Authentication of the Medicinal Plants in Fabaceae by DNA Barcoding Technique

Fabaceae is the third largest family of flowering plants, with a large number of medicinal plants. However, it is arduous to identify some of the species in this family because of morphological similarity and frequent variation. The DNA barcode, a short DNA sequence originating from the genome, was first investigated for the medicinal plant in Fabaceae. Now we have completed 86 species of medicinal plants in Fabaceae including over 30 genera. Through six candidates, promising markers, four coding (rpoB, rpoC1, rbcL, matK) and two noncoding (ITS, ITS2) chloroplast regions, we identified potential barcodes of the medicinal plants in Fabaceae by comparing DNA barcoding sequences. The results indicated, efficiency of amplification for six candidate DNA barcodes range from 100% (ITS2) to 93% (matk). Intraspecific variation and interspecific variation for six chloroplast regions derived Wilcoxon signed rank tests of divergence showed that rpoC1 was the least discriminatory region, while ITS2 was the potential candidate of medicinal plant barcoding in Fabaceae in our study. Overall, our findings showed that DNA barcoding is an efficient and powerful tool for the identification of the medicinal plants in Fabaceae. Acknowledgements: This work is supported by the International Cooperation Program of Science and Technology (No. 2007DFA30990) and the Special Founding for Healthy Field (No. 200802043). References: [1] Gregory TR, (2005), Nature, 434: 1067. [2] Kress WJ, Erickson DL (2007) PloS One, 2: 508. [3] Kress WJ, Erickson DL (2008) Proceedings of the National Academy of Sciences, USA, 105: 2761–2762. [4] Frézal L, Leblois R (2008) Infection, Genetics and Evolution, 8: 727–736. [5] Yao H, et al. (2008), Planta Medica (Accepted). [6] Lahaye R, et al. (2007) PNAS, 1–6.