Complete Chloroplast Genome Analysis of Casearia kurzii: Gene Loss at IR Boundaries and Monophyletic Evolution within Casearia
Description
Casearia kurzii is a near-threatened medicinal plant in Salicacea. C. kurzii has important medicinal values. However, the similarity in morphological characters of casearia species and the controversial phylogenetic relationships within the genus have led to misidentification and hindered clinical application studies. To improve molecular methods for distinguishing casearia species, we report the complete chloroplast genome of C. kurzii obtained by high-throughput Illumina sequencing. It was also analyzed in comparison with 14 other closely related species. The results showed that the chloroplast genome of C. kurzii was 157,998 bp long and presented a typical tetrad structure with unique features: (1) absence of rpl22 and ycf1 genes at the IR boundary, and (2) presence of 60 exclusively mononucleotide SSRs. Ten highly variable regions were identified as potential molecular markers for species identification. Phylogenetic analysis strongly supported the monophyletic grouping of C. kurzii with C. velutina and C. glomerata (100% bootstrap support), with an estimated divergence time of 15.8 Mya (95% HPD: 5.2-28.9 Mya). In conclusion, This study not only reports the first complete chloroplast genome sequence and structural features of C. kurzii but also provides insights into the evolutionary history of Casearia. The identified molecular markers and unique genomics features present valuable tools for conservation genetics research and germplasm resource management of C. kurzii,establishing a foundation for investigating the species’ adaptive evolutionary mechanisms. Supporting data inclond: 1. Figures_raw_data；2. Analysis_data；3. Phylogenetic_data three parts，and a data documentation file is named README.txt