Although molecular analysis offers a wide range of options for species identification, a universal methodology for classifying and distinguishing closely related species remains elusive. This study validated the effectiveness of utilizing the entire chloroplast (cp) genome as a super-barcode to help identify and classify closely related species.
We here compared 26 complete cp genomes of ten Fritillaria
species including 18 new sequences sequenced in this study. Each species had repeats and the cp genomes were used as a whole DNA barcode to test whether they can distinguish Fritillaria species.
The cp genomes of Fritillaria
medicinal plants were conserved in genome structure, gene type, and gene content. Comparison analysis of the Fritillaria
cp genomes revealed that the intergenic spacer regions were highly divergent compared with other regions. By constructing the phylogenetic tree by the maximum likelihood and maximum parsimony methods, we found that the entire cp genome showed a high discrimination power for Fritillaria
species with individuals of each species in a monophyletic clade. These results indicate that cp genome can be used to effectively differentiate medicinal plants from the genus Fritillaria
at the species level.
This study implies that cp genome can provide distinguishing differences to help identify closely related Fritillaria
species and has the potential to be served as a universal super-barcode for plant identification.