INSITU NUCLEAR-MAGNETIC-RESONANCE IMAGING OF ROOTS - INFLUENCE OF SOIL TYPE, FERROMAGNETIC PARTICLE CONTENT, AND SOIL-WATER
INSITU NUCLEAR-MAGNETIC-RESONANCE IMAGING OF ROOTS - INFLUENCE OF SOIL TYPE, FERROMAGNETIC PARTICLE CONTENT, AND SOIL-WATER
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DOI：
10.2134/agronj1987.00021962007900060003x
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发表时间：
1987-11-01
期刊：
影响因子：
2.1
通讯作者：
BOTTOMLEY, PA
中科院分区：
文献类型：
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作者：
ROGERS, HH;BOTTOMLEY, PA
根信息的匮乏，加上获取根信息的困难，使得新的方法势在必行。对根的观察对于了解植物的生长和生产力是必不可少的。质子(1H)核磁共振成像为原位研究牙根形态和功能提供了一种无创方法。在这里，使用1，5-特斯拉医学研究核磁共振成像系统和种植在土壤中的蚕豆幼苗，评估了美国东南部30个不同地点的农业土壤系列和8个常见的人造土壤基质的植物根系的核磁共振成像，作为土壤类型、铁磁颗粒含量和土壤水分的函数。在铁磁性颗粒重量含量大于约4%的土壤中，核磁共振成像和常规核磁共振都无法检测到直径约1毫米的根和1毫米直径的水毛细管。在4%以下，铁磁性颗粒含量与核磁共振图像质量没有很好的相关性，但在常规核磁共振实验中，嵌入土壤样品中的含水毛细管的核磁共振信号的存在与否可靠地反映了土壤适合进行核磁共振根部成像。4种人工土壤(珍珠岩、渥太华沙、泥炭岩和豌豆)和7种原生土壤(Wynnville细沙壤土、Lucy壤土、Dothan沙壤土、Lakland沙土、Kinston壤土、Blanton壤土和Eustis细沙壤土)的苗木图像显示，从土壤中分离出的根系具有良好的空间分辨率和准确的重现性。然而，三种人工土壤(珍珠岩、渥太华、沙子和泥炭)的结果明显受到来自土壤水的背景核磁共振信号的影响。在七种天然土壤中，通过使用核磁共振成像序列，土壤水分达到接近饱和的程度基本上是不可见的，从而显示出良好的根与土壤图像对比度。在图像中发现了几种明显的根部病变。结果表明，在水分胁迫周期的几乎任何阶段，1H核磁共振成像是非破坏性、非侵入性地研究许多天然农业土壤中的植物根系的实用工具。
The paucity of root information combined with the difficulty in obtaining it make new approaches imperative. The observation of roots is essential to the understanding of plant growth and productivity. Proton (1H) nuclear magnetic resonance (NMR) imaging offers a noninvasive method for the study of both root morphology and function in situ. Herein, NMR imaging of plant root systems was evaluated for southeastern USA agricultural soil series from 30 different site, and eight common artificial soil substrates, as a function of soil type, ferromagnetic particle content, and soil water, using a 1,5-tesla medical research NMR imaging system and Vicia faba L. seedlings grown in the soils. Roots of about 1 mm in diameter and 1-mm-diam capillaries of water were undetectable by NMR imaging and conventional NMR in soils with ferromagnetic particle contents of greater than about 4% by weight. Below 4%, ferromagnetic particle content did not correlate well with NMR image quality, but the presence or absence of NMR signals from water-containing capillaries embedded in soil samples in a conventional NMR experiment reliable reflected soil suitability for NMR root imaging. Images of seedlings in four of the artificial soils (perlite, Ottawa sand, peatlite, and pea) and seven of the native soils (Wynnville fine sandy loam, Lucy loamy sand, Dothan sandy loam, Lakeland sand, Kinston loamy sand, Blanton loamy sand, and Eustis fine sandy loam) showed excellent spatial resolution and accurate reproduction of the root systems when they were extricated from the soils. However, the results from three of the artificial soils (perlite, Ottawa, sand, and peat) were significantly compromised by background NMR signals that derived from soil water. In the seven native soils, soil water to near saturation was rendered essentially invisible by the NMR imaging sequence employed, thereby demonstrating excellent root-to-soil image contrast. Several root pathologies apparent in the images were identified. The results reveal that 1H NMR imaging is a practical tool for the nondestructive, noninvasive investigation of plant root systems in many natural agricultural soils at virtually any stage of a water stress cycle.