Genetic differences among varieties of Saccharina japonica in northern Japan as determined by AFLP and SSR analyses

The genetic diversity of Saccharina japonica inhabiting the Hokkaido coastline and the surrounding area was investigated by AFLP and SSR analyses. A STRUCTURE analysis based on the AFLP data identified two clusters in the species, although a few local populations with genetic structures different from that of the neighboring populations were detected. The two clusters could be identified even within each current variety. In the SSR analysis, genetic variation in nucleotide sequences in all samples was located in four DNA regions (MS10, MS11, MS16, and MS29), and it is thought that these regions can be used as markers to detect individual-level variation in S. japonica. The STRUCTURE analysis of the SSR data identified four clusters in the species. Since the geographical distribution of these four different clusters does not correspond exactly to the currently recognized varieties in this species, it will be necessary to re-evaluate the distribution of the varieties of S. japonica.