Monogenic Vs Polygenic Inheritance

Monogenic and polygenic inheritance describe fundamentally different patterns of trait expression in cannabis breeding. Monogenic traits are controlled by a single gene locus, producing predictable Mendelian ratios across generations—examples include leaf morphology variants and certain pigmentation patterns. Polygenic traits involve multiple gene loci working additively, resulting in continuous variation and more unpredictable offspring phenotypes; plant height, yield potential, and terpene profiles are commonly polygenic. Understanding this distinction is essential for breeders selecting parents and predicting F1 and F2 outcomes. Monogenic traits enable faster stabilization in breeding programs, while polygenic traits require longer selection cycles and larger population sizes to establish true-breeding lines.

Breeders targeting specific morphological markers (dwarf phenotypes, leaf shape) often work with monogenic traits for rapid, predictable results. Polygenic trait improvement—such as cannabinoid ratios or disease resistance—demands multi-generational selection and careful population management to accumulate favorable alleles.