Phylogeography of the high alpine cushion-plant Androsace alpina (Primulaceae) in the Alps

Abstract

Androsace alpina is a perennial cushion plant endemic to high alpine to nival habitats in silicious mountain ranges of the European Alps where it ascends up to 4200 m. The plant can be round in major portions of the Alps, but although the distribution is rather continuous, A. alpina does not occur in postulated major refugial areas in the Southwestern Alps or the Eastern Alps. This distribution pattern might be interpreted as an indication for in situ survival on nunataks during the ice ages. To test this hypothesis, we investigated 259 individuals from 53 populations covering the entire distribution area of A. alpina using AFLP-fingerprinting. With three primer combinations used, 218 unambigously scorable fragments were generated, 177 of which (81.2 % ) were polymorphic. The FST-value under the random-mating hypothesis among all populations was 0.8 (95% C.l. 0.45–0.51), the Shannon-Index ranged from 4.26-4.50. Both a UPGMA clustering or the populations and a Principal Coordinate Analysis between pairs of individuals revealed a relatively high geographical structuring beween groups of populations. An AMOVA conducted on those groups partitioned the overall variation into 57.7% variation within populations, 19.7% among populations and the comparatively high value of 22.6% among regions.