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褪黑素调控根系生长和根际互作的机制研究进展 总被引:1,自引:0,他引:1
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低磷环境下接种丛枝菌根真菌促进紫花苜蓿生长和磷素吸收的机理 总被引:1,自引:0,他引:1
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大豆和玉米影响后茬作物氮素供应的研究进展 总被引:1,自引:0,他引:1
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集约化互作体系植物根系高效获取土壤养分的策略与机制 总被引:6,自引:1,他引:5
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根系分泌物与土传病害的关系研究进展 总被引:5,自引:0,他引:5
根系分泌物是植物–土壤–病原微生物相互作用的桥梁,是决定病原菌–作物关系的关键生态因子,影响着土传病害的发生与发展。本文阐述了根系分泌物的定义、分类及产生机理;重点从根系分泌物的化感自毒效应,根系分泌物诱导根际微生物群落,根系分泌物影响病原菌丰度,根系分泌物影响根际土壤环境4个方面阐述了根系分泌物与土传病害的关系;并从研究方法和研究领域方面展望了今后研究的方向与重点。未来需要建立根系分泌物的原位收集、实时监测、量化方法技术体系,耦合利用组学技术,建立植物根系分泌物–根际微生物组成与功能–病害之间关系的数据库网络公用平台,加强根际病原菌与其他微生物相互作用关系研究,亟需根系分泌物作用下导致植物发病的病原菌浓度阈值研究,以期为发展土传病害的产生原理和完善土传病害根际防控技术提供依据。 相似文献
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腐植酸促进植物生长的机理研究进展 总被引:18,自引:5,他引:13
【目的】腐植酸在我国农业生产中发挥了重要作用,许多研究证实,腐植酸具有促进植物生长的功能,本文从腐植酸刺激植物根系生长、调控土壤与肥料养分转化及肥料利用率和影响土壤微生物和酶活性方面,系统总结了国内外施用腐植酸促进植物生长的途径,阐述了腐植酸对植物生长促进作用的机理,旨在梳理腐植酸促进植物生长机理的研究现状,为腐植酸的进一步研究和应用提供参考依据。[主要进展]1)腐植酸能够对植物产生类似生物刺激素的效应。它能够提高植物根系H+-ATP酶等的活性、刺激植物根伸长和侧根生长点的增加,从而增加根系活力及植物根系与土壤养分的接触面积,增加植物对养分的吸收;2)逆境胁迫下,腐植酸能够通过调节植物体内的新陈代谢并改善植物生长环境,缓解甚至消除逆境胁迫对植物的伤害,从而促进植物生长;3)腐植酸能够通过与氮素、磷素和钾素发生结合效应,与磷酸盐产生竞争效应和对钾离子的吸附作用固持与活化土壤与肥料中的养分,提高土壤肥料有效性和缓释性能,提高肥料利用率,从而促进植物生长;4)腐植酸还能够影响土壤中与养分转化相关的酶活性和微生物群落结构及数量,在活化养分的同时,保蓄养分,降低养分的损失,为植物生长保障持久的养分供应;5)腐植酸对植物生长的促进效应受腐植酸结构特征、添加量和供试植物种类等因素的影响。[建议与展望]由于技术手段的限制和研究技术的差异,人们对腐植酸促进植物生长机理的认识还不够系统和深入,因此,腐植酸的基本特征、影响腐植酸作用的主控因子、土壤-植物系统中腐植酸促进植物生长的主要途径和腐植酸对土壤功能性微生物等的影响都将成为未来研究的重要方向。 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(14):2127-2151
Spatial distribution of roots is of paramount importance for nutrient acquisition by crop plants. The objective of this study was to assess the spatial distribution of root length density (RLD), root mass density (RMD), and root morphological parameters in maize. Soil monoliths were completely sampled in form of 84 cubic samples of 10-cm edge length. Total root length and mass were dominated by fine roots (<1 mm diameter). Root parameters revealed variability in all three spatial dimensions, notably also parallel to the plant row. Root morphological parameters depended more on the horizontal location with respect to location of plants than on depth. Multiple regression analysis indicated that RLD, proportion of fine roots, and root diameters can be predicted from RMD, soil depth, and distance to plant. These three-dimensional (3D) data could be utilized for evaluation of 3D root growth and nutrient uptake models. 相似文献
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Mechanical and biological approaches to alleviate soil compaction in tropical soils: assessed by root growth and activity (Rb uptake) of soybean and maize grown in rotation with cover crops 下载免费PDF全文
Chiselling has been used to alleviate soil compaction but cover crops with deep, vigorous roots can improve root growth and activity of the cash crop for a longer time. The determination of root activity in addition to root mass or length may improve the understanding of plant response to compaction. The objective of this experiment was to evaluate root growth and activity as affected by the alleviation of soil compaction using mechanical and biological methods. The experiment was conducted in Botucatu, São Paulo, Brazil, from 2009 to 2011, on a clay, Typic Rhodudalf soil. Crop rotations including pear millet (Pennisetum glaucum), soybean (Glycine max), grain sorghum (Sorghum bicolor), maize (Zea mays), ruzi grass (Brachiaria ruziziensis) and castor bean (Ricinus communis) in plots, either chiselled or not. Root growth was assessed by core sampling and root activity was determined indirectly using rubidium injected at several depths as a marker. Root activity was instrumental in interpreting the effects of tillage and crop rotations on soil amelioration. Compared with the initial compacted condition, chiselling increased root growth and activity just for the first 18 months of the experiment, but crop rotations, mainly including ruzi grass and castor bean, increased root growth and activity in the soil profile from the second year on. Generally, root mass was poorly correlated with root activity, except in the case of ruzi grass. Introduction of ruzi grass plus castor bean into the cropping system improves not only root growth and activity in the soil profile but also soybean yield. 相似文献
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缺锌对玉米根系发育、生长素含量及生长素转运基因表达的影响 总被引:5,自引:3,他引:2
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Artificial pores attract barley roots and can reduce artifacts of pot experiments 总被引:1,自引:0,他引:1 下载免费PDF全文
Soil compaction is a severe agricultural problem. It is characterized by an increased resistance to root penetration and by a decreased amount of porosity in the soil. Until today it is not clear whether crop roots are able to actively detect remaining pores in compacted soil. Moreover, little is known about the capability of roots to leave pores again if the mechanical resistance of the bulk soil allows so. The aim of this study was to investigate the root growth response of spring barley (Hordeum vulgare L. cv. Ascona) in different configurations of a compacted loamy soil containing pores. The three‐dimensional configurations of the root systems from three well watered and fertilized treatments were analyzed with X‐ray computed tomography. All soil‐filled cylindrical plastic pots (diameter: 60 mm, height: 210 mm) contained loose topsoil but differed in subsoil structure. In treatment ‘Loose' [L] the pots were entirely filled with loose soil. Treatment ‘Lower part compacted' [C] contained compacted soil in the lower part of the pots. Likewise, treatment ‘Pores' [P] contained compacted soil in the lower part too, but here 16 artificial pores (1 mm diameter) were generated in the central part of the compacted subsoil zone. Comparison of the two treatments with compacted soil [C] and [P] showed that the roots were able to detect pores. However, the roots frequently grew across the pores or left the pores again after having grown into them, leading to a significantly higher fraction of roots exploring the compacted soil in the treatment with pores compared to the treatment without pores. These findings are useful for designing controlled experiments in pots of limited size that can mimic root growth in relatively complex soil structures which are more similar to field situations than usual pot experiments. 相似文献
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P. O. Aina 《植物养料与土壤学杂志》1980,143(3):317-323
A greenhouse study was conducted to evaluate the performance of maize (Zea mays L.) on Iwo Soil in relation to different levels of soil moisture, soil compaction and K fertilization. Reductions in dry matter yields of maize were closely associated with soil moisture stress and compaction. There was significant interaction between soil moisture and bulk density, with highest yields occurring at 17% and 21% soil moisture levels for 1.6 and 1.2 g/cm3 bulk densities, respectively. Moisture stress and compaction resulted in greater reductions in the yield of roots than that of shoot. Yield and K uptake were more adversely affected by compaction compared to soil moisture stress. Addition of K increased yield and plant K content but the 60 ppm and 120 ppm rates were not significantly different in terms of improving crop performance. Implications of the results relative to long-term management of Iwo Soil are discussed. 相似文献
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[目的] 探究季冻区公路边坡植物根系对冻融作用影响,为季冻区边坡防护工程的植物选择提供科学参考。[方法] 通过调查季冻区高速公路边坡土壤及植被特征,采用对比分析的方法研究不同植物根系对冻融循环作用的影响。[结果] 3种试验植物根系抵抗冻融破坏的强弱关系依次表现为:刺槐 > 胡枝子 > 紫穗槐。植物根系通过调节土壤物理性质以及发挥根系结构作用影响冻融循环过程,根系的存在调节了土壤含水率从而降低了土体发生融沉或裂缝的概率。[结论] 在季冻区公路边坡冻融破坏防治中,垂直根系生长较深,根系分布范围更广的植物能够提供更好的抵抗冻融破坏的能力。 相似文献
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Tor J. Johansen Mette G. Thomsen Anne-Kristin Løes Hugh Riley 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(2):182-192
Row crops such as potatoes (Solanum tuberosum L.) and carrots (Daucus carota L.) are of high economic value in the Nordic countries. Their production is becoming more and more specialized, including continuous arable cropping and heavier farm machinery, with increased risk of soil compaction. The result may be restricted root development and economic losses. Potatoes have widely branched adventitious roots, whereas carrots have taproots with fibrous roots extending from them. Under optimal soil conditions, total root length per surface area may reach more than 10 km m?2 for both species. Maximal root depth is about 140 cm for potato and more than 200 cm in carrots. Most of the root mass is usually distributed within the upper 100 cm, whereof more than 50% may be deeper than 30 cm. Soil compaction causes a dense soil with few large pores, poor drainage and reduced aeration, especially in wet soils with low organic matter content and high proportions of silt or clay. With compacted subsoil layers, roots will be concentrated more in the upper layers and thus explore a smaller soil volume. This will lead to reduced water and nutrient uptake, reduced yields and low nutrient utilization efficiency. In this review article, we describe the interactions between root development and soil conditions for potatoes and carrots, with special focus on sub-optimal conditions caused by soil compaction. We also discuss the effects of tilling strategies, organic material, irrigation and fertilization strategies and controlled traffic systems on root and yield development. To reduce subsoil compaction there is a need to implement practises such as controlled traffic farming, new techniques for ploughing, better timing of soil operations, crop rotations with more perennial crops and supplements of organic material. Moreover, there is a need for a stronger focus on the impacts of farm machinery dimensions. 相似文献
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覆盖作物根系对砂姜黑土压实的响应 总被引:2,自引:0,他引:2
轮作直根系的覆盖作物被认为是缓解土壤压实的有效手段,但不同覆盖作物对土壤压实的适应性在不同气候和土壤条件下存在较大差异。为筛选更适宜缓解砂姜黑土压实的覆盖作物品种(模式),在安徽典型砂姜黑土设置不压实(Non-compacted,NC)与压实(Compacted,C)处理,通过种植不同覆盖作物(休闲、苜蓿、油菜、萝卜+毛苕子混播),分析覆盖作物根系对压实土壤的响应。结果表明:与不压实处理相比,压实处理显著增加了0~30 cm土层土壤容重(8.65%);显著增加了0~27.5 cm和37.5~45 cm土层的穿透阻力;显著改变0~20 cm土层土壤收缩特征。同时,土壤压实大幅度降低了0~50 cm土层苜蓿、油菜、萝卜+毛苕子的根干重密度,增加了苜蓿、油菜、萝卜+毛苕子的根比表面积。压实处理下50~70 cm土层萝卜+毛苕子根干重密度、根体积密度和根长密度均大于苜蓿和油菜,表明萝卜+毛苕子混播种植模式下根系穿透压实土壤能力最强。压实处理下不同覆盖作物地上覆盖度和生物量均表现为由大到小依次为萝卜+毛苕子、油菜、苜蓿。与不压实处理相比,压实处理分别减少苜蓿、油菜、萝卜+毛苕子地上部分生物量的62.5%、67.6%、15.8%,地下部分生物量的61.4%、57.7%、47.8%。因此,萝卜+毛苕子种植模式下根系生长受压实影响最小,在压实土壤中适应性最好。 相似文献