Genetic diversity and differentiation of a narrowly distributed and endemic species, Aster spathulifolius maxim (Asteraceae), revealed with inter simple sequence repeat markers

Aster spathulifolius Maxim is a narrowly distributed and endemic species occurring in coastal regions of Korea and Japan. The genetic diversity and differentiation of fifteen populations of the species were analyzed in eight-two loci using six Inter Simple Sequence Repeat primers. Total genetic diversity at species level was extremely high (P=98.78%, Hsp=0.333±0.144, I=0.501±0.180), whereas the genetic diversity at population level was relatively low (P=43.74%, Hpop=0.150±0.189, I=0.227±0.274). High genetic differentiation among populations was detected based on genetic differentiation coefficient (Gst=0.549) and analysis of molecular variance (AP=54.06%). These findings together with low gene flow estimates (Nm=0.205) suggest that genetic drift by isolation is the most critical factor for establishing the current genetic structure of the species. The decrease in abundance of A. spathulifolius along with low levels of genetic diversity indicates that conservation strategies are necessary.