Abstract
Chloroplast DNA variation in Pedicularis resupinata L. (Scrophulariaceae) was studied in 48 populations from the Japanese archipelago and adjacent regions. Nine distinct cpDNA haplotypes, based on the intergenic spacer between the trnL (UAA) 5'exon and trnF (GAA), were recognized. One cpDNA haplotype was distributed widely (type A), and most of the other haplotypes were found to be geographically structured. Two major clades (I and II) were revealed in phylogenetic analyses among the haplotypes by adding the sequence data from the intergenic spacers of trnT (UGU) and trnL (UAA) 5'exon, and atpB and rbcL. The haplotypes of Clade I were widely distributed not only within the Japanese archipelago, but also on the Korean Peninsula and Sakhalin. Clade II, however, was found only in plants from central Honshu and Shikoku, Japan. These results suggest that the cpDNA haplotypes of Clade II originated within the Japan and remain as relics in central Honshu and Shikoku. The Japanese origins of two endemic taxa, P. resupinata var. caespitosa Koidz. and var. microphylla Honda are also discussed.
