DNA Barcoding Cinnamomum osmophloeum Kaneh. Based on the Partial Non-Coding ITS2 Region of Ribosomal Genes
SHIH-CHIEH LEE1*, SHU-JIAU CHIOU2,3, JUI-HUNG YEN2, TSAI-YUN LIN3,
KUN-TING HSIEH4 AND JENG-CHUAN YANG5
1. Department of Bioindustry Technology, Da-Yeh University, Changhua 51591, Taiwan, R.O.C.
2. Biomedical Engineering Research Laboratories, Industrial Technology Research Institute, Hsinchu 31040, Taiwan, R.O.C.
3. Department of Life Science and Institute of Bioinformatics and Structural Biology, National Tsing Hua University,
Hsinchu 30013, Taiwan, R.O.C.
4. Department of Molecular Biotechnology, Da-Yeh University, Changhua 51591, Taiwan, R.O.C.
5. Department of Forestry and Nature Conservation, Chinese Culture University, Taipei 11114, Taiwan, R.O.C.
(Received: April 24, 2009; Accepted: January 25, 2010)
ABSTRACT
This paper investigated the DNA barcoding of indigenous cinnamon. The essential oil composition of leaves and the partial non-coding internal transcribed spacer (ITS2) region of ribosomal genes from indigenous cinnamon plants (Cinnamomum osmophloeum Kaneh.) were investigated. Leaf essential oils from seven geographical strains of C. osmophloeum Kaneh. were obtained by hydrodistillation and characterized by gas chromatography-mass spectrometry. Six chemotypes, including cinnamaldehyde, cinnamaldehyde/cinnamyl acetate, cinnamyl acetate, linalool, camphor and mixed, were identified. Seven representative geographical strains were further used to study their genetic diversity based on the partial ITS2 region using PCR amplification and DNA sequencing to evaluate the region’s use in the application of DNA barcoding C. osmophloeum Kaneh. A phylogenetic tree was constructed using UPGMA clustering method. Our results indicate that the partial ITS2 nucleotide sequences for all seven geographical strains are identical and not correlated with essential oil composition. The partial ITS2 sequences is sufficient for barcoding C. osmophloeum Kaneh., while that additional genes will need to be analyzed to identify samples of various chemotypes. We believe that this partial ITS2 locus serves as a good starting point for large-scale testing of DNA barcoding of other plant species across Taiwan.
Key words: Cinnamomum osmophloeum Kaneh., chemotype, internal transcribed spacer, barcode