Abstract: Root system is the important organ of plant for absorbing and transporting nutrients and water from soil to the plant body. However, the opaque attributes of soil hinder the observation of root system, and the lack of root system observation methods in situ has become the technological bottleneck for the in-depth study of root system. In view of the technical needs of root system research, this paper summarized the destructive root system research method (traditional method), non-destructive two-dimensional root system observation method (minirhizotron), and three-dimensional root system architecture observation methods in situ, including X-ray computed tomography (XCT) and magnetic resonance imaging (MRI), and generalized their advantages and disadvantages, with the focus on the comparison XCT and MRI. Some literatures indicated that MRI was not suitable for the observation of three-dimensional root system architecture. It was suggested that applying XCT to quantitatively analyze the three-dimensional root system architecture in natural soil media would be the development trend of related researches in the future.

Key words: Epiblema strenuana, Ambrosia artemisiifolia, Parthenium hysterophorus, Biocontrol of weed, Risk analysis