Why Breeding Terminology Matters
Whether you're reading strain descriptions, shopping for seeds, or digging into lineage charts, cannabis genetics uses a specific vocabulary. Understanding the terms helps you evaluate strains more critically — and appreciate the work that went into creating them. This glossary covers the most important concepts in cannabis genetics and breeding.
A–Z of Cannabis Genetics
Backcross (BC) — Crossing a hybrid back to one of its parent strains to reinforce specific traits. For example, BC1 (first backcross) is 75% genetically identical to the parent. Written as "Strain A x (Strain A x Strain B)." Used to stabilize desirable characteristics like potency, aroma, or flowering time.
Chemotype — The chemical profile of a cannabis plant, determined by its cannabinoid and terpene production. Chemotypes are categorized by THC:CBD ratios: Type I (high THC), Type II (balanced THC:CBD), Type III (high CBD).
Cubing — Repeated backcrossing over multiple generations to create a seed line that consistently produces a specific phenotype. Named for the cube shape of a Punnett square. Typically takes 4-6 generations to achieve reliable uniformity.
F1 (First Filial Generation) — The direct offspring of two distinct parent strains. F1s display hybrid vigor — they grow faster, yield more, and are more resilient than either parent. Most commercial seed strains are F1 hybrids.
F2 (Second Filial Generation) — F1 hybrids crossed with each other. Recessive traits from the grandparents can reappear, creating more genetic variety. F2 populations are where breeders hunt for novel phenotypes.
Genotype — The complete genetic makeup of a plant. Unlike phenotype (what you see), genotype includes all genetic potential — including traits that may not be expressed in a particular individual.
Hemiep — A plant that has been chemically or genetically modified to produce only female flowers, used in feminized seed production. Colloidal silver or silver thiosulfate is applied to trigger male flowers on a female plant.
Landrace — A pure, naturally occurring cannabis variety that evolved in a specific geographic region over centuries without human-directed cross-breeding. Examples: Afghani, Thai, Durban Poison, Acapulco Gold. All modern hybrids trace back to landrace ancestors.
Phenotype (Pheno) — The physical expression of a plant's genetics — its appearance, aroma, potency, growth pattern. Same genotype can produce different phenotypes depending on which recessive genes express and environmental factors. "Pheno hunting" is the process of growing many seeds from a cross and selecting the best individual.
Polyhybrid — A hybrid with three or more distinct genetic lines in its background. Most modern strains are polyhybrids — for example, Gelato is a polyhybrid of Sunset Sherbet (itself GSC x Pink Panties) crossed with Thin Mint GSC (a GSC phenotype). Polyhybrids have complex genetics that are harder to stabilize.
Reversal — The process of forcing a female plant to produce male flowers (pollen). Reversed female pollen carries only X chromosomes, producing feminized seeds with no male offspring. Used to create feminized seed lines.
Stabilization — The process of breeding a strain over multiple generations until offspring consistently display the same traits. A stabilized strain produces uniform plants from seed, with minimal variation in phenotype.
Trichome — The resin glands on cannabis flowers that produce cannabinoids and terpenes. Trichomes appear as tiny crystal-like structures under magnification. Their color (clear → cloudy → amber) indicates harvest timing for desired effects.
Using This Glossary
Every strain profile on this site uses these terms in descriptions, lineage information, and genetic family tags. For example, when a strain is described as an "F1 hybrid of two stabilized landrace lines," you now know that means it's the first-generation cross of two pure, predictable genetic lines. Bookmark this page — it's your reference for understanding the language of cannabis breeding.