Using nuclear and organelle DNA markers to discriminate among Picea rubens, Picea mariana, and their hybrids

The pattern of nuclear ribosomal alleles in controlled-cross black spruce X red spruce hybrids was compared with that of samples from provenance tests of the entire range of red spruce (Picea rubens Sarg.) and the eastern complex of black spruce (Picea mariana (Mill.) BSP). In addition, restriction fragment length polymorphisms were identified for the organelle genomes of red spruce and black spruce. Organelle haplotypes were closely associated with species, but were not species specific. Data from controlled-cross hybrids suggest that mitochondria are maternally inherited and chloroplasts are paternally inherited in these spruce species. Organelle markers were combined with restriction fragment length polymorphism data from the nuclear rDNA repeat to derive a simple three-character index capable of identifying red spruce, black spruce, and hybrids of the two species.