Transcript The Future of Cannabis Genetics

The Future of Cannabis Genetics
Jonathan Page
Cannabis has been used for millennia
Food and oil (hemp)
Fibre (hemp)
Drug and Medicine
(“marijuana”)
OH
THC
O
Cannabis produces a complex suite of bioactive metabolites:
The mixture is the medicine
Cannabinoids
OH
OH
O
HO
psychoactivity
+ pain relief,
appetite,
antispasticity
…
OH
O
Terpenes
How are cannabinoids synthesized?
?
Cannabis sativa
(marijuana, hemp)
Glandular trichomes on cannabis flowers
100 µm
Cannabis
trichomes
Subcuticular
cavities
Secretory
disc cells
Trichome-specific gene expression analysis
RNA
Protein
Cannabis is the first medicinal plant with a sequenced genome
Collaboration with Tim Hughes (University of Toronto)
Published in Genome Biology in November 2011
Article accessed 97,925 times!
Cannabis haploid genome is ~820 Mbp
Genome organization
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2n = 20
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Nine autosomes
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Two sex chromosomes (X and Y)
We sequenced three types:
1. Marijuana ‘Purple Kush’
• ~19% THCA
2. Hemp ‘Finola’
• Low THCA, 4% CBDA
3. Hemp ‘USO-31’
• Low to zero cannabinoids
www.genomevolution.org
The cannabinoid biosynthetic pathway
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Cannabinoid pathway bifurcation: “Marijuana” vs hemp
Marijuana – 18% THCA
THCA
CBGA
THCA synthase
CBDA synthase
CBDA
Hemp – 4% CBDA
Cannabis chemotypes result from simple genetics
• Chemotypes are chemical phenotypes
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Chemotype III (high CBD)
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% CBD
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12
10
Chemotype II (THC:CBD)
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4
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2
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Chemotype I (high THC)
0
0
5
10
15
20
% THC
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Genetics of cannabinoid biosynthesis
Fatty Acids
THCA synthase
THCA synthase
Olivetolic acid
Chemotype I
(high THC)
C10 terpene
THCA synthase
CBDA synthase
CBGA
THCA
synthase
THCA
Heat
THC
Chemotype II
(THC:CBD mix)
CBDA
synthase
CBDA
Heat
CBD
CBDA synthase
CBDA synthase
Chemotype III
(high CBD)
Classification of Cannabis is (still!) unclear
Cannabaceae
FAMILY
Cannabaceae
Cannabis
GENUS
Cannabis
sativa
SPECIES?
sativa
indica
ruderalis
Hemp and marijuana
• many strains and cultivars
• four chemotypes
SUBSPECIES?
sativa
indica
ruderalis
Hemp and marijuana
• many strains and cultivars
• four chemotypes
Marijuana strains: Indica vs Sativa
• Thousands of strains exist
• Most strains were developed for recreational use
• Patients report that strains differ in their effects
Patients and growers differentiate two general types:
“Indica”
• Short plant with broad leaves
• Sedative and “body stone”
“Sativa”
• Tall plant with narrow leaves
• Stimulating and cerebral effects
Cannabis genotyping
Three main questions:
1. What is the genetic structure of the genus Cannabis?
2. Are hemp and marijuana genetically distinct?
3. Are Indica and Sativa genetically distinct?
• Collaboration with Sean Myles (Dalhousie University)
• Accessed DNA samples representing diverse cannabis types:
• 43 hemp
• 81 marijuana samples
• Analyzed using GBS (genotyping-by-sequencing)
• 14,031 single-nucleotide polymorphisms (SNPs)
Cannabis genotyping: “marijuana” and hemp
Sawler et al, PLOS ONE 2015
The problem of germplasm - is cannabis endangered?
Genetic diversity is the basis of agricultural innovation!
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Sources of new genetic traits such as disease resistance
BUT
Cannabis is undergoing genetic reduction
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Drug prohibition has destroyed plants e.g. feral hemp
Legal exchange of seeds and plants is difficult
“Dutchification” is replacing landraces across the globe
Reliance on vegetative propagation (cloning)
Long-term seed viability is limited
MMPR restricts access to genetics
Preserving crop diversity requires seed banks (not just seed
companies…), sustained funding and research efforts
The future of cannabis breeding
Cannabis breeding has been a huge success:
• THC levels and yields have increased; CBD too
But has led to a narrowing of gene pool with focus on indoor
cultivation and clonal propagation
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High THC product with lower levels of other cannabinoids
Genetic traits for consumers:
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Novel cannabinoid profiles for medical use
New terpene profiles
Sensory properties
Genetic traits for growers:
• Disease and pest resistance
• Higher yield, flowering time, plant architecture
Genomics assisted breeding of cannabis
X
Select plants
from DNA & Chemotype
100s of seeds
back to breeder
100,000+
seeds
Analysis & prediction
DNA sequencing
Cannabis patents
Q: Is patenting of cannabis strains possible in Canada?
A: No. Canadian law does not allow patenting of higher life forms
such as plants.
Registration of new varieties through Plant Breeders Rights is
possible. PBR helps “protect the variety from exploitation by
others”.
Varieties must be:
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New
Distinct
Uniform
Stable
Currently 6 registered hemp varieties and 1 registered marijuana
variety
Cannabis needs for more science!
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Science leadership
Health Canada licensed lab
Analytical testing and QC
Genotyping services
Developing advanced cannabis strains
[email protected]
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