共查询到19条相似文献，搜索用时 156 毫秒
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农用稀土的生态毒理学效应 总被引：4，自引：0，他引：4
稀土农用给中国农业带来巨大经济效益,但环境安全问题也随之产生。本研究从生态毒理学角度,综述了稀土对土壤微生物、植物、动物的影响,指出稀土可以改变土壤微生物的种群结构、种群数量及其土壤酶活性,影响植物的生长发育、生理生化过程及富集规律,并对动物生殖系统、肝脏、儿童智力及人体健康造成损害。稀土对生物的生态毒理作用,可以是稀土对生物的直接影响,也可以是食物链蓄积的间接效应,在稀土农用中应充分考虑其对环境与人体的影响。 相似文献
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本文简述了国外以及我国的稀土农用进展的历史情况及其现状,施用稀土后,各种作物的增产情况;综述了有关稀土放射性的具体内容及其对农业环境的影响、稀土毒理学资料及稀土促进作物增产的机理,以及在保护农业环境前提下,如何合理地施用稀土。作者搜集了大量资料,尤其是通过作者进行的试验,详细论述了稀土属于金属激活物质,具有调节植物体内的生理活性功能,主要作用为促进酶活性、促进作物对磷素的吸收、增多叶绿素的含量、促进种子萌发及含糖量增加等。只有严格做到按照国定标准,符合质量要求的,才允许稀土产品出厂;和具体生态环境条件下,合理、适量地施用稀土,做到经济效益、环境效益、社会效益的统一,则既不会污染农业环境,对人、畜也是安全的。 相似文献
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稀土金属离子对蚕豆根尖微核率及对蚕豆早期生长发育的影响 总被引：10，自引：0，他引：10
应用蚕豆初生根尖细胞微核技术研究Ｌａ＾３＋,Ｓｍ＾３＋,Ｙ＾３＋,Ｇｄ＾３＋等稀土金属离子的诱变性,发现稀土金属离子在达到一定剂量时均可引起蚕豆根尖细胞微核率的升高,与对照组相比差异显著（Ｐ〈０．０５,Ｐ〈０．０１）。在早期生长试验中,应用７ｄ生长的蚕豆幼苗干重表征蚕豆的早期生长情况,比较蚕豆的发芽率及幼苗干重,反映稀土金属离子对蚕豆早期生长发育的毒性。结果表明,稀土金属离子在高浓度时对蚕豆的发芽 相似文献
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外源稀土元素对花生增产效应的机理研究 总被引：9，自引：0，他引：9
通过砂培和田间小区试验以及电子显微技术,研究了外源稀土对花生的增产机理。结果表明,适宜浓度稀土浸种花生不仅提高了叶绿素含量和光合强度,而且还促进了叶细胞叶绿体的生长发育,使叶绿体结构完整、排列整齐,基粒片层数增多,紧密度高,从而有利于光能的吸收和转化,提高荚果产量。浸种花生各器官中稀土元素分布为:根叶茎果壳果仁;总吸收量为:叶根果壳果仁。 相似文献
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植物叶表面的气孔保卫细胞是研究信号转导的模式实验系统,对环境变化反应灵敏而准确,采用蚕豆叶面气孔保卫细胞,研究了铝（AlCl3）对细胞的毒性效应。结果表明,在1～10 mmol.L^-1范围内,AlCl3可使气孔保卫细胞活性降低,部分细胞死亡,且随着浓度的增高细胞死亡率增高;死细胞呈现核固缩、核降解、凋亡小体等典型凋亡特征。凋亡抑制剂Z-Asp-CH2-DCB或TLCK与AlCl3共同作用时,保卫细胞死亡率显著降低;一定浓度的抗坏血酸（AsA）或过氧化氢酶（CAT）以及Ca2＋螯合剂乙二醇四乙酸酯（EGTA）或Ca2＋通道抑制剂LaCl3与AlCl3共同作用时,细胞死亡率降低。研究结果表明,铝诱导的蚕豆保卫细胞死亡可能是一种细胞凋亡过程,由胁迫诱发的活性氧介导,通过激活质膜钙通道,引起胞内Ca2＋水平改变,进而介导细胞凋亡。 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(7):1259-1271
We investigated effects of phosphorus (P) and iron (Fe) on root elongation (RE) of lettuce in arsenic (As)–spiked soils using response surface methodology (RSM). To stabilize interactions between As and Fe in a soil preparation, the sequential incorporation method using Fe and P (SIMFe-P) was applied. From a phytotoxicity assay, As in roots (Asroot) was negatively associated with RE, Fe in soils, and P in roots and soils. The P in roots was also positively related to RE. In a model study, As and interaction factor between P and Fe showed negative coefficients but others showed positive ones. From a confirmation study, RE on exposure to As was verified to be much greater in soils treated by SIMFe-P than in soils separately treated with both elements. These results indicated that application of SIMFe-P to As-contaminated soils might be expected to have an advantage during the early stage of plant root growth. 相似文献
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Porcella Donald B. Bowie George L. Sanders James G. Cutter Gregory A. 《Water, air, and soil pollution》1991,(1):3-11
Toxic substances exert impacts on ecosystems at several levels: biogeochemical, toxicological, and populations/communities. Integrating exposure (biogeochemistry) and effects (toxicology) into an ecological context requires models as a necessary step to prediction and assessment of effects on populations and their interactions. To this end, research is being conducted to develop techniques for predicting the effects of Se on aquatic ecosystems. The objective is to develop mechanistic models to predict biogeochemical cycling, toxicological processes, and toxic effects on population and community dynamics. Earlier research demonstrated that different chemical forms of Se have different toxicological properties. Biogeochemical research culminated with a dynamic model of the Se cycle. In ongoing research, experiments are being conducted on microorganisms, phytoplankton, microzooplankton, zooplankton, benthic invertebrates, and fish to measure uptake, biotransformation, and depuration kinetics of different chemical forms of Se, transfer through the food web, and effects on growth, reproduction, community interactions, and survival. This information will provide the basis for the ecosystem effects model. 相似文献
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PCR-RFLP analysis of mitochondrial DNA: a reliable method for species identification 总被引：14，自引：0，他引：14
A method for identification of game species has been developed on the basis of the amplification of a specific part of the mitochondrial genome (tRNA(Glu)/cytochrome b) using the polymerase chain reaction (PCR). To distinguish between several game species, the obtained 464-bp-long PCR products were cut with different restriction endonucleases (RE) resulting in species-specific restriction fragment length polymorphism (RFLP). Even closely related deer species could be distinguished by application of one or two RE. Natural polymorphisms of the target sequence within one species were examined for red deer (Cervus elaphus), and base pair substitutions were identified affecting the RFLP pattern. 相似文献
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镉（Cd）在联合国环境规划署提出的12种具有全球性意义的危害化学物质中居于首位,此类物质的污染危害主要表现在水环境中。与有机污染物不同的是,水环境中的镉不能通过水生生物降解,但会在其体内蓄积并通过食物链逐渐富集,进而对水产品质量和安全造成隐患,以及引起水环境污染和人类健康等问题,因此镉对水环境及水生生物的污染和危害引起全球范围内的广泛关注。本文整理归纳了目前镉在甲壳类水生生物中的蓄积现状及富集规律研究进展,并围绕梭子蟹和虾蛄这2种典型镉蓄积的甲壳类水生生物,论述其不同部位组织间镉蓄积的差异性问题,同时对目前关于镉形态的提取方法、定性分析和毒理学效应等相关研究进展进行了综述、分析和展望,可为甲壳类水产品中镉的形态甄别、定量分析以及不同形态镉的毒理学研究提供参考依据。 相似文献
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南方红豆杉组织培养研究进展 总被引：6，自引：0，他引：6
阐述了组培微繁诱苗过程中不同外植体诱导愈伤组织的效果差别、培养基选取和优化、植物生长调节剂浓度和配比、生理碳源、光条件和小分子添加剂等因素的作用影响;从细胞次生代谢诱导和生物反应器应用两方面总结了细胞悬浮培养生产紫杉醇研究现状。此外,对南方红豆杉组织培养的主要问题和方向进行了探讨和展望。 相似文献
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草莓根系分泌物障碍效应的模拟研究 总被引：8，自引：2，他引：6
草莓是一种营养丰富、经济价值较高的水果,但连作障碍使草莓生长发育不良,产量与品质下降,而造成连作障碍的因素种类繁多,极其复杂。本文以“全明星”生根试管苗为材料,应用组织培养技术分析了根系分泌物对草莓生长的影响。结果表明,根系分泌物显著抑制了植株的生长,降低了根系活力、叶片SOD活性和叶绿素含量,而叶片中的MDA含量和细胞质膜相对透性增加,导致草莓抗病性下降。根系分泌物对草莓的不利影响随浓度的增加而增大,表明草莓根系分泌物可能是造成草莓连作障碍的一个重要原因。 相似文献
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Xenobiotic organic compounds in runoff from fields irrigated with treated wastewater 总被引：5，自引：0，他引：5
Investigations of agricultural nonpoint source pollution typically focus on a relatively narrow range of targeted toxic and biostimulatory compounds (e.g., specific pesticides, nutrients). Regular application of numerous other organic compounds to agricultural fields in pesticide formulations, irrigation water, soil amendments, and fertilizers may result in their transport into surface waters via runoff. We examined whether potentially toxic dissolved and particle-associated "nontarget" organic compounds were present in surface runoff from agricultural fields irrigated with disinfected tertiary recycled water or wastewater effluent-dominated streamwater. Gas chromatographic-mass spectrometric analyses of filtered runoff samples revealed the presence of numerous nontarget compounds of potential toxicological significance including pesticide transformation products, pesticide adjuvant chemicals, plasticizers, flame retardants, pharmaceuticals, and personal care product ingredients. Although the toxicity of many of these compounds is poorly characterized, some may elicit subtle but profound toxicological effects. Agricultural runoff also represented a source of allochthonous natural organic matter to the stream system. 相似文献