Migration of Lobelia zeylanica (Campanulaceae) from Taiwan to the Ryukyu Archipelago Inferred from Chloroplast DNA Data Goro Kokubugata 1, * , Yukiko Saito 1 , Koh Nakamura 2 , Aurea Lopez-Feliciano 3 , Mina L. Labuguen 4 and Masatsugu Yokota 5 1 Department of Botany, National Museum of Nature and Science, Amakubo 4–1–1, Tsukuba, Ibaraki 305–0005, Japan 2 Biodiversity Research Center, Academia Sinica, Nangang, Taipei 115, Taiwan 3 Isabela State University, Echague, Isabela, Philippines 4 Community Environment and Natural Resources Office, Cauayan, Isabela, Philippines 5 Laboratory of Ecology and Systematics, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903–0213, Japan * E-mail: gkokubu@kahaku.go.jp (Received 12 February 2013; accepted 25 March 2013) Abstract Molecular phylogenetic analysis of Lobelia zeylanica, broadly distributed in tropical Asia, were conducted to elucidate its migration route to the northernmost populations in subtropic Yonaguni Island, the Ryukyu Archipelago of Japan. The present analysis using rbcL gene and trnL-F intergenic spacer region of chloroplast DNA revealed that all two Yonaguni plants and three of four Taiwanese plants shared the identical sequences in the two markers. They formed a well- supported clade with a Taiwanese remainder and were separated from plants from Malesian regions. The present study suggests that L. zeylanica have likely migrated from Taiwan to Yona- guni Island. Key words : Lobelia, migration, phylogeography, Ryukyus, Taiwan. Introduction The Ryukyu Archipelago (the Ryukyus) is sit- uated between Kyushu Island of Japan and Tai- wan, and comprises about 140 islands (Fig. 1). The Ryukyus is biogeographically divided into three major areas, namely, the northern, central and southern Ryukyus, each of which has a char- acteristic biota (e.g., Tagawa and Miyagi, 1991; Ota, 1998; Nakamura et al., 2009). Yonaguni Island studied herein belongs to the southern Ryukyus, and is about 130 km away from Taiwan Island (Fig. 1). Yonaguni and Taiwan islands share many floristic elements including those presumably originated in Malesian region (Hatusima, 1975), but few phylogeographical study has been conducted to elucidate migratory history of such plant taxa. Lobelia zeylanica L. (Campanulaceae, sect. Delostemon) (Fig. 2) is a perennial herb, and widely distributed from New Guinea and Sri Lank (Lammers, 2007) to Yonaguni Island of the Ryukyus (Hatusima, 1975). In Japan, this species is known from only three populations in Yona- guni Island (unpublished data), which marks the northern limit of its distribution range. Thus L. zeylanica is treated as a critically endangered species in the Japanese plant redlist (Japanese Ministry of the Environment, 2012). In this study, we conducted molecular phylogenetic analysis on L. zeylanica collected from Yonaguni Island, Taiwan Island, Luzon Island of the Philip- pines and Borneo Island of Malaysia, using rbcL gene and trnL-F intergenic spacer region of chlo- roplast DNA for discussing its migration route to Yonaguni Island. Bull. Natl. Mus. Nat. Sci., Ser. B, 39(2), pp. 95–100, May 22, 2013