title: The inheritance of chemical phenotype in Cannabis sativa L.
abstract: Four crosses were made between inbred Cannabis sativa plants with pure cannabidiol (CBD) and pure Delta-9-tetrahydrocannabinol (THC) chemotypes. All the plants belonging to the F(1)'s were analyzed by gas chromatography for cannabinoid composition and constantly found to have a mixed CBD-THC chemotype. Ten individual F(1) plants were self-fertilized, and 10 inbred F(2) offspring were collected and analyzed. In all cases, a segregation of the three chemotypes (pure CBD, mixed CBD-THC, and pure THC) fitting a 1:2:1 proportion was observed. The CBD/THC ratio was found to be significantly progeny specific and transmitted from each F(1) to the F(2)'s derived from it. A model involving one locus, B, with two alleles, B(D) and B(T), is proposed, with the two alleles being codominant. The mixed chemotypes are interpreted as due to the genotype B(D)/B(T) at the B locus, while the pure-chemotype plants are due to homozygosity at the B locus (either B(D)/B(D) or B(T)/B(T)). It is suggested that such codominance is due to the codification by the two alleles for different isoforms of the same synthase, having different specificity for the conversion of the common precursor cannabigerol into CBD or THC, respectively. The F(2) segregating groups were used in a bulk segregant analysis of the pooled DNAs for screening RAPD primers; three chemotype-associated markers are described, one of which has been transformed in a sequence-characterized amplified region (SCAR) marker and shows tight linkage to the chemotype and codominance.
authors.affiliation: HortaPharm B.V., 1075 VS, Amsterdam, The Netherlands.
authors.forename: Etienne P M
authors.initials: EP
authors.lastname: de Meijer
authors.forename: Manuela
authors.initials: M
authors.lastname: Bagatta
authors.forename: Andrea
authors.initials: A
authors.lastname: Carboni
authors.forename: Paola
authors.initials: P
authors.lastname: Crucitti
authors.forename: V M Cristiana
authors.initials: VM
authors.lastname: Moliterni
authors.forename: Paolo
authors.initials: P
authors.lastname: Ranalli
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Mandolino
mesh_terms: D002185:Cannabidiol / Q000378:metabolism*; D002188:Cannabis / Q000235:genetics* / Q000378:metabolism; D003433:Crosses, Genetic; D013759:Dronabinol / Q000378:metabolism*; D005819:Genetic Markers; D014644:Genetic Variation
chemical_list: D005819:Genetic Markers; D002185:Cannabidiol; D013759:Dronabinol