Unraveling the Chloroplast Genome of Stellaria media: Comprehensive Analysis, Taxonomic Implications, and Evolutionary Perspectives.

The chloroplast (Cp) genome offers valuable perceptions into plant evolution, systematics, and phylogenetics. Here we are reporting complete chloroplast genome of Stellaria media (L.) Vill. collected from Dokdo Island, South Korea. The genome, assembled at 6340 × coverage, is 147,329 bp with a typical quadripartite structure, covering two inverted repeat (IR) regions of 25,600 bp and one single copy of large (79,366 bp) and small region (16,763 bp) each. Genome annotation identified 129 genes, including 84 protein-coding genes, 8 rRNA and 37 tRNA genes. In the IR region, ycf3 and clpP1 each contain two introns, while 17 genes, including rpl2, trnL-CAA, ycf2, and ndhB are present in duplicate, whereas rps19 is present as a single copy, reflecting structural conservation and evolutionary mechanisms such as intron retention and gene duplication. Comparative genomic analysis revealed substantial variations both among Stellaria species and in the formerly classified Stellaria dichotoma var. lanceolata. Codon usage showed a biasness toward codons ending with A/U, with leucine being most frequently encoded amino acid. Phylogenetic reconstruction based on complete chloroplast genomes positioned S. media within the Alsineae tribe and highlighted monophyletic relationships in the genus. Sliding window analysis identified hypervariable regions, including ycf1, ndhF-rpl32, and trnK-rps16 as potential molecular markers. This study provides crucial perceptions into chloroplast genome evolution, comparative genomics, and phylogeny within Caryophyllaceae, contributing essential data for taxonomic and conservation research. Additionally, multiple lines of evidence, including comparative chloroplast genomics, analyses of long and short repeat sequences, codon usage patterns, and phylogenetic relationships, support the taxonomic revision of inclusion of the genus Myosoton within Stellaria, and the exclusion of Stellaria dichotoma var. lanceolata from the genus Stellaria.