Polygenic Inheritance

Polygenic inheritance in cannabis describes the expression of traits controlled by multiple genes rather than a single locus. This genetic architecture is common in cannabis, affecting characteristics like plant height, flowering time, cannabinoid ratios, and terpene profiles. Unlike monogenic traits that follow simple Mendelian patterns, polygenic traits show continuous variation across populations and are heavily influenced by environmental conditions. Understanding polygenic inheritance is essential for breeders attempting to stabilize desired phenotypes across generations, as offspring from polygenic-controlled parents rarely produce uniform results. This complexity explains why selecting for specific terpene combinations or growth structures requires multi-generational work rather than single-cross breeding.

Breeders working with polygenic traits typically employ selection across multiple generations, backcrossing programs, or polyhybrid crosses to accumulate favorable alleles. Marker-assisted selection and phenotypic screening of large F2 or F3 populations are common strategies to identify and concentrate desired polygenic expressions.