Intraspecific Variation of cpDNA in Magnolia virginiana Native to Eastern-southeastern North America and Cuba

摘要

Magnolia virginiana is a native American species belonging to section Magnolia. To better understand intraspecific taxonomy of Magnolia virginiana, we conducted molecular phylogenetic analysis based on sequences of cpDNA. Fresh leaves were collected from 25 populations covering the entire distribution of the species, including the recently discovered Cuban population, and sequences of seven non-coding regions of the cpDNA were determined (ca. 5000 bp). A total of nine haplotypes were recognized in the sequence data matrix of M. virginiana. Phylogenetic analysis of the sequences clearly indicated that populations ofM virginiana are divided into two major groups - one in the north and one across the south - which are essentially concordant with the morphological classification. Five nucleotide substitutions were found between them. Within the southern group, populations of Texas (and adjacent areas) and Tennessee formed a clade by additional substitution (s), respectively. Three haplotypes were found only in Florida. The haplotype of the Cuban population was the same as the major haplotype of the southern group.