A preliminary <i>in silico</i> evaluation of standard DNA barcodes and chloroplast genome super-barcoding for discriminating two medicinal <i>Talinum</i> species

Accurate species identification is crucial for the effective use and conservation of medicinal <i>Talinum</i> plants. This preliminary study evaluated the discriminatory power of three standard DNA barcodes (internal transcribed spacer [ITS], <i>matK</i>, and <i>rbcL</i>) and compared the complete chloroplast genomes of <i>Talinum fruticosum</i> and <i>T. paniculatum</i> using an <i>in silico</i> approach. Based on the analysis of available GenBank sequences, barcode gap and genetic distance analyses showed that ITS provided the highest resolution, <i>matK</i> showed moderate performance, and <i>rbcL</i> had the lowest discriminatory power. The plastomes of both species were highly conserved (~156 kb) with a typical quadripartite structure. A sliding window analysis identified several divergence hotspots (e.g., <i>ycf1</i>, <i>psbN</i>, <i>petD</i>, <i>trnS–trnG</i>, and <i>rpoB–trnC</i>) with nucleotide diversity peaks in the range of 0.83–1.05%. Cis- and trans-splicing gene structures, including <i>rps12</i>, were conserved, indicating plastome stability. Given the limited sampling in this study, these results serve as a preliminary framework for species authentication. Overall, ITS is recommended as the primary barcode, while plastome hotspots or whole plastome data can provide complementary resolutions. Future studies with broader sampling and verified herbarium vouchers are recommended to confirm these findings and support more extensive phylogenomic research focusing on <i>Talinum</i>.