Polygenic Selection

Polygenic selection refers to breeding practices targeting traits controlled by multiple genes rather than single-gene (monogenic) traits. In cannabis cultivation, breeders use polygenic selection to develop characteristics like plant height, leaf morphology, yield potential, and terpene profiles—each influenced by numerous genetic loci working together. This approach differs from selecting for single-gene traits (such as cannabinoid ratios in some lineages), requiring larger populations and multiple generations to achieve consistent results. Polygenic traits show continuous variation across a population, making them more complex to stabilize but offering breeders opportunities to fine-tune desired phenotypic expressions. Understanding polygenic inheritance helps explain why cannabis cultivars often display a range of expressions even within the same genetic line.

Breeders working with polygenic selection must maintain larger population sizes and conduct multi-generational testing to reliably shift trait distributions. This approach is foundational for developing cultivars with refined plant architecture, cannabinoid and terpene complexity, and environmental adaptation—traits that typically involve additive gene action across multiple loci.