Assessment of genetic and biochemical diversity of Stevia rebaudiana Bertoni by DNA fingerprinting and HPLC analysis

The genomic DNA polymorphism and phytochemical variation of Stevia rebaudiana Bertoni was investigated by RAPD-PCR and HPLC analysis. For initial PCR screening, about hundred oligo-nucleotide primers were used to amplify the genomic DNA from three accessions of S. rebaudiana (L1 to L3). The concentration of stevioside content was quantified by using HPLC analysis. A total of 9 primers were finally selected to generate RAPD fingerprints that revealed 111 bands, in which 90 bands (81%) were found to be polymorphic bands. Three accessions were clustered into two major groups in the dendrogram and the stevioside content variation was linearly associated with these groups. This result was further confirmed by principle coordinate analysis. There was also high diversity in the concentration of active compounds in the collected samples as revealed by HPLC analysis. Data revealed that stevioside content varied between 15.82 mg/g DW (L1) to 4.68 mg/g DW (L3). The present results suggested that there was a strong correlation between the phytochemical variables and the DNA polymorphism data. The present study concluded that the results of the genetic and phytochemical diversity could be used to select best accessions for planting and conservation of S. rebaudiana for pharmaceutical applications.