2005 Volume 56 Issue 2 Pages 163-172
New combinations for two taxa, Arabidopsis kamchatica (Fisch. ex DC.) K. Shimizu & Kudoh and A. kamchatica subsp. kawasakiana (Makino) K. Shimizu & Kudoh, are proposed. The lectotypes of both names were chosen. The former taxon was previously recognized as either Arabis kamchatica, Cardaminopsis kamchatica or an infraspecific taxon under Arabis lyrata or Arabidopsis lyrata. The latter was previously recognized as either Arabis kawasakiana, Arabis lyrata subsp. kawasakiana or a synonym of Arabidopsis lyrata subsp. kamchatica. We here report the bivalent nature of meiotic chromosome of A. kamchatica subsp. kawasakiana, n=16_<II> and 2n=32. We also provide a molecular evidence of allotetraploidy using a nuclear Chalcone Synthase (CHS) sequence. In conjunction with former chromosomal and morphological studies, we considered that both taxa should be placed under the genus Arabidopsis but distinct from Arabidopsis lyrata. Arabidopsis kamchatica will provide a unique opportunity for the molecular genetic analysis of genome duplication, by utilizing the genetic and genomic information on a model species Arabidopsis thaliana.