Molecular Systematic Research On Epimedium L.

Epimedium L. (Berberidaceae) is an important genus, for 1) no good taxonomic system of the genus has been proposed till now, and the relationships among the species of the genus are not very clear. It is considered that this genus is difficult taxonomically like other genera in Berberidaceae ; 2) herb epimedii, as a traditional Chinese medicine, has been used for very long time, and is the hotpot of modern pharmaceutical studies for its wide and good curative effects. In the present study, the ITS sequences and RAPD characters were used as molecular markers to study the relationships among the taxa of the genus , then a new more reasonable and natural taxonomic system of the genus Epimedium should be proposed.1) The ITS1 and ITS2 sequences of 19 species in Epimedium and 2 species in Vcmcouveria, as outgroups, were determined. It was obvious that Epimedium was quite different from Vcmcouveria. But their pairwise sequence divergence rate is much lower than that among Epimedium and other relative genera in Berberidaceae. This two were sister genera . The pairwise sequence divergence rates among the species of Epimedium were so low, from 0% to 2.5%, that few divergence positions (and information positions) can be used for phylogenetic analysis. The relationships among many groups were suggested with very low support rate. The reason for low level of pairwise sequence divergence rate in Epimedium can not be explained by means of the hypothesis of rapid adaptive radiation and its a little long generation time .2) 202 information bands were obtained from 32 species (populations) in Epimedium including important taxa except E.elatum and 2 outgroup Vcmcouveria species, amplified by 15 RAPD primers. These bands were analyzed, and the neighbor-joining tree and cluster map were established. According to the genetic distance given by RAPD analysis, the relationships among main groups in Epimedium were well resolved, and four groups were divided, i.e. group I ,Chinese species; group II , two species without leaves on the stem distributed in...