Tandem repeats in plant mitochondrial genomes: application to the analysisof population differentiation in the conifer Norway spruce

Mitochondrial DNA, widely applied in studies of population differentiation in animals, is rarely used in plants because of its slow rate of sequence e volution and its complex genomic organization. We demonstrate the utility o f two polymorphic mitochondrial tandem repeats located in the second intron of the nad1 gene of Norway spruce. Most of the size variants showed pronou nced population differentiation and a distinct geographical distribution. A GenBank search revealed that mitochondrial tandem repeats occur in a broad range of plant species and may serve as a novel molecular marker for unrav elling population processes in plants.