Cannabis Botany and Breeding with Ryan Lee


Project CBD: Welcome to another edition of Cannabis Conversations. I’m Martin Lee with Project CBD and today I’m delighted to have as our guest Ryan Lee, an expert cannabis botanist who works with a company called Chemovar Health as one of the founders. It’s based in British Columbia. Ryan, thanks for joining us.

Lee: Thanks for having me.

Project CBD: Tell us a little bit about your background as a cannabis botanist. How does one become a cannabis botanist?

Lee: It was really through personal interest. There hasn’t been a lot of educational courses in this space. You know, I was a cannabis cultivator when I was going through university and really enjoyed the plant and enjoyed the diversity of the plant. And I started growing and studying genetics at university, and that really just pushed me down a path where I was able to learn some things through school that I guess weren’t really available in the cannabis community. I became very lucky to meet our mutual friends Rob Clarke and David Watson – they really kind of took me under their wing and introduced me to a lot of folks and gave me a hands-on experience.

Project CBD: I think Dave Watson and Rob Clarke would be professors at a cannabis cultivation university, if there ever was one. But you mentioned university — where did you go to school?

Lee: In Ottawa. I actually started in the kind of bio-psychology, neuroscience field. I was really interested in drugs and behavior. Studying cannabis at that time wasn’t really possible, pre-the acceptance of medical cannabis. None of the professors were really too interested in it. I also have family members with addiction issues. And so just understanding drugs and behavior was an interesting thing for me. I really used that opportunity to learn about the endocannabinoid system. Every time I had a project that I had to study, a personal study project, I would investigate the cannabinoid system in some way, or the endocannabinoid system, which was really just starting to be discovered.

Project CBD: Now we’re talking late ’80s.

Lee: Early ’90s really was when it was.

Domestic cannabis cultivation

Project CBD: Let’s roll back the clock a little bit to the time when I, as a teenager, was first exposed to cannabis. We didn’t really call it cannabis — it was just weed or grass or marijuana. But in those days, when we got some stuff, a dime bag, a nickel bag (and we’re talking about a few decades back), we had access to cultivars called Panama Red, Acapulco Gold, and later came Thai Stick and Colombian and Jamaican. It was always a name associated with a place. And yet these days, it’s quite different. You’ve all kinds of crazy names for cultivars, but not typically associated with a place. What happened there? What’s the difference between the cultivars of old, those place-located cultivars, and today?

Lee: Well obviously those place-located cultivars involved smuggling, right. I think back in the 70s and the 80s that was a very different world: People bringing in boatloads of cannabis and hashish from various countries into the States. The States has always had the largest market for cannabis consumption. As that market shifted to more of domestic production, people realized that the seeds that came from those populations that were brought in didn’t really perform in the same way that they might have grown in their native environments in Columbia or Mexico or Thailand. And so there had to be this adaptation process of the cultivars to be able to grow in the California environment. Then subsequently as the pressures came on from projects like CAMP [Campaign Against Marijuana Cultivation], the eradication projects all over the world (mostly the States, but also state-sponsored all over the world) that really forced growers indoors. Again, the type of plant that’s needed to grow indoors is very different than outdoors. So domestic home breeders have actually made some quite significant progress in being able to create varieties that are suitable to cultivate indoors and that also have increased market appeal.

Increasing THC

Project CBD: So, would you say that compared to the old landrace strains that we’ve got something up on them these days? Or that we’ve improved upon these landrace strains? Or the place-located strains or cultivars, they weren’t as good as what we’ve got today? Because you know we hear this phrase “right now the weed is so strong, it’s not like your grandmother’s or your grandfather’s marijuana.” Was the cannabis of old, as it were, was it weaker? What’s the difference?

Lee: On average, population average, the cannabinoid content was lower. There was probably individuals in those populations that had high THC content, or higher THC content, even the varying THC contents that we see today. But most of the imports were probably in the 5-10% THC range.

Project CBD: And does that suggest that its quality is not as good? What does that say about that?

Lee: That depends on who you ask. I know a lot of folks from your generation that they just don’t want to smoke the cannabis today because it’s too damn strong. They prefer something in that 7-10 percent [THC] range. We’ve done a lot of lab testing and characterized a lot of varieties, and some of these populations and families were created by people through what we call organic elective sampling. You evaluate the plant based on its characteristics, sense characteristics, with our five senses. I guess the sixth sense being how the cannabis makes you feel. We’ve come to see something, there’s this kind of weird biphasic curb where at low to moderate doses THC can actually feel quite invigorating, but if you turn the volume up and make these very strong THC varieties they can actually be quite sedating. And a lot of people will have a couple of puffs on these very strong cannabis, and they’re not regular users with tolerance, and they just end up stoned and staring at the wall or kind of zonked out on the couch. That’s not very social cannabis, you know. I think there’s really something to be said about the interplay between tolerance and the level of THC. Unfortunately, our market and production statistics, everybody wants to see, you know the most amount of not only grams per square foot, but also the total cannabinoid content per square foot.

Interpreting THC percentages

Project CBD: If it’s a THC-rich strain, the cannabinoid content is going to be mainly THC. So if someone walks into a dispensary these days in California, typically the products are labeled with numbers. Different cultivars have different numbers. Should we assume that the higher number for THC means it’s better?

Lee: It definitely isn’t. I mean in terms of enjoyable experience. I think that that’s the dogma that we operate under but I make this comparison with the wine industry: You don’t go into a liquor store and ask for — if you’re trying to buy a nice bottle of wine — you don’t ask for the highest alcohol content wine. And even with whisky, you don’t do that. There’s so much more to the user experience than just the sheer strength of the product. If it wasn’t like that, everybody would be drinking this grain straight alcohol, the almost pure ethanol, Everclear, that type of thing. That’s just not a user preference. Yeah, it’s a thing that exists on the market but it’s not the largest selling SKU.

Project CBD: You know, when I see some of the numbers associated with the THC-rich cultivars, it seems a little bit crazy to me sometimes. They say 20 percent, 22 percent, sometimes up to 30 percent – is that really what’s going on here? I don’t want to say the maximum – what is a realistic number in terms of cannabinoid content for a cultivar that would be a cannabinoid-rich cultivar? What’s the sort of the top that we’re looking at, that if we exceeded it, it would kind of make you wonder was this the correct lab test, or this is a marketing ploy?

Lee: It’s always very important to, not just say the number because when we’re talking about THC the plant actually doesn’t contain — it contains very little THC — as you know it contains a molecule called the THC-acid [THC-A]. That’s the pre-decarboxylated state of the molecule. When you convert THC-acid to THC, they’re not a 1:1 ratio because THC-acid obviously is a heavier molecule so as a percentage of the total compounds in the flower it makes up a larger ratio. And when you convert it into THC, the number is different. So, it’s always, it’s kind of like saying, it’s like a vector without a direction. You know, it’s like saying we’re traveling 100 but we don’t say it as miles an hour or kilometers per hour. It’s not just the number. It’s always important to have a context with the number. We do see plants that are above 30% total cannabinoid acids. The highest one I’ve seen is about 34-35 percent.

Project CBD: And that’s the plant itself, not the extract?

Lee: That’s a single plant. That’s a flower from a single plant. So you can have these higher numbers. When a laboratory has a result that’s above 30% THC-acid, that really merits what we call a re-prep, where they re-run the sample through the laboratory to make sure that there wasn’t a problem either with the calibration of the machine or the measuring of the sample before it’s put in.

Rediscovering CBD

Project CBD: Let’s talk about CBD for a moment. Back in the old days people didn’t really know much about CBD. But some of these cultivars coming in from Nepal or from Morocco or these different places – and this is before we did a lot of domestic breeding – did these have CBD in them? Because the CBD, if it was there, it seems to have disappeared for a while and it had to be rediscovered about 10 years ago in northern California. What happened with CBD? Did it disappear, and if so why?

Lee: CBD was essentially effectively bred out of the plant by humans.

Project CBD: Was that intentional?

Lee: Again, you have to remember, at this point in time we weren’t doing the laboratory analysis.

Project CBD: What time are we talking about here?

Lee: I guess really domestic cannabis production, I would say, really took a boom in the 80s. But even in the 70s, I think even the native populations that were growing these location-of-origin genetics, were able to through sampling and cross-breeding — you know people would always save the seeds from the most beautiful smelling or the largest yielding plant, to plant for next year’s crop. Through doing that over a couple of generations, especially if you’re limiting the pollen contributors from that family, you’re actually quite easily able to shift the population to either THC-dominant or CBD-dominant, just by sampling the plants that make you the highest. And I think that that’s probably what happened. You know, we weren’t going after these compounds through chemical analysis. We just weren’t monitoring these things. So, all of that type of selection pressure was really done by consumption and determining how the plants made us feel. As you know, a mixed CBD and THC plant might have a different effect from a THC plant. And so people that were really focused on that strength of effect could effectively segregate those THC plants from the population. And when you breed them between themselves you effectively purge the CBD from the population.

The art of breeding cannabis

Project CBD: Final question, about breeding. You are an expert breeder. When one breeds, how much of it is just rolling the dice and chance and, hey, you come up with something interesting? Or how much is intentional, that you’re looking to get somewhere with the work?

Lee: You can do it both ways. To me breeding is both a science and an art. So if you bring in tools from a scientific understanding and you use your passions that you have for the plant, I think that’s the most effective way. Humanity and breeders have been using just art and no science for years, and you can make certain gains to a degree. But we’re at this point now where cannabis is becoming a legitimate agricultural crop and that kind of production merits the scientific investigation and actual expenditure of resources to use science to improve the crop. And we just haven’t been able to do that through prohibition.

Project CBD: Well thank you Ryan Lee for joining us on Cannabis Conversations. We’ll see you next time.

Copyright, Project CBD. May not be reprinted without permission.

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Male vs. female cannabis: How to determine the sex of your plant

In the world of plants, reproduction can happen in a variety of ways. Monoecious plants produce two different types of flowers on the same plant, and hermaphrodite plants grow single flowers that have both male and female reproductive organs.

Cannabis is a dioecious plant, meaning male or female reproductive organs appear on different plants.

With cannabis, females are usually isolated away from males—introducing males into a garden will result in pollination, causing females to create seeds.

This is important for a breeder to achieve new genetics, but most growers remove the males to allow females to produce seedless buds, also called sinsemilla. These are the resinous buds that appear on the store shelf; they all come from female plants.

Seeded buds are generally regarded as low-quality cannabis. When seeds are present, the smoke is harsh and unpleasant.

Female genetics can be guaranteed by obtaining clones and feminized seeds. If, however, you’re working with regular seeds and are unsure of your seed’s sex, knowing how to determine the sex of your plant is vital to developing new genetics, gathering seeds, or growing sinsemilla.

Sexing cannabis plants is easy. Let’s see how to tell.

Check out these additional resources for more info on cannabis seeds:

Female cannabis pre-flowers grow as tiny bracts with hair-like stigma peeking out. Male plants produce small, round balls at the nodes. (Amy Phung/Leafly)

Cannabis plants show their sex by what grows in between their nodes (where leaves and branches extend from the stalk). Pollen sacs will develop on a male plant to spread seeds and stigma will develop on a female to catch pollen. You can see these differences weeks before they actually start serving their purposes in the reproduction cycle. These are known as “pre-flowers.”

Pre-flowers begin to develop four weeks into growth, but they may take a little longer depending on how quickly the sprouting phase occurs. By the sixth week, you should be able to find the pre-flowers and confidently determine the sex of your plant.

Pre-flowers can initially be extremely small and hard to identify with the naked eye, but you can use a magnifying glass to get a better look. Examine the nodes of the plant and look for either the early growth of small sacs on a male, or two bracts on a female, which will eventually produce the hair-like stigma.

Though there are other methods to determine what sex the plant is, examining pre-flower formation is the most reliable.

Removing males early on is important for two reasons: it frees up space in your garden so females can grow bigger and stronger, and it prevents males from pollinating females.

Hermaphrodite cannabis can express both sex organs and self-pollinate. (Amy Phung/Leafly)

When a female plant develops both male and female sex organs, it is considered a hermaphrodite. This means your cannabis plant is now capable of producing pollen that can pollinate your entire garden. “Herming out,” as some call it, is something that generally happens when a plant becomes excessively stressed. Some plant stressors include:

  • Plant damage
  • Bad weather
  • Disease
  • Nutrient deficiencies

There are two types of hermaphrodite plants:

  • A plant that develops both buds and pollen sacs
  • A plant that produces anthers, commonly referred to as “bananas” due to their appearance

While both result in pollen production, true hermaphrodites produce sacs that need to rupture, while anthers are exposed, pollen-producing stamen.

Because this occurs when cannabis is under stress, it’s important to monitor plants after they have been exposed to stressors—indoors: high temperatures or light leaks are often the cause; outdoors: a snapped branch might be repaired and then turn into a hermaphrodite.

The other primary cause of hermaphrodite plants lies in the plant’s genetics. A plant with poor genetics or a history of hermaphrodite development should be avoided to protect your garden. If you notice any pollen sacs or anthers at any point, remove the plant from your garden immediately to prevent pollination of female plants.

If you’re interested in pollinating portions of your crop, remember that pollen is extremely potent and very good at traveling. Keep your males intended for pollination far from your garden space and work carefully with that pollen.

This post was originally published on September 19, 2017. It was most recently updated on February 11, 2020.

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