对中国知网和万方数据库中2003至2013年间农田土壤重金属污染的相关文献进行基于文献计量和地理信息技术的农田土壤污染指数时空分布信息挖掘.结果表明:全国农田土壤重金属污染处于轻度污染到中度污染之间,并表现出一定的时空分异规律.湖南、云南两省的农田土壤重金属污染最为严重,东南地区以广东、广西为核心形成高-高聚集.在探讨的几种重金属元素中,污染严重程度依次为Cd＞ Pb＞ Cu＞ As＞ Cr.Pb、Cd污染较为严重,多与地区矿产资源的开发利用方式有关,应作为优先控制元素.研究成果或成为全国土壤污染状况调查的重要补充,可以促进区域土壤、环境相关研究的开展.

镉(Cd)是非必需的有毒元素，是农业环境和农产品的重要污染 物，易被水稻吸收并在籽粒中积累。不同水稻品种拥有不同的独特基因，导致水稻籽粒吸收积累Cd的能力存在一定的差异。因此，开展不同水稻品种耐Cd特性及 其不同生育期的吸收转运效率研究具有重要意义。本文采用水培试验，研究了两个水稻（Oryza sativa L.）品种：D83A/R527（低吸收累积Cd）和辐优838（高吸收累积Cd）在不同质量浓度Cd胁迫下籽粒Cd质量分数及不同生育时期水稻根、茎、 叶内Cd的吸收积累量及其动态变化特点。结果表明，两种水稻品种在Cd胁迫下籽粒Cd积累量差异显著，辐优838在1.0 mg·L-1 Cd质量浓度胁迫下籽粒Cd质量分数就已超过国家食品卫生标准；在1.0~3.0 mg·L-1 Cd质量浓度胁迫下，D83A/R527籽粒内Cd质量分数仅为辐优838的50~60%。随着Cd处理浓度增加和生育时期推进，两种水稻各部位Cd吸收 量均表现为逐渐增加，其增加幅度总体表现为：辐优838>D83A/R527；不同部位中，根的积累效应最强，叶片吸收积累能力最低，辐优838 茎、叶吸收积累效率分别是D83A/R527的1.5~2.0倍左右。在1.0~3.0mg·L-1 Cd胁迫下，水稻Cd积累差异较为显著的时期为灌浆期，辐优838的根系向茎、叶的转移效率大于D83A/R527，且D83A/R527主要表现为由根 系向茎Cd转移效率较高，叶片Cd积累相对较少。灌浆期是水稻籽粒干物质积累的重要时期，也是吸收累积Cd的重要时期，这为筛选低吸收积累水稻品种和调控 Cd在水稻籽粒中的吸收累积奠定了重要理论基础。

The effects of different cadmium levels（0,200,400,600 mg/L）on stem diameter,height,weight of hundred leaves,weight of stems and flowers,malondialdehyde (MDA),relative conductivity (REC),superoxide dismutase (SOD),peroxidase (POD),catalase (CAT) and ascorbate peroxidase (APX),as well as photosynthetic parameters (Chl a+b, P n , G s , T r , WUE ) were studied in six marigold cultivars.The results showed that:(1)No reduction in the stem diameter and height were noted when the plants were grown at Cd 2+ supply levels up to 400 mg/L.However,fresh weight of hundred leaves stems and flowers of all cultivars were decreased with the increase of Cd 2+ concentrations.Moreover,‘Great Hero’ and ‘Durango’were more sensitive than other cultivars.(2)MDA and REC were increased gradually as Cd 2+ concentration increasing.However,the activities of antioxidative enzymes significantly changed with the increasing of Cd 2+ concentrations from 0 to 600 mg/L.(3)Cadmium stress also caused Chl a+b and Chl a/b decrease,especially in Cd stress-sensitive cultivars.Moreover,Net photosynthetic rate decreased significantly under Cd stress,while the decrease of stomatal conductance ( G s ),transpiration rate ( T r ) and WUE were little.It was concluded that there was significant different response to Cd among marigold cultivars.The physiological characteristics of marigold responding to Cd might be important factors for the tolerance of cultivars.The photosynthetic efficiency and activities of antioxidative enzymes in sensitive cultivars were all decreased under Cd stress,which may cause lipid peroxidation to increase.In summary,‘Janie’and ‘Gate gold’had adaptation mechanism to Cd stress.The two cultivars are recommended for the heavy metal contaminated soils.

以6个万寿菊品种为研究对象,研究了不同浓度的重金属镉（Cd）胁迫（0、200、400、600 mg/L）对万寿菊基径、株高以及百叶重、茎叶重和单花质量等生长指标及其质膜透性（丙二醛、相对电导率）、保护酶活性（SOD、POD、CAT、APX）以及光合特性(叶绿素含量、净光合速率、气孔导度、蒸腾速率、水分利用效率)等生理指标的影响。结果显示:(1)低于400 mg/L的Cd胁迫对6个万寿菊品种的基径、株高无明显影响,而百叶重、茎叶重和单花质量却随着Cd浓度的增加显著降低,尤其是‘大英雄’和‘迪阿哥’2个品种表现的抗性较差。(2)随着Cd胁迫浓度的增加,各品种丙二醛（MDA）含量和相对电导率（REC）显著增加,而其保护酶活性不同程度降低。(3)Cd胁迫降低了万寿菊的叶绿素Chl a+b含量和Chl a/b,且抗性差的品种降低的幅度更大;叶片净光合速率（ P n ）明显降低,但蒸腾速率( T r )和气孔导度( G s )相对降幅较小,对水分利用效率（ WUE ）影响较小。研究表明,不同品种万寿菊对Cd毒害响应存在明显的差异,且Cd胁迫下生理响应的差异是品种间耐性差异的重要原因之一;抗性差的品种在高浓度Cd胁迫下,光合作用能力降低,抗氧化系统酶的活性受到显著抑制,膜质过氧化加剧,且品种‘珍妮’和‘金门’的抗性强于其他品种,可选择作为Cd污染区栽植植物。

摘　要： 筛选耐镉亚麻品种并对其耐性进行综合评价,是利用亚麻进行重金属污染农田生物修复的基础。本研究用800μM的CdCl_2,溶液对来自36个国家的412份亚麻种质在种子萌发期进行镉胁迫试验,检测了各品种对照和处理的发芽势、发芽率、相对芽长等指标,并利用隶属函数的方法对这些亚麻种质的耐镉性进行了综合评价。结果表明：（1）镉胁迫对芽长的抑制作用最大,品种间的发芽势变异程度最大,发芽率变异程度最小;（2）大部分品种的平均隶属函数值位于0.6～0.8,0.8以上强耐镉品种和0.4以下的弱耐镉品种较少;（3）根据平均隶属函数值将412份品种分为5个耐性级别,1级（平均隶属函数值≥0.8）高耐镉性种质均来自中国和立陶宛。

The rapid industrialization causes the large areas of heavy metal contaminated soils, which has become a threat to the local ecosystems. Cadmium (Cd) is a heavy metal which has aroused great concerns in the environmental science community, because of its toxicity to animals and humans. Screening and breeding high cadmium tolerant ramie genotype is one of the effective alternatives to utilize the cadmium contaminated soil, since ramie could minimize the potential hazard of bringing toxic metals into food chains.In this study, a hydroponic culture experiment and a field micro-plot trial were carried out tocompare nine ramie genotypes and their respective screening indices for Cd tolerance. In the hydroponic culture experiment, substantial differences and significant genotypic variations in plant height, leaf number per plant, shoot dry weight and root dry weight were found in different Cd treatments. The shoot dry weight well correlated with plant height, SPAD of leaf and root dry weight. In the field trial, the shoot dry weight well correlated with plant weight, diameter of stem and thickness of bark. This suggests that these characteristics could be used as Cd tolerance indicators. Cluster analysis using comprehensive Cd tolerance characteristics as evaluation parameters indicated that nine genotypes were divided into three categories. These results suggested that it would probably be an effective method to use the plant height, SPAD of leaf, shoot dry weight and root dry weight in ramie hydroponic culture experiment with different Cd treatments as selection indicators.

以营养液盆栽试验结合田间微区试验调查9个苎麻品种耐镉差异并筛选耐镉指标。结果表明，营养液盆栽试验中，不同镉处理下苎麻株高、单株叶片数、地上部干重和地下部干重差异显著，各性状具有较大的品种间差异。地上部干重与株高、叶片SPAD值和地下部干重均呈显著或极显著正相关，相关系数分别为0.95、0.82和0.85。田间微区试验中，地上部干重与株高、茎粗、皮厚均呈显著或极显著正相关，相关系数分别为0.86、0.72和0.76。分别对营养液盆栽试验和微区试验各指标耐镉指数的隶属函数值进行聚类分析，9个品种均被分为3类，结果基本一致。说明以营养液盆栽苎麻的株高、叶片SPAD值、地下部干重和地上部干重作为指标筛选苎麻耐镉品种是一条有效途径。

为选择一种科学有效的甘蓝型油菜幼苗期耐镉性评价方法,用0、1、2.5、5、10、20、30mg/L的镉液处理13个品种的幼苗1周,观察形态学变化,统计其生长指标,并利用多种方法进行耐镉性评价.结果表明:(1)镉胁迫后甘蓝型油菜幼苗表现出植株矮小、主根和侧根变短、侧根数减少、叶片面积减小、叶片发黄等症状;(2)选择5mg/L和相对根长、相对茎叶长、相对植株总长、相对根鲜重、相对茎叶鲜重、相对植株总鲜重、相对根干重、相对茎叶干重和相对植株总干重共9个指标,分别作为甘蓝型油菜幼苗期耐镉性评价的处理浓度和评价指标;(3)依据单个指标进行耐镉性评价的结果比较片面,多指标评价综合了幼苗镉胁迫后多方面的表型变化,评价结果更加科学.多指标评价方法中的主成分分析法选择累积方差贡献率为0.92的三个主成分对甘蓝型油菜进行耐镉性评价,能够客观地将参试的材料分成耐镉性和镉敏感两组,较综合得分法和隶属函数值法为最优方法.

为了明确圆果种黄麻主要经济性 状与单株纤维产量间的主次关系,本试验采用灰色关联和相关性分析的方法,对黄麻14个主要经济性状进行了研究。结果表明,14个主要经济性状的变异系数为 3.03%~15.59%,变异系数最大的为分枝数,最小的为分枝高度;在相关分析中,单株纤维产量与株高、分枝高度、单株鲜皮重呈显著或极显著正相关; 在关联度分析中,分枝高度、单株鲜皮重、鲜皮晒干率与单株纤维产量关联度较高。因此,黄麻在高产栽培和品种选育方面,除了应该选择分枝高度、单株鲜皮重和 鲜皮晒干率作为主要目标性状外,同时也要注意多性状的综合选择。

To clarify the drought resistance and salt tolerance of Medicago varia and M. ruthenica at seed germination period, the effect of seed germination and seedling growth of the seed of M. ruthenica (collected from Jingtai) and M. varia (Algonquin) were studied by using different concentration of polyethylene glycol (PEG-6000) and NaCl solution to simulating drought and salt stress. The results showed that the both stress of NaCl and PEG decreased the germination percentage, germination index, vigor index of M. ruthenica and M. varia and inhibited the growth of plumule and radical. The differences of relative germination percentage between M. varia and M. ruthenica seeds were not significant under the PEG stress from -0.3 to -0.9 MPa and -1.5 MPa (P>0.05), but the relative germination percentage of M. varia was significantly higher than that of M. ruthenica under -1.2 MPa (P<0.05). The relative germination index of M. varia was significantly higher than that of M. ruthenica under PEG stress from -0.3 to -1.2 MPa, while the relative radical length were not significantly. The relative germination percentage of M. varia were significantly higher than that of M. ruthenica under the NaCl stress from -0.9 to -1.5 MPa, the relative germination index and relative vigor index of M. varia were significantly higher than that of M. ruthenica under the NaCl stress from -0.3 to -1.2 MPa. The comprehensive evaluation of the relative germination percentage, relative germination index, relative vigor index, relative plumule length and relative radical length of M. ruthenica (Jingtai) and M. varia (Algonquin)was done by membership function method which indicated that the drought tolerance and salt tolerance of M. varia seed were stronger than that of M. ruthenica . This result is not consistent with past understanding of \"drought resistance and salt resistance of M. ruthenica were stronger than that of M. sativa and M. varia.

为明晰扁蓿豆（Medicago ruthenica（Linn.）Trautv.）和苜蓿（Medicago varia Martin.）种子萌发期的抗旱性和耐盐性强弱，以不同浓度的聚乙二醇（PEG-6000）和NaCl溶液模拟干旱和盐胁迫，研究了不同程度干旱和盐浓度对采自甘肃景泰的扁蓿豆和苜蓿品种阿尔冈金（M. varia Martin. cv. Algonquin）种子萌发和幼苗生长的影响。结果表明，干旱胁迫和盐胁迫降低了扁蓿豆和苜蓿种子的发芽率、发芽指数、活力指数，抑制了胚芽和胚根的生长。-0.3～-0.9 MPa和-1.5 MPa的PEG处理下苜蓿和扁蓿豆种子的相对发芽率间无显著差异（P>0.05），-1.2 MPa的PEG胁迫下苜蓿种子的相对发芽率显著高于扁蓿豆（P<0.05）。-0.3～-1.2 MPa的PEG胁迫下苜蓿种子的相对发芽指数均显著高于扁蓿豆，其相对芽长无显著差异。NaCl渗透势为-0.9～-1.5 MPa时，苜蓿种子的相对发芽率显著高于扁蓿豆；-0.3～-1.2 MPa的NaCl 胁迫下苜蓿种子的相对发芽指数和相对活力指数均显著高于扁蓿豆。通过种子萌发期的相对发芽率、相对发芽指数、相对活力指数、相对胚根长和相对胚芽长5项指标，应用隶属函数法对参试材料种子萌发期抗旱性和耐盐性进行综合评价的结果表明，苜蓿品种阿尔冈金种子萌发期的抗旱性、耐盐性均强于来自景泰的扁蓿豆。此结果和人们以往对扁蓿豆和苜蓿的认识－“扁蓿豆的抗旱性和耐盐性优于苜蓿”不一致。