Comparative chloroplast genomes and phylogenetic analysis of .

PREMISE

is an ideal taxon for studying the evolution of adaptive radiation. Current phylogenies of based on different molecular markers are inconsistent, and therefore a clear and accurate phylogeny remains uncertain. Analyzing the chloroplast genome, with its simple structure and low recombination rate, may help solve this problem.

METHODS

Next-generation sequencing data were generated or downloaded for species, enabling their chloroplast genomes to be assembled. The assemblies were used to estimate the genome characteristics and infer the phylogeny of .

RESULTS

In this study, chloroplast genome sequences were assembled for species distributed across Asia, North America, and Europe. Three of the genes analyzed (, , and ) were shown to be under positive selection and may be related to adaptation. The phylogenetic tree of showed that its member species formed two clades with high support, North American and European species, with the Asian species being paraphyletic; and clustered with the North American species, while the remaining Asian species were found in the European clade. In addition, var. should be considered as a separate species rather than a variety.

DISCUSSION

The complete chloroplast genomes of these species provide new insights into the reconstruction of the phylogeny of related species and contribute to the further study of this genus.