Phenotype

A phenotype is the observable physical expression of a plant's genetics in a specific environment. In cannabis breeding, phenotypes represent the visible traits—plant structure, leaf shape, flower density, color, and aroma—that result from both genetic makeup and growing conditions. Breeders working with a given strain often observe multiple distinct phenotypes within a single genetic line, sometimes called "phenos," which reflect natural genetic variation or environmental response. Understanding phenotypic diversity is foundational to selective breeding, as it allows breeders to identify and preserve desired trait combinations. Phenotypes differ from genotypes (the underlying genetic code) because identical genetics can express differently under varying light, temperature, and nutrient conditions. Documenting phenotypic variation helps breeders stabilize desirable characteristics across

Breeders use phenotypic selection to isolate and perpetuate specific trait expressions—such as vigor, yield structure, or terpene profile—across multiple generations. Identifying stable, repeatable phenotypes within a line is central to creating consistent cultivars and establishing breeding populations.