Development of Stevia rebaudiana Production in Europe: Germplasm Evaluation and Molecular Markers Development for Breeding Purposes

Stevia rebaudiana belongs to the Asteraceae family. Its leaves can accumulate high concentrations (up to 30%) of different glycosides derived from the tetracyclic diterpene steviol. These steviol glycosides have the characteristics of high sweetness and low calories. Leaf powder of Stevia or steviol glycosides extracts are used for several years in many countries. Recently, in 2011, using RebA extract from Stevia rebaudiana leaves was allowed for use as a food additive in EU countries. At that time, Stevia rebaudiana is mainly produced in China. But, the opening of this new market leads to the development of Stevia rebaudiana production in European countries. The main point is to be able to provide farmers with adapted cultivars. For that purpose, we gathered Stevia rebaudiana germplasm. A collection of 15 genotypes was studied in two environnements in the South West of France. Plants were evaluated for biomass traits and Steviol glycosides (SGs) content and quality. This first analyse revealed the potential of some genotypes in our field conditions. In the same time, due to a huge lack of sequence data SSR markers were developed to classify this germplasm. The polymorphism of the 42 selected microsatellite markers was assessed on a set of 26 genotypes from different geographical area including commercialized genotypes and other species belonging to Stevia genus. This allowed us to classify our genetic diversity. The development of SNP markers is ongoing to support our breeding program.