Nutrient behavior and function of root exudate in rhizosphere

根际根系分泌物的营养行为和功能

• 批准号: 04806010
• 负责人: CHINO Mitsuo
• 金额: $ 1.28万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04806010/
• 关键词: Rhizobox; Rhizosphere; Nutrient distribution; Diffusion massflow; Soil pH; Manganese; Iron; Root exudate; ダイズ; オオムギ; 微量元素

In this investigation, we have newly developed a rhizobox system to study the behavior of nutrients in rhizosphere. The rhizobox is a box which consist of several compartments of 1mm thickness and each compartment was filled with soil of 40g (dry soil) mixed with nutrients. Nylon cloth of 25 mum mesh was used to separate the soil compartments of rhizobox and this nylon cloth was successfully used to limit the root growth to the central compartment where the plants were grown. Thus, we succeeded to sample the soil from each compartment of certain distance from root without root contamination and to determine the distribution of total and soluble fraction of the nutrients (Ca, Mg, K,Na, SO4, NO3, Cl, Zn, Cu, Mn and Fe) in the rhizosphere. The following results were obtained.1) The concentrations of total fraction of the nutrients were not affected by the root and only soluble fraction of them changed in the rhizosphere. Soil pH of rhizosphere sometimes in creased and other times decreased due to cation/anion balances in the soil solution.2) Soluble Ca, Mg, Na, SO4 and Cl were increased in the rhizosphere due to the greater amount of massflow than the plant uptake.3) Soluble K and NO3 were decreased in rhizospere due to the greater amount of plant uptake than massflow.4) Changes in soil pH in rhizosphere affected the solubility of Zn and Cu but not the solubility of Fe and Mn. Soluble fractions of Fe and Mn always increased in rhizosphere in spite of soil pH change.5) Tracer studies using ^<59>Fe and ^<54>Mn were carried out and these experiments showed that massflow and/or diffusion of Mn and Fe were very slow. The tracer experiments also showed that rhizosphere soil and root exudates increased the solubilities of MnO2 and Fe2O3. Thus, in the rhizosphere, some compounds exuded from the plant root dissolved insoluble Mn and Fe in the soil.

在这项研究中，我们新开发了一个根箱系统来研究根际营养物质的行为。根箱是一个由1 mm厚的几个隔室组成的盒子，每个隔室内填满了40g土壤(干土)和混合的养分。用25微米的尼龙布隔开根箱的土壤隔间，成功地将根生长限制在植物生长的中央隔室。因此，我们成功地采集了距根部一定距离的土壤样品，并测定了根际养分(钙、镁、钾、钠、硫酸盐、硝酸盐、氯、锌、铜、锰和铁)的总和可溶部分的分布。结果表明：1)根际养分总量浓度不受根系的影响，根际中只有可溶性养分含量发生变化。由于土壤溶液中阳离子/阴离子的平衡，根际土壤pH时而升高，时而降低。2)根际土壤中可溶性钙、镁、钠、硫酸盐和氯离子的质量流量大于植物吸收的量而增加。3)由于植物吸收的量大于流量，根际土壤中的可溶性钾和硝酸盐含量降低。4)根际土壤pH的变化影响了锌和铜的溶解，但不影响铁和锰的溶解。无论土壤pH如何变化，根际中可溶态的铁和锰总是增加的。5)用~&lt；59&gt；Fe和^&lt；54&gt；Mn进行示踪研究表明，Mn和Fe的质量流动和/或扩散非常缓慢。示踪实验还表明，根际土壤和根分泌物增加了MnO2和Fe2O3的溶解度。因此，在根际，一些从植物根中渗出的化合物溶解了土壤中不溶性的锰和铁。

项目成果

Cai-De LONG et al.: "Studies on the Behavior of Micronutrient Fertilizer in the Rhizosphere of Wheat Plant When the Chemical From and Composition of Fertilizer Were Changed. (Japanese)" Japanese Soc.of Soil Sci. Plant Nutr.64 (2). 126-133 (1993)

Cai-De LONG 等：“当肥料的化学成分和成分发生变化时，微量营养素肥料在小麦植物根际的行为研究。（日语）”日本土壤学会。

R.A.Youssef: "Movement of Metals from soil to plant roots." Water,Air,and Soil Pollution. 57-58. 249-258 (1991)

R.A.Youssef：“金属从土壤到植物根部的移动。”

蔡徳龍等: "根圏における微量元素肥料の挙動に関する植物間・品種間差異" 日本土壌肥料学雑誌. 64. 34-41 (1993)

蔡德龙等人：“植物和品种之间关于根际微量元素肥料行为的差异”日本土壤与肥料杂志 64. 34-41 (1993)。

蔡徳龍等: "根圏における微量元素肥料の挙動に及ぼす微量元素肥料の形態と組成の影響" 日本土壌肥料学雑誌. 64. 126-133 (1993)

蔡德龙等：“微量元素肥料的形态和成分对其根际行为的影响”日本土壤施肥杂志64。126-133（1993）。

Cai-De LONG et al.: "Behavior of Micronutrient Fertilizer in the Rhizosphere of Different Plant Species and Cultivars (Japanese)" Japanese Soc.of Soil Sci. Plant Nutr.64 (1). 34-41 (1993)

Cai-De LONG 等：“微量营养素肥料在不同植物种类和品种根际的行为（日文）”日本土壤学会。