Chloroplast DNA diversity within and among populations of the allotetraploid Prunus spinosa L.

High chloroplast DNA (cpDNA) diversity was found within and among populations of Prunus spinosa sampled from seven European deciduous forests. A study of 12% of the total chloroplast genome detected 44 mutations, which were distributed over 24 haplotypes; four were common to two or more populations and the rest were unique haplotypes. The most-abundant and widely distributed haplotype was H2 (frequency = 41% approximately). Six of the seven populations were polymorphic. All of the six polymorphic populations had ”private” haplotypes (frequency < 5%) in addition to common haplotypes. The UPGMA dendrogram demonstrated a correlation between populations and their geographical locations. The total diversity was high (h_T= 0.824) and a major portion of it was within populations (h_s= 0.663). The level of population subdivision for unordered alleles was low (G_ST= 19.5%) and for ordered alleles was lower (N_ST= 13.6%). No phylogeographic structure could be demonstrated in the present geographical scale. High polymorphism in the cpDNA of P. spinosa has to be considered carefully when planning phylogenetic studies involving this species. Received: 20 September 1999 / Accepted: 10 November 1999