title: The Complete Chloroplast Genome Sequences of Six Rehmannia Species.
abstract: Rehmanniais a non-parasitic genus in Orobanchaceae including six species mainly distributed in central and north China. Its phylogenetic position and infrageneric relationships remain uncertain due to potential hybridization and polyploidization. In this study, we sequenced and compared the complete chloroplast genomes of sixRehmanniaspecies using Illumina sequencing technology to elucidate the interspecific variations.Rehmanniaplastomes exhibited typical quadripartite and circular structures with good synteny of gene order. The complete genomes ranged from 153,622 bp to 154,055 bp in length, including 133 genes encoding 88 proteins, 37 tRNAs, and 8 rRNAs. Three genes (rpoA,rpoC2,accD) have potentially experienced positive selection. Plastome size variation ofRehmanniawas mainly ascribed to the expansion and contraction of the border regions between the inverted repeat (IR) region and the single-copy (SC) regions. Despite of the conserved structure inRehmanniaplastomes, sequence variations provide useful phylogenetic information. Phylogenetic trees of 23 Lamiales species reconstructed with the complete plastomes suggested thatRehmanniawas monophyletic and sister to the clade ofLindenbergiaand the parasitic taxa in Orobanchaceae. The interspecific relationships withinRehmanniawere completely different with the previous studies. In future, population phylogenomic works based on plastomes are urgently needed to clarify the evolutionary history ofRehmannia.
authors.affiliation: Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China. zengsy.nwu@outlook.com.
authors.forename: Shuyun
authors.initials: S
authors.lastname: Zeng
authors.affiliation: Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China. woody196@163.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China. hank.nwu@outlook.com.
authors.forename: Kai
authors.initials: K
authors.lastname: Han
authors.affiliation: Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China. yycjyl@163.com.
authors.forename: Yanci
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China. yunjin1991@163.com.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China. liuzl@nwu.edu.cn.
authors.forename: Zhan-Lin
authors.initials: ZL
authors.lastname: Liu
keywords: Rehmannia; chloroplast genome; phylogeny; positive selection; repeat