Genetic analysis of silver-fir populations in the North Carpathian and Sudeten Mountains

Abstract

Seeds collected from individual trees in the 16 Carpathian and 2 Sudeten silver-fir (Abies alba) populations were studied with the starch gel electrophoresis in megagametophytes using 14 enzyme systems with 28 loci. The results show that the geographical distance between populations are in a small part reflected in genetic distances. There are two main groups of populations: Sudeten and Carpathian with a very big genetic distance between them. Other populations consist of a few small groups with low gene flow between them (N_m = 3.286). About 80% of genetic variation is located within populations (F_ST = 0.223). Average values for genetic multiplicity and diversity for Carpathian populations are as follows: number of alleles per locus: Na = 2.308, with effective number of alleles Ne = 1.552 and proportion of polymorphic loci 71.21%. The mean number of alleles per locus (Na) varied from 2.107 to 2.607 in population. The mean effective number of alleles per locus (Ne) ranged from 1.429 to 1.662. Average Fis for Carpathian populations was -0.021, which means that there is small excess of heterozygotes. The average observed heterozygosity amounted to Ho = 0.275 and expected heterozygosity was He = 0.269. The dendrogram structure and presence of rare alleles found in silver-fir of Czech, and Slovakian populations allow for a hypothesis that in postglaciation the silver-fir moved into the Polish Carpathians not westward from the east but from the south along river valleys from some Balkan refuges, getting North bypassing the High Tatra Range. This way, a highly diversified set of populations originated, differ in the presence of rare alleles. This differentiation is not prevented by a relatively small flow of genes between populations. The calculated gene flow Nm = 3.286 also indicates isolation between the populations. It means 3.3 immigrants per generation into the studied populations.