Genetic variation and population history of three related fir species Abies sachalinensis, A. nephrolepis and A. gracilis (Pinaceae) revealed by nuclear microsatellites

Seventeen nuclear microsatellite loci (nSSR) were used to study the genetic diversity and historical demography of three Northeast Asian fir species: insular Sakhalin fir Abies sachalinensis (Fr. Schmidt) Mast., continental A. nephrolepis (Trautv.) Maxim. and Kamchatka endemic A. gracilis Kom. Bayesian clustering, performed using the STRUCTURE software separated the considered species from each other and divided A. sachalinensis populations into several groups located from south to north. According to the results of ABC analysis, the ancestors of A. nephrolepis and the ancestors of southern populations of A. sachalinensis split about 600 ka BP. Populations of A. sachalinensis of northern Sakhalin originated from A. nephrolepis about 300 ka BP. Populations of central Sakhalin were formed, probably, as a result of mixing of populations of northern and southern Sakhalin during the late glacial (about 18 ka BP). The origin of the A. gracilis is inferred as a result of separation from populations of northern Sakhalin, probably before the last glacial maximum.