共查询到19条相似文献，搜索用时 171 毫秒
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湿地植物具有强大的通气组织和根部渗氧能力特征,使得其根际微环境处于氧化状态从而适应湿地土壤浸水的环境。近年来,湿地植物通气组织和渗氧在重金属吸收和耐性研究方面已引起了人们的关注,并对此进行了相关的研究。本文分别对湿地植物通气组织和渗氧特征,通气组织和渗氧对重金属吸收和耐性影响、对根际微环境影响等方面的研究进展和存在问题进行了综述,并提出了该领域未来可能的研究方向。认为针对从通气组织和渗氧角度出发研究湿地植物重金属耐性机理,应重点对湿地植物根际重金属的环境化学行为展开深入研究,在研究方法和手段上应注重新技术的开发与应用。 相似文献
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在溶液培养条件下研究了不同介质pH和氮形态对5种不同的水稻(Oryza.sativa.L.)基因型(常规籼稻、杂交籼稻、常规粳稻、杂交粳稻和旱稻)根部通气组织形成的影响。结果表明,不同形态的氮与不同介质pH对水稻根通气组织形成的影响存在基因型差异。以NH4+-N为单一氮源时,低pH(pH.4.5)更有利于籼稻根的通气组织形成,而粳稻和旱稻根通气组织的形成受介质pH的影响不明显。以NO3--N为单一氮源时,近中性条件(pH.6.5)更有利于粳稻和旱稻根的通气组织形成,介质pH对籼稻根通气组织形成的影响未显示出明显差异。低pH条件下且以NH4+-N为单一N源时,稻根皮层处更易形成通气组织,可能是植物为了减轻低pH条件下铵毒害而产生的一种适应性机制。 相似文献
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《土壤通报》2014,(6):1297-1304
湿地植物为了适应渍水环境,形成了大量的通气组织,植物可以通过通气组织将氧气输送到根系,从而将Fe2+氧化成铁的氧化物或氢氧化物沉积在植物的根表,形成铁膜。淹水土壤中植物根表形成铁膜必须具备两个条件,一是植物根际处于局部氧化状态,二是生长介质中存在大量的Fe2+。通过溶液培养和土-砂联合培养法,研究了Fe2+浓度、植物种类、诱导时间、p H值、水位变化、根系分泌物对根表铁膜形成的影响。结果表明:苔草和虉草根表铁膜的含量随Fe2+浓度的增加而增加,随诱导时间的延长呈上升的趋势,根系分泌物浓度与铁膜的量呈负相关,随水位的增加呈现先升高后降低的趋势,在水位2~3 cm,p H为5.5~6时根表铁膜的生成量达到最大值。 相似文献
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水稻根表铁氧化物胶膜对水稻吸收磷的影响 总被引：19，自引：2，他引：19
本文采用营养液培养方法研究了根表铁氧化物胶膜对水稻吸收磷的影响。结果表明，水稻报表的铁氧化物胶膜随营养液中Fe2+浓度的增加而增加。铁氧化物胶膜可富集生长介质中的磷，根表铁膜数量越多，富集的磷量也越多。根表铁股可促进水稻对磷的吸收，但这种促进作用的大小依赖于根表铁膜数量。根表铁膜数量为24570mp／kg时，促进作用达到最大，此后随着铁膜数量的增加，水稻吸收磷的数量下降，但仍高于根表没有铁膜的水稻。因此，水稻根表形成的铁氧化物胶膜在一定程度上是一个磷富集库，对水稻吸收磷起促进作用。在此过程中，缺铁条件下水稻根分泌物中的植物铁载体对淀积铁氧化物胶膜的水稻根系吸收磷没有明显的作用。 相似文献
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将耐性植物芥蓝（Brassicacapitata）与敏感植物小白菜（Brassica chinenzis）暴露于含Pb的营养液中,通过添加磷灰石矿尾料（PR）、重过磷酸钙（TSP）及二者混合物（P＋T）处理,研究含磷物质对两种植物吸收Ph的影响以及Pb在植物根表面形态变化过程。结果显示：添加含磷物质降低了耐性植物芥蓝根部Pb的含量,但对地上部Ph吸收的影响不显著;对敏感植物小白菜来说,PR和P＋T处理的植物根部及地上部Pb的含量与对照基本一致,而TSP处理促进了Pb的吸收,表现出小白菜根部及地上部Pb的含量显著高于对照组。含磷物质添加诱导了Pb在植物根表面形成Pb5（PO4）3Cl、Pb5（PO4）3OH的沉淀,但这并没有直接导致两种植物对Pb吸收量的减少。 相似文献
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植物有机营养无菌培养试验方法的研究与应用 总被引：18，自引：1，他引：17
本文对植物有机营养研究中无菌培养实验室的结构,功能作了描述,对有机营养无菌水培液的配制及无蓝图苗的筛选和培育方法作了检验。用此无菌试验法进行的水稻有机氮营养试验证明,水稻能直接吸收根际营养液中的氨基酸,在频繁更换营养液的培养条件下,等氮量有机、无机 氮对对水稻的营养效果依次为甘氨酸态（无菌条件）〉谷氨酸态氮（无菌条件）〉铵态氮（无菌条件）〉铵态氮（常规条件）,反映出有机、无机氮种类及无菌、常规试验 相似文献
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采前营养液处理对水培小白菜硝酸盐积累的影响 总被引：10，自引：0，他引：10
开展了在采收前减少小白菜营养液中的氮量或在去除硝态氮的基础上加入渗调离子以试图降低小白菜的硝酸盐积累的试验。结果表明,在去除营养液中的硝态氮后,在营养液中加入Cl-、SO42-、苹果酸根离子、山梨酸根离子、乙酸根离子是降低溶液培养小白菜硝酸盐积累的有效措施,但处理后采收的时间不可推迟太久。而只减少营养液中氮肥用量会使产量迅速下降,硝酸盐含量降低却缓慢,加入渗调离子可缓解因去除氮肥引起的小白菜产量的下降。 相似文献
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研究了不同Ｐ营养基因型小麦“８１（８５）５－３－３－３”和“ＮＣ３７”在苗期对根系局部供Ｐ（０．１ｍｍｏｌ／Ｌ）后的反应。结果表明,只有３ｃｍ根段处于完全营养液（ＬＨＬ）中的小麦植株不能正常生长,其干物质量分别为全部根系处于完全营养液（ＨＨＨ）中的小麦植株的５４．０％和４９．６％。但给绝大部分根系供Ｐ,只有３ｃｍ根段处于缺Ｐ营养液（ＨＬＨ）中的小麦植株的干物质量、株高、叶面积、根长、根轴长和侧根数 相似文献
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The aim of this study was to assess initial effects of warming on the nutrient pools of carbon and nitrogen of two most widespread ecosystem types, swamp meadow and alpine meadow, in the Qinghai-Tibet Plateau, China. The temperature of the air and upper-soil layer was passively increased using open-top chambers (OTCs) with two different temperature elevations. We analyzed air and soil temperature, soil moisture, biomass, microbial biomass, and nutrient dynamics after 2 years of warming. The use of OTCs clearly raised temperature and decreased soil moisture. The aboveground plant and root biomass increased in all OTCs in two meadows. A small temperature increase in OTCs resulted in swamp meadow acting as a net carbon sink and alpine meadow as a net source, and further warming intensified this processes, at least in a short term. On balance, the alpine ecosystems in the Fenghuoshan region acted as a carbon source. 相似文献
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The rhizosphere is the soil zone adjacent to plant roots which is physically, chemically, and biologically different from bulk or non-rhizosphere soil. Adaptative mechanisms of plants influence physical (temperature, water availability, and structure), chemical [pH, redox potential, nutrient concentration, root exudates, aluminum (Al) detoxification and allelopathy], and biological properties (microbial association) in the rhizosphere. These changes affect nutrient solubility, transport, and uptake and ultimately plant growth. Major rhizosphere changes are synthesized and their influence on nutrient availability is discussed. In the last decade, significant progress has been made in understanding the rhizosphere environment and nutrient availability. However, the subject matter is very complex and more research is needed to understand the interaction between the plant, the rhizosphere environment, and nutrient availability. 相似文献
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Maple forests in southern Quebec are suffering in the 1980s from a serious decline thought to be associated, in part, with acid deposition effects on their nutrient status. Research was undertaken to determine if conifers were subject to similar phenomena. The nutrient status of three Norway spruce plantations in southwestern Quebec were studied through foliar and soil analyses. In all locations low N and K and marginal Mg foliar concentrations were identified. Diagnostic fertilization resulted in improved K and P and in some cases Mg and N levels. The foliage of the treated trees has an improved dark green color as compared with the controls. From this research it is evident that nutrient deficiencies of N, K and Mg, in particular, are showing up in spruce stands in the areas where air pollution and acid rain are relatively severe. Proper diagnostic fertilization helped to correct the nutrient disturbances. 相似文献
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S. A. Prior H. A. Torbert G. B. Runion G. L. Mullins H. H. Rogers J. R. Mauney 《Journal of plant nutrition》2013,36(7):1407-1426
The rise in atmospheric carbon dioxide (CO2) concentration is predicted to have positive effects on agro‐ecosystem productivity. However, an area which requires further study centers on nutrient dynamics of crops grown under elevated CO2 in the field. In 1989 and 1990, cotton [Gossypium hirsutum (L.) ‘Deltapine 77'] was grown under two CO2 levels [370 umol mol‐1=ambient and 550 μmol mor‐1=free‐air CO2 enrichment (FACE)]. At physiological maturity, nutrient concentration and content of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) were determined for whole plant and individual plant organs. While the effects of added CO2 on whole plant nutrient concentrations and contents were consistent, some differences among plant organs were observed between years. FACE often decreased tissue nutrient concentration, but increased total nutrient accumulation. Results indicate that under elevated CO2, field grown cotton was more nutrient efficient in terms of nutrient retrieval from the soil and nutrient utilization in the plant. This implies more efficient fertilizer utilization, better economic return for fertilizer expenditures, and reduced environmental impact from agricultural fertilization practices in the future. 相似文献
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Francesco Giuffrida Giulia Graziani Vincenzo Fogliano Domenica Scuderi Daniela Romano Cherubino Leonardi 《Journal of plant nutrition》2014,37(9):1455-1474
The effects of nutrient or sodium chloride (NaCl) salinity on pepper grown in closed soilless culture systems were studied. A control (2 dS m?1) and two saline nutrient solutions (4 dS m?1) differing in the salt sources (fertilizers or NaCl) were studied. Shoot biomass production as well as total and marketable yield were more affected by NaCl than nutrient salinity. Fruit dry matter and total soluble solids increased in both salinity treatments compared to the control. Total phenol content rose slightly (10%) with NaCl salinity, while the concentration of carotenoids was enhanced by 40% with NaCl compared to the control and nutrient salinity. The results showed that the response of pepper to salinity is both osmotic and ion specific, but a more negative effect was recorded under NaCl stress. Moreover, the highest content of antioxidant compounds in NaCl treated fruits may indicate that NaCl caused more stressful conditions than nutrient salinity. 相似文献
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经过对国内外水培技术中各自独具特色的增氧技术和方法的总结和分析，提出了营养液深液流栽培的动态液位增氧法(DSS)。DSS利用了滴液法、液流法、露根法、湿气根法等几方面增氧的原理和方法，在由水泵向栽培槽中供给营养液时，在回液套管的作用下，营养液向栽培槽底面流动，这种流动方式，有利于向植株根系更好地供应养分和氧气；在水泵停止工作时，随着液面的不断下降，植株的上层根系便暴露在空气中，可以充分进行氧气的吸收，以弥补营养液中氧含量的亏缺。 相似文献
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营养缺乏和水分胁迫各自对春小麦的生长发育和产量形成有直接影响.分析了春小麦的植株水分状况、生育期、叶片生长、干物质积累和产量构成等在受到水分胁迫下的变化后,认为在一定水分胁迫条件下增加无机营养,能促使春小麦绝对产量显著增加;生活在营养缺乏条件下的春小麦则能产生一系列适应于干旱环境的性状,遇到水分胁迫时受到的影响相对较小(营养充足条件下水分胁迫使产量下降的比率大于营养缺乏条件下的比率).据此如何掌握各种不同程度干旱下的施肥技术,既能使作物维持必需的生长量,同时又能抵御一定程度的水分胁迫,是一个值得进一步研究 相似文献
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Air pollutant emissions from the industrial complex of Cubatão, SE-Brazil, have caused a severe decline of the Atlantic Forest in that region. In order to test the influenceof air pollution on the mineral nutrition of trees, leaves of the native species Tibouchina pulchra Cogn. (Melastomataceae), Miconia pyrifolia Naud. (Melastomataceae) and Cecropia glazioui Snethl. (Cecropiaceae) were sampled during winter and summer seasons at four sites with different pollution characteristics. Additionally, saplings of T. pulchra were cultivated in uniform soil and exposed to ambient air at the same experimentalsites for periods of 16 weeks. In both kinds of leaf samples, the concentrations of macro-nutrients were determined and nutrient ratios calculated. In leaves of mature T. pulchraand C. glazioui growing at polluted sites N, P and S levels were significantly higher than in trees from the reference area. With respect to K contents, C. glaziouishowed an increase, T. pulchra a decrease when compared to reference trees. Mg and Ca concentrations generally did not exhibit great variations. As a consequence of the changes in mineral contents nutrient ratios (N/K, N/Ca, S/K, S/Ca) shifted to higher values. The results of the exposure experiments together with data on pollutant concentrations inambient air and rain water demonstrated that atmosphericdeposition to the plants and pollution effects on the soilchemistry are the main reasons for the observed alterations inmineral nutrition of trees. 相似文献