Abstract
<ns3:p> <ns3:italic>Dianthus helenae</ns3:italic> Vved. is an endemic medicinal species of the Nuratau Mountains, Uzbekistan, and its genomic resources have remained largely unavailable. In this study, we sequenced, assembled, and characterized the complete chloroplast genome of <ns3:italic>D. helenae</ns3:italic> and evaluated its phylogenetic position within <ns3:italic>Dianthus.</ns3:italic> The plastome exhibited a typical circular quadripartite structure with a total length of 149,567 bp, comprising a large single-copy (LSC) region of 82,856 bp, a small single-copy (SSC) region of 17,105 bp, and a pair of inverted repeats (IRs) of 24,804 bp each. The genome contained the typical set of chloroplast genes, including protein-coding genes, transfer RNAs, and ribosomal RNAs, with duplicated genes located in the IR regions. Phylogenetic analysis based on complete chloroplast genome sequences strongly supported the placement of <ns3:italic>D. helenae</ns3:italic> within <ns3:italic>Dianthus</ns3:italic> and recovered it as a distinct lineage relative to other sampled species. Sliding window analysis of nucleotide diversity revealed uneven sequence variation across the plastome, with higher variability in the SSC and LSC regions than in the IRs. Several highly variable loci, including <ns3:italic>trnK-UUU</ns3:italic> , <ns3:italic>rps16–trnQ-UUG</ns3:italic> , <ns3:italic>rpl32</ns3:italic> , <ns3:italic>ycf1</ns3:italic> , and ndh-associated regions, were identified as potential molecular markers. These results provide an important genomic resource for <ns3:italic>Dianthus</ns3:italic> and establish a foundation for future phylogenetic, taxonomic, conservation, and molecular identification studies of this endemic Central Asian species. </ns3:p>