Did you know that cannabis plants actually boast the potential for great genetic diversity? In fact, cannabis researchers worldwide have discovered that cannabis plants have unprecedented genomic plasticity, with genetic diversity potentially up to 20 times greater than the human genome.
What does this mean for Australian agriculture? As one of the world’s most unique agricultural markets in terms of our arid growing conditions and demand for resilient crops, Australia’s flourishing cannabis industry is spearheading innovation in plant genetic testing and strain cultivation. Australia is also uniquely positioned to develop brand new strain cultivars, expanding on global cannabis research to produce more climate-resilient crops for future generations.
Here are just a few ways cannabis seed genetics can vary, plus more information on how these different genetic factors can translate into other agricultural markets.
Genetic engineering for the production of feminised plants
Genetic engineering to ensure 100% female or male seed variants isn’t a new concept. Horticulturalists and plant nurseries have been maintaining similar practices for decades now, from engineering gingko trees to produce only male seedlings, to poplar trees and other dioecious (having strictly separate male and female trees) species. In fruit farming, controlling sex-determining hormones also boosts yields year-round, ensuring greater and more consistent profits for farmers.
Genetic engineering in cannabis seeds works in a similar way. By developing feminised cannabis seeds for Australian growing conditions, licensed cannabis producers in Australia can maintain greater consistency in their yields, which ultimately makes our national cannabis market not only more profitable, but also more resourceful, less wasteful and thus, more environmentally-friendly.
How do growers manipulate sex hormones in cannabis plants?
Breeding feminised plants begins by first ensuring that self-pollination is possible. This is achieved by targeting and modifying ethylene-controlling genes (i.e. genes tasked with ethylene production) to ensure that plants produce only female cannabis flowers from female pollen – which in turn, only delivers female seeds.
Autoflowering vs. photoperiod – what’s the difference?
Cannabis plant genetics can also account for growing and flowering patterns. Some plants maintain photosensitive (light sensitive) flowering patterns that may deliver higher yields with strategic cultivation. Contrastingly, there are other cannabis cultivars that are specifically bred for being autoflowering plants, which don’t require light control outside of natural day/night cycles. Instead, autoflowering plants enter their flowering cycle based on age, maintaining a longer but more relaxed growing timeline.
Cannabis researchers have been experimenting with yields across both autoflowering and photoperiod plants for decades now, with researchers in the medicinal cannabis sector recognising the cost-value of photoperiod plants grown in highly controlled laboratory growing environments. This is why medicinal cannabis facilities utilise indoor, hydroponic methods that allow for optimal yields, keeping up with growing demands for medicinal products nationwide.
Genotypes, phenotypes and…chemotypes?
Alongside genotypic and phenotypic information that’s typical for most if not all plant species on the planet, cannabis seed banks also take into account plant chemotypes for all recorded cannabis strains. Chemotypes (or chemovars) allow medicinal cannabis producers to classify strains based on their specific chemical and terpene profiles.
Through understanding plant chemotypes, cannabis growers can not only accurately record THC and CBD levels in harvests, but also breed plants specifically to deliver certain pre-approved chemotypic information, or THC to CBD ratios. This is naturally essential for monitoring and maintaining THC (tetrahydrocannabinol) and CBD (cannabidiol) levels in medicinal cannabis products.
Under market regulations, medicinal cannabis products that contain over 2% THC are legally classified as Schedule 8 drugs of dependence. There are particular permits required state by state for medicinal cannabis prescribers looking to prescribe a Schedule 8 medicinal cannabis product to a patient with a history of drug-dependence. Prescribers who are found to offer products with incorrect cannabinoid profiles (i.e. falsely recording THC and CBD levels) may incur penalties for negligent practices under healthcare regulations and civil laws.
What’s the difference between THC and CBD?
THC and CBD are the two main chemical compounds that are naturally occurring in Cannabis sativa plant cultivars. While both THC and CBD interact with the body's endocannabinoid system, the effect they have differs greatly.
THC is the main psychoactive component found in cannabis, meaning that plants with a higher THC will naturally produce a "high”, and results in temporary cognitive impairment not dissimilar to alcohol consumption. This “high” is created when THC binds to cannabinoid receptors in the brain, altering motor skills, coordination, reaction time, and short-term memory.
Contrastingly, CBD is non-intoxicating and it provides therapeutic benefits that target the body rather than the mind, as CBD does not bind to cannabinoid receptors in the brain. Instead, CBD can provide a calming, soothing effect across both the body and the mind, making CBD products useful in treating anxiety, muscle ache, and alleviating chronic pain across a range of conditions.
While cannabis products that are high in THC are heavily regulated for patient and public safety, CBD products may be more readily available, and can even be purchased over the counter in some states.
How does cloning work in cannabis plants?
For growers who’ve found a phenotype and chemotype that aligns best with their product requirements (i.e. for medicinal cannabis markets), it’s actually possible to take cuttings from photoperiod cannabis plants to effectively clone the plant with desired phenotypes and preserve its specific genetics indefinitely.
For licensed cannabis producers and research facilities across Australia, studies into photoperiod cannabis cloning are supporting advancements in the quality, reliability, and consistency of medicinal cannabis products. This consistency is also supporting policymakers in spearheading cannabis industry regulations faster.
Cannabis research will continue to provide new opportunities for Australia’s agricultural sector
With medicinal cannabis being widely legalised across Australia and demand only continuing to grow, agricultural sector enterprises are investing more into cannabis research. This equates to greater skilled job growth in the sector, and more opportunities for Australian researchers to contribute to global projects, both relating to cannabis but even to climate adaptations via genetic engineering and innovations in cultivation techniques and technologies.
Regardless of whether all this work leads to cannabis reform (i.e. legalisation or even decriminalisation ) both here or abroad, one thing is abundantly clear: exploring the sheer diversity of cannabis plants is delivering vital insights that we cannot afford to ignore in the face of the global climate crisis.
