Quantitative Inheritance

Quantitative inheritance refers to traits controlled by multiple genes rather than a single locus, resulting in continuous variation across a population. In cannabis breeding, traits like plant height, yield potential, cannabinoid ratios, and flowering time typically follow polygenic inheritance patterns. Because many genes contribute to the phenotype, offspring often display a range of expressions rather than discrete categories. Breeders working with quantitative traits must track trait distributions across generations and use selective breeding to shift population means toward desired characteristics. Understanding this genetic architecture is essential for stabilizing lines and predicting progeny variance, though environmental factors often compound the complexity of selection.

Breeders select for quantitative traits by identifying individuals at phenotypic extremes, growing large populations to detect rare recombinants, and maintaining detailed records across multiple generations. Polygenic traits typically show slow progress under selection and require patience and large effective population sizes to avoid genetic drift.