Complete Chloroplast Genomes and Phylogenetic Relationships of Bougainvillea spectabilis and Bougainvillea glabra (Nyctaginaceae)

Bougainvillea L. (Nyctaginaceae) is a South American native woody flowering shrub of high ornamental, economic, and medicinal value which susceptible to cold damage. We sequenced the complete chloroplast (cp) genome B. glabra spectabilis, two morphologically similar species differing in resistance. Both genomes showed typical quadripartite structure consisting one large single-copy region, small inverted repeat regions. The cp size spectabilis was 154,520 154,542 bp, respectively, with 131 genes, including 86 protein-coding, 37 transfer RNA, 8 ribosomal RNA genes. In addition, contained 270 271 simple sequence repeats, mononucleotide repeats being most abundant. Eight highly variable sites (psbN, psbJ, rpoA, rpl22, psaI, trnG-UCC, ndhF, ycf1) nucleotide diversity were identified as potential molecular markers. Phylogenetic analysis revealed close relationship between spectabilis. These findings not only contribute understanding mechanism by responds low-temperature stress elucidating evolutionary characteristics phylogenetic relationships among species, but also provide important evidence for accurate identification breeding superior cold-tolerant cultivars.