Breeding starts with clear goals (chemistry, yield, morphology, disease resistance) and rigorously selected parents. In cannabis, the foundational chemotype—high-THC, high-CBD, or “intermediate”—is strongly influenced by the cannabinoid-synthase genes THCAS and CBDAS. Classic crossing work showed that functional vs. non-functional alleles at these loci largely predict THC:CBD ratios across offspring, giving breeders a genetic handle on…