Quantitative Traits

Quantitative traits in cannabis refer to characteristics controlled by multiple genes rather than single genetic loci, resulting in continuous variation across populations. Examples include plant height, cannabinoid and terpene ratios, flowering time, and yield potential. Unlike qualitative traits (single-gene determined), quantitative traits show polygenic inheritance patterns and are heavily influenced by environmental conditions, making them more complex to predict and stabilize in breeding programs. Breeders working with quantitative traits must evaluate large populations to identify individuals expressing desired combinations, then selectively breed across multiple generations to concentrate favorable alleles. Understanding quantitative inheritance is fundamental to developing stable cultivar lines and responding to market demands for specific cannabinoid or terpene profiles.

Quantitative trait loci (QTL) mapping and marker-assisted selection are increasingly used to accelerate breeding timelines and identify plants carrying favorable allele combinations without waiting for phenotypic expression. Multi-generational selection pressure on quantitative traits allows breeders to shift population means toward desired characteristics like higher CBD content, specific terpene