Let’s face it: We are sometimes guilty of not visiting our mothers often enough, yet assume they will be there for us when we need them most. Our mothers are the foundation of what we have grown into, yet, sadly, they often are neglected. (Well, except for the obligatory flowers or phone call on Mother’s Day.) So, visit your Mom. And, while you’re thinking of your Mom, maybe you should also check your mother plants and see how they’re getting along; mother plants, like Moms, create your future generations.
A major challenge for the modern cannabis cultivator is keeping up with the never-ending demand for cuttings. Sourcing plants from nurseries can be unreliable, and you increase the odds of serious calamities every time you introduce a new plant into a facility—whether it’s bringing in unseen pests and pathogens that may spread throughout the entire production line, or receiving clones tainted with disallowed pesticides and fungicides. The best way to mitigate these problems is to start by sprouting seeds, closing the door to new cuttings (unless they are free of pests and pathogens), and only growing mother plants from cuttings taken from clean stock.
Getting the (Genetic) Drift
Once a desirable clone is acquired, it may be asexually reproduced indefinitely. A common misconception is that there is “photocopy effect” from taking a cutting and growing a mother plant from it, then repeating this cycle over and over again; the clone gradually becoming merely a faded copy of the original. This is an urban myth. Numerous well-known clones that have been around for decades are in production today, and they still exhibit the same favorable characteristics as the original mother; that said, many of us have witnessed clones go awry. They may lose their vigor or begin exhibiting unfavorable traits that have never appeared before. A commonly used, though inaccurate explanation for this phenomenon is “genetic drift.”
Genetic drift is an evolutionary mechanism by which the frequency of alleles within a given population is impacted by random events, which results in a gradual “drift” of the genome that affects the organism’s phenotype and fitness. Although genetic drift is certainly a possibility, the noticeable phenotypic changes are more likely the result of random mutations—the creation of new alleles—rather than changes in the frequency of existing alleles. Mutations occur in all plants, including Cannabis. Mutations may sometimes be obvious, but more often they result in small, nearly imperceptible changes that often impinge on a plant’s physiology. Many mutations are neutral or produce deleterious effects, and some are even lethal. But occasionally a desirable trait may appear, and if a grower favors that trait, selects it and multiplies it asexually via cuttings, it may become a new clone with slight genetic differences.
In other asexually reproduced clonal crops, such as the genetically unstable wine grape Pinot Noir, simple single mutations have created entirely new varieties with dramatically different appearances, aromas and flavors. Three grape varieties with distinctively different fruit types—deep purple Pinot Noir, lavender blush Pinot Gris and light green Pinot Blanc—are all clonally reproduced variations of Pinot Noir that each preserve their unique skin color mutation. In addition to skin color, other traits also vary due to spontaneous mutations, and around a thousand different Pinot clones currently exist, but not all are grown in volume.
Such wide variation was not created through spontaneous hybridization that occurs naturally in outdoor environments, nor by intentional selection and careful breeding by farmers, but rather through a combination of both. Farmers eventually noticed spontaneous mutations in skin color and other traits, then selected and multiplied those mutated varieties. They are so clearly different from each other that they are given different names and classifications in the marketplace, yet apart from a tiny change in their DNA, their genetics are almost identical. The Pinot clonal group, having been in cultivation for more than a millennium, found countless opportunities to mutate as the original clone found its way around the world and came to be cultivated in widely different climates and conditions.
It is likely that countless indoor growers of modern sinsemilla varieties spanning decades favored certain mutations that were preserved through the selective pressures of artificial light cultivation, environmental stress and/or human intervention. In the case of Cannabis, understanding the range of possible mutations and the mechanisms that encourage and favor them can only be achieved through continuing genomic studies.
Other factors may also affect the appearance and performance of clones. Plants are often subject to “epigenetic” influences-changes brought on by external factors that, in part, determine the phenotypic expression of genes. When cuttings are taken from old, tired plants with nutrient deficiencies, animal pests or bacterial and viral loads, these problems will accompany the cutting into subsequent populations of that clone. Stressed cuttings usually grow up to be stressed mother plants. If the replacement cutting is not nursed into perfect health before cuttings are removed, all cuttings taken from her will go through the cycle of stress and prolonged recovery. Efforts to explain this phenomenon have perpetuated the “photocopy” myth that clones genetically change during repeated cutting cycles.
Take Care of Your Mothers
Bringing mothers back to optimal health can be extremely difficult and time consuming, and often involves challenges such as eradicating pests without damaging the plant, transplanting an aging mother plant into the next larger pot size when it is already 6 feet tall and 10 months old, or trying to grow sickly plants fast enough to outgrow pests and pathogens. Rescuing neglected plants with techniques such as tissue culture may prove useful, and commercial growers may be purchasing sterile, problem-free plantlets produced in vitro in the near future. (Editor’s note: For more information on tissue culture, see “A Primer on Tissue Culture” in the April 2018 issue of Cannabis Business Times or here: bit.ly/tissue-culture.)
For the time being, we must remember our mother plants, visit them often and treat them well. The major vector spreading pests and pathogens and their associated epigenetic influences is the propagation of old and tired mothers. Humans live out their lives and depart with respect, their “seeds” left to perpetuate family traits into the next generations. But we treat our sinsemilla mother plants differently. Often, we cut as many offspring from them as we want for flower production, and then marginalize our mother plants in compromised conditions where they grow old and weak, vulnerable to a wide variety of opportunistic pests and diseases. When we finally remember them, we desperately salvage a few cuttings that we nurse back to life, along with a host of bacteria, viruses, broad mites and more, including all the physical and epigenetic effects of their damage. But then, as if by some miracle, we expect them to perk right up and become the vibrant young ladies they once were. Is this a respectful way to treat our mothers?
Your mothers form the heart and soul (and profit stream) of your business. Go out and visit your mothers right now. Check thoroughly for any issues, and treat your mothers to a little extra nurturing while you’re at it. Shower them with love and attention. Be sure they are happy, and they will reward you many times over.