Efficiency of improved RAPD and ISSR markers in assessing genetic diversity and relationships in Angelica sinensis (Oliv. ) Diels varieties of China

Background Angelica sinensis is a well-known traditional Chinese medicinal plant. We aimed to assess the genetic diversity and relationships in A. sinensis cultivars collected from different locations of China and also some other Angelica species. Results We employed an improved random amplified polymorphic DNA (RAPD) technique for the amplification of DNA materials from ten Angelica cultivars, and the results were verified by inter-simple sequence repeat (ISSR) analysis. Twenty six RAPD primers were used for RAPD, and the amplified bands were found highly polymorphic (96%). Each primer amplified 8-14 bands with an average of 10.25. The cluster dendrogram showed that the similarity coefficients ranged from 0.41 to 0.92. The similarity coefficients were higher among different cultivars of A. sinensis, and lower among different species. Twenty ISSR primers were used for the amplification, and each primer generated 6-10 bands with an average of 7.2 bands per primer. The cluster dendrogram showed that the similarity coefficients ranged from 0.35 to 0.89. Conclusions This study genetically characterized the Angelica species, which might have a significant contribution to the genetic and ecological conservation of this important medicinal plant. Also, this study indicates that the improved RAPD and ISSR analyses are important and potent molecular tools for the study of genetic diversity and authentication of organisms.

Development and significance of RAPD-SCAR markers for the identification of Litchi chinensis Sonn: by improved RAPD amplification and molecular cloning

Background Analysis of genetic diversity is important for the authentication of a species. Litchi (Litchi chinensis Sonn.) is a subtropical evergreen tree. Recently, L. chinensis has been characterized by an improved random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) analysis. The goal of this study was to develop sequence-characterized amplified region (SCAR) markers from the improved RAPD fragments for the genetic analysis of L. chinensis. Results The improved RAPD fragments from L. chinensis were cloned, sequenced and converted into stable SCAR markers. Sequencing of three cloned RAPD fragments revealed that the clone L7-16 consisted of 222 nucleotides (GenBank accession number KM235222), clone L9-6 consisted of 648 nucleotides (GenBank accession number KM235223), and clone L11-26 consisted of 369 nucleotides (GenBank accession number KM235224). Then, specific primers for SCAR markers L7-16, L9-6, and L11-26 were designed and synthesized. PCR amplification was performed using DNA templates from 24 different samples, including 6 samples of L. chinensis and other plants. The SCAR marker L9-6 was specific for all of the L. chinensis samples, the SCAR marker L11-26 specific for five L. chinensis samples, and the SCAR marker L7-16 only specific for the samples from Luzhou. Conclusions This study developed stable SCAR markers for the identification of L. chinensis by the cloning of the improved RAPD fragments. Combining RAPD and SCAR markers provides a simple and reliable tool for the genetic characterization of plant species.