No clear evidence of ancestry differences between Sativa- and Indica-labelled cannabis

Cannabis labelled ‘Sativa’ and ‘Indica’ may not come from distinct ancestries, according to a study performed by the Canadian Dalhousie University in cooperation with Bedrocan on the genetic differences between the two types and their hybrids. In this study 149 Dutch cannabis samples were analysed, correlating the genotype and chemotype to their reported ancestries. Indica- and Sativa-labelled samples were not as distinct as sub species would be assumed to be, but the genetic differences between them do correlate to their terpene profile (resin fragrance), which could explain the variation between them. Results of this new study have been presented on the International Association for Cannabis as Medicine (IACM) congress in Cologne, Germany, September 2017.

Cannabis breeders

There is perhaps no debate in the world of cannabis more contentious than that of species. The genus Cannabis sativa L. is the only official species, but the terms ‘Sativa’, ‘Indica’ and ‘Hybrid’ have been widely adopted by cannabis breeders and cultivators as a way of advertising their product’s effects, aromas or purported pedigree. The degree to which these labels correspond to their actual ancestry, however, is dubious, and how this informal classification scheme relates to genotype or phenotype has been largely unexplored.

Analysis

In the study an analysis of 149 cannabis samples was performed, correlating the genotype and chemotype (based on terpene and cannabinoid content of the flowers) to their reported ‘ancestry’.  The researchers then compared the reported labels to new scales they generated by reclassifying the samples based on their genetic and chemical similarity.

The Indica/Sativa classification of Dutch cannabis does not correspond to distinct genetic lineages or to cannabinoid type, but there are genetic and chemical similarities that explain the variation between the groups. Deconvolution of the Indica-Sativa ancestry showed a strong relationship between the chemical and genetic profiles, suggesting that the distinct terpene contents of the types are heritable and important to the identity of these two groups. It is likely that strains are classified by their distinct aromas, and not their lineages, which has a direct impact on the genetics of this crop.

Terpene profiles

Bedrocan, worldwide producer of standardised medicinal cannabis, is already working on the terpene profiles that are associated with the current Bedrocan products. Hugo Maassen, head of the phyto engineering department at Bedrocan: “This study shows that the Indica/Sativa differences could be largely based on terpene content, which instead of the current Indica/Sativa labelling might require for more insight in the terpene profiles related to the Bedrocan products available for patient use.”

The terpene profiles of the Bedrocan products are expected to be announced in the near future.