The use of esterase polymorphism for analysis of the genetic diversity and structure of stevia (Stevia rebaudiana Bert. Bertoni) populations

AbstractNative polyacrylamide gel electrophoresis was used in the current study to identify polymorphisms in α- and β-esterase loci in the leaves of Stevia rebaudiana Bert. Bertoni. The esterases produced from the Est-2 and Est-4 loci were observed as strongly stained bands, and four alleles were detected at each of these loci from the 428 analysed S. rebaudiana plants. The observed and expected mean heterozygosity were higher in populations maintained by genetically breeding plants for higher glycoside production than in plant populations propagated by seeds or maintained by vegetative propagation. The esterase analysis employed in this study showed that the artificial selection of plant samples with specific uniform characteristics, such increased height and precocious flowering, may lead to the fixation of alleles and α/β-esterase phenotype patterns in S. rebaudiana populations. The uniform α/β-esterase phenotype may be applied in the monitoring of genetic stability in selected populations for specific traits of interest