Polygenic Stability

Polygenic stability refers to the inheritance of traits controlled by multiple genes rather than single dominant/recessive loci. In cannabis breeding, this describes characteristics like plant height, cannabinoid ratios, and terpene profiles that show continuous variation rather than discrete expression. Breeders working with polygenic traits observe wider phenotypic ranges within seed populations, requiring larger sample sizes and longer observation periods to identify stable lines. This contrasts with monogenic traits, which typically follow predictable Mendelian patterns. Understanding polygenic inheritance is essential for developing consistent cultivars, as these multi-gene systems are more susceptible to environmental influence and recombination shuffling across generations.

Breeders targeting polygenic traits employ phenotypic selection across multiple generations, often maintaining larger parent pools to capture genetic variation. Stabilizing selection—repeatedly choosing plants with desired expression levels—gradually increases heritability and reduces phenotypic variance in offspring, though true stabilization may require 6+ generations of controlled crossing.