Development of four DNA barcoding markers for the identification of orchid species

Illegal poaching and trading on orchids without proper regulations are putting some of the orchid species in endanger. Almost the entire Orchidaceae family was listed in CITES Appendices in which they are protected by law regulations and classified as conserved plant species. Challenges in species identification have emerged when combating illegal trades due to the sharing of similar morphology and hybrid orchids species. In this study, we have developed four potential candidate DNA barcodes as identification tools for orchid speciation using sequencing analysis. PCR amplification success rate, species discrimination power and the quality of DNA sequence are the main concerns in the development of DNA barcoding markers. The results obtained demonstrated PCR success rate among 4 DNA barcoding markers were as the following: ITS1 (73.5%) > rbcL (70.6%) > trnH-psbA (70.6%) > matK (64.7%). As for species discrimination power, rbcL and matK exhibited the highest, both at 95.5% compared to ITS1 (83.3%) and trnH-psbA (78.3 %). Out of 12 orchid samples used in the study, 8 samples with 80 DNA sequences generated from the analysis were successfully identified and the results were consistent in all four DNA barcoding markers. Hence, the study suggests these four DNA barcoding markers as the potential candidates in orchid species identification.