title: A PCR marker linked to a THCA synthase polymorphism is a reliable tool to discriminate potentially THC-rich plants of Cannabis sativa L.
abstract: Neither absolute THC content nor morphology allows the unequivocal discrimination of fiber cultivars and drug strains of Cannabis sativa L. unequivocally. However, the CBD/THC ratio remains constant throughout the plant's life cycle, is independent of environmental factors, and considered to be controlled by a single locus (B) with two codominant alleles (B(T) and B(D)). The homozygous B(T)/B(T) genotype underlies the THC-predominant phenotype, B(D)/B(D) is CBD predominant, and an intermediate phenotype is induced by the heterozygous state (B(T)/B(D)). Using PCR-based markers in two segregating populations, we proved that the THCA synthase gene represents the postulated B locus and that specific sequence polymorphisms are absolutely linked either to the THC-predominant or the THC-intermediate chemotype. The absolute linkage provides an excellent reliability of the marker signal in forensic casework. For validation, the species-specific marker system was applied to a large number of casework samples and fiber hemp cultivars.
authors.affiliation: Department of Forensic Science, Landeskriminalamt (LKA) Rheinland-Pfalz, Valenciaplatz 1-7, D-55118, Mainz, Germany; Biocentre, University of Frankfurt, Marie-Curie Str. 9, D-60439, Frankfurt, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Staginnus
authors.forename: Siegfried
authors.initials: S
authors.lastname: Zörntlein
authors.forename: Etienne
authors.initials: E
authors.lastname: de Meijer
mesh_terms: D002185:Cannabidiol / Q000737:chemistry; D002188:Cannabis / Q000737:chemistry / Q000235:genetics*; D013759:Dronabinol / Q000737:chemistry; D008040:Genetic Linkage; D005819:Genetic Markers; D019746:Intramolecular Oxidoreductases / Q000235:genetics*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D017421:Sequence Analysis; D013045:Species Specificity
chemical_list: D005819:Genetic Markers; D002185:Cannabidiol; D013759:Dronabinol; D019746:Intramolecular Oxidoreductases; C100677:delta(1)-tetrahydrocannabinolic acid synthase
keywords: Cannabis sativa L.; THCA synthase; chemotype; forensic science; genetic segregation; linkage; molecular marker; species-specific