Lepidium olgae Regel is a poorly studied Central Asian species of Brassicaceae occurring in arid mountain habitats of the Nuratau Range, Uzbekistan, and its genomic resources have remained limited. In this study, we sequenced, assembled, and characterized the complete chloroplast genome of L. olgae and evaluated its phylogenetic position within Lepidium using comparative plastome data from 17 species. The plastome of L. olgae exhibited the typical circular quadripartite structure of angiosperms, with a total length of 154,837 base pairs. Comparative analysis showed that chloroplast genome sizes among the sampled Lepidium species ranged from 153,132 to 154,982 base pairs, indicating a high level of structural conservation across the genus. All analyzed plastomes contained 127 unique genes, including 82 protein-coding genes, 37 transfer ribonucleic acid genes, and 8 ribosomal ribonucleic acid genes. Gene content, gene order, and overall genome organization were highly conserved, with only minor variation detected at the boundaries of the large single-copy, small single-copy, and inverted repeat regions. Sliding-window analysis of nucleotide diversity revealed uneven sequence variation across the plastomes, with several highly variable regions, including trnQ–psbK , trnD , trnL–trnF , psbJ–psbL , rpl14–rpl16 , rpl32–ccsA , and especially the ycf1–trnN interval. Phylogenetic analysis based on complete chloroplast genome sequences strongly supported the monophyly of Lepidium and recovered L. olgae as a distinct lineage within the genus. These results provide a useful genomic resource for Lepidium and establish a foundation for future phylogenetic, taxonomic, molecular identification, and conservation-related studies of Central Asian representatives of the genus.
Ergashov et al. (Mon,) studied this question.