Structural Characterization of Trivalvaria costata Chloroplast Genome and Molecular Evolution of rps12 Gene in Magnoliids

Chloroplasts (cp) are important organelles in plant cells that have been widely used phylogenetic, molecular evolution, and gene expression studies due to their conserved structure. In this study, we obtained the complete cp genome of Trivalvaria costata (Annonaceae) analyzed its structural characteristics. Additionally, rps12 phylogenetic framework magnoliids. The T. comprises 162,002 bp contains 132 genes. We detected 48 simple sequence repeats (SSRs) identified 29 high-frequency codons as well 8 optimal codons. Our multiple analyses show codon usage bias is mainly influenced by natural selection. For first time, found be entirely located IR region (in Annona). groups with exon 1 single-copy (SC) exons 2–3 inverted repeat (IR) region, transition rate synonymous substitution were higher than those 2–3. Adaptive evolution a positive selection site (116) 310-helix suggesting may undergo adaptive changes during evolutionary history This study enhances our knowledge regarding genetic information on provides support for reduced rates region.