Premise: How genetic variation within a species affects phytochemical composition is a fundamental question in botany. The ratio of two specialized metabolites in Cannabis sativa, tetrahydrocannabinol (THC) and cannabidiol (CBD), can be grouped into three main classes (THC-type, CBD-type, and intermediate type). We tested a genetic model associating these three groups with functional and nonfunctional alleles of the cannabidiolic acid synthase gene (CBDAS). Methods: We characterized cannabinoid content and assayed CBDAS genotypes of >300 feral C. sativa plants in Minnesota, United States. We performed a test cross to assess CBDAS inheritance. Twenty clinical cultivars obtained blindly from the National Institute on Drug Abuse and 12 Canadian-certified grain cultivars were also examined. Results: Frequencies of CBD-type, intermediate-type, and THC-type feral plants were 0.88, 0.11, and 0.01, respectively. Although total cannabinoid content varied substantially, the three groupings were perfectly correlated with CBDAS genotypes. Genotype frequencies observed in the test cross were consistent with codominant Mendelian inheritance of the THC:CBD ratio. Despite significant mean differences in total cannabinoid content, CBDAS genotypes blindly predicted the THC:CBD ratio among clinical cultivars, and the same was true for industrial grain cultivars when plants exhibited >0.5% total cannabinoid content. Conclusions: Our results extend the generality of the inheritance model for THC:CBD to diverse C. sativa accessions and demonstrate that CBDAS genotyping can predict the ratio in a variety of practical applications. Cannabinoid profiles and associated CBDAS segregation patterns suggest that feral C. sativa populations are potentially valuable experimental systems and sources of germplasm.
Bibliographical noteFunding Information:
This study was supported by the Minnesota Department of Agriculture (H006142601 & H007044801) and Dr. Bronner’s Magic Soaps (All One God Faith, Inc.). We acknowledge the National Institute on Drug Abuse, Contract #N01DA‐15‐7793 for providing the clinical samples and for providing analytical support (cannabinoids analysis of all samples) for this work. We thank Dr. Bronner’s Cosmic Engagement Officer, David Bronner, for patience and John Partridge, U. S. Drug Enforcement Administration, for diligence in developing a protocol for field collection of feral . We acknowledge permission from the Minnesota Department of Natural Resources, the Minnesota Department of Transportation, and Saint Paul Parks and Recreation for access to field locations. We thank M. David Marks and the University of Minnesota College of Biological Sciences Imaging Center for assistance with microscopy and Veronica Tonnell for laboratory assistance. Margaret Wiatrowski, Anthony Cortilet, and Denise Thiede facilitated our participation in the Minnesota Industrial Hemp Pilot Program and with the importation of Canadian‐certified industrial . We are grateful to the offices of the General Counsel and the Vice President for Research at the University of Minnesota, the U. S. congressional delegation for Minnesota, the Minnesota Board of Pharmacy, and the U. S. Drug Enforcement Administration for the opportunity to do this study. We also thank the reviewers of the manuscript for critical insights that helped us to improve the presentation. C. sativa C. sativa
- CBDA synthase
- genetic markers
PubMed: MeSH publication types
- Journal Article