The Complete Chloroplast Genome of Endangered Species Dendrobium flexicaule: Insight into the Phylogenetic Relationship and Conservation Implications

Abstract Dendrobium flexicaule is an endangered species, listed at first-class National Key protected Wild Plant in China, narrowly endemic to China. It has a unique application different from other Dendrobium plants as a cure of infantile convulsions. Studying endangered species is helpful for current management and conservation.To compare analyze of the chloroplast genome (cp DNA) of D. flexicaule and other three related species(D. officinale, D. huoshanense, and D. moniliforme) and to analyze their chloroplast genome difference, we analyzed it from basic feature of chloroplast genome of D. flexicaule, codon usage and IR boundary, simple repeats, and phylogenetic tree, respectively. Download the chloroplast genome sequences of D. flexicaule, D. officinale, D. Huoshanense and D. moniliforme from the public database of NCBI were used to re-annotate by CPGAVAS2 software. We also constructed the MaximumLikehood phylogenetic tree using the MEGA-X tool.Comparing the IR/SC boundaries of the four Dendrobium species found that the IRb/SSC nodes of D. flexicaule and D.moniliforme expanded into the ndhF gene, while the IRb/SSC nodes of D. officinale and D. Huoshanense were between ycf1 and ndhF. The results of phylogenetic analysis show that D. flexicaule and D. officinaleare clustered together. The analysis of the cp genome of D. flexicaule provided crucial genetic information for further studies of this vulnerable species and the taxonomy, phylogenetics and evolution of Dendrobium.