*2.3. PCR Amplification and Purification*

Two plastid barcode regions, rbcL and matK, and one nuclear ribosomal barcode regions, Internal Transcribed Spacer (ITS2), were amplified via Polymerase Chain Reaction (PCR) (Biorad, Biorad Laboratories, Singapore and Applied Biosystems Veriti Thermal Cycler, Life Technologies Holdings Pte. Ltd., Singapore) using forward and reverse primers of rbcL [35,66], matK (proposed by Ki-Joong Kim, see [67]), and ITS2 [68,69] (Table S3). The 25 μL PCR reaction using a 5× FIREPol master mix was prepared to amplify the respective barcode region. The standard thermal profile of all primers used is shown in Table S3. Modification in the annealing temperature was performed wherever required. PCR products were then verified through gel electrophoresis on a 2% agarose gel. Amplified products were purified using the MEGAquick-spinTM plus total fragment DNA Purification Kit (Intron Biotechnology) and then sequenced commercially.
