What is Plant Tissue Culture?

Matt: Hi, this is Matt Wick with Segra International. I've been with the company for a little bit less than a year, and my role is VP of United States Business Development. I'm excited to be here today at MJ BizCon in Las Vegas on the Grow Weed at Home podcast with Mr. Kyle Kushman himself to talk all about tissue culture and the ramifications it has for both you as the home grower and commercial cultivators worldwide. Thanks.

Kyle: Hey everybody, we're here for another great episode of Grow Weed at Home at the MJ BizCon. We're here on 40 Ton Productions Row—this is Equity Row, and that's named for all of the people that have been unduly impacted by the illegality of cannabis. Right here today, I have Matthew Wick from Segra International, a friend of mine. Nice to have you here, Matt.

Matt: Thank you.

Kyle: Segra is renowned—well, maybe not renowned yet, but they're building up a name in the industry for tissue culture. Tissue culture is a very special method of propagation with its own unique attributes, and that's what I wanted to have you here to talk about today. Tell us, what is so unique and special about tissue culture?

Matt: Tissue culture in itself—so, a couple of things, right? It's a method of propagation, and it can dovetail with a bunch of other things that I think people really like, like vegetative propagation. You can support vegetative propagation with tissue culture, but let me rewind for a second.Tissue culture has been around for about 100 years, so it's not new in agriculture. But like everything else in cannabis and the industry that we're in now, and kind of the evolution of where we're at, it's new to cannabis.

Kyle: Right.

Matt: Basically, you take plants that you like—take trees, for example. This is a technology used really widely in almonds and walnut production. For cannabis, basically, here's the most direct application: you find a strain that is really special, clone-only. You want to preserve it, and you want to preserve it as long as possible with as little of a physical footprint as possible, and as cleanly as possible. That's what tissue culture does.

Matt: Basically, we're taking tiny bits of a living plant, sterilizing it, and putting it in a little box of gel, or agar. 

Kyle: Right.

Matt: That agar, depending on what stage of growth we're in, has different hormones or nutrients in it just to keep that plant alive. From there, you're always keeping these plants in what's called an aseptic condition. Aseptic means no bacteria, no fungi. We can also do things like screening for viruses, viroids, and then perform remediation work against a lot of those things too. Tissue culture is kind of like a foundation. It's a really great way to preserve the, you know, the basic building blocks of any cannabis operator.

Kyle: Yeah, and can you give some information or even an opinion on the benefits of propagating through tissue culture as opposed to traditional breeding?

Matt: Oh man, so traditional breeding and tissue culture are two different things entirely.

Kyle: Absolutely.

Matt: Just to clarify that upfront

Kyle: And the work involved, the steps, and the time involved are different. But besides that, talk about some of the benefits that are distinct.

Matt: 100%, yeah. So, tissue culture, let's say, if you're incorporating tissue culture into your grow for example, now you've got, let's say you have a big mother room with mother plants that you kept re-propagating for 5–10 years. Over time, those plants are going to start reducing their output and deteriorating in quality. That’s happening at a vascular level in the plant.

Kyle: It's inevitable.

Matt: And so, like, when a lot of people talk about genetic drift, I think this is something that's worth noting too, right? Genetic drift doesn't—like, for the most part—it's not due to, like, big mutations in the DNA. It's typically just due to a deteriorating quality of that germplasm. 

Kyle: It may just bring on susceptibility of pathogens, or it may just bring on, yeah, I mean, you know, I mean, still going to have the same profile, it’ll still be the same medicine, but it might take on certain negative susceptibilities. 

Matt: Correct, or it'll be less vigorous. Uh, you know, the plant might be spending a lot of its metabolic energy fighting off diseases as opposed to producing turnips.

Kyle: Strawberry Cough, for example. I had been passing it around for 25 years, and I had taken it back into my growth several times. And over the years, fewer, fewer and fewer people wanted to grow the Strawberry Cough because it became difficult, you know. I look at it like, uh, it's kind of like STDs, you know. The plant gets passed around to all these people, you know. And, and especially back in the day, you know, nobody had a really environmentally controlled grow. It was like, in the summertime, you grew in the basement; in the wintertime, you grew in the attic, you know. And it wasn't clean, and so you were constantly degrading your genetic over time.

Kyle: Yeah, you know, especially if it got some kind of disease or an actual pathogen, you know, and you kind of cured it. But some of this stuff is systemic—

Matt: A lot of it is systemic—and a lot of it can only really be addressed by using the techniques that are correlated with tissue culture production.

Kyle: Yeah.

Matt: So I mean, like, when we take stuff in, you know, we're basically sterilizing that plant material, and then we're testing it for viruses and viroids. And then, depending on what is there, we can clean stuff up. We're always going to be able to get rid of, like, what's called, like, basically, you know, systemic bacteria. So, for example, right—like I was working with a strain last week, and, um, you know, we’re doing the initial bit of work on it. You start with, like, a set of nodes from the plant, clean it up, put it in, and then we do it, like, in a way that prevents cross-contamination.

Matt: And, you know, I saw one of the ones about a week later, and it was just—it was gross. And I was like, "Oh man, what happened in there?" And my lab manager, he was like, "Oh, that's an example of the amount of systemic bacteria that that one plant had, this particular cutting." And so, like, you know, we chuck it, you know, or maybe try to do a disinfection again. But that's all part of what's called the initiation process. Basically, you're taking something as a Strawberry Cough and starting fresh. It’d be great to see what Strawberry Cough does if we were to put it through tissue culture, refresh it, and see if it comes back to some of the original glory that you know.

Kyle: Well, it already has. Luckily, I had a relationship with Dark Heart, and that all got refreshed. Can you—without getting too scientific or going over anybody's head—give a brief description of how the plant sheds those things? How do you remove them?

Matt: Oh yeah, for sure. I’ll try to make this a less technical interpretation answer, man.

Kyle: Yeah, like, can you give me a glimpse into, you know, the science of how you can take a plant tha thas been passed around to a 100 different growers and picked up all these nasty STDs and then how you clean it. How the technique of tissue culture actually cleans it up?

Matt: Yes, totally. Did you ask me the question?

Kyle: Yeah, how does that happen? How does that happen?

Matt: So, how does it happen? It’s literally disinfection. Ah, so, I mean, it’s like—it's—or in some cases, like something like an antibiotic. 

Kyle: You’re taking that UV light and shoving it up the rectum 

Matt: Pretty much, man. Yeah, yeah, I get that. Toasting it from the inside, right? Pretty much. No, like, you imagine the plant has a vascular system. It’s got all these things always flowing through it. I mean, if you can take it, you can put it in a jar, and you can treat it repeatedly with, you know, some antifungal or antibacterial things. Now you have a clean piece of material. The plant's always growing, right? So you can now get a new piece of, uh, material, pull it off of there that’s going to be even cleaner, and then restart again until you have a stable culture. That’s what we call it.

Kyle: That is interesting. Yeah, I’m curious if you’ve ever heard of the field technique of growing vegetative plants to, uh, over a height of six feet, okay? And then, uh, they have to be in a very rapid rate of growth—in other words, it can’t be during the wintertime when things are slow. It has to be during the summertime when things are—they’re growing two more inches a day, okay? And that you can, um, you can clone off the top of these plants. And if you do it several times, it’s virtually a tissue culture result.

Matt: Got it. So this is the, uh, the "we’re going to outrun viruses" scenario. Yeah, right. So, I mean, I'll use the example of Hop Latent Viroid (HLVd), right? Uh, so a hop viroid, for example, has this weird phenomenon where it'll be expressed or perhaps more concentrated, more detectable in some parts of the plant than others—sometimes even in different branches. It doesn’t mean that it’s not there if it’s not detected, right? And this again goes back to, even with tissue culture, like, there are some things you can do, but imagine that you're trying to outrun something. You always have, like, the same juice in the plant, you know, like the flow or whatever flowing through —

Kyle: The xylem flow?

Matt: The xylem flow, exactly. And those plants are always carrying little remnants of this viroid around, and all it takes is a couple of those actual viroid particles to exist to continue an infection, right? And so, I mean, like, if you’re trying to do it with a plant you know has Hop Latent Viroid, for example, you’re kind of rolling the dice in a real big way.

Kyle: So you might have a little bit better luck with, you know, bringing back some vigor or some things that are less, uh, less pathogen-related.

Matt: Yeah, maybe. If you’re doing it that way. I mean, like, I’ve talked to a lot of people who’ve done that, and we go back and forth. I haven’t seen any evidence of anybody being able to do that and then prove it with, like, tests or detection for long periods of time. Because even in tissue culture, I’ve worked with—so, I’ve worked with several TC teams now for years, and there’s—even within the industry—there’s a lot of mixed kind of understanding about whether or not tissue culture and certain thermal techniques, as they’re called, where you apply heat and cooling periods to the plant material, actually work to eliminate Hop Latent Viroid.

Matt: I’ve seen examples where, you know, people thought that it was completely eliminated and tested clean for six months in TC, doing all the things everybody, you know, knows how to do. And then six months after that, it comes back fast and hard, and you’re basically starting over. So, I mean, don’t get me wrong, man. There are a lot of people doing a lot of cool research out there and a lot of people doing some really neat experiments. But personally, if I had a Hop Latent Viroid-riddled strain—unless it was an absolute super unicorn—I would probably just say I’m going to put my effort into making something new and fresh that’s going to be clean. 

Kyle: Wow, it’s that serious.

Matt: Honestly, it’s that serious.

Kyle: Obviously, the work that you do, it focuses on pathogen prevention and stuff like that. I'm wondering if there's a preemptive benefit to it—if there are any benefits in the same kind of vein that we're talking about by taking a plant tissue culture that doesn’t have any pathogens.

Matt: Oh yeah, yeah. So, you’re kind of also resetting the biological clock a little bit on that plant material too.

Kyle: Biological clock? What do you mean by that?

Matt: Imagine that, as plants and germplasm, is alive for a long period of time—

Kyle: The farther away you get from the seed.

Matt: The farther away you get from the seed, yeah.

Kyle: Farther away from the seed—I remember that old statement.

Matt: Yeah, there you go. It’s basically that. The further away from the seed you are, you’re going to get susceptibility and deterioration. But you’re basically refreshing it back to, like, what I can call a “very young state”—an embryonic state almost.

Kyle: An embryonic state

Matt: The embryonic state, exactly. That’s why, I mean, there are techniques in tissue culture called embryogenesis, for example, which is another way of doing things—different from what we do.

Kyle: So, obviously, to me, preserving genetics is really important. All of us breeders, you know, we have our favorites and things like that. Talk a little bit about the importance of preserving genetics.

Matt: Oh my gosh, that’s a big question. And that’s a really big question—

Kyle: And it’s not only for cannabis.

Matt: Oh, not only for cannabis—for all ag [agriculture]. Yeah, for all agriculture products. But in cannabis specifically, it’s a big deal. Especially in the last 10 years, you know, everybody I’ve talked to who’s done a lot of the molecular genetic research—actually mapping out cannabis genomes...

Kyle: You’re talking about all the cannabinoids?

Matt: Uh, no, I’m talking at the DNA level. Actually creating identifications at the DNA level with DNA fingerprinting. You can build something called a phylogenetic tree where you can show how related things are that are out there. There’s a huge contraction of the degree of diversity in the gene pool of cannabis, right? Suddenly, as the tides shift and everybody wants to breed towards the Purple Candy Gas, that all takes over the entire market.

Kyle: And then everything else is left behind.

Matt: Everything else is left behind. We all know, I mean, like up where I’m from, there was the Goose strain that nobody can find anymore. That was a classic. And that’s what happens—they end up dropping off.

Kyle: Exactly. And give it a decade, they’re going to want it again. 

Matt: Everybody wants it now. And so this is the other way too. Now you’re preserving genetics using tissue culture in a very small footprint with a lot fewer resources. You’re doing it in a way where the plant material is always going to be clean—if you’re doing it right. And that’s kind of priceless there. Because, I mean, as opposed to keeping a mom plant out in the back of the greenhouse on the back 40 or whatever, and hoping it doesn’t get a bunch of disease, hoping some bugs don’t give it something—a curly top, pythium, whatever, man.

Kyle: So, you know, it’s obvious to me that tissue culture—and Segra specifically—are here in the market to help. It’s all about scaling. 

Matt: This can help scale it all. 

Kyle: How does tissue culture play into that?

Matt: Oh man, so, I mean, when it comes to very, very large-scale propagation, tissue culture is one of the most cost-effective ways to multiply plants. It’s one of those things where you get to a certain level, and you can produce a million plantlets—lab-grade plantlets—over and over again, like every two weeks, forever. So long as there’s a home for all those plants, then it makes sense to do it. 

Kyle: And the space required is reduced by multiples, 

Matt: By pretty much by an order of magnitude. For example, in a 1,500-square-foot space, we can put out enough mother stock to support a million square feet of cultivation.

Kyle: Nice.

Matt: And we can also archive another 70 to 100 genetics.

Kyle: Nice. So, you have a presence in how many countries now?

Matt: Our headquarters are in Vancouver, British Columbia. We ship plants to, I believe, 14 countries on every continent except Antarctica. It feels like every week I’m on a call with the international team, and there’s a new country calling us up to start their new program. It’s really amazing stuff. We’re shipping to Latin America, the EU, Asia, and Australia. We ship seeds and cannabis clones. And the international market? It’s basically agriculture, right? All the countries where it’s legal—

Kyle: Absolutely. There’s nothing special about this plant from a regulatory perspective, which makes it great. Yeah! Officer, there's nothing special about this plant!

Matt: Exactly! And from the perspective of regulation it makes it great, like the international market, everybody's  out there playing, you know, everybody's out there playing.

Kyle: So, how long have you— You said you you've done uh tissue culture with several partners by now. So, how long have you been with Segra?

Matt: I’ve been at Segra about nine months. I started earlier this year.

Kyle: Have you been able to, uh, have you noticed, have you been able to identify upcoming trends or anything that you think—like you said, they're playing to the purple candy and they're playing to the gas. You hear anything in the, in the scuttlebutt?

Matt: Always, man. But I think what's really worth noting is that every market—and this is, I mean, I’m going to speak, like, you know, I’m California-based, right? I worked in California nurseries five or six years ago, right? The swirling juicy core, right? 

Kyle: The birth of the cannabis culture.

Matt: And so, in California, you know, we have our trends, and they’re pretty firm. You can watch them, and it’s not too difficult. And then the more I talk with my team internationally, the more we talk about, well, what are these trends everywhere all over the world? And it’s different everywhere, right? It’s pretty wild, you know. Like, what’s popular in Germany, for example, is a little bit different than what’s popular in the UK. It’s different than what’s popular right now in the US. Like, I work in the licensed California market with a partner, and we’re in the process of building out that relationship to be able to sell mother stock to other licensed California growers.

Kyle: Cool. And is there any chance that, in the future, you might have any service that would, be good for personal home growers?

Matt: I would hope so. I mean, you know, a great example of this is, like, in other countries where they have a direct-to-consumer program, we can supply them with clean clones. And those clones can be sold to retail in some countries.

Kyle: Right.

Matt: Yeah. And so then, if they can get a validated cut that has a bit of providence attached to it with a genetic fingerprint, they can get clones that they know have been tested to be free of viruses. That way, home growers aren’t going to be throwing away all their resources on plants that are never going to perform, no matter how good of a grow they put around them.

Kyle: You guys should do that. You guys should work on that venue. I think that home growers would appreciate it very much.

Matt: I think so too. Yeah. And it’s, uh, what’s wild too is, like, even with seeds, right? So, I mean, the big pathogen I talk about a lot is Hop Latent Viroid, right? But seeds can also have HLVd.

Kyle: Really? I did not know that.

Matt: 100%. You can get transmission. So, if you have a mother plant—this is another avenue where tissue culture becomes very useful for preserving plants to actually do seed propagation or seed runs. Because if you have an infected mother or father plant and you make seeds out of that—especially if the mother plant is infected with Hop Latent Viroid—you’re going to have transmission rates. Depending on which study you look at, it’s anywhere from 8% to 25% transmission rates. So, you figure one out of four, one out of five of those seeds you’ve got is probably going to be hot if one of the parents is hot.

Kyle: Wow.

Matt: Yeah, so it’s pretty wild, man.

Kyle: Well, I love the work you’re doing, and, um, you know, I’m mostly an advocate for the home grower. So, I’ve got to ask, do you have any advice for the home grower that maybe is experiencing some of these pathogen, pest, or lack of vigor problems? Do you have any advice that you've learned? 

Matt: Yeah, man, I think really good advice is, uh, do a little bit of research on clean practices, especially as you’re cloning and propagating. Do a little bit of research about what the signs and symptoms of common pathogens are. If you can, uh, peel off a test—there’s a lot of really great analytical labs in the US that you can send samples to, no problem. They can test your plant material for Hop Latent Viroid. They can test for any sorts of other—there’s usually about 10 to 15 pathogens that a lot of these labs will test for. And it’s anywhere from $25 to $50.

Kyle: You can send this out in the mail now. It’s not even illegal; it’s all considered hemp.

Matt: Just like a small bit of a petiole or something like that? You wash it in rubbing alcohol and send it in. 

Kyle: So, maybe for some of you people out there, you might want to look into that. If you’re thinking about, uh, doing some breeding and passing something on, you might want to know if it’s clean before you go and do that.

Kyle: That’s a great idea.

Matt: Yeah, yeah, yeah. Test yourself first.

Kyle: Test yourself first before you go out partying, right?

Matt: Exactly. Right, I mean, yeah, that's pretty much it, man. But you know, there's a lot of—I think all of this comes from the fact that, like, when cannabis was, you know, completely underground, you know, completely countercultural, you did what you had to do, right? You had to make it happen, and there wasn’t much, you know. And, like, it worked, right? And now, as we're entering this world where you have the regulated market, and you start getting into all the boring stuff like the pressures of maintaining margins, the pressures of maintaining operational regulations—all these things—and your margins shrink, it becomes more and more important for your plants to do exactly what you need them to do.

Kyle: Absolutely.

Matt: And so, I mean, like, when I talk to, like, finance guys at businesses I'm working with, I tell them, like, "Look, we're risk mitigation, right?" That’s really what we are at the end of the day. We’re there to make sure that the $40 million you put into your grow isn’t gone, isn’t going to waste because the plants are never going to be able to convert the energy into the cannabinoids you want because they’re diseased. And that happens a lot. It’s a bummer. 

Kyle: You’re kind of like the—you know, humans, we go out, we get a colonic or something, you know? You’re the—yeah, I’m trying to think of the analogy of what you are for the humans to the plant world.

Matt: It’s like going in and scrubbing the inside, you know?

Kyle: Yeah.

Matt: Yeah, kind of. Pretty much, you’re just cleaning it up, you’re reinvigorating it, and then you’re preserving something forever in a clean environment with some pretty straightforward lab techniques.

Kyle: Well, I wish you guys a lot of success in the future—not the least of which is, I’m planning on working with you guys in the future.

Matt: I’d love to.

Kyle: Yeah, you know, I’d love to make sure that more people have access to the Strawberry Cough.

Matt: Absolutely.

Kyle: And, uh, so before we get out of here—that was very, uh, educational—is there anything that I missed, that I didn’t bring up, that you’d like to mention?

Matt: No, man. It’s a wild world out there. Cannabis is a—it’s a great ride. I mean, I’ve been working in this industry for a long time, and every day is new and exciting.

Kyle: Well, Matt from Segra, I appreciate you coming by Grow Weed at Home, and I hope we’ll talk again soon in the future.

Matt: Yeah, man. Likewise. Thank you, my man.

Kyle: Thank you.

Narrator: Thank you for joining us for another episode of Grow Weed at Home.