Spatial and temporal genetic variation in natural and ex situ populations of two Silene species in Brandenburg/Germany
Lauterbach Daniel1, Birgit Gemeinholzer1
1 Botanischer Garten und Botanisches Museum Berlin- Dahlem, Freie Universität Berlin
D7.O-1 in Molecular Biogeography in Face of Climate Change
16.09.2009, 09:30-09:45, H16, NWII
Climatic change might affect the spatial and temporal distribution pattern of species and populations. For the endangered dry grassland species Silene chlorantha and S. otites we examined, 1) the spatial genetic population pattern 2) the effect of population size upon the genetic diversity of fragmented populations and 3) the temporal influence upon population genetic diversity. Relationships between natural populations as well as 20 year old ex situ cultures at the Berlin Botanic Garden were analysed using AFLP technique. Three primer combinations provided 111 polymorphic bands in 12 populations of S. chlorantha and 203 polymorphic bands in 11 populations of S. otites. Relatively high Fst values indicate clear differences between populations of both species. Neighbour-joining tree and Bayesian approach clustering analyses support regional structuring. There is a correlation between geographical and genetic distances among populations of S. otites in contrast to S. chlorantha. Correlation of population size and amount of genetic variation is slightly positive. Genetic differentiation between in- and ex situ population is not apparent in S. chlorantha and weak in S. otites. However, there is a strong differentiation between natural populations. The current geographic population structure is probably a result of long time fragmentation. Contrary to the general expectation, genetic composition in ex situ culture of these long-lived species was maintained during cultivation time.