Molecular Systematics of the Chinese Yinshania (Brassicaceae): Evidence from Plastid and Nuclear Its DNA Sequence Data

Species of the Chinese endemic genera Yimhania, Hilliella, and Cochleariella were originally i)laced in or closely associated with Cochlearia. A previous preliminary molecular study mainly on European Cochlearia and detailed morphological studies by us showed that this complex was not affined to Cochlearia s. str. Depending on the authority consulted, the number of taxa recognized in this complex ranged from 11 to 25 species in one to four genera. The present phylogcnetic study is based on the analysis of the ITS (internal transcribed spacer regions of the nuclear ribosomal DNA) and the chloroplast frnL-intron sequences from 18 taxa. Resulting phylogenies were compared, and the results demonstrate that there are two different lineages. One lineage combines exclusively the highly polyploid taxa from Hilliella and Cochleariella. The second lineage includes the diploid taxa from Yinshania, However, incon-gruencies when nrDNA-and cpDNA-derived phylogenies were compared suggest hybridization between these two lineages. We followed a concept to combine all taxa of this complex into the genus Yirishania. Our results from phylogcnetic analysis of nr and cpDNA support the association of Yinshania with Cardamine and Rorippa, rather than with Cochlearia, as was suggested by nearly all previous authors.