Characterization of the complete chloroplast genome and evolutionary position of Clematis tomentella (Ranunculaceae)

Abstract

Abstract Background Clematis tomentella 2001 (Ranunculaceae) is a typical drought-tolerant and sand-fixing plant in the desert ecosystem of northwest China. To elucidate the phylogenetic status of C. tomentella and its related species, we determined the complete chloroplast (cp) genome of C. tomentellaand analyzed their interspecific relationships. Methods and results The complete cp genome sequence of C. tomentella was performed in this study. The result suggested that the cp genome of C. tomentella was 159,816 bp in length, including two inverted repeats of 31,045 bp, a large single copy of 79,535 bp, and a small single copy of 18,191 bp. 136 genes were annotated across the whole cp genome, including 92 protein-coding genes, 8 rRNA genes, and 36 tRNA genes, as well as the GC content accounted for 38%. Crucially, we found that the sequencing regions of psbE-petL, trnG_UCC-atpA, ndhF-rpl32, and rps8-infA were highlydivergent, which could be marked as DNA barcodes for the identification of C. tomentella in Ranunculaceae. A maximum likelihood phylogenetic tree revealed that C. tomentella was closely related to C. fruticosa. Conclusions Our results filled the gap in cp genome sequence of C. tomentella, elucidating the taxonomic evolutionary position and relationship among Clematis. It provides the references and implications for the phylogenetic study of Clematis in Ranunculaceae in the future.