Pattern of genetic differentiation in Gentiana pannonica Scop.: did subalpine plants survive glacial events at low altitudes in Central Europe?

Abstract

The molecular population structure of 20 populations of the subalpine plant Gentiana pannonica was studied by use of amplified fragment length polymorphism (AFLP) and sequencing of non-coding regions of plastid DNA. Of the populations sampled, 18 were native (11 were from the Eastern Alps, which is the distribution centre of the species, and seven were from the Bohemian Forest, which is on the margin of the distribution range), and two were from the Giant Mts and of unclear status. No plastid DNA polymorphisms were found within the entire 6,185 bp investigated. The AFLP data revealed grouping of populations at the regional level. However, differentiation at the regional level (10.3 %) and at the interpopulation level (14.2 %) was low. Even though current populations are isolated and contain small numbers of individuals, the within-population variation (75.511 %) was high. Genetic variation was higher for alpine populations than for Bohemian Forest populations, probably because of fundamental differences in historical changes in population size between these regions. Within-population variation was intermediate for populations in the Giant Mts. The results indicate the possibility of a large distribution of species in the unglaciated areas of Central Europe, irrespective of altitude, during the late Pleistocene and early Holocene. Our results do not confirm that G.pannonica was introduced in the Giant Mts, and native status in the Giant Mts is possible.