[Identification of Dendrobium varieties by infrared spectroscopy]

Area of Science:

• Biotechnology
• Analytical Chemistry
• Plant Science

Background:

• Dendrobium species are valuable in traditional medicine and horticulture.
• Accurate identification of Dendrobium varieties is crucial for quality control and research.
• Polysaccharides, particularly fiber, are major components of Dendrobium plants.

Purpose of the Study:

• To analyze the differences between Dendrobium varieties using Fourier transform infrared (FTIR) spectroscopy.
• To establish an effective method for identifying Dendrobium varieties based on their spectral characteristics.
• To evaluate the influence of spectral range and training sample size on identification accuracy.

Main Methods:

• Acquisition of infrared spectra from 206 stems across 30 Dendrobium varieties.
• Application of FTIR spectroscopy combined with Wilks' Lambda stepwise discriminant analysis.
• Analysis of spectral data within various ranges (e.g., 1800-1250 cm⁻¹) and with different numbers of training samples.

Main Results:

• FTIR spectra revealed polysaccharides, especially fiber, as key components in Dendrobium.
• 100% correct discrimination was achieved with as few as 2-6 training samples per species in the 1800-1250 cm⁻¹ range.
• Spectral ranges of 1800-1250 cm⁻¹, 1800-1500 cm⁻¹, and 950-600 cm⁻¹ proved most suitable for variety identification.
• Satisfactory discriminant analysis results were obtained with more than 3 training samples.

Conclusions:

• FTIR spectroscopy, coupled with stepwise discriminant analysis, provides a highly effective and accurate method for distinguishing Dendrobium varieties.
• The study demonstrates the potential of FTIR as a rapid and reliable tool for Dendrobium species identification.
• Optimizing spectral range and training sample size enhances the accuracy of Dendrobium variety discrimination.