The complete chloroplast genome sequence of the North American sclerophyllous evergreen shrub, Quercus turbinella (Fagaceae).

Quercus turbinella (section Quercus; Fagaceae) is an evergreen shrub characteristic in central Arizona and it concerns one of the most abundant and economically important genera of Quercus in the Northern Hemisphere. Here, we have sequenced the complete chloroplast genome to provide insight into the phylogenetic relationship of Q. turbinella. The whole genome is 161,208 bp in length with two inverted repeat regions of 25,827 bp each, which separate a large single-copy region of 90,552 bp and a small single-copy region of 19,002 bp. A total of 136 genes were annotated, including 88 protein-coding genes, eight ribosomal RNAs, and 40 transfer RNAs. The result of the maximum-likelihood phylogenetic analysis strongly suggested that Quercus turbinella had a close relationship to Quercus macrocarpa with strong bootstrap support.

The genetic structure and demographic history of Zabelia tyaihyonii, endemic to Korean limestone karst forests, based on genome-wide SNP markers.

Similar to the global phenomenon, many plant species endemic to Korean limestone karst forests are at risk of extinction due to human intervention. Zabelia tyaihyonii is a familiar shrub, called "Hardy abelia" and "Fragrant abelia" growing in the karst forests of Korea, where it is one of the most threatened species. We investigated the genetic structure and demographic history of Z. tyaihyonii, which allow us to develop appropriate conservation and management strategies. The genetic structure was evaluated using a total of 187 samples from 14 populations, covering the entire distribution of Z. tyaihyonii in South Korea. We utilized 254 and 1753 SNP loci obtained via MIG-seq (Multiplexed ISSR Genotyping by sequencing) for structure and demographic analyses, respectively. The population demographic modeling was performed with site frequency spectrum. To gain further historical insights, we also employed ENM (Ecological Niche Modeling). We found two distinct clusters (CLI and CLII) of ancient origin (ca. 490 ka). Despite CLII experiencing a more severe bottleneck, both clusters showed similar levels of genetic diversity, indicating mutual historical gene flow. Their historical distribution range seems to have changed very little. We proposed a historical distribution scenario for Z. tyaihyonii, taking into account its intrinsic factors, and emphasized a more complex response to Quaternary climate change beyond simple allopatric speciation models. These findings provide valuable insights for conservation and management strategies for Z. tyaihyonii.

The complete chloroplast genome sequence of the medicinal plant, Dracocephalum rupestre (Lamiaceae).

Dracocephalum rupestre (tribe Mentheae; Lamiaceae) is a perennial herb from Korea and China with high ornamental and medicinal value. Here, we report its complete chloroplast genome to provide insight into the phylogenetic relationships of Dracocephalum. The genome is 151,230 bp long, with two inverted repeat regions (25,643 bp each) that separate a large single-copy region (82,536 bp) and a small single-copy region (17,408 bp). It contains 133 genes that encode 88 proteins, eight rRNAs, and 37 tRNAs. The maximum-likelihood phylogenetic analysis strongly supported Dracocephalum monophyly, showing that the genus forms a sister group with the subtribe Menthinae in the tribe Mentheae.

Genetic and demographic signatures accompanying the evolution of the selfing syndrome in Daphne kiusiana, an evergreen shrub.

BACKGROUND AND AIMS: The evolution of mating systems from outcrossing to self-fertilization is a common transition in flowering plants. This shift is often associated with the 'selfing syndrome', which is characterized by less visible flowers with functional changes to control outcrossing. In most cases, the evolutionary history and demographic dynamics underlying the evolution of the selfing syndrome remain poorly understood. METHODS: Here, we characterize differences in the demographic genetic consequences and associated floral-specific traits between two distinct geographical groups of a wild shrub, Daphne kiusiana, endemic to East Asia; plants in the eastern region (southeastern Korea and Kyushu, Japan) exhibit smaller and fewer flowers compared to those of plants in the western region (southwestern Korea). Genetic analyses were conducted using nuclear microsatellites and chloroplast DNA (multiplexed phylogenetic marker sequencing) datasets. KEY RESULTS: A high selfing rate with significantly increased homozygosity characterized the eastern lineage, associated with lower levels of visibility and herkogamy in the floral traits. The two lineages harboured independent phylogeographical histories. In contrast to the western lineage, the eastern lineage showed a gradual reduction in the effective population size with no signs of a severe bottleneck despite its extreme range contraction during the last glacial period. CONCLUSIONS: Our results suggest that the selfing-associated morphological changes in D. kiusiana are of relatively old origin (at least 100 000 years ago) and were driven by directional selection for efficient self-pollination. We provide evidence that the evolution of the selfing syndrome in D. kiusiana is not strongly associated with a severe population bottleneck.

Complete plastid genome sequence of Neolitsea aciculata (Laurales: Lauraceae), an evergreen broad-leaved tree endemic to East Asia.

In this study, we sequenced the complete plastid genome (plastome) of Neolitsea aciculata, an evergreen broad-leaved tree endemic to East Asia, a woody component of East Asian warm-temperate and subtropical forests across China, Korea, and Japan. The plastome of N. aciculata is assembled as a single contig (152,722 bp). A large and a small single copy (93,785 and 18,795 bp, respectively) of the genome are separated by a pair of inverted repeats (20,071 bp). The genome consists of 126 genes, including 80 protein-coding, eight ribosomal RNA, and 36 transfer RNA genes. Two genes in the IR region (ycf1 and ycf2) are pseudogenized. Our phylogenetic analysis revealed the phylogenetic position of N. aciculata in a highly supported clade of the genus Neolitsea along with other two congeners, N. pallens and N. sericea.

Comparative Mitogenomic Analysis Reveals Gene and Intron Dynamics in Rubiaceae and Intra-Specific Diversification in Damnacanthus indicus.

The dynamic evolution of mitochondrial gene and intron content has been reported across the angiosperms. However, a reference mitochondrial genome (mitogenome) is not available in Rubiaceae. The phylogenetic utility of mitogenome data at a species level is rarely assessed. Here, we assembled mitogenomes of six Damnacanthus indicus (Rubiaceae, Rubioideae) representing two varieties (var. indicus and var. microphyllus). The gene and intron content of D. indicus was compared with mitogenomes from representative angiosperm species and mitochondrial contigs from the other Rubiaceae species. Mitogenome structural rearrangement and sequence divergence in D. indicus were analyzed in six individuals. The size of the mitogenome in D. indicus varied from 417,661 to 419,435 bp. Comparing the number of intact mitochondrial protein-coding genes in other Gentianales taxa (38), D. indicus included 32 genes representing several losses. The intron analysis revealed a shift from cis to trans splicing of a nad1 intron (nad1i728) in D. indicus and it is a shared character with the other four Rubioideae taxa. Two distinct mitogenome structures (type A and B) were identified. Two-step direct repeat-mediated recombination was proposed to explain structural changes between type A and B mitogenomes. The five individuals from two varieties in D. indicus diverged well in the whole mitogenome-level comparison with one exception. Collectively, our study elucidated the mitogenome evolution in Rubiaceae along with D. indicus and showed the reliable phylogenetic utility of the whole mitogenome data at a species-level evolution.

The complete plastid genome sequence of Vaccinium japonicum (Ericales: Ericaceae), a deciduous broad-leaved shrub endemic to East Asia.

We here sequenced the complete plastid genome (plastome) of Vaccinium japonicum (Ericaceae), a deciduous broad-leaved shrub endemic to East Asia. This species has considerable practical economic value. The plastome of V. japonicum is assembled as a single contig (187,213 bp). A large single copy (104,637 bp) and a small single copy (3,000 bp) of the genome are separated by a pair of inverted repeats (39,788 bp). The genome consists of 135 genes, which include 88 protein coding, eight ribosomal RNA, and 39 transfer RNA genes. The plastome of V. japonicum is similar to that of Vaccinium macrocarpon in gene content and order. Our phylogenetic analysis revealed the phylogenetic position of V. japonicum in a highly supported clade of the genus Vaccinium together with other four congeners, V. bracteatum, V. vitis-idaea, V. uliginosum and V. macrocarpon.

The complete plastid genome sequence of Quercus acuta (Fagaceae), an evergreen broad-leaved oak endemic to East Asia.

We are reporting the complete plastid genome (plastome) of Quercus acuta, an evergreen broad-leaved oak endemic to East Asia. This species is important for maintaining the warm-temperate evergreen forest biome in East Asia. The Q. acuta plastome is 160,522 base pairs (bp) long, with two inverted repeat (IR) regions (25,839 bp each) that separate a large single copy (LSC) region (90,199 bp) and a small single copy (SSC) region (18,645 bp). The phylogenetic tree shows that Quercus acuta is closely related to Quercus sichourensis with strong bootstrap support.

Rear-edge, low-diversity, and haplotypic uniformity in cold-adapted Bupleurum euphorbioides interglacial refugia populations.

The high genetic diversity of rear-edge refugia populations is predicted to have resulted from species repeatedly migrating to low latitudes during glacial periods over the course of Quaternary climate change. However, several recent empirical studies of cold-tolerant plants revealed the opposite pattern. We investigated whether current habitats of the cold-adapted and range-restricted Bupleurum euphorbioides in the Baekdudaegan, South Korea, and North Korea could be interglacial refugia, and documented how their rear-edge populations differ genetically from those of typical temperate species. Phylogeographic analysis and ecological niche modeling (ENM) were used. The genetic structure was analyzed using microsatellite markers and chloroplast DNA sequences. The congener B. longiradiatum was included as a typical temperate plant species. Despite having almost identical life history traits, these congeneric species exhibited contrasting patterns of genetic diversity. ENM revealed an apparent maximum range contraction during the last interglacial. In contrast, its range expanded northward to the Russian Far East (Primorsky) during the Last Glacial Maximum. Thus, we hypothesize that B. euphorbioides retreated to its current refugia during interglacial periods. Unlike populations in the central region, the rear-edge populations were genetically impoverished and uniform, both within populations and in pooled regional populations. The rear-edge B. euphorbioides survived at least one past interglacial, contributing to the species' genetic diversity. We believe that such genetic variation in the cold-adapted B. euphorbioides gives the species the necessary adaptations to survive an upcoming favorable environment (the next glacial), unless there is artificial environmental change.

A Disjunctive Marginal Edge of Evergreen Broad-Leaved Oak (Quercus gilva) in East Asia: The High Genetic Distinctiveness and Unusual Diversity of Jeju Island Populations and Insight into a Massive, Independent Postglacial Colonization.

Jeju Island is located at a marginal edge of the distributional range of East Asian evergreen broad-leaved forests. The low genetic diversity of such edge populations is predicted to have resulted from genetic drift and reduced gene flow when compared to core populations. To test this hypothesis, we examined the levels of genetic diversity of marginal-edge populations of Quercus gilva, restricted to a few habitats on Jeju Island, and compared them with the southern Kyushu populations. We also evaluated their evolutionary potential and conservation value. The genetic diversity and structure were analyzed using 40 polymorphic microsatellite markers developed in this study. Ecological Niche Modeling (ENM) has been employed to develop our insights, which can be inferred from historical distribution changes. Contrary to our expectations, we detected a similar level of genetic diversity in the Jeju populations, comparable to that of the southern Kyushu populations, which have been regarded as long-term glacial refugia with a high genetic variability of East Asian evergreen trees. We found no signatures of recent bottlenecks in the Jeju populations. The results of STRUCTURE, neighbor-joining phylogeny, and Principal Coordinate Analysis (PCoA) with a significant barrier clearly demonstrated that the Jeju and Kyushu regions are genetically distinct. However, ENM showed that the probability value for the distribution of the trees on Jeju Island during the Last Glacial Maximum (LGM) converge was zero. In consideration of these results, we hypothesize that independent massive postglacial colonization from a separate large genetic source, other than Kyushu, could have led to the current genetic diversity of Jeju Island. Therefore, we suggest that the Jeju populations deserve to be separately managed and designated as a level of management unit (MU). These findings improve our understanding of the paleovegetation of East Asian evergreen forests, and the microevolution of oaks.

The complete chloroplast genome sequence of Taxillus yadoriki (Loranthaceae): a hemi-parasitic evergreen shrub in East Asia.

Taxillus yadoriki (Loranthaceae) is a hemiparasitic evergreen shrub distributed in Korea and Japan. We report the complete chloroplast genome of T. yadoriki to provide insight into the phylogenetic relationship of Loranthaceae. This genome is 122,192 bp long, with two IR regions (22,756 bp each) that separate a large single-copy (LSC) region (70,628 bp) and a small single-copy (SSC) region (6052 bp). It contains 109 genes that encode 68 proteins, 8 rRNAs, and 33 tRNAs. All of ndh genes have been lost and the SSC region consists of only four genes similar to other Taxillus species. In ML phylogenetic, monophyly of Taxillus was strongly supported with high bootstrap value and formed a sister group with Scurrula.

Development of 26 microsatellite markers in Bupleurum latissimum (Apiaceae), an endangered plant endemic to Ulleung Island, Korea.

PREMISE OF THE STUDY: To enhance our understanding of evolutionary consequences and to establish a suitable conservation strategy, we isolated microsatellite markers for the endangered Bupleurum latissimum (Apiaceae), which is endemic to the oceanic Ulleung Island. We also attempted cross-amplification in B. euphorbioides and B. longeradiatum to investigate its continental progenitors. METHODS AND RESULTS: Using high-throughput sequencing data, we developed 26 polymorphic microsatellite loci in three multiplexes, of which 13 loci were polymorphic in the two related species. For B. latissimum, alleles numbered two to four and the observed and expected heterozygosity ranged from 0.000 to 0.500 and 0.061 to 0.529, respectively. CONCLUSIONS: These developed markers will be useful for understanding evolutionary patterns of B. latissimum in an oceanic island system and for establishing suitable conservation strategies at the genetic level.

The complete chloroplast genome of Sarcandra glabra (Chloranthaceae): a perianthless basal angiosperm.

We have obtained the complete chloroplast (cp) genome sequence for Sarcandra glabra. This genome is 158,881 bp long, with 39.2% GC content. It includes a large single copy region of 88,169 bp that is separated from the 18,446-bp small single copy region by two inverted repeat regions (26,133 bp each). This genome contains 130 genes, i.e. 85 protein-coding genes, 37 tRNA, and eight tRNA. Maximum likelihood analysis, based on 13 complete cp genomes, showed that S. glabra is closely related to two other family members, Chloranthus spicatus and C. japonicus.

The complete chloroplast genome sequence of Viburnum Japonicum (Adoxaceae), an evergreen broad-leaved shrub.

The wax-leafed Viburnum japonicum (Adoxaceae) is an evergreen shrub distributed in Japan, Korea, and Taiwan. We sequenced its complete chloroplast (cp) genome to examine its phylogenetic relationship within Dipsacales. This genome is 158,614 bp long and features a large single-copy region (87,059 bp) and a small single-copy region (18,523 bp), separated by two inverted-repeat regions (26,516 bp each). It contains 128 genes, including 84 coding genes, eight rRNAs, and 36 tRNAs. The overall GC content is 38.1%. Our phylogenetic tree showed that V. japonicum is closely related to V. utile and is clustered together with four species in the family Adoxaceae.