CHLOROPLAST DNA PHYLOGEOGRAPHY OF ALNUS-GLUTINOSA (L.) GAERTN

Traditionally, information on the postglacial history of plant species has been gained from the analysis of fossil pollen data. More recentl y, surveys of present patterns of genetic variation have given valuabl e insights into species phylogeography. The genus Alnus, based on foss il data, is known to have had at least four glacial refugia. A survey of chloroplast DNA (cpDNA) diversity in populations of black alder (A. glutinosa) was undertaken in order to gain more insight into its post glacial history. This revealed a high degree of structuring of 13 cpDN A haplotypes on a European scale which indicated that most of northern and central Europe was colonized from a refuge in the Carpathian Moun tains. Based on the distribution of two common cpDNA haplotypes, colon ization routes from this refuge can be determined. The locations of ot her previously identified refugia are confirmed and two formerly uncon firmed refugial areas for alder (southern Spain and Turkey) are propos ed.