Homozygosity Dominance

Homozygosity dominance refers to the genetic expression pattern observed when a cannabis plant inherits identical alleles (homozygous condition) at key loci controlling aroma production. In breeding contexts, homozygous lines often exhibit stable, predictable terpene profiles across generations because both chromosomes carry the same genetic instructions for volatile compound synthesis. This stability contrasts with heterozygous plants, which may display variable aromatic phenotypes. Breeders working toward consistent cultivar profiles frequently select for homozygous dominance at terpene synthase genes and regulatory regions, enabling reproducible seed stock and clonal stability. Understanding this principle is foundational to explaining why some strain families maintain recognizable aromatic signatures across multiple generations, while others show wider variation.

Breeders deliberately stabilize homozygous loci controlling primary and secondary terpene pathways to lock in desired aromatic traits. Lines selected for homozygosity at these sites require fewer generations to achieve true-breeding status and reduce phenotypic drift in commercial seed production.