Phylogenomic Analysis of Dichrocephala benthamii and Comparative Analysis within Tribe Astereae (Asteraceae)

Abstract

Dichrocephala benthamii C. B. Clarke has long been used as traditional Chinese medicine. However, the chloroplast (cp) genome of D. benthamii is poorly understood so far. In this study, we have sequenced and analyzed the cp genome of D. benthamii. The results show that the cp genome is 152,350 bp in length, with a pair of inverted repeat regions (IRa and IRb, each 24,982 bp), a large single-copy (LSC) region comprising 84,136 bp, and a small single-copy (SSC) region comprising 18,250 bp. The GC content of the cp genome was 37.3%. A total of 134 genes were identified, including 87 protein-coding genes (CDS), 38 tRNA genes, 8 rRNA genes, and 1 pseudogene (ycf1). The plastome includes 87 simple repeats and 48 long repeats. The phylogenetic analysis reveals D. benthamii is the basal group of Astereae. Therefore, we confirm that the taxa of Astereae emerges from southern Africa and dispersed to other big continents. The results of this study are a significant contribution to the field of genetics and species identification related to D. benthamii.