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We report the complete chloroplast genomes of four Viola species (V. mirabilis, V. phalacrocarpa, V. raddeana, and V. websteri) and the results of a comparative analysis between these species and the published plastid genome of the congeneric species V. seoulensis. The total genome length of the five Viola species, including the four species analyzed in this study and the species analyzed in the previous study, ranged from 156,507 (V. seoulensis) to 158,162 bp (V. mirabilis). The overall GC contents of the genomes were almost identical (36.2–36.3%). The five Viola plastomes each contained 111 unique genes comprising 77 protein-coding genes, 30 transfer RNA (tRNA) genes, and 4 ribosomal RNA (rRNA) genes. Among the annotated genes, 16 contained one or two introns. Based on the results of a chloroplast genome structure comparison using MAUVE, all five Viola plastomes were almost identical. Additionally, the large single copy (LSC), inverted repeat (IR), and small single copy (SSC) junction regions were conserved among the Viola species. A total of 259 exon, intron, and intergenic spacer (IGS) fragments were compared to verify the divergence hotspot regions. The nucleotide diversity (Pi) values ranged from 0 to 0.7544. The IR region was relatively more conserved than the LSC and SSC regions. The Pi values in ten noncoding regions were relatively high (>0.03). Among these regions, all but rps19-trnH, petG-trnW, rpl16-rps3, and rpl2-rpl23 represent useful molecular markers for phylogenetic studies and will be helpful to resolve the phylogenetic relationships of Viola. The phylogenetic tree, which used 76 protein-coding genes from 21 Malpighiales species and one outgroup species (Averrhoa carambola), revealed that Malpighiales is divided into five clades at the family level: Erythroxylaceae, Chrysobalanaceae, Euphorbiaceae, Salicaceae, and Violaceae. Additionally, Violaceae was monophyletic, with a bootstrap value of 100% and was divided into two subclades. [ABSTRACT FROM AUTHOR]

The chloroplast genome of Tetragonia tetragonioides (Aizoaceae; Caryophyllales) was sequenced to provide information for studies on phylogeny and evolution within Caryophyllales. The chloroplast genome of Tetragonia tetragonioides is 149,506 bp in length and includes a pair of inverted repeats (IRs) of 24,769 bp that separate a large single copy (LSC) region of 82,780 bp and a small single copy (SSC) region of 17,188 bp. Comparative analysis of the chloroplast genome showed that Caryphyllales species have lost many genes. In particular, the rpl2 intron and infA gene were not found in T. tetragonioides, and core Caryophyllales lack the rpl2 intron. Phylogenetic analyses were conducted using 55 genes in 16 complete chloroplast genomes. Caryophyllales was found to divide into two clades; core Caryophyllales and noncore Caryophyllales. The genus Tetragonia is closely related to Mesembryanthemum. Comparisons of the synonymous (Ks), nonsynonymous (Ka), and Ka/Ks substitution rates revealed that nonsynonymous substitution rates were lower than synonymous substitution rates and that Ka/Ks rates were less than 1. The findings of the present study suggest that most genes are a purified selection. [ABSTRACT FROM AUTHOR]

Arabis stellari var. japonica is an ornamental plant of the Brassicaceae family, and is widely distributed in South Korea. However, no information is available about its molecular biology and no genomic study has been performed on A. stellari. In this paper, the authors report the complete chloroplast genome sequence of A. stellari. The plastome of A. stellari was 153,683 bp in length with 36.4% GC and included a pair of inverted repeats (IRs) of 26,423 bp that separated a large single-copy (LSC) region of 82,807 bp and a small single-copy (SSC) region of 18,030 bp. It was also found to contain 113 unique genes, of which 79 were protein-coding genes, 30 were transfer RNAs, and four were ribosomal RNAs. The gene content and organization of the A. stellari chloroplast genome were similar to those of other Brassicaceae genomes except for the absence of the rps16 protein-coding gene. A total of 991 SSRs were identified in the genome. The chloroplast genome of A. stellari was compared with closely related species of the Brassicaceae family. Comparative analysis showed a minor divergence occurred in the protein-coding matK, ycf1, ccsA, accD and rpl22 genes and that the KA/KS nucleotide substitution ratio of the ndhA genes of A. stellari and A. hirsuta was 1.35135. The genes infA and rps16 were absent in the Arabis genus and phylogenetic evolutionary studies revealed that these genes evolved independently. However, phylogenetic analysis showed that the positions of Brassicaceae species are highly conserved. The present study provides A. stellari genomic information that may be found useful in conservation and molecular phylogenetic studies on Brassicaceae. [ABSTRACT FROM AUTHOR]

The complete chloroplast genomes of Lychnis wilfordii and Silene capitata were determined and compared with ten previously reported Caryophyllaceae chloroplast genomes. The chloroplast genome sequences of L. wilfordii and S. capitata contain 152,320 bp and 150,224 bp, respectively. The gene contents and orders among 12 Caryophyllaceae species are consistent, but several microstructural changes have occurred. Expansion of the inverted repeat (IR) regions at the large single copy (LSC)/IRb and small single copy (SSC)/IR boundaries led to partial or entire gene duplications. Additionally, rearrangements of the LSC region were caused by gene inversions and/or transpositions. The 18 kb inversions, which occurred three times in different lineages of tribe Sileneae, were thought to be facilitated by the intermolecular duplicated sequences. Sequence analyses of the L. wilfordii and S. capitata genomes revealed 39 and 43 repeats, respectively, including forward, palindromic, and reverse repeats. In addition, a total of 67 and 56 simple sequence repeats were discovered in the L. wilfordii and S. capitata chloroplast genomes, respectively. Finally, we constructed phylogenetic trees of the 12 Caryophyllaceae species and two Amaranthaceae species based on 73 protein-coding genes using both maximum parsimony and likelihood methods. [ABSTRACT FROM AUTHOR]

Background: Microsatellites, a special class of repetitive DNA sequence, have become one of the most popular genetic markers for population/conservation genetic studies. However, its application to endangered species has been impeded by high development costs, a lack of available sequences, and technical difficulties. The water deer Hydropotes inermis is the sole existing endangered species of the subfamily Capreolinae. Although population genetics studies are urgently required for conservation management, no species-specific microsatellite marker has been reported. Methods: We adopted next-generation sequencing (NGS) to elucidate the microsatellite markers of Korean water deer and overcome these impediments on marker developments. We performed genotyping to determine the efficiency of this method as applied to population genetics. Results: We obtained 98 Mbp of nucleotide information from 260,467 sequence reads. A total of 20,101 di-/tri-nucleotide repeat motifs were identified; di-repeats were 5.9-fold more common than tri-repeats. [CA]n and [AAC]n/[AAT]n repeats were the most frequent di- and tri-repeats, respectively. Of the 17,206 di-repeats, 12,471 microsatellite primer pairs were derived. PCR amplification of 400 primer pairs yielded 106 amplicons and 79 polymorphic markers from 20 individual Korean water deer. Polymorphic rates of the 79 new microsatellites varied from2 to 11 alleles per locus (He: 0.050-0.880; Ho: 0.000-1.000), while those of known microsatellite markers transferred from cattle to Chinese water deer ranged from 4 to 6 alleles per locus (He: 0.279-0.714; Ho: 0.300-0.400). Conclusions: Polymorphic microsatellite markers from Korean water deer were successfully identified using NGS without any prior sequence information and deposited into the public database. Thus, the methods described herein represent a rapid and low-cost way to investigate the population genetics of endangered/non-model species. [ABSTRACT FROM AUTHOR]