Species discrimination of plant roots by Fourier transform infrared (FTIR) spectroscopy

理解植物物种之间的地下竞争是理解间作农业系统、作物与杂草之间以及自然生态系统中复杂相互作用的核心部分。到目前为止，还没有一种简单、快速的方法来区分土壤中的根。我们将开发一种基于傅里叶变换红外(FTIR)-衰减全反射(ATR)光谱的不同物种根识别方法，并扩大其在该领域的应用。FTIR-ATR光谱的吸收模式就像一个单独的指纹一样代表了化学样品的组成。利用多变量方法，根据光谱和化学相似程度对光谱进行分组，以实现物种区分。我们将使用温室中种植的各种品种/种源来研究豌豆和燕麦的根以及玉米和谷仓的草根。豌豆和燕麦是值得推荐的间作物种，以环境可持续的方式实现优异的谷物和蛋白质产量。为了评估间作对田间根系分布的影响，将使用移动FTIR光谱仪在土壤剖面壁上直接测量根段。通过提取主要的根化合物(脂类、蛋白质、碳水化合物)并记录它们的FTIR-ATR光谱作为参考，我们将阐明物种特定差异的化学基础。

Comprehension of belowground competition between plant species is a central part in understanding the complex interactions in intercropped agricultural systems, between crops and weeds as well as in natural ecosystems. So far, no simple and rapid method for species discrimination of roots in the soil exists. We will be developing a method for root discrimination of various species based on Fourier Transform Infrared (FTIR)-Attenuated Total Reflexion (ATR) Spectroscopy and expanding its application to the field. The absorbance patterns of FTIR-ATR spectra represent the chemical sample composition like an individual fingerprint. By means of multivariate methods, spectra will be grouped according to spectral and chemical similarity in order to achieve species discrimination. We will investigate pea and oat roots as well as maize and barnyard grass roots using various cultivars/proveniences grown in the greenhouse. Pea and oat are recommendable species for intercropping to achieve superior grain and protein yields in an environmentally sustainable manner. To evaluate the effects of intercropping on root distribution in the field, root segments will be measured directly at the soil profile wall using a mobile FTIR spectrometer. By extracting the main root compounds (lipids, proteins, carbohydrates) and recording their FTIR-ATR spectra as references, we will elucidate the chemical basis of species-specific differences.