Structural Characterization of the Chloroplast Genome Relative to Related Species in the Genus.

refers to a deciduous tree distributed in Northeast Asia and is a widely used landscaping tree species. Although several studies have been conducted on the species' ecological and economic significance, limited information is available on its phylo-genomics. Our study newly constitutes the complete chloroplast genome of into a 156,645-bp circular DNA, which displayed a typical quadripartite structure. In addition, 133 genes were identified, containing 88 protein-coding genes, 37 tRNA genes, and eight rRNA genes. In total, 107 simple sequence repeats and 49 repetitive sequences were observed. Thirty-two codons indicated that biased usages were estimated across 20 protein-coding genes (CDS) in . Four hotspot regions (, , , and ) were detected among the five analyzed species. Those hotspot regions may be useful molecular markers and contribute to future population genetics studies. The phylogenetic analysis demonstrated that is most closely associated with the species of Sect. . and var. diverged in 22.11 Mya. We selected one of the hypervariable regions () to develop a new molecular marker and designed primers and confirmed that the molecular markers could accurately discriminate five species through Sanger sequencing. By sequencing the cp genome of and comparing it with the relative species of , we can effectively address the phylogenetic problems of at the species level and provide insights into future research on population genetics and genetic diversity.