Hye-Rin KimP, Kweon Heo

Department of Applied Plant Science, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon

Genetic diversity and population structure of Menyanthes trifoliata were investigated using microsatellite (SSR) markers to evaluate patterns of genetic variation among geographically isolated populations. A total of 30 individuals from four regions—Korea, Japan, Russia, and the United Kingdom—were analyzed. Genetic diversity indices, analysis of molecular variance (AMOVA), and principal coordinate analysis (PCoA) were used to assess within- and among-population variation. At the species level, M. trifoliata maintained relatively high genetic diversity despite its clonal growth habit and fragmented wetland habitats. In contrast, genetic diversity varied markedly among populations. AMOVA revealed that a substantial proportion of genetic variation was partitioned among populations, indicating restricted gene flow. PCoA further demonstrated clear genetic structuring corresponding to geographic origin, separating East Asian and European populations. Korean populations showed pronounced genetic distinctiveness, likely reflecting long-term geographic isolation, habitat reduction, and their location at the eastern margin of the geographic range. These patterns are consistent with post-glacial range expansion followed by regional isolation and limited dispersal in wetland environments, highlighting the importance of conserving geographically distinct populations.