Polygenic Expression

Polygenic expression in cannabis refers to the inheritance pattern where multiple genes contribute to a single phenotypic trait, rather than a single dominant gene controlling the outcome. This concept is foundational to understanding why cannabis plants from the same parents often display varying terpene profiles, cannabinoid ratios, plant morphology, and flowering times. Terpene production particularly exemplifies polygenic control—limonene, myrcene, and other volatile compounds are typically regulated by several genetic loci working in combination. Breeders working with this inheritance model recognize that stabilizing specific aroma or terpene profiles requires multiple generations of selection and careful phenotyping. This polygenic inheritance explains both the challenge and opportunity in cannabis breeding: consistent traits are harder to achieve but offer greater genetic diversit

Understanding polygenic expression allows breeders to predict and select for complex traits across multiple generations more strategically. Rather than seeking single-gene knockouts, polygenic-aware breeding programs use population-level phenotyping and backcrossing to stabilize desired terpene combinations and plant structures across varied growing conditions.