[Relation between root structure and accumulation of anthraquinones of Morinda officinalis].

The histological structures of the roots of Morinda officinalis How of different ages were observed, the distribution and accumulation of anthraquinones in the root were studied with the help of paraffin section, fluorescent microscope and ultraviolet spectrophotometer. The results indicated that the mature structures of the roots of M. officinalis were similar to those of common perennial herbs, and that the anthraquinones in the root of M. officinalis distributed in parenchymatous cells and the content of anthraquinones in the root gradually increased in number with age. Based on above mentioned investigation, we came to the conclusion that the root of M. officinalis should be collected after four years of growing and the top grade root should have well developed phloem and thin xylem.