Plant Chemotype

Plant chemotype refers to the chemical profile of a cannabis plant, primarily distinguished by its cannabinoid and terpene composition. Unlike phenotype (physical expression), chemotype describes the biochemical identity—most commonly categorized by THC/CBD ratios and dominant secondary metabolites. Chemotypes are determined by both genetics and environmental factors during cultivation, though hereditary cannabinoid synthase genes establish the primary biochemical pathway. Breeders use chemotype classification to organize germplasm collections and predict offspring chemical profiles. Understanding chemotype is foundational for breeding programs targeting specific cannabinoid ratios or terpene combinations. Chemotype may shift across growing cycles due to stress, light exposure, and harvest timing, making it distinct from fixed genetic markers.

Breeders select parent plants based on stable chemotype expression to develop cultivars with reproducible cannabinoid profiles. Chemotype stability across generations helps identify homozygous lines and guides crossing strategies for targeted cannabinoid or terpene outcomes.