Abstract
Background/Objectives: Soroseris hookeriana, a Tibetan medicinal plant endemic to the high-altitude Qinghai-Tibet Plateau, possesses significant pharmacological value but lacks fundamental genomic characterization. This study aims to generate and comparatively analyse its complete chloroplast genome. Methods: Total DNA was sequenced, assembled with GetOrganelle, annotated with CPGAVAS2, and compared with eight Asteraceae species; phylogenetic placement was inferred with IQ-TREE from 21 complete plastomes. Results: The circular chloroplast genome is 152,514 bp with a typical quadripartite structure (LSC 84,168 bp, SSC 18,528 bp, two IRs 24,909 bp each). It contains 132 unique genes (87 protein-coding, 37 tRNA, 8 rRNA; 18 duplicated in IRs yield 150 total copies). Twenty-three genes harbour introns; clpP and ycf3 have two. Overall GC content is 37.73%, elevated in IRs (43.12%). Codon usage shows strong A/U bias at the third position; 172 SSRs and 39 long repeats are detected. IR-SC boundaries exhibit the greatest inter-specific variation, notably in ycf1 and ndhF. Conclusions: The complete plastome robustly supports S. hookeriana and Stebbinsia umbrella as sister species (100% bootstrap) and provides essential genomic resources for species identification, population genetics, and studies of high-altitude adaptation.