Cannabis Micropropagation

by | Jul 12, 2018

Written by Ellis Smith

Want to learn more about cannabis micropropagation?

Dr. Mitch Day has spent his entire career exploring plant tissue cultures, data visualization, and bioinformatics. He joined Ellis Smith with the American Cannabis Company for a recent deep dive into the micropropagation of cannabis. Their wide-ranging conversation covered both the myths and the realities of micropropagation. A more precise version of cloning, micropropagation technology is within reach for more producers today than you might expect. 

The Big 5 Takeaways of Micropropagation of Cannabis

1. The Basics of Propagation, From Conventional Cloning to Protoplast Culture

There are many methods of propagating plant tissue, from the most rudimentary cuttings all the way down to naked cell regeneration. Each method of propagation serves a different purpose, and each is valuable when used in the correct context.

  • Stem Propagation: Today the vast majority of cannabis propagation is still done through conventional cloning techniques. Cloning is a tried and true method of creating a genetic replica of the mother through relatively large cuttings.
  • Micropropagation: Micropropagation is still a mechanical cutting (i.e. it is completed using a manual cutting process). Its a more precise method of stem propagation, including the relatively small size of the tissue cutting (usually smaller than the size of a dime), and increased need for cleanliness.
  • Meristematic Culture: Refining the propagation process one step further is called meristematic culture, which is a shoot-tip dissection to target the cell-dense, activated meristems specifically. While micropropagation is helpful for removing the risk of microbial contamination, meristematic culture strives to remove any viruses.
  • Protoplast Culture: Achieved through an entirely non-mechanical process, protoplast culture is the most challenging and least likely to be useful for most producers unless you are explicitly getting into biotech applications. It relies exclusively on chemistry, and a method called naked cell regeneration, for tissue propagation.

2. The Top 3 Benefits of Micropropagation

Some of the more difficult methods of propagation, such as meristematic and protoplast cultures require sterile, laboratory-like conditions and a high level of scientific knowledge, micropropagation is relatively accessible to the commercial producer. With careful planning, development of specialized protocols, and a little experimentation, most operations can benefit from the use of micropropagation, especially at scale.

There are three primary benefits to micropropagation:

  • Reduces risk for microbial infection
  • Reduces labor when compared to conventional cloning procedures
  • Significantly reduces space requirements

3. Micropropagation is Not Rocket Science

According to Day, it only makes sense for cannabis producers, of a certain size, to transition towards a micropropagation approach to genetic preservation. Despite the lingering myths about the complexities of the technique, it’s a much more accessible technology than many cultivators may expect.

Micropropagation requires minimal investment in infrastructure, typically a reimagining of the HVAC technology already deployed in the indoor operation. Day suggests that even a small space, with the appropriate HVAC system, can easily become a clean, functional space for micropropagation. One of the key features is the separation from the grow rooms, and the creation of a positive pressure work zone, including the use of HEPA filters.

The significant investment is not so much in infrastructure but towards the operational requirements. Day argues the development and implementation of protocols are the most challenging undertaking for producers. The tissue culture record keeping and labeling are a time-consuming process, which needs proven protocols to ensure functionality at scale.

4. The Top 3 Errors in Micropropagation

Day has found most producers fall into the same three traps when they undertake the transition towards more advanced forms of tissue cultivation:

  • Time to Establishing Stock

Micropropagation takes a very long time before the producer becomes proficient in the technique and develops the necessary protocols. It takes much longer than most expect to build up a genetic stockpile of tissue cultures.

  • Effect on Production Schedule

Growing from tissue culture adds weeks to the production schedule. To take a plant from culture through the vegetative stages can take anywhere from eight to 14 weeks. Nearly double that of a more conventional stem-cloning method.

  • Overestimating the Benefit

There is always a drive towards newer technologies, but according to Day, there is a time and a place for all types of propagation. Cannabis cultivators tend to ignore the many benefits of cloning, as they jump headfirst into micropropagation. However, it’s equally as dangerous to overestimate the benefits of the newer methodology. Rudimentary propagation methods still have usefulness.

5. The Future of Genetic Diversity and Genetic Improvements in Cannabis

Day emphasizes that a transition to micropropagation shouldn’t be taken lightly; its crucial for cannabis cultivators to understand the underlying benefits to the tools they use. When it comes to micropropagation, it’s a critical step towards better cannabis genetics, better plants, and therefore better production. It’s a step towards the future of the industry.

He draws parallels between the increase in corn yields over the last century. According to the numbers, in the previous 75 years, corn crops owe the dramatic increase in yield to the development of double-cross hybrids and various enhanced breeding technologies. Propagation methods in cannabis, like micropropagation, is another essential crop management tool which could prove equally as beneficial for future cannabis yields.