Excellent presentation on the science of Cannabis: Ken-Mackie
Cannabis has acquired considerable importance as a medicinal plant all over the world. Indeed its medical use predates recorded history. The earliest written reference is to be found in the fifteenth century B.C., Chinese Pharmacopeia. Between 1840 and 1900, more than 100 articles on the therapeutic use of Cannabis were published in medical journals. As a plant it is valued for its hallucinogenic and medicinal properties and has also been used to treat a variety of ailments including pain, glaucoma, nausea, asthma, depression, insomnia and neuralgia. The therapeutic values of Cannabis derivatives have also been highlighted against HIV/AIDS and multiple sclerosis. The pharmacologic and therapeutic potency of preparations of Cannabis sativa L. and its main active constituent _9-tetrahydrocannabinol (THC) has been extensively reviewed.
Taxonomic Classification: Cannabaceae family
|Chemical Structure: D9-Tetrahydrocannabinol (D9-THC)||Clinical Trials||Major Metabolites|
|Enzyme Name||EC No||Genbank Accession||GI No|
|Cannabidiolic acid synthase||N/A||BAF65033.1||149999825|
|Tetrahydrocannabinolic acid synthase||N/A||BAE48253.1||81158006|
|Tetrahydrocannabinolic acid synthase||N/A||BAE48252.1||81158004|
|Tetrahydrocannabinolic acid synthase||N/A||BAE48251.1||81158002|
|Tetrahydrocannabinolic acid synthase||N/A||BAE48250.1||81158000|
|Tetrahydrocannabinolic acid synthase||N/A||BAE48249.1||81157998|
|Tetrahydrocannabinolic acid synthase||N/A||BAE48248.1||81157996|
|Tetrahydrocannabinolic acid synthase||N/A||BAE48247.1||81157994|
|Tetrahydrocannabinolic acid synthase||N/A||BAE48246.1||81157992|
|Tetrahydrocannabinolic acid synthase||N/A||BAE48245.1||81157990|
|Tetrahydrocannabinolic acid synthase||N/A||BAE48244.1||81157988|
|Tetrahydrocannabinolic acid synthase||N/A||BAE48243.1||81157986|
|Tetrahydrocannabinolic acid synthase||N/A||BAE48242.1||81157984|
|Tetrahydrocannabinolic acid synthase||N/A||BAE48241.1||81157982|
|Tetrahydrocannabinolic acid synthase||N/A||BAD82954.1||56798209|
|Tetrahydrocannabinolic acid synthase||N/A||BAD82953.1||56798207|
|Tetrahydrocannabinolic acid synthase||N/A||BAD82952.1||56798205|
|Tetrahydrocannabinolic acid synthase||N/A||BAD82951.1||56798203|
|Tetrahydrocannabinolic acid synthase||N/A||BAD82950.1||56798201|
|Tetrahydrocannabinolic acid synthase||N/A||BAD82949.1||56798199|
|Tetrahydrocannabinolic acid synthase||N/A||BAD82948.1||56798197|
|Tetrahydrocannabinolic acid synthase||N/A||BAD82947.1||56798195|
Cannabis Indica Strains
Indoor Indica is one of the most potent strains of cannabis in the world. Depending on your growing method, the THC levels can reach over 25%. Northern Lights indica is the most famous and historical type of cannabis. Indoor cannabis strains will be well adapted to controlled environments. New technology allows the grower endless freedom in manipulating cannabis growing periods. The new autoflower strains allow fast turnover ratios and is thought to be from the Ruderalis strains.
Female indica is tough to obtain in it’s purest sense, so many growers cross breed strains. A true indica is cloned for years on end or seeds are produced that can keep for years. Cloning has been found to diminish resistance and strength. A good seed will perpetuate a good indica strain on a more horticultural scale. There are legal seedbanks out there that can help with purity. DNA Genetics has breed a stable triple backcross pure Indica called “LA Confidential”. Medicinal Genomics has selected this strain for Whole Shotgun Sequencing with 454 750bp reads. It has already proven to be less heterozygous than the outbred Sativa strains.
Broad-leafed Cannabis Indica plants in India, Afghanistan and Pakistan are traditionally cultivated for the production of hashish. Pharmacologically, indica landraces tend to have a higher cannabidiol (CBD) content than sativa strains. Most commercially available indica strains have been selected for low levels of CBD (which is not psychoactive). Indica’s have beneficial properties such as pain relief in addition to being an effective treatment for insomnia and an anxiolytic, as opposed to sativa’s more common reports of mental inebriation, and even, albeit rarely, comprising hallucinations. Differences in the terpenoid content of the essential oil may account for some of these differences in effect. Common indica strains for recreational or medicinal use include LA Confidential, Kush and Northern Lights.
A recent genetic analysis included both the narrow-leaflet and wide-leaflet drug “biotypes” under C. indica, as well as southern and eastern Asian hemp (fiber/seed) landraces and wild Himalayan populations.
Cannabis Sativa Strains
Cannabis sativa can be on of the most favorable and potent types of cannabis grown. The most obvious genetic trait is slender leaves lighter in pigment with less chlorophyll and tall 8 to 20 foot plants when allowed to fully mature. Sativa’s higher THC than CBD expression delivers a more psychoactive impact. The Sativa plant grows up fast but takes longer to mature at 10 to 16 weeks, and requires more intense light than an Indica. Cannabis sativa originally come from Colombia, Mexico, Thailand and Southeast Asia.
Some medical marijuana patients prefer cannabis sativa as it relieves a multitude of symptoms. “Sativas are more of a stimulant, effective in appetite stimulation, relieving depression, migraines, pain and nausea.” – The British Columbia Compassion Society.
Some of the more popular strains are ChemDawg, Bob Marley Sativa, Durban Poison, Purple Bud, Skunk, and Super Silver Haze. Some DNA sequencing has been performed on RNA from trichomes in Skunk. Medicinal Genomics has Shotgun sequenced, Assembled and Annotated the ChemDawg genome.
Hybrid cannabis strains are a mix of indica and sativa strains.
Hybrid cannabis strains are the favorites of all cannabis growers because of the different plant characteristics growers can manipulate. Breeders take the best of the indica world such as high CBD levels and breed that with the best of the sativa world such as high THC levels. Another genetic trait to consider when breeding hybrid cannabis is the indica bush and the sativa long stems to produce a large yielding plant. The Hemp Industry often breeds for many of these growth and fibre features.
White widow being the most famous hybrid cannabis strain could perhaps be the most potent of all in terms of THC. Now growers can choose from cannabis strains that are better suited for outdoor or indoor gardens. A good sativa can have it’s growth period reduced by cross breeding with a fast flowering outdoor indica like a Master Kush and Northern Lights.
The Cannabis Genome
The Cannabis Sativa genome has 10 autosomal Chromosomes plus 2 sex chromosomes and mitochondrial and chloroplast genomes. The mitochondrial genome appears to be in 8 50Kilobase pair (kb)pieces which is substantially larger than human 16Kb mitochondrial genome.
Figure from Sakamoto et al.
Cannabis Sequence Similarity to other Species
Genome Sequence reveals high similarity to Ricinus Communis (Castrol Oil), Carica Papaya (Papaya), Humulus Lupus (Hops) and Vitis Vinifera (Grape) Genomes.
BLAST Alignment of Cannabis Mitochondria contig has highest similarity to Ricinus communis
Chloroplast Genome from Cannabis is more similar to Morus Indica (Mulberry Bush)