Sequence analysis and identification of a chloroplast mat K gene in Rhei Rhizoma from different botanical origins

Rhei Rhizoma is a Chinese medicine with multiple botanical origins. There is a problem to identify it with conventional methods. To compare the characteristics of chloroplast mat K gene sequences of different Rheum species and authenticate inspected species, the mat K gene sequences of different species from different origins were amplified, cloned, and sequenced. Genomic DNA of Rheum plants was extracted using modified DNA extracted Kit and mat K gene sequences were analyzed by ContingExpress, DNAman and MEGA5.0. The length of mat K gene sequences of Rheum palmatum, R. tanguticum and R. officinale were 1 518 bp containing 57 variable loci. According to the mutation sites, R. palmatum, R. tanguticum and R. officinale were divided into different genotypes separately. Based on the established method according to the loci 587, 707, 838, we successfully identified the genuine Rheum species from its adulterants.