Identification of mitochondrial plasmid like DNAs in Picea abies (L.) Karst.

The Norway spruce (Picea abies (L.) Karst.) mitochondrial DNA has been extr acted from embryonal suspensor masses. In addition to a master chromosome, a family of plasmid-like DNAs were identified. These latter shared cross ho mologies but had no evident sequence homology with the master chromosome. T he occurrence of mitochondrial plasmid-like DNAs was investigated in trees from different provenances. A vast majority of trees displayed extrachromos omal DNA elements of variable stoechiometry. For some trees, the sequences homologous to the extrachromosomal DNA elements were found associated with high molecular weight DNA.