The historical evolutionary development of Hemerocallis middendorfii (Hemerocallidaceae) revealed by non-coding regions in chloroplast DNA

A procedure in which combined molecular phylogeographical analyses among populations of Hemerocallis middendorfii (Hemerocallidaceae, Asparagales) were applied allowed comparisons to be made with the geological history. Information on geographical areas in which synapomorphic mutations occurred was used in molecular phylogeographical analyses for the first time in this study, in addition to molecular maximum-parsimonious analyses and TCS analyses. Nucleotide sequences of the intergenic region between the rbcL and atpB genes and the trnL (UAA) intron in chloroplast DNA were analyzed for 28 Japanese and three Chinese populations of H. middendorfii, 10 populations of closely related species and four outgroup species. The data of the three analyses in general agreed with one another and indicated that the separation of this species had proceeded in conjunction with the geological vicariance or orogeny. Where the synapomorphic mutations occurred, three patterns were recognized. They correlated with the geological history, namely, the age when the Japanese Archipelago and the Continent had joined, when the Sea of Japan was formed, and when there was separation from the Continent and the formation of each of the islands in the Japanese Archipelago. It was suggested that ancestors of H. middendorfii originated at latest 25 million years ago when the Japanese Archipelago and the Continent had joined; that is, before the formation of the Sea of Japan.