A Conversation on Commercial Cannabis Breeding

Somebody recently contacted me about starting a cannabis seed and genetics company. This person intended to provide seeds, clones, and teens to commercial growers.

They inquired about different seed and genetic types, as well as their marketability. They asked for a prediction on whether tissue culture or CRISPR technology would be the future of cannabis genetics. 

It was a wide-ranging conversation, and I’ve decided to write down some of the information shared and my thoughts on the state of the cannabis genetics market, and what we might expect moving forward.

Breeding Cannabis for Consumers

In my conversation, I first explained what a useless exercise it is to produce genetics that have no desirability—why produce plants that you can’t sell? Each year, lists of top-selling dried flower varieties are published, highlighting the millions of dollars spent on each cultivar. It would make sense to simply reproduce the most popular genetics, right?

Not quite …

Often, many other growers are already producing those genetics en masse, which accounts for their tremendous sales throughout many legal cannabis markets. Also, in some instances, the original breeders are already producing and selling those cultivars’ seeds and are doing so better than a knockoff seed producer can. (On a similar note, whenever possible, purchase from the original breeder, or from someone authorized to produce seeds by the original breeder.)

 So if following top-seller trends is not a successful path, what seeds should someone looking to contribute to the cannabis genetics landscape produce? Unfortunately for the breadth of genetic variety that exists within the cannabis plant, today’s cannabis consumers remain focused primarily on THC percentage, much more so than terpenes. Anecdotally, I was told by a dispensary owner that customers did not want a product under 30% THC. This means that if one is looking to be a breeder selling clones to commercial producers, one has to optimize for THC content.

THC content is especially critical for extraction companies, whose revenues are directly tied to the amount of oil they extract from plant material—a higher THC content means more oil for the same biomass volume. These growers want trichome-covered buds called “washers” because of their intended use in water extraction. They tend to have higher yields of trichomes, which in turn are pressed to manufacture rosin.

Breeding Cannabis for Seed Production

Breeders looking to produce cannabis seeds need to consider different goals. I interviewed multiple seed company owners and asked what their top customer requests were. Out of those conversations, four priorities emerged:

• Availability of feminized seed stock versions.
• Uniform and stable growth characteristics.
• Viroid-, disease-, pest-, and mold-free seed stock.
• Availability of triploid or tetraploid versions of the plant stock.

In conversing with multiple seed companies, the common consensus was that the No. 1 request was for feminized versions of the genetics they desired. Producing feminized seeds is a straightforward process that involves spraying a female plant with gibberellic acid or silver thiosulfate (STS), the latter being the preferred method.

STS is sprayed onto a female plant soon after flowering is induced by manipulating the photoperiod. The STS causes the female plant to produce male flowers that produce pollen. That pollen can be utilized to pollinate the plant it came from, surrounding plants, or even the next generation of plants if the pollen is stored properly and viable, and the resulting seeds, for the most part, will be female.

The next request was for stable and uniform genetics, and many seed companies noticed customer preference for autoflowering seeds. Autoflower seeds produce plants that begin to flower automatically after they begin growing. They do not have a vegetative stage per se, and they are a short, stocky plant. Autoflower plants typically have a primary cola at their apex and smaller bud clusters on the lower portion of the plants. Autoflower plants also predominantly require only 12 hours of light, reducing lighting costs (vegetative crops typically require 18 hours of light per day).

Autoflower seeds are produced by both self-pollination and cross-pollination. The easiest way to produce autoflower seeds is to cross-breed two autoflowering cultivars, using male pollen and female flowers.

The second method, self-pollination, utilizes STS to encourage a given female autoflower plant to produce male flowers. This results in pollen with autoflower genetics that can then pollinate either the host plant and/or a different female plant. The resulting autoflower seeds would also be feminized due to the STS. In both autoflower production methods, you must start with autoflowering parent plants.

Hop latent viroid disease (HLVd) has rapidly infected the cannabis industry. A survey conducted in 2021 by Dark Heart Nursery that involved 200,000 tissue tests concluded that 90% of cannabis growing facilities in California were contaminated with HLVd.

As the viroid is transmissible from the parent mother plant to the seed it produces, breeders should have a lab test their starting materials for the viroid presence prior to breeding.

Triploid plants have become a more recent interest to growers and seed producers, as noted in the Feb. 15, 2024, Forbes article titled “Can Triploid Genetics Be The Game Changer For The Cannabis Industry?”

The article explores how it has been observed that triploid plants (containing three sets of chromosomes) outperform regular diploids (containing two sets of chromosomes) in almost all traits: higher cannabinoid levels, faster growth, larger yields, and seedless flowers.

Historically, they have been created using colchicine, but there are also natural tetraploid plants.

While there are natural polyploid cannabis plants (containing more than two chromosomes), they can also be created using colchicine. However, colchicine is highly toxic, and it is therefore important to never let it absorb into your skin.

The International Carnivorous Plant Society offers information on how colchicine works. Essentially, it stops microtubule formation during cell division and chromosomes do not separate as they normally would, resulting in a cell that possesses double the number of chromosomes than it normally has.

All of that said, I’ve personally always preferred and employed natural pollination: pollinating a female plant utilizing pollen from a male with desirable and superior traits. If no superior male is available, the best alternative is to utilize STS to produce pollen on a female plant and utilize the pollen to pollinate a chosen female.

But I believe there is a place for triploid cannabis—perhaps that place will be the canna-pharma space? The future will tell.

To Summarize

So, I explained to the person wanting to start a seed company to:

• start with cultivars they know and love;
• breed or cross cultivars in combinations that don’t exist or that have not been bred before in the hopes of producing something unique and truly something you have found or selected; and
• acknowledge where your starting genetics came from and be respectful of the other breeders who exist today.

Breeding goes beyond simply crossing the two most popular cultivars and giving the offspring a catchy name. Proper breeding of a stabilized cultivar can and usually does take years.

I recommend that anyone looking to become a commercial breeder take plant genetics classes at an agriculture-based school such as UC-Davis. Also, I recommend beginning with regular seeds (i.e., male/female), stabilizing them, and then trying to produce a feminized version. I also recommend starting with a limited number of genetic offerings and prioritizing producing legitimate, stabilized cultivars that possess superior characteristics or traits.

From there, it becomes a game of who best reacts to realistic customer demands.