DEOXYRIBONUCLEIC ACID BARCODING OF MORINDA CITRIFOLIA (RUBIACEAE) USING RIBULOSE BISPHOSPHATE CARBOXYLASE GENE MARKER

Abstract

Aim: The current research aims to establish the DNA barcode of M. citrifolia using rbcL gene
sequences, contributing to the development of a molecular database for medicinal plants.
Methods: The procedure involved genomic DNA extraction from M. citrifolia leaves using plant
genomic DNA extraction kit from Bioneer. Molecular identification was performed using
ribulose-1,5-biphosphate carboxylase large subunit (rbcL) gene polymerase chain reaction (PCR)
amplification, gel electrophoresis, then Sangersequencing. The obtained sequence was compared
in National Centre for Biotechnology Information-Basic Alignment Search Tool (NCBI-BLAST)
with similar sequences and the novel sequence was deposited in the Gene bank. Phylogenetic
analysis on the rbcL region was established using NCBI blastn 2.16.0+ online database with the
neighbor-joining (NJ) procedure.
Results: The PCR revealed a single band on the gel electrophoresis with an approximate size of
the rbcL-PCR amplicon, 630bp in comparison with the 1000bp plus DNA ladder, successful
amplification and sequencing of a 526-base pair DNA fragment, which was subsequently aligned
and analyzed through BLAST, revealing a high sequence similarity (94–95%) to other Morinda
species in the GenBank database. Phylogenetic analysis confirmed the close relationship of M.
citrifolia with related taxa where an accession number of OR730434 was retrieved from the
GenBank.
Conclusion: This study highlights the importance of DNA barcoding using the rbcL gene for
accurate identification and authentication of Morinda citrifolia. High sequence similarity with
related species and phylogenetic analysis confirm its utility for species identification and
evolutionary studies. The sequence, deposited in GenBank, contributes to the molecular
database, supporting future research and conservation efforts in herbal medicine.