Pepina (Plukenetia corniculata Sm.) is a climbing woody plant belonging to the family Euphorbiaceae. However, for the said species, the DNA-related studies remain limited, particularly using DNA barcoding techniques. The following study aimed to characterize and verify the pepina from Riau using four DNA barcodes. The total DNA extraction took place, followed by polymerase chain reaction (PCR), electrophoresis, sequencing, and data analysis. The results revealed Pepina from Riau exhibited 100% similarity to the species P. corniculata based on matK and ITS sequences. However, based on the rbcLb and trnL-trnL-trnF IGS sequences, the similarity values of pepina from Riau with the species P. volubilis were 99.64% and 95.22%, respectively. The ITS and trnL-trnL-trnF IGS displayed the highest levels of substitution mutations and indels compared with the protein-coding DNA barcodes (matK and rbcLb). The most informative DNA barcode was trnL-trnL-trnF IGS, with 3.42% variable nucleotide sites. In summary, the pepina from Riau showed an identity as P. corniculata based on the matK and ITS sequences. Meanwhile, the rbcLb and trnL-trnL-trnF IGS sequences obtained in this study are the first released reports and can enrich the DNA barcode sequences of this species in the public GenBank database. Moreover, molecular identification of pepina can be successful using single-locus barcodes (trnL-trnL-trnF IGS and ITS or matK), as well as combinations of these loci.
Pepina (P. corniculata), species, DNA barcode, ITS, matK, rbcLb, trnL-trnL-trnF intergenic spacer, similarity
The identity of Pepina (P. corniculata) can attain reliable confirmation using molecular DNA barcoding, either through single-locus or multi-locus approaches. Accurate taxonomic identification is essential to support both conservation strategies and sustainable utilization efforts.