A phenotype, or pheno, refers to the physical expression of a cannabis plant’s genetic blueprint; when a female cannabis plant produces seeds, each seed is a phenotype that expresses a unique set of traits from the mother and father plants. Phenotypes occur as the result of the interaction between a plant’s genetic blueprint and the environment in which it is grown.
“The phenotype of these Blue Dream seeds grown under full light is different than the same seeds grown in partial shade.”
What is phenotype?
Phenotype, or the physical expression of a cannabis plant, depends on the genetic code—or genotype—of the plant and the way in which the environment influences the expression of that genetic code.
Genes are not activated simply because an organism has them—they are triggered by the environment. Different environments will activate or inhibit the expression of different genes. Environmental factors such as light, air, water, and nutrient levels can trigger or inhibit the expression of certain genes.
Every aspect of the phenotype of a cannabis plant, including its smell, color, potency, resin production, height, etc., is therefore the product of the plant’s genotype and the environment in which it grows.
Plants that are genetically identical can end up with very different phenotypes due to the environmental conditions they are exposed to. For example, seeds of a specific strain will typically grow differently indoors compared to outdoors. The physical differences that result as a consequence of exposure to distinct environmental conditions is called phenotypic plasticity.
How is phenotype used?
Growers use cannabis phenotypes as a way to select for the best expression of physical characteristics in a particular strain: After growing multiple seeds of a strain, growers will choose the one—the phenotype—that is the best in terms of yields, potency, color, flavor, bud density, and other valued features. Clones can then be made of that phenotype for mass production.