Phylogenetic analysis of the DNA sequence of the non-coding region of nuclear ribosomal DNA and chloroplast of Ephedra plants in China

Twenty-four Ephedra plants belonging to 8 species grown in the northern and western parts of China were phylogenetically analyzed for their non-coding DNA sequences, internal transcribed spacers (ITSs) of nuclear ribosomal DNA as well as trnL intron and intergenic spacers between trnL and trnF (trnL/trnF) of the chloroplast. Based on the ITS sequences, the 8 species could be divided into 3 groups: Group 1 (Ephedra intermedia, E. sinica, E. przewalskii), Group 2 (E. equisetina, E. monosperma, E. gerardiana), and Group 3 (E. likiangensis, E. minuta). The species classified into Group 1 grow mainly in the north, Group 3 in the south and Group 2 in the center, suggesting their genetic and geographic relationships. A specific primer set was designed to classify the 3 groups by routine PCR. Combined analysis of ITS and trnL/trnF differentiated the 8 Ephedra species.