Characterization of the complete chloroplast genome of an endangered species dwarf birch (Betula nana L.)

Betula nana L. is a deciduous shrub belonging to the Betulaceae family, which is recorded as endangered species in the Red List. The complete chloroplast genome of B. nana was reported in this study. The size of the B. nana chloroplast genome is 160,579 bp, with an average GC content of 36.1 %. This circular molecule has a typical quadripartite structure containing a large single copy region of 89,492 bp, a small single copy region of 19,343 bp, and two inverted repeat regions of 25,872 bp. It encodes an identical set of 114 unique genes, including 79 protein coding, 31 transfer RNA and 4 ribosomal RNA genes. The total of 20 genes were duplicated in the inverted repeats. A maximum likelihood phylogenetic tree supported that the chloroplast genome of B. nana is closely related to that of Ostrya rehderiana.