Additive Genetic Effects

Additive genetic effects describe the cumulative contribution of multiple genes to a trait's expression in cannabis breeding. Unlike single-gene traits, additive effects involve many loci working together, each contributing small, measurable amounts to the final phenotype—such as plant height, cannabinoid production, or terpene profiles. This polygenic model is central to understanding how breeders select for complex characteristics across generations. Breeders working in this framework rely on quantitative genetics principles, tracking trait variance within populations rather than discrete Mendelian ratios. Understanding additive effects helps explain why trait stabilization often requires multiple breeding cycles and why environmental factors can influence final expression.

Cannabis breeders use additive genetic models to predict offspring trait ranges and design selection strategies for quantitative traits. Population-level phenotyping and genomic markers increasingly help breeders identify and combine favorable alleles across multiple loci.