# Comparative chloroplast genomes of Dactylicapnos species: insights into phylogenetic relationships

## TL;DR

This study analyzes the chloroplast genomes of seven Dactylicapnos species to understand their genetic structure and evolutionary relationships.

## Contribution

The first comparative analysis of chloroplast genomes in Dactylicapnos, revealing structural and phylogenetic insights.

## Key findings

- Chloroplast genomes of Dactylicapnos have a typical quadripartite structure with lengths between 172,344 bp and 176,370 bp.
- Phylogenetic analysis grouped the seven species into three main clades corresponding to the three sections of the genus.
- 31 codons showed high synonymous codon usage in the chloroplast genomes of Dactylicapnos.

## Abstract

Dactylicapnos is a climbing herbaceous vine, distributed from the Himalayas to southwestern China, and some of the species have important medicinal values. However, the chloroplast genomes of Dactylicapnos have never been investigated. In this study, chloroplast genomes of seven Dactylicapnos species covering all three sections and one informal group of Dactylicapnos were sequenced and assembled, and the detailed comparative analyses of the chloroplast genome structure were provided for the first time.

The results showed that the chloroplast genomes of Dactylicapnos have a typical quadripartite structure with lengths from 172,344 bp to 176,370 bp, encoding a total of 133–140 genes, containing 88–94 protein-coding genes, 8 rRNAs and 37–39 tRNAs. 31 codons were identified as relative synonymous codon usage values greater than one in the chloroplast genome of Dactylicapnos genus based on 80 protein-coding genes. The results of the phylogenetic analysis showed that seven Dactylicapnos species can be divided into three main categories. Phylogenetic analysis revealed that seven species form three major clades which should be treated as three sections.

This study provides the initial report of the chloroplast genomes of Dactylicapnos, their structural variation, comparative genomic and phylogenetic analysis for the first time. The results provide important genetic information for development of medical resources, species identification, infrageneric classification and diversification of Dactylicapnos.