RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISMS OF A CHLOROPLAST PHOTOSYSTEM-II GENE FROM POPLAR AND THEIR USE FOR SPECIES IDENTIFICATION

In a total DNA library from the poplar clone Beaupre (Populus trichocarpa X P. deltoides) one DNA clone was found to identify restriction site polymorphisms in different poplar species. This clone represents a cpDNA gene that shows close homology to a photosystem II gene of pea and spinach coding for the D2 protein and the 44 kDa reaction centre. In Southern blot analysis this probe identified interspecific restriction site variation among the different poplar species; intraspecific variation was not detectable. As the chloroplast genome is maternally inherited in poplars this cpDNA probe was used for identification of P. nigra or P. deltoides as the seed parents of F-1 hybrid trees in natural stands of western Germany.