Quantitative Trait Loci

Quantitative Trait Loci (QTL) refers to specific chromosomal regions that influence quantitative (polygenic) traits—characteristics controlled by multiple genes rather than a single locus. In cannabis genetics, QTL mapping helps identify which DNA segments correlate with complex traits like plant height, flowering time, cannabinoid yield, and terpene profile diversity. Unlike single-gene traits that follow Mendelian inheritance patterns, QTL traits show continuous variation across populations and are heavily shaped by environmental factors. Breeders and researchers use QTL analysis to understand the genetic architecture underlying economically important phenotypes. This molecular approach has become increasingly relevant as cannabis breeding moves toward more precise, data-driven selection methods.

QTL mapping allows breeders to identify and track multiple genetic contributors to desirable traits simultaneously, rather than relying on single-gene selection. This enables more informed marker-assisted breeding programs and helps predict trait expression in offspring across diverse genetic backgrounds.