Quantitative Genetics

Quantitative genetics refers to the study of traits controlled by multiple genes, each contributing small additive effects to a phenotype. In cannabis breeding, quantitative traits—such as cannabinoid potency, plant height, flowering time, and terpene production—are inherited across many loci rather than following simple Mendelian patterns. Breeders working with these polygenic traits must track phenotypic variation across generations and select parents showing desired trait combinations. This approach is fundamental to modern cultivar development, as most commercially relevant characteristics display quantitative inheritance. Understanding quantitative genetic principles helps breeders predict heritability and response to selection, improving breeding efficiency and consistency.

Breeders employ quantitative genetic methods—including progeny testing, pedigree analysis, and marker-assisted selection—to accumulate favorable alleles for complex traits. Population-level data collection and multi-generational tracking remain essential for refining cultivars with stable, desired trait expressions.