共查询到20条相似文献，搜索用时 15 毫秒
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《Communications in Soil Science and Plant Analysis》2012,43(8):1353-1398
Soil fertility and crop management are the two most important factors of modern agricultural activity. Managing the balance of vegetative and reproductive growth is the essence of managing a cotton crop. It is well known from numerous fertilizer experiments that the yield of agricultural crops has been strongly dependent on the supply of mineral nutrients, which have been used in crop cultivation to exploit the full genetic potential of the plant. Supplying optimal quantities of mineral nutrients to growing crop plants is one way to improve crop yields. In recent years, several approaches have been tried to break this yield plateau, and among them is application of plant growth regulators (PGRs). In maximizing the quantity and quality of a crop it is necessary to identify the constraints that may affect it and to devise methods of overcoming them through the use of inputs or changes in management practices. 相似文献
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Abstract. The factors influencing uptake of radionuclides from soils into vegetation are discussed with reference to soil type, radionuclide, plant species and organ, and time since initial contamination. Gaps in knowledge are identified, particularly as highlighted by the unexpected behaviour of radiocaesium in many upland areas of Britain, following deposition after the Chernobyl accident. The importance of resuspended soil for contamination of aerial plant parts is also considered in relation to radionuclide type, vegetation height, and meteorological conditions.
The development of an international database by the International Union of Radioecologists for soil to crop transfer factors of radionuclides derived from European experiments is briefly described. This database is now being used for statistical analyses aimed at quantifying the importance of environmental and biological factors in influencing uptake of radionuclides from the soil. 相似文献
The development of an international database by the International Union of Radioecologists for soil to crop transfer factors of radionuclides derived from European experiments is briefly described. This database is now being used for statistical analyses aimed at quantifying the importance of environmental and biological factors in influencing uptake of radionuclides from the soil. 相似文献
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Mohammad Miransari 《Journal of plant nutrition》2014,37(14):2227-2235
Plant growth promoting rhizobacteria (PGPR) are soil bacteria with some beneficial effects on soil properties, plant growth and the environment. In this article, some of the most important advancements in the field of PGPR and their related properties are presented. Such knowledge can be important for understanding regarding the use of PGPR for different uses such as biological fertilization and alleviation of different stresses on plant growth and the environment. 相似文献
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《Journal of plant nutrition》2013,36(3):379-392
ABSTRACT A greenhouse experiment was conducted to determine the bioavailability of copper (Cu) in clay loam and sandy clay loam soil. Lettuce (Lactuca sativa) and spinach (Spinacia oleracea) were grown in pots for 45 d. When mature, plants were treated for 15 additional days with 0, 100, 250, 500, or 1000 mg Cu kg?1 as CuSO4·5H2O. After harvest, Cu in soils and plant tissues was determined. In soils, applied Cu raised total and EDTA-extractible Cu. Results also revealed that the amounts of Cu extracted from sandy clay loam soil (80%) were higher than those extracted from clay loam soil (70%). In plants, increasing soil Cu concentration increased plant concentration of the metal. Plant species vary in their capacity for Cu accumulation: Lettuce has a relatively higher potential for Cu uptake and translocation than does spinach. Cu accumulation also differs among plant organs. In lettuce, metal accumulation is higher in roots than in shoots, where 60% to 80% of the total Cu of the plant is located in the roots. However, in spinach, there is no significant difference in Cu content between roots and shoots. The transfer of the metal from soil to plant is higher for plants grown on sandy clay loam soil. For a given rate of applied Cu, metal content in plant tissues is higher on sandy clay loam soil due to its higher transfer coefficient (CT) from soil to plant. Nevertheless, all crops studied showed a positive linear relationship between extractible soil Cu and plant Cu. 相似文献
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丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)能与宿主植物形成共生体,广泛存在于陆地生态系统中。大量研究表明,不同水分条件下,植物通过接种AMF比未接种AMF的植物具有更强的水分吸收能力和更高的水分利用效率。在干旱、盐胁迫下,接种AMF能有效提高宿主植物的耐旱性与耐盐性。本文综述了不同水分条件下,与植物共生的AMF通过扩大植物根系吸收面积、改善根系结构,增强植物根系吸收水分能力的相关研究进展。土壤中根外菌丝网络的形成,不但为植物增加了水分吸收途径(菌根途径),还通过改善植物体内的矿质营养来调节植物对水分的吸收,进而影响植物的水分吸收状况；不同水分条件下,根系被AMF侵染后植物的光合作用、蒸腾作用以及气孔导度都得到增强,植物蒸腾作用的增强能够直接有效的提升植物的蒸腾拉力,因此植物对水分的吸收能力得以提升。同时,被AMF侵染的植物的水分利用率、蒸腾速率以及净光合速率得以提升从而提高了植物的水分利用能力。进一步总结了缺水胁迫(干旱胁迫、盐胁迫)严重影响植物体内的水分状况,通过接种AMF可以有效调节植物在缺水胁迫下植物体内渗透调节物质的含量、抗氧化酶的活性,平衡植物体内离子平衡,提升植物光合、蒸腾作用水平,从而提高植物的耐胁迫能力。本文通过综述不同水分条件下,接种AMF对植物的影响及机制,期望为未来新型菌剂的研发与菌根互作对植物水分状况的改善提供支撑。 相似文献
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[目的]分析优先流在香根草边坡中的发育特征,研究植物根系与优先流之间的关系,为进一步研究降雨条件下植物根系对边坡土体稳定性的影响提供理论依据。[方法]以种植间距为50 cm和10 cm的香根草为研究对象,模拟30 mm和50 mm两种不同的降雨量,采用示踪剂试验研究了香根草边坡土壤的优先流发育特征。[结果]香根草种植间距从50 cm减少到10 cm会增大边坡的水力响应。在50 mm的降雨量作用下,10 cm种植间距的香根草边坡土壤的染色面积比率和优先流比分别是50 cm的1.55,1.76倍。表层土0—10 cm土层深度范围内染色路径数量变化不明显,在10—35 cm深度土层范围,10 cm种植间距的染色路径数量多于50 cm种植间距的香根草边坡土壤。当降雨量由30 mm增加至50 mm时,水流会通过优势通道更迅速迁移到边坡土壤中。降雨量为30 mm土壤的染色面积比率(36.11%)和优先流比(67.25%)小于50 mm土壤的染色面积比率(49.68%)和优先流比(79.96%),并且染色路径数量随着降雨量的增加而增多。[结论]香根草根系特征与优先流关系密切。选择植物护坡时,应合理选... 相似文献
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植物种间联结关系的研究 总被引：26，自引：0，他引：26
对植物种间联结关系的研究进展进行综述,介绍了其测定方法、测定指标及影响因素,分析讨论了各种测定指标的特点,并指出了进一步研究的方向。 相似文献
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Several years ago the writers (6) found peculiar amorphous grains having a low refractive index (n = 1.45) in the tine sand fraction of Japanese volcanic-ash soils, especially in the A horizons of glassy-ash soils (Onji type). These grains have been considered PELE's tears (liquid lava drops) or bead-like glassy grains on the basis of their relative abundance in volcanic-ash soils. Their morphological, and chemical characteristics have been reported elsewhere by the authors (6). Furthermore, it has been noticed that many of red-yellow soils and paddy soils contain varying amounts of these grains. Some Japanese agronomists and phytopathologists have previously pointed out that silica cells in leaves of Oryza sativa have the effective power of resistance to blast (Imochi disease). 相似文献
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植物抗旱的分子机制研究 总被引：21，自引：0，他引：21
干旱是影响植物生长发育最主要的逆境因子。植物在水分胁迫下会引起一系列分子反应和信号传递，干旱胁迫诱导基因表达一些重要的功能蛋白和调节蛋白以保护细胞不受水分胁迫的伤害，目前已研究证实相关蛋白有跨膜运输蛋白（水通道蛋白、ATP酶等）、水分胁迫调节剂（K^ 、Na^ 、蔗糖、脯氨酸、甜菜碱等）、运输或合成相关的酶、Lea蛋白、抗氧化作用相关的酶（SOD、CAT等）、水分胁迫蛋白、调控蛋白（蛋白激酶、转录因子）等。干旱胁迫诱导基因的活化至少涉及4条途径：植物细胞可能通过膨压变化或膜受体的构象变化感知水分胁迫，将胞外信号转为胞内信号，从而触发相应的信号途径，并可导致第二信使（Ca^2 、IP3等）生成，在这原始信号被逐级传递放大的过程中，其中2条传递途径是依赖ABA的，另外2条传递途径是不依赖ABA的。通过基因表达调控已分析鉴定出一些水分胁迫有关的顺式作用元件（ABRE、DRE、Myc等）和转录因子（bzip、DREBP、MYC／MYB等）。 相似文献
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土壤肥力与植物生长密不可分，本论述了土壤肥力对植物生长的影响，并提出培植地力，实现可持续发展的建议。 相似文献
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