Comparative analysis of the medicinal plant (Asparagaceae) with related verticillate leaf types of the species based on chloroplast genomes.

BACKGROUND

has been widely used as a traditional Chinese medicine as well as a healthy food. Because of its highly variable morphology, this medicinal plant is often difficult to distinguish from other related verticillate leaf types of the species. The contaminants in products not only decrease the products' quality but also threaten consumer safety, seriously inhibiting the industrial application of .

METHODS

Nine complete chloroplast (cp) genomes of six verticillate leaf types of the species were assembled and systematically analyzed.

RESULTS

The total lengths of newly sequenced cp genomes ranged from 155,437 to 155,977 bp, including 86/87 protein-coding, 38 tRNA, and 8 rRNA genes, which all exhibited well-conserved genomic structures and gene orders. The differences in the IR/SC (inverted repeats/single-copy) boundary regions and simple sequence repeats were detected among the verticillate leaf types of the cp genomes. Comparative cp genomes analyses revealed that a higher similarity was conserved in the IR regions than in the SC regions. In addition, 11 divergent hotspot regions were selected, providing potential molecular markers for the identification of the species with verticillate leaf types. Phylogenetic analysis indicated that, as a super barcode, plastids realized a fast and efficient identification that clearly characterized the relationships within the verticillate leaf types of the species. In brief, our results not only enrich the data on the cp genomes of the genus but also provide references for the germplasm resource protection, herbal cultivation, and drug production.

CONCLUSION

This study not only accurately identifies species, but also provides valuable information for the development of molecular markers and phylogenetic analyses of the species with verticillate leaf types.