Evaluation of the Genetic Fidelity of In Vitro Propagated Natural Sweetener Plant (Stevia rebaudiana Bert.) Using DNA-Based Markers

The genetic fidelity of in vitro-raised Stevia rebaudiana clones was assessed by using Random Amplified Polymorphic DNA (RAPD) analysis. A total of 40 RAPD primers were used for initial screening with the mother plant of Stevia but only 29 RAPD decamer produced clear and reproducible bands. The number of scorable bands for each RAPD primer varied from 2 (OPA-15) to 9 (OPA-2). The 29 RAPD primers produced 106 distinct and scorable bands, with an average of 3.6 bands per primer. Each primer generated a unique set of amplification products ranging in size from 350 bp to 2,200 bp. No polymorphism was detected with RAPD analysis using DNA from in vitro-raised plantlets. In this study, the true-to- type nature of the in vitro raised plants was confirmed using DNA-based markers. No genetic variability was detected among the tissue culture-raised plantlets; hence, nodal explants can be successfully employed for the commercial multiplication of Stevia without much risk of genetic instability.