedum plumbizicola)的植物萃取能力,采用盆栽试验研究螯合剂乙二胺四乙酸(EDTA)和植物激素脱落酸(ABA)单独和联合作用的叶面调控对伴矿景天生长和Cd吸收转运的影响,并通过大田试验进行验证。结果表明:盆栽试验叶面喷施EDTA、ABA均能提高伴矿景天对Cd的转运,地下部至地上部的Cd转运系数为EDTA＞ABA,但叶面EDTA处理对生长旺盛期伴矿景天的生长有抑制。伴矿景天各部位Cd富集浓度差异很大,呈现新叶＞地下部＞茎＞老叶,新叶中Cd浓度是老叶的3.6~5.4倍,且主要富集在细胞壁和细胞器中,占总富集量的88%~94%。EDTA处理新叶细胞器中Cd浓度剧增,ABA处理新叶细胞壁中Cd浓度增加,ABA和EDTA联合使用可以缓解EDTA对生长的抑制,且更有利于Cd从根系向地上部转运。大田小区试验叶面诱导强化伴矿景天Cd萃取是可行的,ABA和EDTA联合处理显著增加伴矿景天总Cd积累量,增幅达到37.87%。研究结果为伴矿景天修复Cd污染土壤提供理论指导。     

Inhibition of native arbuscular mycorrhizal fungi induced increases in cadmium loss via surface runoff and interflow from farmland

Arbuscular mycorrhizal fungi (AMF) can form symbiotic relationships with most crops, but their impact on the environmental migration of cadmium (Cd) in farmland is limited. A field experiment was performed in the rainy season (May–October) for two years in Cd-polluted farmland used for maize cultivation. A fungicide (benomyl) was used to specifically inhibit native AMF growth in the farmland. The growth and Cd uptake of maize and the Cd concentration and loss in runoff and interflow were investigated. Benomyl strongly and significantly inhibited AMF colonization rate in maize roots, reduced the contents of total and easily extractable glomalin-related soil protein (GRSP) in soil and the Cd uptake in maize roots, and increased the Cd uptake in shoots. Particulate Cd was the main form of Cd loss in runoff, while dissolved Cd was the main form of Cd leaching loss at depths of 20 cm and 40 cm. Inhibiting AMF increased the Cd concentration in runoff and interflow and promoted dissolved Cd loss in runoff and interflow at 20 cm depth by 34.7% and 68.0% and particulate Cd loss by 46.4% and 19.7%, respectively. Furthermore, the AMF colonization rate in maize roots and the GRSP content in soil were significantly positively correlated with Cd uptake in roots and negatively correlated with the concentration and loss of Cd in runoff and interflow. These results indicated that the benomyl-induced inhibition of native AMF promoted Cd transfer to maize shoots and increased Cd loss via runoff and interflow from polluted farmland.     

外源硒对镉胁迫下芥菜种子萌发生理效应的影响

采用水培的方法,以芥菜为材料,研究了施加不同质量浓度外源硒（Se）（1,2,6,8 mg/L）对单一质量浓度镉（Cd）（10 mg/L）胁迫下芥菜种子萌发生理效应的影响。结果表明,单一质量浓度Cd胁迫显著抑制了芥菜种子的发芽（P＜0．01）,种子萌发过程中幼苗中的可溶性糖含量和淀粉含量显著低于对照（P＜0．01）,丙二醛（MDA）含量则明显高于对照（ P＜0．01）,表明单一Cd对芥菜种子的萌发产生了一定程度的伤害;单一Cd胁迫下加入不同质量浓度外源Se后,能够有效地提高种子的发芽率,使可溶性糖和淀粉含量增加,MDA含量明显降低,表明外源Se可以有效地缓解Cd对芥菜种子萌发造成的伤害;当外源Se质量浓度为2 mg/L时,芥菜的发芽率、可溶性糖含量和淀粉含量为最大值,且与对照相比变化不大（P＞0．05）,但均显著高于单一Cd胁迫下的相应值（P＜0．01）,MDA含量最低,且显著低于对照和单一Cd胁迫下的相应值（P＜0．01）,表明当外源Se的质量浓度为2 mg/L时,对单一质量浓度Cd胁迫下芥菜种子萌发的缓解作用最佳。     

ICP-MS同时测定红参中8种微量元素

目的 建立ICP-MS同时测定红参中8种元素含量的分析方法.方法 硝酸-高氯酸体系进行湿法消解,ICP-MS分析,同时分析锰、铜、锌、钡、钴、铁、镍、鎘8种元素.结果 该方法线性范围宽,Mn、Cu、Zn、Ba、Co、Fe线性在0μg/L～500μg/L之间,Ni、Cd线性在0μg/L-100μg/L之间,线性相关系数0.9847～ 0.9999之间,检出限在0.0007～ 0.02mg/Kg之间.标准物质的RSD在4.45％～9.13％之间.结论利用该方法对标准物质茶叶中Mn、Cu、Zn、Ba、Co、Fe、Ni、Cd含量进行测定,表明该方法能够满足上述8种元素的分析要求.将方法应用于4、5年生红参中8种元素含量水平测定,获得了较满意的分析结果.