Effectiveness of an innovative prototype subtracted diversity array (SDA) for fingerprinting plant species of medicinal importance

The accurate identification of medicinal plants is becoming increasingly important due to reported concerns about purity, quality and safety. The previously developed prototype subtracted diversity array (SDA) had been validated for the ability to distinguish clade-level targets in a phylogenetically accurate manner. This study represents the rigorous investigation of the SDA for genotyping capabilities, including the genotyping of plant species not included during the construction of the SDA, aswell as to lower classification levels including family and species. The results show that the SDA, in its current form, has the ability to accurately genotype species not included during SDA development to clade level. Additionally, for those species that were included during SDA development, genotyping is successful to the family level, and to the species level with minor exceptions. Twenty polymorphic SDA features were sequenced in a first attempt to characterize the polymorphic DNA between species, which showed that transposon-like sequences may be valuable as polymorphic features to differentiate angiosperm families and species. Future refinements of the SDA to allow more sensitive genotyping are discussed with the overall goal of accurate medicinal plant identification in mind.