title: DNA-based identification of Calendula officinalis (Asteraceae).
abstract: OBJECTIVE
  For the economically important species Calendula officinalis, a fast identification assay based on high-resolution melting curve analysis was designed. This assay was developed to distinguish C. officinalis from other species of the genus and other Asteraceae genera, and to detect C. officinalis as an adulterant of saffron samples.
  
  
  RESULTS
  For this study, five markers (ITS, rbcL, 5' trnK-matK, psbA-trnH, trnL-trnF) of 10 Calendula species were sequenced and analyzed for species-specific mutations. With the application of two developed primer pairs located in the trnK 5' intron and trnL-trnF, C. officinalis could be distinguished from other species of the genus and all outgroup samples tested. Adulterations of Calendula DNA in saffron could be detected down to 0.01%.
  
  
  CONCLUSIONS
  With the developed assay, C. officinalis can be reliably identified and admixtures of this species as adulterant of saffron can be revealed at low levels.
authors.affiliation: University of Veterinary Medicine, Institute of Animal Nutrition and Functional Plant Compounds, Veterinärplatz 1, 1210 Vienna, Austria.
authors.forename: Corinna
authors.initials: C
authors.lastname: Schmiderer
authors.affiliation: University of Veterinary Medicine, Institute of Animal Nutrition and Functional Plant Compounds, Veterinärplatz 1, 1210 Vienna, Austria.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Lukas
authors.affiliation: University of Veterinary Medicine, Institute of Animal Nutrition and Functional Plant Compounds, Veterinärplatz 1, 1210 Vienna, Austria.
authors.forename: Joana
authors.initials: J
authors.lastname: Ruzicka
authors.affiliation: University of Veterinary Medicine, Institute of Animal Nutrition and Functional Plant Compounds, Veterinärplatz 1, 1210 Vienna, Austria.
authors.forename: Johannes
authors.initials: J
authors.lastname: Novak
keywords: Asteraceae; Calendula; Calendula officinalis; high-resolution melting curve analysis (HRM); molecular phylogeny