Kim, Changkyun , KIM, JOO-HWAN .
Molecular phylogeny, historical biogeography, and divergence timeestimates of Maianthemum sensu stricto (Asparagaceae).
Maianthemum sensu stricto, as currently circumscribed, contains three species, i.e., M. bifolium, M. canadense, and M. dilatatum, which have a disjunct distribution in eastern Asia, Europe, and North America. The species of Maianthemum s.s. have variable morphological characters and a wide and often partly overlapping distribution, which makes the identification within and between this group and other Maianthemum species difficult. To clarify the systematic classification and biogeographical history of Maianthemum s.s., a phylogenetic reconstruction based on one nuclear ribosomal internal transcribed spacer and five chloroplast DNA regions (ndhF, rpl16, rps16, trnL-F, and psbAtrnH) was conducted. Our molecular phylogeny suggests that Maianthemum s.s. is monophyletic. However, the accessions of M. dilatatum are divided into two well-defined lineages: one composed of western North American accessions, and the other composed of northeast Asian accessions. The latter is the sister clade of the M. bifolium and M. canadense clade. Molecular dating and biogeographic reconstructions suggest a northeast Asian origin of Maianthemum s.s. and that a complicated divergent evolution began approximately in the late Miocene. Intercontinental disjunctions of Maianthemum s.s. in the Northern Hemisphere appear to have spread during at least two geologic periods: one occurred during the late Miocene between East Asia and western North America, and the other may have occurred during the Pliocene, with relatively recent separations between Eurasia and eastern North America. Based on our results, a new classification of Maianthemum s.s. inferred from a molecular phylogeny is required. We propose to merge the three Maianthemum s.s. species to ensure monophyly at the species level. The biogeographic patterns of Maianthemum s.s. with molecular dating suggest both vicariance and longdistance dispersal events as key mechanisms for its diversification.
1 - Gachon University, Life Science, 1342 Seongnamdae-ro, Sujeong-gu, Seongnam, 13120, KOREA
2 - Gachon University, Dept Of Life Science, 1342 Seongnam-daero, Bokjeong-dong, Sujeong-gu, Seongnam, Gyeonggi-do, N/A, 461-701, Korea
Presentation Type: Oral Paper
Candidate for Awards:None