In vitro tissue culture and genetic analysis of two high-CBD medical cannabis (Cannabis sativa L.) breeding lines

Abstract

The species Cannabis sativa L. has recently witnessed a resurgence of interest all over the world due to its multipurpose applications and the scientific confirmation of its pharmacological properties. Genotypes with high cannabinoid content are appreciated in the pharmaceutical and cosmetic industries due to their therapeutic potential. These genotypes, with predominantly high cannabidiol (CBD) content, are the subject of research and breeding in several programs, but to date, little data is published on the in vitro tissue culture of cannabis. Our study focused on the establishment of an efficient micropropagation method for two high-CBD breeding lines (MX-CBD-11 and MX-CBD-707) as the basis for advanced biotechnological breeding approaches. The results demonstrated that the in vitro culture of medical cannabis can be initiated on different culture media, that cultured plants can be successfully acclimatized, and that nodal position, and especially the genotype, have a significant influence on the success of shoot culture establishment. They showed that the published tissue culture media optimized for one high-THC strain of Mexican cannabis are not as efficient for other genotypes of (medical) cannabis. We complemented this research with a genetic study of 95 plants of the two breeding lines with 16 microsatellite (SSR) markers which clustered the plants based on breeding line. The results demonstrated that only 8 markers are needed for discrimination of all analyzed plants and their usefulness for clonal identification.