Quantitative Traits

Quantitative traits in cannabis refer to characteristics controlled by multiple genes rather than a single dominant gene, resulting in continuous variation across a population. These traits—including plant height, internode spacing, flowering time, and resin production—do not follow simple Mendelian inheritance patterns and instead display a range of phenotypes influenced by both genetic architecture and environmental factors. Understanding quantitative inheritance is essential for cannabis breeders seeking to stabilize desired traits across generations. Lineage records frequently report that selection for quantitative traits requires larger populations and longer breeding cycles compared to qualitative (single-gene) traits. This polygenic control makes quantitative traits valuable for fine-tuning cultivar characteristics and adapting germplasm to specific growing environments.

Breeders working with quantitative traits employ phenotypic selection across multiple generations to accumulate favorable alleles, a process known as polygenic selection. Stabilizing these traits in seed lines demands careful population management, detailed phenotypic recording, and often multi-year evaluation cycles to ensure consistency and heritability.