Phylogeographical structure in Zelkova serrata in Japan and phylogeny in the genus Zelkova using the polymorphisms of chloroplast DNA

The genetic differentiation inherent in Zelkova serrata in Japan and the southern portion of the Korean Peninsula was examined by comparing a chloroplast DNA (cpDNA) sequence over a 16 k baselength in 40 individual samples collected from an area covering the natural distribution range of Z. serrata in Japan and the southern portion of the Korean Peninsula. We detected over 50 single-nucleotide polymorphisms in the protein-coding and intergenic regions, and over 30 insertions/deletions in the intergenic region. From the polymorphisms detected in the cpDNA, 14 haplotypes were identified. These 14 haplotypes had cluster-like structures and genetic differentiation between the clusters was large. Closely related haplotypes existed in adjacent regions. One haplotype existed in both Japan and the Korean Peninsula. By comparison with other Zelkova species, Z. serrata is apparently distinct from European and East Asian Zelkova species and Z. serrata is closest to the Ulmus species in the genus Zelkova. The effects of the analyzed length of the cpDNA sequence on the detection of polymorphisms were analyzed by re-sampling simulation.