Microsatellite Variation and its Comparison with Allozyme and RAPD Variation in Elymus Fibrosus (Schrenk) Tzvel. (Poaceae)

Genetic variation of ten Elymus fibrosus populations was analyzed using six microsatellite loci. The mean number of alleles per locus (A) was 1.8, ranging from 1.3 to 2.3, the mean percent of polymorphic loci (P) was 53.3%, ranging from 16.7% to 83.3%, and the mean gene diversity (HT) was 0.252, varying from 0.063 to 0.444. The total microsatellite variation for the species was HT=0.548. When partitioned (GST), 54% of the total variation was found among populations. Specific alleles were observed for different populations and geographical areas. In comparison with the genetic variation detected by allozymes and RAPDs, microsatellite loci always showed higher levels of genetic variation. For instance, the gene diversity (He) found at microsatellite loci was approximately 30 and 3 times higher than that at allozyme and RAPD loci (He= 0.008 and He= 0.097, respectively). In general, different pictures of the amount of the genetic variation were given by isozyme, RAPD and microsatellites but agreement was found regarding how this genetic variation is distributed among populations. In addition, a geographical pattern of population differentiation, where the Finnish and Russian populations were clearly separated from each other, was revealed by both the cluster and principal coordinates analyses when using both RAPDs and microsatellites.