Abstract: The infrared spectra of roots, stems and leaves of Dendrobium nobile from Qiyun Mountain, Anhui Province, Dendrobium officinale from Lu’an and Wenzhou areas were determined by Fourier transform infrared spectroscopy in this paper, which aimed to explore the infrared spectral characteristics of Dendrobium nobile from Qiyun Mountain and the differences of chemical components among them. It was found that the infrared absorption peaks of roots, stems and leaves of Dendrobium from three areas were similar in shape and position, mainly distributed around 3 420, 2 920, 1 730, 1 240, 1 320 and 1 150 cm-1, but there were some differences in the intensity of each absorption peak. Their chemical compositions were basically the same, including polysaccharide, protein, tertiary amide, lignin, etc, but their contents were different. In the fingerprint region of 900500 cm-1, the similarity between the stem and leaf of Dendrobium nobile from Qiyun Mountain was higher than that of root. In the range of 1 500500 cm-1, there were significant differences in infrared spectrum peak shape and peak intensity of roots, stems and leaves of Dendrobium from three areas. The results showed that Fourier transform infrared spectroscopy could effectively identify the similarities and differences of chemical components among different Dendrobium germplasm resources. The leaves and stems of Dendrobium nobile from Qiyun Mountain, Anhui Province have similar infrared spectra, and the leaves of Dendrobium nobile from Qiyun Mountain can be used as a medicinal substitute for its stems.

Key words: Dendrobium nobile from Qiyun Mountain of Anhui Province, fourier infrared spectroscopy, identify