The complete chloroplast genome sequence of Fagopyrum cymosum

The complete chloroplast genome of Persicaria perfoliata and comparative analysis with Four Medicinal Plants of Polygonaceae

Polygonaceae is a large family of medicinal herbs that includes many species used as traditional Chinese medicine, such as Persicaria perfoliate. Here, we sequenced the complete cp genome of P. perfoliata using Illumina sequencing technology with the purpose to provide a method to facilitate accurate identification. After being annotated, the cp genome of P. perfoliata was compared with Fagopyrum tataricum, Persicaria chinensis, Fagopyrum dibotrys and Fallopia multiflora. The complete cp genome of P. perfoliata is 160,730 bp in length, containing a small single copy (SSC) region of 12,927 bp, a large single copy (LSC) region of 85,433 bp and a pair of inverted repeats (IR) regions of 62,370 bp. A total of 131 genes were annotated, including eight rRNA genes, 34 tRNA genes and 84 protein-coding genes. Forty-two simple sequence repeats and fifty-five repeat sequences were identified. Mutational hot spots analyses indicated that five genes (matK, ndhF, ccsA, cemA, rpl20) could be selected as candidates for molecular markers. Moreover, phylogenetic analysis showed that all the Polygonaceae species formed a monophyletic clade, and P. perfoliata showed the closest relationship with P. chinense. The study provides valuable molecular information to accurately identify P. perfoliata and assist in its development and application.

Chloroplast Genome of Rambutan and Comparative Analyses in Sapindaceae

Rambutan (Nephelium lappaceum L.) is an important fruit tree that belongs to the family Sapindaceae and is widely cultivated in Southeast Asia. We sequenced its chloroplast genome for the first time and assembled 161,321 bp circular DNA. It is characterized by a typical quadripartite structure composed of a large (86,068 bp) and small (18,153 bp) single-copy region interspersed by two identical inverted repeats (IRs) (28,550 bp). We identified 132 genes including 78 protein-coding genes, 29 tRNA and 4 rRNA genes, with 21 genes duplicated in the IRs. Sixty-three simple sequence repeats (SSRs) and 98 repetitive sequences were detected. Twenty-nine codons showed biased usage and 49 potential RNA editing sites were predicted across 18 protein-coding genes in the rambutan chloroplast genome. In addition, coding gene sequence divergence analysis suggested that ccsA, clpP, rpoA, rps12, psbJ and rps19 were under positive selection, which might reflect specific adaptations of N. lappaceum to its particular living environment. Comparative chloroplast genome analyses from nine species in Sapindaceae revealed that a higher similarity was conserved in the IR regions than in the large single-copy (LSC) and small single-copy (SSC) regions. The phylogenetic analysis showed that N. lappaceum chloroplast genome has the closest relationship with that of Pometia tomentosa. The understanding of the chloroplast genomics of rambutan and comparative analysis of Sapindaceae species would provide insight into future research on the breeding of rambutan and Sapindaceae evolutionary studies.

Complete chloroplast genome sequence of Fagopyrum dibotrys: genome features, comparative analysis and phylogenetic relationships

Fagopyrum dibotrys, belongs to Polygonaceae family, is one of national key conserved wild plants of China with important medicinal and economic values. Here, the complete chloroplast (cp) genome sequence of F. dibotrys is reported. The cp genome size is 159,919 bp with a typical quadripartite structure and consisting of a pair of inverted repeat regions (30,738 bp) separated by large single copy region (85,134 bp) and small single copy region (13,309 bp). Sequencing analyses indicated that the cp genome encodes 131 genes, including 80 protein-coding genes, 28 tRNA genes and 4 rRNA genes. The genome structure, gene order and codon usage are typical of angiosperm cp genomes. We also identified 48 simple sequence repeats (SSR) loci, fewer of them are distributed in the protein-coding sequences compared to the noncoding regions. Comparison of F. dibotrys cp genome to other Polygonaceae cp genomes indicated the inverted repeats (IRs) and coding regions were more conserved than single copy and noncoding regions, and several variation hotspots were detected. Coding gene sequence divergence analyses indicated that five genes (ndhK, petL rpoC2, ycf1, ycf2) were subject to positive selection. Phylogenetic analysis among 42 species based on cp genomes and 50 protein-coding genes indicated a close relationship between F. dibotrys and F. tataricum. In summary, the complete cp genome sequence of F. dibotrys reported in this study will provide useful plastid genomic resources for population genetics and pave the way for resolving phylogenetic relationships of order Caryophyllales.

The complete chloroplast genome sequence of Tartary Buckwheat Cultivar Miqiao 1(Fagopyrum tataricum Gaertn.)

Chloroplasts (cp) are indispensable organelles in plant cells that perform photosynthesis amongst other functions, including producing pigments, synthesizing sugars and certain amino acids. The complete chloroplast genome of Tartary Buckwheat Cultivar Miqiao 1 is sequenced in this study. Miqiao 1 is currently the only Tartary Buckwheat variety that can produce the whole nutritive Tartary Buckwheat Rice by hulling. The Miqiao 1 cp genome size is 159,272 bp in length, including 79 protein-coding genes, 30 tRNA genes and 4 rRNA genes. A pair of inverted repeats (IRs) of 30,817 bp were disconnected by a large single copy (LSC) of 84,397 bp and a small single copy (SSC) of 13,241 bp. The cp genome with 37.9% GC content contained 113 annotated genes.