Genomics is the study of an organism’s genes, encompassing the whole genetic profile and interactions with the environment. Cannabis genome maps can help breeders design plants with certain physical and chemical profiles. [1,2] This not only includes maximizing certain cannabinoids (e.g., cannabichromene, CBC), but also improving disease resistance, nutrient requirements, and even plant structure. Researchers have pushed cannabis genome sequencing to advanced stages that make such applications reality. 
In 2019, for example, Laverty et al  sequenced two chemovars: Purple Kush, with high tetrahydrocannabinolic acid (THCA), and Finola, with high cannabidiolic acid (CBDA). The researchers generated 820 million DNA letters across 10 chromosomes. They also crossed the cannabis varieties for analysis and pinpointed a discrepancy on chromosome 6: unique cannabinoid synthase genes. They thus determined the genetic location that determines whether the plant produces high THCA or CBDA.
The authors didn’t stop there. They inserted one of the plant genes into the genome of yeast cells. Then, they fed the yeast cannabigerolic acid (CBGA), the precursor molecule to numerous other cannabinoids. Amazingly, the yeast regurgitated CBC. Thus, they also pinned down the gene for CBC synthesis.  Relatedly, companies Cronos Group and Ginkgo Bioworks united to manufacture (with yeast) cultured or ‘brewed’ cannabinoids.
Another company known as Trait Biosciences is at the edge of genetic engineering, having successfully transformed (inserted plant DNA into) and stabilized hemp plants. According to Dr. Richard Sayre, Chief Science Officer, “Plants grown with [this technology] are expected to have more trichomes, have greater photosynthetic efficiency and are expected to generate cannabinoid yields 2x – 5x higher than conventional plants for whole plant extracts, in addition to being able to produce water-soluble cannabinoids, which have far greater bioavailability and onset time than fat-soluble cannabinoids.”
Canopy Growth is also no stranger to cannabis genomics. With Australian patent (pending) AU2017250794A1, the corporation outlines a genetic engineering approach to create a “cannabis that does not require flowering in order to produce trichomes comprising secondary compounds… herein is a plant of the genus cannabis that has trichomes on non-flowering parts of the plant, such as leaves.” In other words, a plant completely covered in trichomes.
Cannabis genome raw data is freely available online via sites including 1000 Cannabis Genomes Project and Cannabis Genome Research Initiative. Although environment and cultivation practices will always play significant roles in cannabis cultivation, genetic data is also becoming paramount. [1,2]
- Dolgin E. Inner workings: Genomics blazes a trail to improved cannabis cultivation. Proc Natl Acad Sci. 2019;116(18):8638 LP – 8640. doi:10.1073/pnas.1904094116. [Impact Factor: 9.412; Times Cited: 2 (Semantic Scholar)]
- Backer R, Mandolino G, Wilkins O, ElSohly MA, Smith DL. Editorial: cannabis genomics, breeding and production. Front Plant Sci. 2020;11:1553. https://www.frontiersin.org/article/10.3389/fpls.2020.591445. [Impact Factor: 4.407; Times Cited: n/a]
- Laverty KU, et al. A physical and genetic map of Cannabis sativa identifies extensive rearrangements at the THC/CBD acid synthase loci. Genome Res. 2019;29:146–156. [Impact Factor: 11.093; Times Cited: 49 (Semantic Scholar)]