Tissue Culture: How in the World to Source International Genetics

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October 30, 2023

The burgeoning international legal cannabis industry is marked by tremendous potential, but it also comes with its fair share of challenges. One of the most significant hurdles for cannabis cultivation companies is sourcing high-quality cannabis tissue culture from other countries. 

Many recently legalized medical or adult-use cannabis markets require imported cannabis genetics to be registered within existing seed banks or medical cannabis strain registries, which are often limited to a few countries. Additionally, verifying strain legitimacy and ensuring sterility can be complex, with the looming threat of Hop Latent Viroid (HLVd) in cannabis causing concerns. Moreover, the international legal status of shipping cannabis material across borders adds further complexity.

In this blog, we’ll get you up to speed on cannabis tissue culture propagation—it’s a solution that addresses many challenges for cannabis cultivators and product manufacturers. 

We’ll delve into the benefits of cannabis tissue culture and how it can revolutionize the way companies source cannabis genetics for their operations. Cannabis tissue culture is not only a game changer in terms of genetic preservation but also in ensuring that your genetics are free from pathogens and undesirable traits. Additionally, in utilizing a method called Callus Culture, only cells are present on Petri dishes, and they possess no detectable THC—or even recognizable leaves, for that matter—allowing for simple, compliant shipment. These cells can then be “dedifferentiated” or grown back into a plant later.

Which Countries Have a Legal Market for Cannabis Tissue Culture?

Many countries have legalized medical cannabis to some degree in recent years, including

  • Argentina
  • Australia
  • Brazil
  • Canada
  • Chile
  • Colombia
  • Croatia
  • Costa Rica
  • Czech Republic
  • Denmark
  • Ecuador
  • Finland
  • Germany
  • Greece
  • Ireland
  • Israel
  • Italy
  • Jamaica
  • North Macedonia
  • Mexico
  • Netherlands
  • New Zealand
  • Norway
  • Peru
  • Poland
  • Portugal
  • the territory of Puerto Rico
  • Rwanda
  • South Africa
  • Spain
  • Sri Lanka
  • Switzerland
  • Thailand
  • Turkey
  • United Kingdom
  • Uruguay
  • Zambia
  • Zimbabwe

Genetics sourcing in particular remains challenging in this evolving legal landscape, however. There are a few reasons why sourcing the right cannabis tissue culture for your operation can be a daunting task, particularly in regions with strict regulations.

Why Is Sourcing International Cannabis Tissue Culture Such a Challenge? Limited Access to Registered Cannabis Genetics

Many of the above countries require that imported cannabis genetics be previously registered within an existing seed bank or medical cannabis strain registry. This limits access to a narrow selection of cultivars and makes it challenging for new entrants to obtain the genetics they need. It also limits available source materials to cannabis seeds, which can dramatically increase propagation time and phenotype inconsistencies. 

While national registries do exist, their legitimacy, quality and cleanliness is often in question, forcing operators to source seeds from the small pool of available strains and utilize the “switcheroo” technique or what is widely known as “immaculate conception” in order to achieve their variety and quality goals.

Strain Legitimacy: Confirming the legitimacy of strains can be difficult when sourcing genetics internationally. There's a risk of receiving mislabeled or counterfeit genetics, which can have dire consequences for your cultivation operation, costing you money, time and potentially reputation.

Sterility and HLVd: The presence of pathogens, such as Hop Latent Viroid (HLVd), can be a major concern when importing cannabis seeds and clones. HLVd is a particularly problematic pathogen known to devastate cannabis crops. Lettuce Chlorosis Virus, Cannabis Cryptic Virus, Tobacco Mosaic Virus, and Beet Curly Top Virus have also increasingly been reported in cannabis plants. Cannabis tissue culture is the only tool available to removing these viruses and ensuring sterility is critical to preventing disease outbreaks.

Legal Barriers: The international legal status of shipping cannabis material is complex and fraught with legal challenges. Even if customs eventually approves the shipment of clones or cuttings, the delicate nature of plants in this state means that any delay or temperature variation during transit can easily lead to crop loss. Seeds are obviously more hardy and resistant than cuttings or clones, but there is significant time required to phenohunt a winning variety from seed, mother it, and cut a crop of clones from it—this can easily be a six-month time investment.

Cannabis Tissue Culture: A Game-Changing Solution

Cannabis tissue culture propagation offers a revolutionary solution to these challenges. It involves growing and maintaining plant cells, tissues, or organs in aseptic conditions on a nutrient culture medium. This method allows for the storage of a large number of plantlets or genetics indefinitely, all within a minimal space: typically on petri dishes. 

Tissue culture laboratories can "clean" genetics by propagating only the cells necessary for propagation, leaving behind unwanted pathogens like HLVd. This ensures that the genetics you receive are free from harmful diseases. A technique called Meristem Culture is most commonly used to remediate pathogens, and it consists of removing the apical dome that has not connected to vascular tissue (~1 mm). Callus Culture can also be used depending on the sample, or "explant."

These methods provide a stable genetic platform, eliminating unwanted traits or susceptibilities to issues like powdery mildew or botrytis. You can be confident that the genetics you receive are consistent and reliable.

Tissue culture also allows for the efficient storage of plantlets and genetics in a small space. This means you can maintain an extensive strain library without the need for extensive physical space.

Sourcing genetics through a Tissue Culture Bank is one of the most reliable and compliant ways for medical and recreational cannabis cultivators to ensure they receive clean and proven genetics, meeting the stringent regulations of many markets.

The Process of Sourcing Tissue Culture Genetics

Now that we’ve covered the potential of tissue culture, let's explore how you can source tissue culture genetics internationally through an established Tissue Culture Bank. Here's a step-by-step breakdown of the process:

1. Strain Selection: As a licensed cultivator, you review the current available strain list provided by the Tissue Culture Bank and place your strain order. This ensures you're getting the genetics that best suit your specific needs.

2. Tissue Collection: The tissue is collected and sterilized before it’s transferred into new media containing nutrients, hormones, and vitamins. This stage typically takes one day.

3. Multiplication: Once established and shoots begin to form, they can be rapidly multiplied over the course of four to six weeks to produce roughly 50x times the number of copies, compared to cloning from a mother plant.

4. Shipment: Vessels containing pathogen-free plantlets (rooted or unrooted) or callus cells,  can easily be shipped, typically taking three to five days for transit.

5. In-House Tissue Culture: Once received, the plantlets can continue to be multiplied to fast-track copies for cultivation and long-term storage.

6. Growth: The plantlets will then be transferred into rooting media (if not requested before shipment) where a root system develops. This phase takes up to three weeks.

7. Acclimatization: Plantlets are “hardened off” to the receiving garden’s regular environmental conditions before transplanting into growing substrate.

8. Recurring Orders: To continually improve the genetic quality of your strain library and to remain competitive within your specific market, repeat the process a few times per year. This allows you to refine and enhance your genetic variety and product offerings over time.

Why International Cannabis Businesses Need Access to Cannabis Tissue Culture

Cannabis tissue culture propagation offers licensed businesses a reliable, compliant, and efficient solution to their international cannabis genetics sourcing problem. With the ability to store a vast number of plantlets and genetics in a small space, tissue culture not only ensures pathogen-free genetics but also supports genetic stability. 

By following the outlined process of sourcing cannabis tissue cultures, you can confidently build a superior cannabis genetic portfolio for your cultivation operation, meeting the demands of the ever-evolving cannabis market regulations. Embrace tissue culture and secure the future of your cannabis cultivation business. Contact Next Big Crop today to begin sourcing high-quality and reliable tissue culture cannabis genetics.

If your cultivation facility is in need of a strain update, NBC offers cannabis genetics consulting and sourcing services to operators at any stage and any size. Hit us up at info@nextbigcrop.com to track down these flavors or anything else you’re hunting. Good genetics win every time.

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