DNA barcoding for identification of agarwood source species using trnL-trnF and matK DNA sequences

Agarwood is a type of resinous wood found in the trunks of Aquilaria, Gonystylus, and Gyrinops species [1]. High-quality agarwood is extraordinarily expensive and therefore its source plant species have become depleted due to exploitation. In 2005, these species were added to Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora [1]. Because these wild agarwood resources have become depleted, commercial production of agarwood has long been a desirable goal. In addition, inauthentic agarwood is sometimes produced from non-agarwood species. Few reports have attempted to identify source species in order to distinguish genuine from false agarwood. In this study, DNA was extracted from putative agarwood samples collected from Japanese, Indonesian, Thai, and Vietnamese markets. The trnL-trnF region and matK gene were amplified from each sample by PCR to serve as DNA barcodes for identifying the plant species to which each sample belonged. One of the wood samples did not originate from a genuine agarwood species. Although some species were identified, sequence data for agarwood source species currently available in GenBank is insufficient to identify the species to which all of these putative agarwood samples belonged. Thus, positive identification of remaining samples will require further exploration.