CBG, or cannabigerol, dominance is bred into cannabis plants through targeted genetic selection and breeding strategies that focus on increasing CBG expression while reducing the activity of enzymes that convert CBG into other cannabinoids like THC or CBD.

Because CBG dominance is a recessive trait, the only way to breed true CBG seed lines is by starting with plants that already express a CBG-dominant chemotype.

CBG is the precursor to THC, CBD, and CBC. It begins as CBGA, or cannabigerolic acid. In most cannabis plants, CBGA is rapidly converted by specific enzymes into other cannabinoids.

THCA synthase converts CBGA into THCA, which becomes THC. CBDA synthase converts CBGA into CBDA, which becomes CBD. CBCA synthase converts CBGA into CBCA, which becomes CBC.

To breed CBG-dominant plants, breeders need to minimize or eliminate the genes responsible for those synthases so that CBGA accumulates instead of being converted into other cannabinoids.

Some rare cannabis genotypes naturally produce high levels of CBG while remaining low in THC. Breeders start by identifying those rare outliers through cannabinoid profiling and genetic screening.

Testing methods such as HPLC or GC can be used to identify plants with strong CBG expression. Genetic screening can also help locate plants with inactive or reduced THCA and CBDA synthase activity.

Once CBG-dominant plants are identified, inbreeding and backcrossing are used to stabilize the trait. Breeders cross high-CBG parents together to reinforce the CBG-dominant genotype over multiple generations.

Marker-assisted selection can also speed up the process by using DNA markers linked to desired cannabinoid profiles. The goal is to develop homozygous lines that reliably express CBG dominance.

A stable CBG seed line should carry the genetics needed to accumulate CBG while reducing or eliminating conversion into THC and CBD pathways.

In simple terms, CBG dominance is created by selecting rare high-CBG, low-THC and low-CBD plants, stabilizing those genetics, and reducing or eliminating THCA and CBDA synthase expression through careful breeding.