Characterization of the complete chloroplast genomes of two Pachysandra species in the family Buxaceae.

Abstract

Pachysandra is a small genus with only three species. In the present study, the complete chloroplast (cp) genome of two species in Pachysandra was assembled and annotated using the data sequenced by the Illumina HiSeq 2500 Sequencing System. Moreover, the cp genome of P. axillaris is reported for the first time. The lengths of the complete cp genomes of P. axillaris and P. terminalis were 157,353 bp and 160,805 bp, respectively, with a typical quadripartite structure comprising a pair of inverted repeat regions (IRs; 24,870 bp vs. 28,019 bp), a large single-copy region (LSC; 89,535 bp vs. 86,013 bp), and a small single-copy region (SSC; 18,080 bp vs. 18,752 bp). The whole cp genomes of P. axillaris and P. terminalis contained 134 and 130 genes, respectively, including 89 (or 85) protein-coding genes (PCGs), 37 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes. The maximum-likelihood (ML) phylogenetic analysis indicated that Pachysandra was closely related to the genus Buxus in the family Buxaceae, based on 25 taxa from 12 families. The two cp genomes reported here can serve as basic data for genetic research on Pachysandra and Buxaceae.