Development of a method for a quick measurement of the root capacity of water uptake and solute transport

开发快速测量根系吸水和溶质运输能力的方法

基本信息

批准号：
13556005
负责人：
HIRASAWA Tadashi
金额：
$ 5.12万
依托单位：
National University Corporation Tokyo University of Agriculture and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2004
项目状态：
已结题

项目摘要

In order to develop a method for a quick measurement of the root capacity of water uptake and solute transport, we examined whether the root properties of water uptake and solute transport can be estimated by monitoring xylem pressure of a root (referred to the equipment as a root pressure probe) by using the theory of Steudle and Jescke based on the root function as an osmometer or not. The followings are obtained results in the research.(1)Hydraulic conductivity measured under the steady state is considered to be reliable. Hydraulic conductivity measured with the root pressure probe under non-steady state was compared with that measured under the steady state in a maize root. There was a close linear correlation between the hydraulic conductivity obtained from both measurements.(2)NaCl transport was investigated in the excised root of Rhizophora stylosa Griff. The reflection coefficient of the roots was smaller than 0.1 and was smaller remarkably than those previously reported for th … More e herbaceous species. The osmotic potential of the exudated sap from the excised root in the nutrient solutions containing various concentration of NaCl was always equivalent to that of the nutrient solution. These results indicate that NaCl transport accompanied by water is not restricted significantly in the excised root of Rhizophora stylosa Griff.(3)The concentrations of Na^+ and Cl^-became equivalent to that of the nutrient solution in the root about 10 days after the seedlings of Rhizophora stylosa Griff, were transferred to the solution containing NaCl, but the concentration of a shoot remained low. This indicates that Na^+ and Cl^-transport from roots to shoot is restricted significantly. The calculated concentration of Na+ and Cl-in the transpirational stream in roots was also far low compared with the concentration of the nutrient solution. This indicates the transports of Na^+ and Cl^-into roots are also restricted.(4)From the results mentioned above, we conclude that the method, considered in the research, can be employed in evaluating the root capacity of water uptake and, however, it is still required to be investigated whether this method can be adopted for evaluating root properties of solute transport. Less

为了开发一种快速测量根部吸水和溶质运输能力的方法，我们研究了是否可以通过监测根系的木质部压力来估计根部的吸水和溶质运输特性（该设备称为根部吸收和溶质运输的设备）。 (1)稳态下测得的水力传导率被认为是将根部压力探针在非稳态下测得的水力传导率与稳态下测得的水力电导率进行了比较，两种测量结果之间存在密切的线性相关性。(2)NaCl传输情况良好。在 Rhizophora stylosa Griff 的切除根中进行了研究，根部的反射系数小于 0.1，并且显着小于先前报道的草本植物的渗透势。含不同浓度NaCl的营养液中离体根的渗出液始终与营养液相当。这些结果表明，在红树离体根中，伴随水的NaCl转运并未受到显着限制。(3)将红树幼苗转移到含有NaCl，但地上部的浓度仍然较低，这表明根部蒸腾流中 Na+ 和 Cl- 的运输受到显着限制。这表明Na^+和Cl^-向根部的转运也受到限制。(4)从上述结果我们得出结论，本研究中考虑的方法可以用于评估根系容量。的吸水量但该方法能否用于评价根系的溶质迁移特性还有待研究。