Raw data (in FASTQ format) of seashore spatulate aster (Aster spathulifolius-oharae complex) samples collected from the east coast of the Korean Peninsula and Ulleungdo Island (East Sea)

The eastern coast of the Korean Peninsula and the volcanic island of Ulleungdo together constitute a part of the East Sea (Sea of Japan) biogeographic region in which plant populations and lineages are often distributed allopatrically. This pattern includes the perennial coastal herb commonly known as the seashore spatulate aster (of the Aster spathulifolius–oharae species complex). In our ongoing project, we investigate the disjunct distribution of this coastal specialist using molecular markers (e.g., SNPs) to assess its genomic diversity and population structure, and to infer the number of independently evolving lineages within this region.Here, we present the raw genomic data (in FASTQ files) of 96 individuals sampled across seven natural populations from the Korean east coast (mainland distribution/'AS_ SAMPLES'), and Ulleungdo (island distribution/'AO_SAMPLES'). The data were generated via high-throughput Illumina sequencing of reduced-representation libraries prepared following the genotyping-by-sequencing (GBS) protocol. The resulting paired-end reads were demultiplexed using STACKS v2 'process_radtags’ program which discarded reads with low quality scores (-q 10).Each sample comprises a set of two files. The ‘process_radtags’ program keeps the reads in phase hence, for instance, SAMPLE_###.1.fq file is the mate of SAMPLE_###.2.fq file (Rochette et al., 2019; Rivera-Colon and Catchen, 2022). Here, each sample starts with the taxon/distribution and population code ‘AS_XX’ or ‘AO_XX_XX’ for mainland and island individuals, respectively. They are then followed by the sample numbers and the file name extension (e.g., ‘###.1.fq’ and ‘###.2.fq’).These data underpin our current study, provisionally entitled “Patterns of genomic variation and population structure suggest the strong influence of allopatry between peninsular and island distributions of seashore spatulate aster along the Korean east coast region”, which has been submitted to the Journal of Plant Research.