Chloroplast DNA Variation in Some Representatives of the Asian, North American and Mediterranean Firs (Abies spp)

Using PCR-RFLP analysis, a comparative study on the restriction site polymorphism within 8 genes and regions of the Abies chloroplast DNA has been conducted covering 15 Asian, 6 North American and 7 Mediterranean species. A variable degree of divergence was observed among individual species of a given region as well as between geographical groups. A group of the Mediterranean firs, consisting of closely related species, differed profoundly from both Asian and North American representatives. Although a higher level of restriction site variants was detected among the Asian firs, two thirds of them were allocated to the difference between A. mariesii and the other Asian firs. The North American species exhibited the highest level of polymorphism resulting in several subgroups on a cladogram. At the individual species level, the Asian species A. mariesii and the North American species A. lasiocarpa diverged conspicuously from their counterparts in their respective regions. The results of restriction site polymorphism analysis are discussed with ragard to crossability and taxonomic status of individual species.