Abstract:

The restriction fragment length polymorphism (RFLP) of cpDNA among five larch species were detected by using six endonucleases and eleven probes (cloned fragments from cpDNA of P. contorta). The results showed that there are differentiation in cpDNA among the larch species one another. Polymorphisms were largely concentrated on the combinations of enzyme Dral, Be1l, HindIII, and probes H132, H273, H157 and K140. The estimates of the number of cpDNA nucleotide substitutions per site (d) based on all 193 characters between all pairs of species ranged from 0.00017 to 0.00873. The phylogenrtic tree conducted with d values suggested that there are three groups of evolution phylogeny. L. gmelinii and L. kaempfora belong to one group with miner differentiation between them. L. sibiraca and L. laricina were the Pair of species with a close relationship, though there were evident polymorphisms between them. This relationship provided a new information for the polygeny of larch species between Eurasian and America. Having a great differentiation in cpDNA with other species suggested that L. griffithiana was one of the most primary species in Larix genus.

Key words: La ch Species, cpDNA Polymorphism, Polygenetic Relationship