Characterization of the Complete Chloroplast Genome of Four Species in Callerya.

The article focuses on sequencing and analyzing the complete chloroplast (cp) genomes of four medicinal species in the genus Callerya—Callerya reticulata, Callerya dielsiana, Callerya nitida var. hirsutissima, and Callerya nitida—to develop molecular markers for accurate species identification and phylogenetic analysis. Using Illumina and nanopore sequencing, the study found that the cp genomes are circular molecules ranging from 130,435 to 132,546 base pairs, lacking large inverted repeat regions, and containing 108 to 111 annotated genes with similar GC content. Comparative analyses revealed high similarity among the genomes but identified the rpl32 region as a mutational hotspot with potential as a DNA barcode to distinguish closely related species. Phylogenetic analysis based on complete cp genomes supported the separation of Callerya from related genera and provided a molecular basis for resolving taxonomic ambiguities and improving the identification of Callerya medicinal plants.