Genetic Diversification of Oberonia (Orchidaceae) in Japan, with Implications for the Species Taxonomy

抄録

The taxonomy of Japanese Oberonia, particularly O. makinoi, has been confusing. Molecular analyses of Japanese Oberonia, including plants called “O. makinoi,” were performed. Phylogenetic trees deduced from the nuclear internal transcribed spacer (ITS) region, the plastid matK with trnK introns, and single-nucleotide polymorphisms (SNPs) data derived from MIG-seq show that “O. makinoi” collected from Shikoku and Kyushu is distinctive from the other species of Oberonia. The plants called “O. makinoi” differ from O. japonica in the leaf size and the flowering season. Furthermore, samples from the Ryukyus (Okinawa and Amami Islands) appear conspecific with, or closely related to “O. makinoi.” The taxonomic treatment of Japanese Oberonia requires further analyses using samples collected from central Japan and comparison to congeners in neighboring areas, particularly in Taiwan, where similar species are distributed.