Genotype screening of Cannabis sativa L. based on the specifics of minor cannabinoids manifestation

Abstract

Analysis of hemp collection samples based on the content of minor (rare) non-psychotropic cannabinoids, such as cannabichromene (CBC), cannabidivarin (CBDV), and cannabinol (CBN); determination of correlation relationships between them and common compounds; selection of valuable breeding genotypes. Methods. Field, biochemical (gas chromatography of cannabinoid compounds), and statistical (pair, partial, and multiple linear correlations). Results. Quantitative analysis of 210 samp­les of various ecological-geographical and genetic origin (local and wild forms, self-filing lines, hybrids, varieties, synthetic populations, polyploids) with a tetrahydrocannabinol (THC) content of less than 0.08% in dried plants showed the level of manifestation of the trait from its absence within the sensitivity of the gas chromatograph up to 0.6838% CBC, 0.1719% CBC and 0.3274% CBN. In the studied hemp samples, a medium negative relationship was found between the signs of the CBC and cannabidiol (CBD) contents (r = –0.53), a weak negative relationship between CBC and CBDV contents (r = –0.35), medium positive relationships between the signs of CBC and THC contents (r = 0.57) and CBC and CBN contents (r = 0.59). A medium positive correlation (r = 0.57) was found between the signs of CBDV and CBD contents, while CBN had a strong positive relationship with THC (r = 0.82). There is almost no correlation between cannabigerol (CBG) and the minor cannabinoids under study. The biosynthesis of minor cannabinoid compounds is quite complex. Signs manifestation is affected by many genetic and external factors. Partial correlation coefficients (given that one of the three signs is eliminated) and multiple correlation coefficients (given that the relationship of one sign is determined and two other signs are combined) give grounds to state that the gene for CBCA-synthase affects the production of CBD and, in particular THC. Conclusions. The closeness of the linear relationships between minor cannabinoids and common components allows selecting valuable hemp samples with a high content of one or several compounds under the absence or low content of psychotropic THC.