Complete chloroplast genomes of Rubus species (Rosaceae) and comparative analysis within the genus

Abstract

Abstract Background Rubus is the largest genus of the family Rosaceae and is valued as medicinal, edible, and ornamental plants. Here, we sequenced and assembled eight chloroplast (cp) genomes of Rubus from the Dabie Mountains in Central China. Fifty-one Rubus species were comparatively analyzed for the cp genomes including the eight newly discovered genomes and forty-three previously reported in GenBank database (NCBI). Results The eight newly obtained cp genomes had the same quadripartite structure as the other cp genomes in Rubus. The length of the eight plastomes ranged from 155,546 bp to 156,321 bp with similar GC content (37.0 to 37.3%). The results indicated 133–134 genes were annotated for the Rubus plastomes, which contained 88 or 89 protein coding genes (PCGs), 37 transfer RNA genes (tRNAs), and eight ribosomal RNA genes (rRNAs). Among them, 16 (or 18) of the genes were duplicated in the IR region. Structural comparative analysis results showed that the gene content and order were relatively preserved. Nucleotide variability analysis identified nine hotspot regions for genomic divergence and multiple simple sequences repeats (SSRs), which may be used as markers for genetic diversity and phylogenetic analysis. Phylogenetic relationships were highly supported within the family Rosaceae, as evidenced by sub-clade taxa cp genome sequences. Conclusion Thus, the whole plastome may be used as a super-marker in phylogenetic studies of this genus.

Keywords

• Rubus
• Chloroplast genome
• Compare analysis
• Phylogeny