Comparative Plastome Analyses of Ephedra przewalskii and E. monosperma (Ephedraceae)

Ephedra species were erect, branching shrubs found in desert or arid regions worldwide as the source of ephedrine alkaloids. In this study, complete chloroplast genome przewalskii and E. monosperma on Qinghai-Tibet Plateau sequenced, assembled, annotated. Compared with other four published species, genomes highly conservative, a quadripartite structure. The length was 109,569 bp 36.6% GC 109,604 GC. We detected 118 genes both including 73 PCGs, 37 tRNA genes, eight rRNA genes. Among them, ndh family lost, which could be used to study phylogeny genetic diversity genus Ephedra, combined multiple variable intergenic spacer (IGS) regions. Codon usage preference weak. ratio non-synonymous substitutions synonymous low, showing that PCGs may under pressure purifying selection. ML BI analysis showed similar phylogenetic topologies. clustered together well-supported monophyletic clade. not gathered one clade, consistent classification system by Flora China. This reveals differences providing valuable abundant data for identification Ephedra.