The complete chloroplast genomes of four Aspidopterys species and a comparison with other Malpighiaceae species

The genus Aspidopterys has multiple functions in medicine, food and ecological restoration. Due to the similar morphological characteristics of some species and the limited genomic information hinder the studies on germplasm identification and molecular phylogeny analysis. In this study, we compared and explored the six complete chloroplast (cp) genomes including four Aspidopterys species (A. glabriuscula, A. concava, A. cavaleriei, A. obcordata), Banisteriopsis caapi and Bunchosia argentea. Their cp genomes in length were 158,473 to 161,091 bp, displaying the high conserved degree in the structure, gene arrangement and GC content. Moreover, 57-80 long repeats and 61-92 SSRs were identified, most of which were forward or palindromic repeats and mononucleotides, respectively. Eleven non-coding regions and 12 coding regions, especially ndhH_ndhA, rpl32_ndhF and ycf1, had the higher nucleotide diversity values that could can be regarded as DNA barcodes of Malpighiaceae species. In addition, the 9 genes (like accD, atpE, atpF, clpP) were conducted positive selection (Ka/Ks > 1). As indicated by phylogenetic analysis, those four Aspidopterys were clustered into single clade with other Malpighiaceae species and were closely related to B. caapi and B. argentea. This study sheds more lights on further phylogenetic, evolutionary and genetic diversity studies on the genus Aspidopterys and even the Malpighiaceae species.