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 first complete chloroplast genome sequence from Violaceae (Viola seoulensis).

The complete chloroplast genome of Viola seoulensis, an endemic species to Korea, was determined in this study. The total genome size was 156 507 bp in length, containing a pair of inverted repeats (IRs) of 26 404 bp, which were separated by large single copy (LSC) and small single copy (SSC) of 85 691 and 18 008 bp, respectively. The overall GC contents of the plastid genome were 36.3%. One hundred and thirty genes were annotated, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. In these genes, 17 genes contained one or two introns. A phylogenetic tree showed that Violaceae was closely related to Salicaceae.

The complete plastid genome sequence of Abies koreana (Pinaceae: Abietoideae).

The nucleotide sequence of the chloroplast genome from Abies koreana is the first to have complete genome sequence from genus Abies of family Pinaceae. The circular double-stranded DNA, which consists of 121,373 base pairs (bp), contains a pair of very short inverted repeat regions (IRa and IRb) of 264 bp each, which are separated by a small and large single-copy regions (SSC and LSC) of 54,197 and 66,648 bp, respectively. The genome contents of 114 genes (68 peptide-encoding genes, 35 tRNA genes, four rRNA genes, six open reading frames and one pseudogene) are similar to the chloroplast DNA of other species of Abietoideae. Loss of ndh genes was also identified in the genome of A. koreana like other genomes in the family Pinaceae. Thirteen genes contain one (11 genes) or two (rps12 and ycf3 genes) introns. In phylogenetic analysis, the tree confirms that Abies, Keteleeria and Cedrus are strongly supported as monophyletic. Other inverted repeat sequences located in 42-kb inversion points (1186 bp) include trnS-psaM-ycf12- ψtrnG genes.

The complete plastid genome sequence of Picea jezoensis (Pinaceae: Piceoideae).

The nucleotide sequence of the complete chloroplast genome of P. jezoensis was completed. The total genome size was 124 146 bp, containing a pair of very short inverted repeats (IRa and IRb) of 422 bp, which were separated by large single copy (LSC) and small single copy (SSC) with 66 956 bp and 56 346 bp, respectively. The overall GC contents of the plastid genome were determined as 38.8%. One hundred fifteen genes including 68 peptide-encoding genes, 35 tRNA genes, four rRNA genes, six open-reading frames, and two pseudogenes were annotated. In these genes, 15 genes contained only one or two introns. Phylogenetic analyses using maximum likelihood (ML) methods were performed from fully sequenced Gymnosperms and other species of dataset composed of 69 protein-coding genes.