How Controlling Cannabis Genetics Can Boost Crops

Where are the cannabis genetics headlines?

Are you looking for new and novel genetics? The next great chemovar (strain) is being created right now by a small group of sophisticated breeders in effort to solve real agronomic problems and maybe even help hemp and cannabis farmers survive the great price collapse of 2022. Unfortunately, we don’t often get to read hopeful headlines because the THC Conspiracy (lab shopping) and Hop Latent Hysteria (the spread of the viroid among cannabis crops) have hijacked the cannabis industry news cycle for at least the past year. These issues could compromise the safety and effectiveness of products and potentially put consumers at risk and damage the credibility of the entire industry. Action needs to be taken. And one such action could be improving the genetic makeup of cannabis crops. Let’s nerd out on recent advances in cannabis plant breeding to find out more.

Where’s the GMO cannabis and double haploid breeding?

In general, most major commodity crops have transitioned away from the old, traditional breeding regimens conducted solely in the field to new methods taking place in sophisticated laboratories with the capability to rapidly screen DNA and create genetically modified plants for commercialization. Although CRISPR/Cas9-mediated genetic transformation has been successfully carried out in cannabis, there are still some significant challenges for this technology to be commercialized into millions of genetically modified cannabis plants. Genetic transformation with CRISPR/Cas9 requires a process known as regeneration, or the regeneration of viable plants from transformed callus plant tissue (totipotent plant cells, AKA stem cells). The regeneration of viable cannabis plants from transformed callus tissue has proven extremely difficult, but it’s likely only a matter of time until roundup-ready cannabis is the headline.

Haploid induction is another modern plant breeding technique that eludes cannabis breeders. Haploid plants are created by regenerating new plants from pollen or egg cells. The resulting plant, which has only one set of chromosomes, is then treated with chemicals to double the chromosome. The result is a doubled-haploid plant – a homozygous parental line developed in half the time it would take using traditional plant breeding techniques. Again, the inability to consistently regenerate cannabis plants from tissue has prevented widespread cannabis breeding utilizing double haploid plants. It is only a matter of time before researchers master this technique with cannabis.

While the laboratory breeders are trying to get their techniques dialed in, traditional breeders are pushing forward in impressive ways. Farmers are always looking to improve their bottom line with plants that are more productive (higher yields, are pest and disease resistant, etc.) or produce products that are unique in the marketplace. The goal for most breeders is to put all of those great attributes into one awesome plant. Let’s face it, all farmers want high yielding, robust plants that result in a product that is truly unique and highly sought after in the marketplace.

Traditional cannabis breeders isolate traits to send to the lab

Growing plant populations in the worst possible environments – for instance, high-humidity environments that increase disease pressure – is the best way to find resistance in your crops. Plants are grown out, misted periodically with inoculated water (contains the pathogen), and observed closely to identify those exhibiting tolerance to diseases like powdery mildew and Botrytis. Researchers are keen on taking the pathogen-resistant plants and identifying powdery mildew-resistant genes in cannabis. In fact, qualitative inherited resistance has been observed, but the complexity of polygenic resistance in cannabis stalled there. More work needs to be done before the development of commercially-useful predictive tools.

Traditional breeding to improve agronomic productivity

Molecular Farms, a cultivator in Salinas, California, uses traditional breeding techniques to tackle the isolation of many traits concurrently. Like the work highlighted above, Molecular Farms utilizes extreme environments to identify pathogen resistance and cultivate in extreme temperatures simply to stress plants with heat, humidity, and cold. When breeding for robustness, a crop’s capacity to recover from stress has become particularly more important over the years. Farmers want crops that will perform in any environment during any weather pattern.

Hot and dry temperatures are used to stress plants to measure their robustness in drought and heat waves – this is very important for outdoor cannabis and hemp farmers. One field trial conducted in 2022 – overseen by Napro Research – spanned nearly two hundred acres and was transplanted in August. Temperatures were in excess of 105 degrees Fahrenheit for most of the planting window. While all hybrids performed well, there were several that demonstrated accelerated rooting and growth during the hot dry planting cycle. These plants were selected to continue developing more heat tolerance.

Plant robustness is a critical feature because it directly impacts agronomic productivity. For example, flowering cannabis plants during winter can add an additional harvest and increase productivity. As such, winter weather performance is a highly sought-after trait on the Central Coast of California. This region of California has cool, cloudy, mild winters, but because many farmers do not have heat or supplemental lighting, yields are often low and some farmers may not want to take the monetary risk. However, this risk is greatly reduced with cannabis plants that can flower effectively in low-light and cooler temperature environments.

Terpenes and trichome size

The highest-value commodity on the cannabis plant is the trichome head. It is akin to a cut on a cow known as filet mignon. The trichome head is where all of the yummy essential oils and mind-blowing cannabinoids are housed. It is difficult to separate the trichome effectively from the plant and yields are extremely low. Thus, Molecular Farms has been working with hash and rosin producers focusing on trichome size and the relationship to production yields. Breeding plants that yield higher for specific extraction processes will be critical moving forward as margins continue to tighten and prices continue to fall.

One of the more interesting projects is the creation of exotic flavor profiles that do not exist in cannabis today. Innovation is magical when a breeder is creating a new flavor of cannabis. While many of the traditional breeding projects above utilize visual observation and empirical data, creating new flavors is a more artistic pursuit like working to become a great chef. There are very few “chefs” in cannabis and hemp; there are a tone of entrepreneurs, but because the costs to permit and operate a cannabis farm are so high, very few, if any, are conducting the type of research and development outlined above – especially not to create new dishes in for their metaphorical restaurant of weed.

Competitive markets are navigated with agronomically productive crops and unique product offerings. For example, hemp essential oil producers rely on new and novel essential oil profiles in their genetics to differentiate their products in the market. The same goes in cannabis. Most cultivators are wrapped up in only one number, THC percent. So boutique essential oil, terpene, and cannabinoid profiles are what kept margins high and sales flowing for several partner farms of Molecular. One project involved breeding cannabis plants to increase the concentration of hexyl butyrate (>0.7% by dry weight). The result was a pungent cherry aroma – completely unique in cannabis today. Simpler profiles like the combination of equal amounts of terpinolene and myrcene often result in a bright orange or clementine aroma. These aromas are then paired through targeted breeding to produce plants with the desired flavor and aroma that also contain high THC, THCV, and our favorite THC and CBD together. 

This article originally appeared in the Analytical Cannabis - February 2023 Digest.