The Japanese Society for Plant Systematics NII-Electronic Library Service The JapaneseSociety for Plant Systematics ISSN 1346-7565 Acta Phytotax. Geobot,56 {2): 163-172 (2005) Arabidopsis kamchatica (Fisch. ex DC.) K. Shimizu & Kudoh andA. kamchatica subsp. kawasakiana (Makino) K. Shimizu & Kudoh, New Combinations KENTARO K. SHIMIZUi･2', SHINJI FUJII3, KAROL MARHOLD4･5, KUNIAKI WATANABE6 and HIROSHI KUDOH6 iDepartment ofGenetics, IVOrth Caroiina State Uhiversity, 3513 GanherHdt4 Rateigh, IVC 27695,[JSA; 2Department ofBotanM thcul4] ofSlrience, 1<),oto U}iiversic" SZikyo-ku, Rbpoto 606-8502, .Jku)an; 3Division of Htiman Environmunt University ofHiiman Environments, Mbtojukzt, Ohazaki, Aiehi 444-3503, .L4RtlN]' 4institute of Botatzy Slovak Acadenry qfScience, DiZbvavskd cesta 14, SKL845 23 Bratistava, SlovakRepublic; 5Dqpartment of Bota,zM Chartes UitiversicM Bendtskd 2, CZ-128 Ol Praha 2, C2ech Republic; tiDepartment ofBiology Facutty of Sbience,Kbbe-Uhiversipt ?Vdda-ku,Kbbe 657-8501, Japan New combinations fbr twe taxa, ArabidQpsis hamchatica (Fisch. ex DC.) K. Shimizu & Kudoh and A, hamchaticasubsp. kawasaldana (Makino) K. Shimizu & Kudoh, are proposed. The lectotypes of bothnames werc choscn, The fbrmertaxon was previously recognized as either Arabis kamchatiea, Catddminopsis kamehatiea or an infraspecific taxon undcr Avabis lyrata or Arabictqpsis lyrata. The lat- terwas previeusly recogriized as either Arabis ha}vasakiana, Arabis lyrata subsp. hawasantana or a syn- enym ofAfttbitmpsis 4viuta subsp. kamchatica.We hcrc rcport the bivalcnt naturc of mciotic chromosomc ofA. kamchatica subsp. kawasakiana, n = 16ii and 2n = 32. We also proyidc a molecular evidence of allotetraploidy using a nuclear ChalconeSynthase (CJIS) sequence. In coajunction with fbrmer chro- mosomal and morphological studies, we considered that bothtaxa should bc placcd undcr thc gcnus Arabidopsis but distinct fi:om Arabidqpsis lyrata, Arabidopsis kanichatica will provide a unique oppertunity for the molecular genetic analysis of genome duplication, by utilizing the genetic and genom- ic infbnnation on a mode] species Anabidopsis thaliana. Key wordsi Ambidopsis, Avabis,bivalent chromosome, lyrata, tetraploid Cketzinminopsis, Cms, hamchatica,hawasakiana' Arabidopsis thaliana (L,) Heynh. has been exten- sively studied as a model organism for genetic and genomic research. Recently, other species of the genus Arabidopsis (DC.) Heynh, have also been studied as model systems fbr evolutionary and eco- logical studies. The wide array ofnatural variation in morphology, phenology, and physiology found in these species can be a rich source for molecular genetic studics, given the huge amount of infbr- mation already available for Arabidepsis thaiiana (Alonso-Blanco & Koomneef2000, Mitchell-Olds 2001, Meyerowitz 2002, Shimizu 2002, Weigel & Glazebrook 2002,Shimizu& Purugganan 2005). Arabidopsis lyrata (L.) O'Kane & Al-Shehbaz subsp. Ly'rata and subsp. petraea (L.) O'Kane & Al-Shehbaz are often used as reference taxainevo- " corrcspondcnce should be addressed (email: kshimizu@ncsu.edu)