PATERNAL CHLOROPLAST DNA INHERITANCE IN PINUS-CONTORTA AND PINUS-BANKSIANA - INDEPENDENCE OF PARENTAL SPECIES OR CROSS DIRECTION

We studied chloroplast DNA inheritance in 133 Pinus contorta seedlings and in 88 seedlings of interspecific matings between P. contorta and P. banksiana, to determine if the mode of inheritance is consistent in matings within and between these two species. Segregation data from matings of 14 P. contorta parents and five P. banksiana parents, representing a diversity of chloroplast DNA genotypes and geographic sources, were consistent with paternal chloroplast DNA inheritance. Nonetheless, nine nonpaternal seedling genotypes were observed, which may have resulted from contamination, parental chimerism, maternal leakage, or recombination. Our results, taken together with earlier reports, suggest that the paternal predominance of chloroplast DNA inheritance in P. contorts and P. banksiana is independent of parental genotype, geographic source, species, or mating direction. This apparent consistency will be useful for interpretation of cytonuclear data from sympatric populations of these two species.